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* move zlib source from ghostscript to ape/lib/z and update to latest zlib
@ 2020-03-02  5:15 Lucas Francesco
  2020-03-02  8:33 ` [9front] " cinap_lenrek
  0 siblings, 1 reply; 6+ messages in thread
From: Lucas Francesco @ 2020-03-02  5:15 UTC (permalink / raw)
  To: 9front

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Moin 9front, on this patchset I've updated zlib and made it independent of gs.

I've been using the newest zlib as my system default for the last 2
weeks and I don't think any regressions will come from it, the need
for update it came from the Netsurf port and ports's libpng
complaining about zlib being too old and me looking at the bugfixes
then thinking they would be nice, I've sent a patchset recently to
update zlib on the ports side, but Ori ended up thinking that its
better to do a little extra effort and update the 9front source, and I
agree with him.

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# HG changeset patch
# User uramekus
# Date 1583125091 14400
# Node ID 83acefe9acdfc66fe917220390805892cc950ad2
# Parent  0dd419f096e2bcb4b5845ce4eea850f6b84b4a85
make zlib independent and update gs to use it

diff -r 0dd419f096e2 -r 83acefe9acdf sys/include/ape/zconf.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/include/ape/zconf.h	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,535 @@
+/* zconf.h -- configuration of the zlib compression library
+ * Copyright (C) 1995-2016 Jean-loup Gailly, Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* @(#) $Id$ */
+
+#ifndef ZCONF_H
+#define ZCONF_H
+
+
+/*
+ * If you *really* need a unique prefix for all types and library functions,
+ * compile with -DZ_PREFIX. The "standard" zlib should be compiled without it.
+ * Even better than compiling with -DZ_PREFIX would be to use configure to set
+ * this permanently in zconf.h using "./configure --zprefix".
+ */
+#ifdef Z_PREFIX     /* may be set to #if 1 by ./configure */
+#  define Z_PREFIX_SET
+
+/* all linked symbols and init macros */
+#  define _dist_code            z__dist_code
+#  define _length_code          z__length_code
+#  define _tr_align             z__tr_align
+#  define _tr_flush_bits        z__tr_flush_bits
+#  define _tr_flush_block       z__tr_flush_block
+#  define _tr_init              z__tr_init
+#  define _tr_stored_block      z__tr_stored_block
+#  define _tr_tally             z__tr_tally
+#  define adler32               z_adler32
+#  define adler32_combine       z_adler32_combine
+#  define adler32_combine64     z_adler32_combine64
+#  define adler32_z             z_adler32_z
+#  ifndef Z_SOLO
+#    define compress              z_compress
+#    define compress2             z_compress2
+#    define compressBound         z_compressBound
+#  endif
+#  define crc32                 z_crc32
+#  define crc32_combine         z_crc32_combine
+#  define crc32_combine64       z_crc32_combine64
+#  define crc32_z               z_crc32_z
+#  define deflate               z_deflate
+#  define deflateBound          z_deflateBound
+#  define deflateCopy           z_deflateCopy
+#  define deflateEnd            z_deflateEnd
+#  define deflateGetDictionary  z_deflateGetDictionary
+#  define deflateInit           z_deflateInit
+#  define deflateInit2          z_deflateInit2
+#  define deflateInit2_         z_deflateInit2_
+#  define deflateInit_          z_deflateInit_
+#  define deflateParams         z_deflateParams
+#  define deflatePending        z_deflatePending
+#  define deflatePrime          z_deflatePrime
+#  define deflateReset          z_deflateReset
+#  define deflateResetKeep      z_deflateResetKeep
+#  define deflateSetDictionary  z_deflateSetDictionary
+#  define deflateSetHeader      z_deflateSetHeader
+#  define deflateTune           z_deflateTune
+#  define deflate_copyright     z_deflate_copyright
+#  define get_crc_table         z_get_crc_table
+#  ifndef Z_SOLO
+#    define gz_error              z_gz_error
+#    define gz_intmax             z_gz_intmax
+#    define gz_strwinerror        z_gz_strwinerror
+#    define gzbuffer              z_gzbuffer
+#    define gzclearerr            z_gzclearerr
+#    define gzclose               z_gzclose
+#    define gzclose_r             z_gzclose_r
+#    define gzclose_w             z_gzclose_w
+#    define gzdirect              z_gzdirect
+#    define gzdopen               z_gzdopen
+#    define gzeof                 z_gzeof
+#    define gzerror               z_gzerror
+#    define gzflush               z_gzflush
+#    define gzfread               z_gzfread
+#    define gzfwrite              z_gzfwrite
+#    define gzgetc                z_gzgetc
+#    define gzgetc_               z_gzgetc_
+#    define gzgets                z_gzgets
+#    define gzoffset              z_gzoffset
+#    define gzoffset64            z_gzoffset64
+#    define gzopen                z_gzopen
+#    define gzopen64              z_gzopen64
+#    ifdef _WIN32
+#      define gzopen_w              z_gzopen_w
+#    endif
+#    define gzprintf              z_gzprintf
+#    define gzputc                z_gzputc
+#    define gzputs                z_gzputs
+#    define gzread                z_gzread
+#    define gzrewind              z_gzrewind
+#    define gzseek                z_gzseek
+#    define gzseek64              z_gzseek64
+#    define gzsetparams           z_gzsetparams
+#    define gztell                z_gztell
+#    define gztell64              z_gztell64
+#    define gzungetc              z_gzungetc
+#    define gzvprintf             z_gzvprintf
+#    define gzwrite               z_gzwrite
+#  endif
+#  define inflate               z_inflate
+#  define inflateBack           z_inflateBack
+#  define inflateBackEnd        z_inflateBackEnd
+#  define inflateBackInit       z_inflateBackInit
+#  define inflateBackInit_      z_inflateBackInit_
+#  define inflateCodesUsed      z_inflateCodesUsed
+#  define inflateCopy           z_inflateCopy
+#  define inflateEnd            z_inflateEnd
+#  define inflateGetDictionary  z_inflateGetDictionary
+#  define inflateGetHeader      z_inflateGetHeader
+#  define inflateInit           z_inflateInit
+#  define inflateInit2          z_inflateInit2
+#  define inflateInit2_         z_inflateInit2_
+#  define inflateInit_          z_inflateInit_
+#  define inflateMark           z_inflateMark
+#  define inflatePrime          z_inflatePrime
+#  define inflateReset          z_inflateReset
+#  define inflateReset2         z_inflateReset2
+#  define inflateResetKeep      z_inflateResetKeep
+#  define inflateSetDictionary  z_inflateSetDictionary
+#  define inflateSync           z_inflateSync
+#  define inflateSyncPoint      z_inflateSyncPoint
+#  define inflateUndermine      z_inflateUndermine
+#  define inflateValidate       z_inflateValidate
+#  define inflate_copyright     z_inflate_copyright
+#  define inflate_fast          z_inflate_fast
+#  define inflate_table         z_inflate_table
+#  ifndef Z_SOLO
+#    define uncompress            z_uncompress
+#    define uncompress2           z_uncompress2
+#  endif
+#  define zError                z_zError
+#  ifndef Z_SOLO
+#    define zcalloc               z_zcalloc
+#    define zcfree                z_zcfree
+#  endif
+#  define zlibCompileFlags      z_zlibCompileFlags
+#  define zlibVersion           z_zlibVersion
+
+/* all zlib typedefs in zlib.h and zconf.h */
+#  define Byte                  z_Byte
+#  define Bytef                 z_Bytef
+#  define alloc_func            z_alloc_func
+#  define charf                 z_charf
+#  define free_func             z_free_func
+#  ifndef Z_SOLO
+#    define gzFile                z_gzFile
+#  endif
+#  define gz_header             z_gz_header
+#  define gz_headerp            z_gz_headerp
+#  define in_func               z_in_func
+#  define intf                  z_intf
+#  define out_func              z_out_func
+#  define uInt                  z_uInt
+#  define uIntf                 z_uIntf
+#  define uLong                 z_uLong
+#  define uLongf                z_uLongf
+#  define voidp                 z_voidp
+#  define voidpc                z_voidpc
+#  define voidpf                z_voidpf
+
+/* all zlib structs in zlib.h and zconf.h */
+#  define gz_header_s           z_gz_header_s
+#  define internal_state        z_internal_state
+
+#endif
+
+#if defined(__MSDOS__) && !defined(MSDOS)
+#  define MSDOS
+#endif
+#if (defined(OS_2) || defined(__OS2__)) && !defined(OS2)
+#  define OS2
+#endif
+#if defined(_WINDOWS) && !defined(WINDOWS)
+#  define WINDOWS
+#endif
+#if defined(_WIN32) || defined(_WIN32_WCE) || defined(__WIN32__)
+#  ifndef WIN32
+#    define WIN32
+#  endif
+#endif
+#if (defined(MSDOS) || defined(OS2) || defined(WINDOWS)) && !defined(WIN32)
+#  if !defined(__GNUC__) && !defined(__FLAT__) && !defined(__386__)
+#    ifndef SYS16BIT
+#      define SYS16BIT
+#    endif
+#  endif
+#endif
+
+/*
+ * Compile with -DMAXSEG_64K if the alloc function cannot allocate more
+ * than 64k bytes at a time (needed on systems with 16-bit int).
+ */
+#ifdef SYS16BIT
+#  define MAXSEG_64K
+#endif
+#ifdef MSDOS
+#  define UNALIGNED_OK
+#endif
+
+#ifdef __STDC_VERSION__
+#  ifndef STDC
+#    define STDC
+#  endif
+#  if __STDC_VERSION__ >= 199901L
+#    ifndef STDC99
+#      define STDC99
+#    endif
+#  endif
+#endif
+#if !defined(STDC) && (defined(__STDC__) || defined(__cplusplus))
+#  define STDC
+#endif
+#if !defined(STDC) && (defined(__GNUC__) || defined(__BORLANDC__))
+#  define STDC
+#endif
+#if !defined(STDC) && (defined(MSDOS) || defined(WINDOWS) || defined(WIN32))
+#  define STDC
+#endif
+#if !defined(STDC) && (defined(OS2) || defined(__HOS_AIX__))
+#  define STDC
+#endif
+
+#if defined(__OS400__) && !defined(STDC)    /* iSeries (formerly AS/400). */
+#  define STDC
+#endif
+
+#ifndef STDC
+#  ifndef const /* cannot use !defined(STDC) && !defined(const) on Mac */
+#    define const       /* note: need a more gentle solution here */
+#  endif
+#endif
+
+#if defined(ZLIB_CONST) && !defined(z_const)
+#  define z_const const
+#else
+#  define z_const
+#endif
+
+#ifdef Z_SOLO
+   typedef unsigned long z_size_t;
+#else
+#  define z_longlong long long
+#  if defined(NO_SIZE_T)
+     typedef unsigned NO_SIZE_T z_size_t;
+#  elif defined(STDC)
+#    include <stddef.h>
+     typedef size_t z_size_t;
+#  else
+     typedef unsigned long z_size_t;
+#  endif
+#  undef z_longlong
+#endif
+
+/* Maximum value for memLevel in deflateInit2 */
+#ifndef MAX_MEM_LEVEL
+#  ifdef MAXSEG_64K
+#    define MAX_MEM_LEVEL 8
+#  else
+#    define MAX_MEM_LEVEL 9
+#  endif
+#endif
+
+/* Maximum value for windowBits in deflateInit2 and inflateInit2.
+ * WARNING: reducing MAX_WBITS makes minigzip unable to extract .gz files
+ * created by gzip. (Files created by minigzip can still be extracted by
+ * gzip.)
+ */
+#ifndef MAX_WBITS
+#  define MAX_WBITS   15 /* 32K LZ77 window */
+#endif
+
+/* The memory requirements for deflate are (in bytes):
+            (1 << (windowBits+2)) +  (1 << (memLevel+9))
+ that is: 128K for windowBits=15  +  128K for memLevel = 8  (default values)
+ plus a few kilobytes for small objects. For example, if you want to reduce
+ the default memory requirements from 256K to 128K, compile with
+     make CFLAGS="-O -DMAX_WBITS=14 -DMAX_MEM_LEVEL=7"
+ Of course this will generally degrade compression (there's no free lunch).
+
+   The memory requirements for inflate are (in bytes) 1 << windowBits
+ that is, 32K for windowBits=15 (default value) plus about 7 kilobytes
+ for small objects.
+*/
+
+                        /* Type declarations */
+
+#ifndef OF /* function prototypes */
+#  ifdef STDC
+#    define OF(args)  args
+#  else
+#    define OF(args)  ()
+#  endif
+#endif
+
+#ifndef Z_ARG /* function prototypes for stdarg */
+#  if defined(STDC) || defined(Z_HAVE_STDARG_H)
+#    define Z_ARG(args)  args
+#  else
+#    define Z_ARG(args)  ()
+#  endif
+#endif
+
+/* The following definitions for FAR are needed only for MSDOS mixed
+ * model programming (small or medium model with some far allocations).
+ * This was tested only with MSC; for other MSDOS compilers you may have
+ * to define NO_MEMCPY in zutil.h.  If you don't need the mixed model,
+ * just define FAR to be empty.
+ */
+#ifdef SYS16BIT
+#  if defined(M_I86SM) || defined(M_I86MM)
+     /* MSC small or medium model */
+#    define SMALL_MEDIUM
+#    ifdef _MSC_VER
+#      define FAR _far
+#    else
+#      define FAR far
+#    endif
+#  endif
+#  if (defined(__SMALL__) || defined(__MEDIUM__))
+     /* Turbo C small or medium model */
+#    define SMALL_MEDIUM
+#    ifdef __BORLANDC__
+#      define FAR _far
+#    else
+#      define FAR far
+#    endif
+#  endif
+#endif
+
+#if defined(WINDOWS) || defined(WIN32)
+   /* If building or using zlib as a DLL, define ZLIB_DLL.
+    * This is not mandatory, but it offers a little performance increase.
+    */
+#  ifdef ZLIB_DLL
+#    if defined(WIN32) && (!defined(__BORLANDC__) || (__BORLANDC__ >= 0x500))
+#      ifdef ZLIB_INTERNAL
+#        define ZEXTERN extern __declspec(dllexport)
+#      else
+#        define ZEXTERN extern __declspec(dllimport)
+#      endif
+#    endif
+#  endif  /* ZLIB_DLL */
+   /* If building or using zlib with the WINAPI/WINAPIV calling convention,
+    * define ZLIB_WINAPI.
+    * Caution: the standard ZLIB1.DLL is NOT compiled using ZLIB_WINAPI.
+    */
+#  ifdef ZLIB_WINAPI
+#    ifdef FAR
+#      undef FAR
+#    endif
+#    include <windows.h>
+     /* No need for _export, use ZLIB.DEF instead. */
+     /* For complete Windows compatibility, use WINAPI, not __stdcall. */
+#    define ZEXPORT WINAPI
+#    ifdef WIN32
+#      define ZEXPORTVA WINAPIV
+#    else
+#      define ZEXPORTVA FAR CDECL
+#    endif
+#  endif
+#endif
+
+#if defined (__BEOS__)
+#  ifdef ZLIB_DLL
+#    ifdef ZLIB_INTERNAL
+#      define ZEXPORT   __declspec(dllexport)
+#      define ZEXPORTVA __declspec(dllexport)
+#    else
+#      define ZEXPORT   __declspec(dllimport)
+#      define ZEXPORTVA __declspec(dllimport)
+#    endif
+#  endif
+#endif
+
+#ifndef ZEXTERN
+#  define ZEXTERN extern
+#endif
+#ifndef ZEXPORT
+#  define ZEXPORT
+#endif
+#ifndef ZEXPORTVA
+#  define ZEXPORTVA
+#endif
+
+#ifndef FAR
+#  define FAR
+#endif
+
+#if !defined(__MACTYPES__)
+typedef unsigned char  Byte;  /* 8 bits */
+#endif
+typedef unsigned int   uInt;  /* 16 bits or more */
+typedef unsigned long  uLong; /* 32 bits or more */
+
+#ifdef SMALL_MEDIUM
+   /* Borland C/C++ and some old MSC versions ignore FAR inside typedef */
+#  define Bytef Byte FAR
+#else
+   typedef Byte  FAR Bytef;
+#endif
+typedef char  FAR charf;
+typedef int   FAR intf;
+typedef uInt  FAR uIntf;
+typedef uLong FAR uLongf;
+
+#ifdef STDC
+   typedef void const *voidpc;
+   typedef void FAR   *voidpf;
+   typedef void       *voidp;
+#else
+   typedef Byte const *voidpc;
+   typedef Byte FAR   *voidpf;
+   typedef Byte       *voidp;
+#endif
+
+#if !defined(Z_U4) && !defined(Z_SOLO) && defined(STDC)
+#  include <limits.h>
+#  if (UINT_MAX == 0xffffffffUL)
+#    define Z_U4 unsigned
+#  elif (ULONG_MAX == 0xffffffffUL)
+#    define Z_U4 unsigned long
+#  elif (USHRT_MAX == 0xffffffffUL)
+#    define Z_U4 unsigned short
+#  endif
+#endif
+
+#ifdef Z_U4
+   typedef Z_U4 z_crc_t;
+#else
+   typedef unsigned long z_crc_t;
+#endif
+
+#ifdef HAVE_UNISTD_H    /* may be set to #if 1 by ./configure */
+#  define Z_HAVE_UNISTD_H
+#endif
+
+#ifdef HAVE_STDARG_H    /* may be set to #if 1 by ./configure */
+#  define Z_HAVE_STDARG_H
+#endif
+
+#ifdef STDC
+#  ifndef Z_SOLO
+#    include <sys/types.h>      /* for off_t */
+#  endif
+#endif
+
+#if defined(STDC) || defined(Z_HAVE_STDARG_H)
+#  ifndef Z_SOLO
+#    include <stdarg.h>         /* for va_list */
+#  endif
+#endif
+
+#ifdef _WIN32
+#  ifndef Z_SOLO
+#    include <stddef.h>         /* for wchar_t */
+#  endif
+#endif
+
+/* a little trick to accommodate both "#define _LARGEFILE64_SOURCE" and
+ * "#define _LARGEFILE64_SOURCE 1" as requesting 64-bit operations, (even
+ * though the former does not conform to the LFS document), but considering
+ * both "#undef _LARGEFILE64_SOURCE" and "#define _LARGEFILE64_SOURCE 0" as
+ * equivalently requesting no 64-bit operations
+ */
+#if defined(_LARGEFILE64_SOURCE) && -_LARGEFILE64_SOURCE - -1 == 1
+#  undef _LARGEFILE64_SOURCE
+#endif
+
+#if defined(__WATCOMC__) && !defined(Z_HAVE_UNISTD_H)
+#  define Z_HAVE_UNISTD_H
+#endif
+#ifndef Z_SOLO
+#  if defined(Z_HAVE_UNISTD_H) || defined(_LARGEFILE64_SOURCE)
+#    include <unistd.h>         /* for SEEK_*, off_t, and _LFS64_LARGEFILE */
+#    ifdef VMS
+#      include <unixio.h>       /* for off_t */
+#    endif
+#    ifndef z_off_t
+#      define z_off_t off_t
+#    endif
+#  endif
+#endif
+
+#if defined(_LFS64_LARGEFILE) && _LFS64_LARGEFILE-0
+#  define Z_LFS64
+#endif
+
+#if defined(_LARGEFILE64_SOURCE) && defined(Z_LFS64)
+#  define Z_LARGE64
+#endif
+
+#if defined(_FILE_OFFSET_BITS) && _FILE_OFFSET_BITS-0 == 64 && defined(Z_LFS64)
+#  define Z_WANT64
+#endif
+
+#if !defined(SEEK_SET) && !defined(Z_SOLO)
+#  define SEEK_SET        0       /* Seek from beginning of file.  */
+#  define SEEK_CUR        1       /* Seek from current position.  */
+#  define SEEK_END        2       /* Set file pointer to EOF plus "offset" */
+#endif
+
+#ifndef z_off_t
+#  define z_off_t long
+#endif
+
+#if !defined(_WIN32) && defined(Z_LARGE64)
+#  define z_off64_t off64_t
+#else
+#  if defined(_WIN32) && !defined(__GNUC__) && !defined(Z_SOLO)
+#    define z_off64_t __int64
+#  else
+#    define z_off64_t z_off_t
+#  endif
+#endif
+
+/* MVS linker does not support external names larger than 8 bytes */
+#if defined(__MVS__)
+  #pragma map(deflateInit_,"DEIN")
+  #pragma map(deflateInit2_,"DEIN2")
+  #pragma map(deflateEnd,"DEEND")
+  #pragma map(deflateBound,"DEBND")
+  #pragma map(inflateInit_,"ININ")
+  #pragma map(inflateInit2_,"ININ2")
+  #pragma map(inflateEnd,"INEND")
+  #pragma map(inflateSync,"INSY")
+  #pragma map(inflateSetDictionary,"INSEDI")
+  #pragma map(compressBound,"CMBND")
+  #pragma map(inflate_table,"INTABL")
+  #pragma map(inflate_fast,"INFA")
+  #pragma map(inflate_copyright,"INCOPY")
+#endif
+
+#endif /* ZCONF_H */
diff -r 0dd419f096e2 -r 83acefe9acdf sys/include/ape/zlib.h
--- a/sys/include/ape/zlib.h	Sun Mar 01 23:23:01 2020 +0100
+++ b/sys/include/ape/zlib.h	Mon Mar 02 00:58:11 2020 -0400
@@ -1,5 +1,1914 @@
-#ifndef __ZLIB
-#define __ZLIB
+/* zlib.h -- interface of the 'zlib' general purpose compression library
+  version 1.2.11, January 15th, 2017
+
+  Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  Jean-loup Gailly        Mark Adler
+  jloup@gzip.org          madler@alumni.caltech.edu
+
+
+  The data format used by the zlib library is described by RFCs (Request for
+  Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950
+  (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
+*/
+
+#ifndef ZLIB_H
+#define ZLIB_H
+
 #pragma lib "/$M/lib/ape/libz.a"
-#include "/sys/src/cmd/gs/zlib/zlib.h"
-#endif /* __ZLIB */
+
+#include "zconf.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define ZLIB_VERSION "1.2.11"
+#define ZLIB_VERNUM 0x12b0
+#define ZLIB_VER_MAJOR 1
+#define ZLIB_VER_MINOR 2
+#define ZLIB_VER_REVISION 11
+#define ZLIB_VER_SUBREVISION 0
+
+/*
+    The 'zlib' compression library provides in-memory compression and
+  decompression functions, including integrity checks of the uncompressed data.
+  This version of the library supports only one compression method (deflation)
+  but other algorithms will be added later and will have the same stream
+  interface.
+
+    Compression can be done in a single step if the buffers are large enough,
+  or can be done by repeated calls of the compression function.  In the latter
+  case, the application must provide more input and/or consume the output
+  (providing more output space) before each call.
+
+    The compressed data format used by default by the in-memory functions is
+  the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
+  around a deflate stream, which is itself documented in RFC 1951.
+
+    The library also supports reading and writing files in gzip (.gz) format
+  with an interface similar to that of stdio using the functions that start
+  with "gz".  The gzip format is different from the zlib format.  gzip is a
+  gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
+
+    This library can optionally read and write gzip and raw deflate streams in
+  memory as well.
+
+    The zlib format was designed to be compact and fast for use in memory
+  and on communications channels.  The gzip format was designed for single-
+  file compression on file systems, has a larger header than zlib to maintain
+  directory information, and uses a different, slower check method than zlib.
+
+    The library does not install any signal handler.  The decoder checks
+  the consistency of the compressed data, so the library should never crash
+  even in the case of corrupted input.
+*/
+
+typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
+typedef void   (*free_func)  OF((voidpf opaque, voidpf address));
+
+struct internal_state;
+
+typedef struct z_stream_s {
+    z_const Bytef *next_in;     /* next input byte */
+    uInt     avail_in;  /* number of bytes available at next_in */
+    uLong    total_in;  /* total number of input bytes read so far */
+
+    Bytef    *next_out; /* next output byte will go here */
+    uInt     avail_out; /* remaining free space at next_out */
+    uLong    total_out; /* total number of bytes output so far */
+
+    z_const char *msg;  /* last error message, NULL if no error */
+    struct internal_state FAR *state; /* not visible by applications */
+
+    alloc_func zalloc;  /* used to allocate the internal state */
+    free_func  zfree;   /* used to free the internal state */
+    voidpf     opaque;  /* private data object passed to zalloc and zfree */
+
+    int     data_type;  /* best guess about the data type: binary or text
+                           for deflate, or the decoding state for inflate */
+    uLong   adler;      /* Adler-32 or CRC-32 value of the uncompressed data */
+    uLong   reserved;   /* reserved for future use */
+} z_stream;
+
+typedef z_stream FAR *z_streamp;
+
+/*
+     gzip header information passed to and from zlib routines.  See RFC 1952
+  for more details on the meanings of these fields.
+*/
+typedef struct gz_header_s {
+    int     text;       /* true if compressed data believed to be text */
+    uLong   time;       /* modification time */
+    int     xflags;     /* extra flags (not used when writing a gzip file) */
+    int     os;         /* operating system */
+    Bytef   *extra;     /* pointer to extra field or Z_NULL if none */
+    uInt    extra_len;  /* extra field length (valid if extra != Z_NULL) */
+    uInt    extra_max;  /* space at extra (only when reading header) */
+    Bytef   *name;      /* pointer to zero-terminated file name or Z_NULL */
+    uInt    name_max;   /* space at name (only when reading header) */
+    Bytef   *comment;   /* pointer to zero-terminated comment or Z_NULL */
+    uInt    comm_max;   /* space at comment (only when reading header) */
+    int     hcrc;       /* true if there was or will be a header crc */
+    int     done;       /* true when done reading gzip header (not used
+                           when writing a gzip file) */
+} gz_header;
+
+typedef gz_header FAR *gz_headerp;
+
+/*
+     The application must update next_in and avail_in when avail_in has dropped
+   to zero.  It must update next_out and avail_out when avail_out has dropped
+   to zero.  The application must initialize zalloc, zfree and opaque before
+   calling the init function.  All other fields are set by the compression
+   library and must not be updated by the application.
+
+     The opaque value provided by the application will be passed as the first
+   parameter for calls of zalloc and zfree.  This can be useful for custom
+   memory management.  The compression library attaches no meaning to the
+   opaque value.
+
+     zalloc must return Z_NULL if there is not enough memory for the object.
+   If zlib is used in a multi-threaded application, zalloc and zfree must be
+   thread safe.  In that case, zlib is thread-safe.  When zalloc and zfree are
+   Z_NULL on entry to the initialization function, they are set to internal
+   routines that use the standard library functions malloc() and free().
+
+     On 16-bit systems, the functions zalloc and zfree must be able to allocate
+   exactly 65536 bytes, but will not be required to allocate more than this if
+   the symbol MAXSEG_64K is defined (see zconf.h).  WARNING: On MSDOS, pointers
+   returned by zalloc for objects of exactly 65536 bytes *must* have their
+   offset normalized to zero.  The default allocation function provided by this
+   library ensures this (see zutil.c).  To reduce memory requirements and avoid
+   any allocation of 64K objects, at the expense of compression ratio, compile
+   the library with -DMAX_WBITS=14 (see zconf.h).
+
+     The fields total_in and total_out can be used for statistics or progress
+   reports.  After compression, total_in holds the total size of the
+   uncompressed data and may be saved for use by the decompressor (particularly
+   if the decompressor wants to decompress everything in a single step).
+*/
+
+                        /* constants */
+
+#define Z_NO_FLUSH      0
+#define Z_PARTIAL_FLUSH 1
+#define Z_SYNC_FLUSH    2
+#define Z_FULL_FLUSH    3
+#define Z_FINISH        4
+#define Z_BLOCK         5
+#define Z_TREES         6
+/* Allowed flush values; see deflate() and inflate() below for details */
+
+#define Z_OK            0
+#define Z_STREAM_END    1
+#define Z_NEED_DICT     2
+#define Z_ERRNO        (-1)
+#define Z_STREAM_ERROR (-2)
+#define Z_DATA_ERROR   (-3)
+#define Z_MEM_ERROR    (-4)
+#define Z_BUF_ERROR    (-5)
+#define Z_VERSION_ERROR (-6)
+/* Return codes for the compression/decompression functions. Negative values
+ * are errors, positive values are used for special but normal events.
+ */
+
+#define Z_NO_COMPRESSION         0
+#define Z_BEST_SPEED             1
+#define Z_BEST_COMPRESSION       9
+#define Z_DEFAULT_COMPRESSION  (-1)
+/* compression levels */
+
+#define Z_FILTERED            1
+#define Z_HUFFMAN_ONLY        2
+#define Z_RLE                 3
+#define Z_FIXED               4
+#define Z_DEFAULT_STRATEGY    0
+/* compression strategy; see deflateInit2() below for details */
+
+#define Z_BINARY   0
+#define Z_TEXT     1
+#define Z_ASCII    Z_TEXT   /* for compatibility with 1.2.2 and earlier */
+#define Z_UNKNOWN  2
+/* Possible values of the data_type field for deflate() */
+
+#define Z_DEFLATED   8
+/* The deflate compression method (the only one supported in this version) */
+
+#define Z_NULL  0  /* for initializing zalloc, zfree, opaque */
+
+#define zlib_version zlibVersion()
+/* for compatibility with versions < 1.0.2 */
+
+
+                        /* basic functions */
+
+ZEXTERN const char * ZEXPORT zlibVersion OF((void));
+/* The application can compare zlibVersion and ZLIB_VERSION for consistency.
+   If the first character differs, the library code actually used is not
+   compatible with the zlib.h header file used by the application.  This check
+   is automatically made by deflateInit and inflateInit.
+ */
+
+/*
+ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
+
+     Initializes the internal stream state for compression.  The fields
+   zalloc, zfree and opaque must be initialized before by the caller.  If
+   zalloc and zfree are set to Z_NULL, deflateInit updates them to use default
+   allocation functions.
+
+     The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
+   1 gives best speed, 9 gives best compression, 0 gives no compression at all
+   (the input data is simply copied a block at a time).  Z_DEFAULT_COMPRESSION
+   requests a default compromise between speed and compression (currently
+   equivalent to level 6).
+
+     deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_STREAM_ERROR if level is not a valid compression level, or
+   Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
+   with the version assumed by the caller (ZLIB_VERSION).  msg is set to null
+   if there is no error message.  deflateInit does not perform any compression:
+   this will be done by deflate().
+*/
+
+
+ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
+/*
+    deflate compresses as much data as possible, and stops when the input
+  buffer becomes empty or the output buffer becomes full.  It may introduce
+  some output latency (reading input without producing any output) except when
+  forced to flush.
+
+    The detailed semantics are as follows.  deflate performs one or both of the
+  following actions:
+
+  - Compress more input starting at next_in and update next_in and avail_in
+    accordingly.  If not all input can be processed (because there is not
+    enough room in the output buffer), next_in and avail_in are updated and
+    processing will resume at this point for the next call of deflate().
+
+  - Generate more output starting at next_out and update next_out and avail_out
+    accordingly.  This action is forced if the parameter flush is non zero.
+    Forcing flush frequently degrades the compression ratio, so this parameter
+    should be set only when necessary.  Some output may be provided even if
+    flush is zero.
+
+    Before the call of deflate(), the application should ensure that at least
+  one of the actions is possible, by providing more input and/or consuming more
+  output, and updating avail_in or avail_out accordingly; avail_out should
+  never be zero before the call.  The application can consume the compressed
+  output when it wants, for example when the output buffer is full (avail_out
+  == 0), or after each call of deflate().  If deflate returns Z_OK and with
+  zero avail_out, it must be called again after making room in the output
+  buffer because there might be more output pending. See deflatePending(),
+  which can be used if desired to determine whether or not there is more ouput
+  in that case.
+
+    Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
+  decide how much data to accumulate before producing output, in order to
+  maximize compression.
+
+    If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
+  flushed to the output buffer and the output is aligned on a byte boundary, so
+  that the decompressor can get all input data available so far.  (In
+  particular avail_in is zero after the call if enough output space has been
+  provided before the call.) Flushing may degrade compression for some
+  compression algorithms and so it should be used only when necessary.  This
+  completes the current deflate block and follows it with an empty stored block
+  that is three bits plus filler bits to the next byte, followed by four bytes
+  (00 00 ff ff).
+
+    If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the
+  output buffer, but the output is not aligned to a byte boundary.  All of the
+  input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.
+  This completes the current deflate block and follows it with an empty fixed
+  codes block that is 10 bits long.  This assures that enough bytes are output
+  in order for the decompressor to finish the block before the empty fixed
+  codes block.
+
+    If flush is set to Z_BLOCK, a deflate block is completed and emitted, as
+  for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to
+  seven bits of the current block are held to be written as the next byte after
+  the next deflate block is completed.  In this case, the decompressor may not
+  be provided enough bits at this point in order to complete decompression of
+  the data provided so far to the compressor.  It may need to wait for the next
+  block to be emitted.  This is for advanced applications that need to control
+  the emission of deflate blocks.
+
+    If flush is set to Z_FULL_FLUSH, all output is flushed as with
+  Z_SYNC_FLUSH, and the compression state is reset so that decompression can
+  restart from this point if previous compressed data has been damaged or if
+  random access is desired.  Using Z_FULL_FLUSH too often can seriously degrade
+  compression.
+
+    If deflate returns with avail_out == 0, this function must be called again
+  with the same value of the flush parameter and more output space (updated
+  avail_out), until the flush is complete (deflate returns with non-zero
+  avail_out).  In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
+  avail_out is greater than six to avoid repeated flush markers due to
+  avail_out == 0 on return.
+
+    If the parameter flush is set to Z_FINISH, pending input is processed,
+  pending output is flushed and deflate returns with Z_STREAM_END if there was
+  enough output space.  If deflate returns with Z_OK or Z_BUF_ERROR, this
+  function must be called again with Z_FINISH and more output space (updated
+  avail_out) but no more input data, until it returns with Z_STREAM_END or an
+  error.  After deflate has returned Z_STREAM_END, the only possible operations
+  on the stream are deflateReset or deflateEnd.
+
+    Z_FINISH can be used in the first deflate call after deflateInit if all the
+  compression is to be done in a single step.  In order to complete in one
+  call, avail_out must be at least the value returned by deflateBound (see
+  below).  Then deflate is guaranteed to return Z_STREAM_END.  If not enough
+  output space is provided, deflate will not return Z_STREAM_END, and it must
+  be called again as described above.
+
+    deflate() sets strm->adler to the Adler-32 checksum of all input read
+  so far (that is, total_in bytes).  If a gzip stream is being generated, then
+  strm->adler will be the CRC-32 checksum of the input read so far.  (See
+  deflateInit2 below.)
+
+    deflate() may update strm->data_type if it can make a good guess about
+  the input data type (Z_BINARY or Z_TEXT).  If in doubt, the data is
+  considered binary.  This field is only for information purposes and does not
+  affect the compression algorithm in any manner.
+
+    deflate() returns Z_OK if some progress has been made (more input
+  processed or more output produced), Z_STREAM_END if all input has been
+  consumed and all output has been produced (only when flush is set to
+  Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
+  if next_in or next_out was Z_NULL or the state was inadvertently written over
+  by the application), or Z_BUF_ERROR if no progress is possible (for example
+  avail_in or avail_out was zero).  Note that Z_BUF_ERROR is not fatal, and
+  deflate() can be called again with more input and more output space to
+  continue compressing.
+*/
+
+
+ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
+/*
+     All dynamically allocated data structures for this stream are freed.
+   This function discards any unprocessed input and does not flush any pending
+   output.
+
+     deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
+   stream state was inconsistent, Z_DATA_ERROR if the stream was freed
+   prematurely (some input or output was discarded).  In the error case, msg
+   may be set but then points to a static string (which must not be
+   deallocated).
+*/
+
+
+/*
+ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
+
+     Initializes the internal stream state for decompression.  The fields
+   next_in, avail_in, zalloc, zfree and opaque must be initialized before by
+   the caller.  In the current version of inflate, the provided input is not
+   read or consumed.  The allocation of a sliding window will be deferred to
+   the first call of inflate (if the decompression does not complete on the
+   first call).  If zalloc and zfree are set to Z_NULL, inflateInit updates
+   them to use default allocation functions.
+
+     inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
+   version assumed by the caller, or Z_STREAM_ERROR if the parameters are
+   invalid, such as a null pointer to the structure.  msg is set to null if
+   there is no error message.  inflateInit does not perform any decompression.
+   Actual decompression will be done by inflate().  So next_in, and avail_in,
+   next_out, and avail_out are unused and unchanged.  The current
+   implementation of inflateInit() does not process any header information --
+   that is deferred until inflate() is called.
+*/
+
+
+ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
+/*
+    inflate decompresses as much data as possible, and stops when the input
+  buffer becomes empty or the output buffer becomes full.  It may introduce
+  some output latency (reading input without producing any output) except when
+  forced to flush.
+
+  The detailed semantics are as follows.  inflate performs one or both of the
+  following actions:
+
+  - Decompress more input starting at next_in and update next_in and avail_in
+    accordingly.  If not all input can be processed (because there is not
+    enough room in the output buffer), then next_in and avail_in are updated
+    accordingly, and processing will resume at this point for the next call of
+    inflate().
+
+  - Generate more output starting at next_out and update next_out and avail_out
+    accordingly.  inflate() provides as much output as possible, until there is
+    no more input data or no more space in the output buffer (see below about
+    the flush parameter).
+
+    Before the call of inflate(), the application should ensure that at least
+  one of the actions is possible, by providing more input and/or consuming more
+  output, and updating the next_* and avail_* values accordingly.  If the
+  caller of inflate() does not provide both available input and available
+  output space, it is possible that there will be no progress made.  The
+  application can consume the uncompressed output when it wants, for example
+  when the output buffer is full (avail_out == 0), or after each call of
+  inflate().  If inflate returns Z_OK and with zero avail_out, it must be
+  called again after making room in the output buffer because there might be
+  more output pending.
+
+    The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH,
+  Z_BLOCK, or Z_TREES.  Z_SYNC_FLUSH requests that inflate() flush as much
+  output as possible to the output buffer.  Z_BLOCK requests that inflate()
+  stop if and when it gets to the next deflate block boundary.  When decoding
+  the zlib or gzip format, this will cause inflate() to return immediately
+  after the header and before the first block.  When doing a raw inflate,
+  inflate() will go ahead and process the first block, and will return when it
+  gets to the end of that block, or when it runs out of data.
+
+    The Z_BLOCK option assists in appending to or combining deflate streams.
+  To assist in this, on return inflate() always sets strm->data_type to the
+  number of unused bits in the last byte taken from strm->next_in, plus 64 if
+  inflate() is currently decoding the last block in the deflate stream, plus
+  128 if inflate() returned immediately after decoding an end-of-block code or
+  decoding the complete header up to just before the first byte of the deflate
+  stream.  The end-of-block will not be indicated until all of the uncompressed
+  data from that block has been written to strm->next_out.  The number of
+  unused bits may in general be greater than seven, except when bit 7 of
+  data_type is set, in which case the number of unused bits will be less than
+  eight.  data_type is set as noted here every time inflate() returns for all
+  flush options, and so can be used to determine the amount of currently
+  consumed input in bits.
+
+    The Z_TREES option behaves as Z_BLOCK does, but it also returns when the
+  end of each deflate block header is reached, before any actual data in that
+  block is decoded.  This allows the caller to determine the length of the
+  deflate block header for later use in random access within a deflate block.
+  256 is added to the value of strm->data_type when inflate() returns
+  immediately after reaching the end of the deflate block header.
+
+    inflate() should normally be called until it returns Z_STREAM_END or an
+  error.  However if all decompression is to be performed in a single step (a
+  single call of inflate), the parameter flush should be set to Z_FINISH.  In
+  this case all pending input is processed and all pending output is flushed;
+  avail_out must be large enough to hold all of the uncompressed data for the
+  operation to complete.  (The size of the uncompressed data may have been
+  saved by the compressor for this purpose.)  The use of Z_FINISH is not
+  required to perform an inflation in one step.  However it may be used to
+  inform inflate that a faster approach can be used for the single inflate()
+  call.  Z_FINISH also informs inflate to not maintain a sliding window if the
+  stream completes, which reduces inflate's memory footprint.  If the stream
+  does not complete, either because not all of the stream is provided or not
+  enough output space is provided, then a sliding window will be allocated and
+  inflate() can be called again to continue the operation as if Z_NO_FLUSH had
+  been used.
+
+     In this implementation, inflate() always flushes as much output as
+  possible to the output buffer, and always uses the faster approach on the
+  first call.  So the effects of the flush parameter in this implementation are
+  on the return value of inflate() as noted below, when inflate() returns early
+  when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of
+  memory for a sliding window when Z_FINISH is used.
+
+     If a preset dictionary is needed after this call (see inflateSetDictionary
+  below), inflate sets strm->adler to the Adler-32 checksum of the dictionary
+  chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
+  strm->adler to the Adler-32 checksum of all output produced so far (that is,
+  total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
+  below.  At the end of the stream, inflate() checks that its computed Adler-32
+  checksum is equal to that saved by the compressor and returns Z_STREAM_END
+  only if the checksum is correct.
+
+    inflate() can decompress and check either zlib-wrapped or gzip-wrapped
+  deflate data.  The header type is detected automatically, if requested when
+  initializing with inflateInit2().  Any information contained in the gzip
+  header is not retained unless inflateGetHeader() is used.  When processing
+  gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output
+  produced so far.  The CRC-32 is checked against the gzip trailer, as is the
+  uncompressed length, modulo 2^32.
+
+    inflate() returns Z_OK if some progress has been made (more input processed
+  or more output produced), Z_STREAM_END if the end of the compressed data has
+  been reached and all uncompressed output has been produced, Z_NEED_DICT if a
+  preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
+  corrupted (input stream not conforming to the zlib format or incorrect check
+  value, in which case strm->msg points to a string with a more specific
+  error), Z_STREAM_ERROR if the stream structure was inconsistent (for example
+  next_in or next_out was Z_NULL, or the state was inadvertently written over
+  by the application), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR
+  if no progress was possible or if there was not enough room in the output
+  buffer when Z_FINISH is used.  Note that Z_BUF_ERROR is not fatal, and
+  inflate() can be called again with more input and more output space to
+  continue decompressing.  If Z_DATA_ERROR is returned, the application may
+  then call inflateSync() to look for a good compression block if a partial
+  recovery of the data is to be attempted.
+*/
+
+
+ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
+/*
+     All dynamically allocated data structures for this stream are freed.
+   This function discards any unprocessed input and does not flush any pending
+   output.
+
+     inflateEnd returns Z_OK if success, or Z_STREAM_ERROR if the stream state
+   was inconsistent.
+*/
+
+
+                        /* Advanced functions */
+
+/*
+    The following functions are needed only in some special applications.
+*/
+
+/*
+ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
+                                     int  level,
+                                     int  method,
+                                     int  windowBits,
+                                     int  memLevel,
+                                     int  strategy));
+
+     This is another version of deflateInit with more compression options.  The
+   fields next_in, zalloc, zfree and opaque must be initialized before by the
+   caller.
+
+     The method parameter is the compression method.  It must be Z_DEFLATED in
+   this version of the library.
+
+     The windowBits parameter is the base two logarithm of the window size
+   (the size of the history buffer).  It should be in the range 8..15 for this
+   version of the library.  Larger values of this parameter result in better
+   compression at the expense of memory usage.  The default value is 15 if
+   deflateInit is used instead.
+
+     For the current implementation of deflate(), a windowBits value of 8 (a
+   window size of 256 bytes) is not supported.  As a result, a request for 8
+   will result in 9 (a 512-byte window).  In that case, providing 8 to
+   inflateInit2() will result in an error when the zlib header with 9 is
+   checked against the initialization of inflate().  The remedy is to not use 8
+   with deflateInit2() with this initialization, or at least in that case use 9
+   with inflateInit2().
+
+     windowBits can also be -8..-15 for raw deflate.  In this case, -windowBits
+   determines the window size.  deflate() will then generate raw deflate data
+   with no zlib header or trailer, and will not compute a check value.
+
+     windowBits can also be greater than 15 for optional gzip encoding.  Add
+   16 to windowBits to write a simple gzip header and trailer around the
+   compressed data instead of a zlib wrapper.  The gzip header will have no
+   file name, no extra data, no comment, no modification time (set to zero), no
+   header crc, and the operating system will be set to the appropriate value,
+   if the operating system was determined at compile time.  If a gzip stream is
+   being written, strm->adler is a CRC-32 instead of an Adler-32.
+
+     For raw deflate or gzip encoding, a request for a 256-byte window is
+   rejected as invalid, since only the zlib header provides a means of
+   transmitting the window size to the decompressor.
+
+     The memLevel parameter specifies how much memory should be allocated
+   for the internal compression state.  memLevel=1 uses minimum memory but is
+   slow and reduces compression ratio; memLevel=9 uses maximum memory for
+   optimal speed.  The default value is 8.  See zconf.h for total memory usage
+   as a function of windowBits and memLevel.
+
+     The strategy parameter is used to tune the compression algorithm.  Use the
+   value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
+   filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
+   string match), or Z_RLE to limit match distances to one (run-length
+   encoding).  Filtered data consists mostly of small values with a somewhat
+   random distribution.  In this case, the compression algorithm is tuned to
+   compress them better.  The effect of Z_FILTERED is to force more Huffman
+   coding and less string matching; it is somewhat intermediate between
+   Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY.  Z_RLE is designed to be almost as
+   fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data.  The
+   strategy parameter only affects the compression ratio but not the
+   correctness of the compressed output even if it is not set appropriately.
+   Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler
+   decoder for special applications.
+
+     deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid
+   method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is
+   incompatible with the version assumed by the caller (ZLIB_VERSION).  msg is
+   set to null if there is no error message.  deflateInit2 does not perform any
+   compression: this will be done by deflate().
+*/
+
+ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
+                                             const Bytef *dictionary,
+                                             uInt  dictLength));
+/*
+     Initializes the compression dictionary from the given byte sequence
+   without producing any compressed output.  When using the zlib format, this
+   function must be called immediately after deflateInit, deflateInit2 or
+   deflateReset, and before any call of deflate.  When doing raw deflate, this
+   function must be called either before any call of deflate, or immediately
+   after the completion of a deflate block, i.e. after all input has been
+   consumed and all output has been delivered when using any of the flush
+   options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH.  The
+   compressor and decompressor must use exactly the same dictionary (see
+   inflateSetDictionary).
+
+     The dictionary should consist of strings (byte sequences) that are likely
+   to be encountered later in the data to be compressed, with the most commonly
+   used strings preferably put towards the end of the dictionary.  Using a
+   dictionary is most useful when the data to be compressed is short and can be
+   predicted with good accuracy; the data can then be compressed better than
+   with the default empty dictionary.
+
+     Depending on the size of the compression data structures selected by
+   deflateInit or deflateInit2, a part of the dictionary may in effect be
+   discarded, for example if the dictionary is larger than the window size
+   provided in deflateInit or deflateInit2.  Thus the strings most likely to be
+   useful should be put at the end of the dictionary, not at the front.  In
+   addition, the current implementation of deflate will use at most the window
+   size minus 262 bytes of the provided dictionary.
+
+     Upon return of this function, strm->adler is set to the Adler-32 value
+   of the dictionary; the decompressor may later use this value to determine
+   which dictionary has been used by the compressor.  (The Adler-32 value
+   applies to the whole dictionary even if only a subset of the dictionary is
+   actually used by the compressor.) If a raw deflate was requested, then the
+   Adler-32 value is not computed and strm->adler is not set.
+
+     deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
+   parameter is invalid (e.g.  dictionary being Z_NULL) or the stream state is
+   inconsistent (for example if deflate has already been called for this stream
+   or if not at a block boundary for raw deflate).  deflateSetDictionary does
+   not perform any compression: this will be done by deflate().
+*/
+
+ZEXTERN int ZEXPORT deflateGetDictionary OF((z_streamp strm,
+                                             Bytef *dictionary,
+                                             uInt  *dictLength));
+/*
+     Returns the sliding dictionary being maintained by deflate.  dictLength is
+   set to the number of bytes in the dictionary, and that many bytes are copied
+   to dictionary.  dictionary must have enough space, where 32768 bytes is
+   always enough.  If deflateGetDictionary() is called with dictionary equal to
+   Z_NULL, then only the dictionary length is returned, and nothing is copied.
+   Similary, if dictLength is Z_NULL, then it is not set.
+
+     deflateGetDictionary() may return a length less than the window size, even
+   when more than the window size in input has been provided. It may return up
+   to 258 bytes less in that case, due to how zlib's implementation of deflate
+   manages the sliding window and lookahead for matches, where matches can be
+   up to 258 bytes long. If the application needs the last window-size bytes of
+   input, then that would need to be saved by the application outside of zlib.
+
+     deflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
+   stream state is inconsistent.
+*/
+
+ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
+                                    z_streamp source));
+/*
+     Sets the destination stream as a complete copy of the source stream.
+
+     This function can be useful when several compression strategies will be
+   tried, for example when there are several ways of pre-processing the input
+   data with a filter.  The streams that will be discarded should then be freed
+   by calling deflateEnd.  Note that deflateCopy duplicates the internal
+   compression state which can be quite large, so this strategy is slow and can
+   consume lots of memory.
+
+     deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
+   enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
+   (such as zalloc being Z_NULL).  msg is left unchanged in both source and
+   destination.
+*/
+
+ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
+/*
+     This function is equivalent to deflateEnd followed by deflateInit, but
+   does not free and reallocate the internal compression state.  The stream
+   will leave the compression level and any other attributes that may have been
+   set unchanged.
+
+     deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent (such as zalloc or state being Z_NULL).
+*/
+
+ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
+                                      int level,
+                                      int strategy));
+/*
+     Dynamically update the compression level and compression strategy.  The
+   interpretation of level and strategy is as in deflateInit2().  This can be
+   used to switch between compression and straight copy of the input data, or
+   to switch to a different kind of input data requiring a different strategy.
+   If the compression approach (which is a function of the level) or the
+   strategy is changed, and if any input has been consumed in a previous
+   deflate() call, then the input available so far is compressed with the old
+   level and strategy using deflate(strm, Z_BLOCK).  There are three approaches
+   for the compression levels 0, 1..3, and 4..9 respectively.  The new level
+   and strategy will take effect at the next call of deflate().
+
+     If a deflate(strm, Z_BLOCK) is performed by deflateParams(), and it does
+   not have enough output space to complete, then the parameter change will not
+   take effect.  In this case, deflateParams() can be called again with the
+   same parameters and more output space to try again.
+
+     In order to assure a change in the parameters on the first try, the
+   deflate stream should be flushed using deflate() with Z_BLOCK or other flush
+   request until strm.avail_out is not zero, before calling deflateParams().
+   Then no more input data should be provided before the deflateParams() call.
+   If this is done, the old level and strategy will be applied to the data
+   compressed before deflateParams(), and the new level and strategy will be
+   applied to the the data compressed after deflateParams().
+
+     deflateParams returns Z_OK on success, Z_STREAM_ERROR if the source stream
+   state was inconsistent or if a parameter was invalid, or Z_BUF_ERROR if
+   there was not enough output space to complete the compression of the
+   available input data before a change in the strategy or approach.  Note that
+   in the case of a Z_BUF_ERROR, the parameters are not changed.  A return
+   value of Z_BUF_ERROR is not fatal, in which case deflateParams() can be
+   retried with more output space.
+*/
+
+ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
+                                    int good_length,
+                                    int max_lazy,
+                                    int nice_length,
+                                    int max_chain));
+/*
+     Fine tune deflate's internal compression parameters.  This should only be
+   used by someone who understands the algorithm used by zlib's deflate for
+   searching for the best matching string, and even then only by the most
+   fanatic optimizer trying to squeeze out the last compressed bit for their
+   specific input data.  Read the deflate.c source code for the meaning of the
+   max_lazy, good_length, nice_length, and max_chain parameters.
+
+     deflateTune() can be called after deflateInit() or deflateInit2(), and
+   returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
+ */
+
+ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
+                                       uLong sourceLen));
+/*
+     deflateBound() returns an upper bound on the compressed size after
+   deflation of sourceLen bytes.  It must be called after deflateInit() or
+   deflateInit2(), and after deflateSetHeader(), if used.  This would be used
+   to allocate an output buffer for deflation in a single pass, and so would be
+   called before deflate().  If that first deflate() call is provided the
+   sourceLen input bytes, an output buffer allocated to the size returned by
+   deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed
+   to return Z_STREAM_END.  Note that it is possible for the compressed size to
+   be larger than the value returned by deflateBound() if flush options other
+   than Z_FINISH or Z_NO_FLUSH are used.
+*/
+
+ZEXTERN int ZEXPORT deflatePending OF((z_streamp strm,
+                                       unsigned *pending,
+                                       int *bits));
+/*
+     deflatePending() returns the number of bytes and bits of output that have
+   been generated, but not yet provided in the available output.  The bytes not
+   provided would be due to the available output space having being consumed.
+   The number of bits of output not provided are between 0 and 7, where they
+   await more bits to join them in order to fill out a full byte.  If pending
+   or bits are Z_NULL, then those values are not set.
+
+     deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent.
+ */
+
+ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
+                                     int bits,
+                                     int value));
+/*
+     deflatePrime() inserts bits in the deflate output stream.  The intent
+   is that this function is used to start off the deflate output with the bits
+   leftover from a previous deflate stream when appending to it.  As such, this
+   function can only be used for raw deflate, and must be used before the first
+   deflate() call after a deflateInit2() or deflateReset().  bits must be less
+   than or equal to 16, and that many of the least significant bits of value
+   will be inserted in the output.
+
+     deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough
+   room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the
+   source stream state was inconsistent.
+*/
+
+ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
+                                         gz_headerp head));
+/*
+     deflateSetHeader() provides gzip header information for when a gzip
+   stream is requested by deflateInit2().  deflateSetHeader() may be called
+   after deflateInit2() or deflateReset() and before the first call of
+   deflate().  The text, time, os, extra field, name, and comment information
+   in the provided gz_header structure are written to the gzip header (xflag is
+   ignored -- the extra flags are set according to the compression level).  The
+   caller must assure that, if not Z_NULL, name and comment are terminated with
+   a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
+   available there.  If hcrc is true, a gzip header crc is included.  Note that
+   the current versions of the command-line version of gzip (up through version
+   1.3.x) do not support header crc's, and will report that it is a "multi-part
+   gzip file" and give up.
+
+     If deflateSetHeader is not used, the default gzip header has text false,
+   the time set to zero, and os set to 255, with no extra, name, or comment
+   fields.  The gzip header is returned to the default state by deflateReset().
+
+     deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent.
+*/
+
+/*
+ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
+                                     int  windowBits));
+
+     This is another version of inflateInit with an extra parameter.  The
+   fields next_in, avail_in, zalloc, zfree and opaque must be initialized
+   before by the caller.
+
+     The windowBits parameter is the base two logarithm of the maximum window
+   size (the size of the history buffer).  It should be in the range 8..15 for
+   this version of the library.  The default value is 15 if inflateInit is used
+   instead.  windowBits must be greater than or equal to the windowBits value
+   provided to deflateInit2() while compressing, or it must be equal to 15 if
+   deflateInit2() was not used.  If a compressed stream with a larger window
+   size is given as input, inflate() will return with the error code
+   Z_DATA_ERROR instead of trying to allocate a larger window.
+
+     windowBits can also be zero to request that inflate use the window size in
+   the zlib header of the compressed stream.
+
+     windowBits can also be -8..-15 for raw inflate.  In this case, -windowBits
+   determines the window size.  inflate() will then process raw deflate data,
+   not looking for a zlib or gzip header, not generating a check value, and not
+   looking for any check values for comparison at the end of the stream.  This
+   is for use with other formats that use the deflate compressed data format
+   such as zip.  Those formats provide their own check values.  If a custom
+   format is developed using the raw deflate format for compressed data, it is
+   recommended that a check value such as an Adler-32 or a CRC-32 be applied to
+   the uncompressed data as is done in the zlib, gzip, and zip formats.  For
+   most applications, the zlib format should be used as is.  Note that comments
+   above on the use in deflateInit2() applies to the magnitude of windowBits.
+
+     windowBits can also be greater than 15 for optional gzip decoding.  Add
+   32 to windowBits to enable zlib and gzip decoding with automatic header
+   detection, or add 16 to decode only the gzip format (the zlib format will
+   return a Z_DATA_ERROR).  If a gzip stream is being decoded, strm->adler is a
+   CRC-32 instead of an Adler-32.  Unlike the gunzip utility and gzread() (see
+   below), inflate() will not automatically decode concatenated gzip streams.
+   inflate() will return Z_STREAM_END at the end of the gzip stream.  The state
+   would need to be reset to continue decoding a subsequent gzip stream.
+
+     inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
+   version assumed by the caller, or Z_STREAM_ERROR if the parameters are
+   invalid, such as a null pointer to the structure.  msg is set to null if
+   there is no error message.  inflateInit2 does not perform any decompression
+   apart from possibly reading the zlib header if present: actual decompression
+   will be done by inflate().  (So next_in and avail_in may be modified, but
+   next_out and avail_out are unused and unchanged.) The current implementation
+   of inflateInit2() does not process any header information -- that is
+   deferred until inflate() is called.
+*/
+
+ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
+                                             const Bytef *dictionary,
+                                             uInt  dictLength));
+/*
+     Initializes the decompression dictionary from the given uncompressed byte
+   sequence.  This function must be called immediately after a call of inflate,
+   if that call returned Z_NEED_DICT.  The dictionary chosen by the compressor
+   can be determined from the Adler-32 value returned by that call of inflate.
+   The compressor and decompressor must use exactly the same dictionary (see
+   deflateSetDictionary).  For raw inflate, this function can be called at any
+   time to set the dictionary.  If the provided dictionary is smaller than the
+   window and there is already data in the window, then the provided dictionary
+   will amend what's there.  The application must insure that the dictionary
+   that was used for compression is provided.
+
+     inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
+   parameter is invalid (e.g.  dictionary being Z_NULL) or the stream state is
+   inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
+   expected one (incorrect Adler-32 value).  inflateSetDictionary does not
+   perform any decompression: this will be done by subsequent calls of
+   inflate().
+*/
+
+ZEXTERN int ZEXPORT inflateGetDictionary OF((z_streamp strm,
+                                             Bytef *dictionary,
+                                             uInt  *dictLength));
+/*
+     Returns the sliding dictionary being maintained by inflate.  dictLength is
+   set to the number of bytes in the dictionary, and that many bytes are copied
+   to dictionary.  dictionary must have enough space, where 32768 bytes is
+   always enough.  If inflateGetDictionary() is called with dictionary equal to
+   Z_NULL, then only the dictionary length is returned, and nothing is copied.
+   Similary, if dictLength is Z_NULL, then it is not set.
+
+     inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
+   stream state is inconsistent.
+*/
+
+ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
+/*
+     Skips invalid compressed data until a possible full flush point (see above
+   for the description of deflate with Z_FULL_FLUSH) can be found, or until all
+   available input is skipped.  No output is provided.
+
+     inflateSync searches for a 00 00 FF FF pattern in the compressed data.
+   All full flush points have this pattern, but not all occurrences of this
+   pattern are full flush points.
+
+     inflateSync returns Z_OK if a possible full flush point has been found,
+   Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point
+   has been found, or Z_STREAM_ERROR if the stream structure was inconsistent.
+   In the success case, the application may save the current current value of
+   total_in which indicates where valid compressed data was found.  In the
+   error case, the application may repeatedly call inflateSync, providing more
+   input each time, until success or end of the input data.
+*/
+
+ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
+                                    z_streamp source));
+/*
+     Sets the destination stream as a complete copy of the source stream.
+
+     This function can be useful when randomly accessing a large stream.  The
+   first pass through the stream can periodically record the inflate state,
+   allowing restarting inflate at those points when randomly accessing the
+   stream.
+
+     inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
+   enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
+   (such as zalloc being Z_NULL).  msg is left unchanged in both source and
+   destination.
+*/
+
+ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
+/*
+     This function is equivalent to inflateEnd followed by inflateInit,
+   but does not free and reallocate the internal decompression state.  The
+   stream will keep attributes that may have been set by inflateInit2.
+
+     inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent (such as zalloc or state being Z_NULL).
+*/
+
+ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm,
+                                      int windowBits));
+/*
+     This function is the same as inflateReset, but it also permits changing
+   the wrap and window size requests.  The windowBits parameter is interpreted
+   the same as it is for inflateInit2.  If the window size is changed, then the
+   memory allocated for the window is freed, and the window will be reallocated
+   by inflate() if needed.
+
+     inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent (such as zalloc or state being Z_NULL), or if
+   the windowBits parameter is invalid.
+*/
+
+ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
+                                     int bits,
+                                     int value));
+/*
+     This function inserts bits in the inflate input stream.  The intent is
+   that this function is used to start inflating at a bit position in the
+   middle of a byte.  The provided bits will be used before any bytes are used
+   from next_in.  This function should only be used with raw inflate, and
+   should be used before the first inflate() call after inflateInit2() or
+   inflateReset().  bits must be less than or equal to 16, and that many of the
+   least significant bits of value will be inserted in the input.
+
+     If bits is negative, then the input stream bit buffer is emptied.  Then
+   inflatePrime() can be called again to put bits in the buffer.  This is used
+   to clear out bits leftover after feeding inflate a block description prior
+   to feeding inflate codes.
+
+     inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent.
+*/
+
+ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm));
+/*
+     This function returns two values, one in the lower 16 bits of the return
+   value, and the other in the remaining upper bits, obtained by shifting the
+   return value down 16 bits.  If the upper value is -1 and the lower value is
+   zero, then inflate() is currently decoding information outside of a block.
+   If the upper value is -1 and the lower value is non-zero, then inflate is in
+   the middle of a stored block, with the lower value equaling the number of
+   bytes from the input remaining to copy.  If the upper value is not -1, then
+   it is the number of bits back from the current bit position in the input of
+   the code (literal or length/distance pair) currently being processed.  In
+   that case the lower value is the number of bytes already emitted for that
+   code.
+
+     A code is being processed if inflate is waiting for more input to complete
+   decoding of the code, or if it has completed decoding but is waiting for
+   more output space to write the literal or match data.
+
+     inflateMark() is used to mark locations in the input data for random
+   access, which may be at bit positions, and to note those cases where the
+   output of a code may span boundaries of random access blocks.  The current
+   location in the input stream can be determined from avail_in and data_type
+   as noted in the description for the Z_BLOCK flush parameter for inflate.
+
+     inflateMark returns the value noted above, or -65536 if the provided
+   source stream state was inconsistent.
+*/
+
+ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
+                                         gz_headerp head));
+/*
+     inflateGetHeader() requests that gzip header information be stored in the
+   provided gz_header structure.  inflateGetHeader() may be called after
+   inflateInit2() or inflateReset(), and before the first call of inflate().
+   As inflate() processes the gzip stream, head->done is zero until the header
+   is completed, at which time head->done is set to one.  If a zlib stream is
+   being decoded, then head->done is set to -1 to indicate that there will be
+   no gzip header information forthcoming.  Note that Z_BLOCK or Z_TREES can be
+   used to force inflate() to return immediately after header processing is
+   complete and before any actual data is decompressed.
+
+     The text, time, xflags, and os fields are filled in with the gzip header
+   contents.  hcrc is set to true if there is a header CRC.  (The header CRC
+   was valid if done is set to one.) If extra is not Z_NULL, then extra_max
+   contains the maximum number of bytes to write to extra.  Once done is true,
+   extra_len contains the actual extra field length, and extra contains the
+   extra field, or that field truncated if extra_max is less than extra_len.
+   If name is not Z_NULL, then up to name_max characters are written there,
+   terminated with a zero unless the length is greater than name_max.  If
+   comment is not Z_NULL, then up to comm_max characters are written there,
+   terminated with a zero unless the length is greater than comm_max.  When any
+   of extra, name, or comment are not Z_NULL and the respective field is not
+   present in the header, then that field is set to Z_NULL to signal its
+   absence.  This allows the use of deflateSetHeader() with the returned
+   structure to duplicate the header.  However if those fields are set to
+   allocated memory, then the application will need to save those pointers
+   elsewhere so that they can be eventually freed.
+
+     If inflateGetHeader is not used, then the header information is simply
+   discarded.  The header is always checked for validity, including the header
+   CRC if present.  inflateReset() will reset the process to discard the header
+   information.  The application would need to call inflateGetHeader() again to
+   retrieve the header from the next gzip stream.
+
+     inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent.
+*/
+
+/*
+ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
+                                        unsigned char FAR *window));
+
+     Initialize the internal stream state for decompression using inflateBack()
+   calls.  The fields zalloc, zfree and opaque in strm must be initialized
+   before the call.  If zalloc and zfree are Z_NULL, then the default library-
+   derived memory allocation routines are used.  windowBits is the base two
+   logarithm of the window size, in the range 8..15.  window is a caller
+   supplied buffer of that size.  Except for special applications where it is
+   assured that deflate was used with small window sizes, windowBits must be 15
+   and a 32K byte window must be supplied to be able to decompress general
+   deflate streams.
+
+     See inflateBack() for the usage of these routines.
+
+     inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
+   the parameters are invalid, Z_MEM_ERROR if the internal state could not be
+   allocated, or Z_VERSION_ERROR if the version of the library does not match
+   the version of the header file.
+*/
+
+typedef unsigned (*in_func) OF((void FAR *,
+                                z_const unsigned char FAR * FAR *));
+typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
+
+ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
+                                    in_func in, void FAR *in_desc,
+                                    out_func out, void FAR *out_desc));
+/*
+     inflateBack() does a raw inflate with a single call using a call-back
+   interface for input and output.  This is potentially more efficient than
+   inflate() for file i/o applications, in that it avoids copying between the
+   output and the sliding window by simply making the window itself the output
+   buffer.  inflate() can be faster on modern CPUs when used with large
+   buffers.  inflateBack() trusts the application to not change the output
+   buffer passed by the output function, at least until inflateBack() returns.
+
+     inflateBackInit() must be called first to allocate the internal state
+   and to initialize the state with the user-provided window buffer.
+   inflateBack() may then be used multiple times to inflate a complete, raw
+   deflate stream with each call.  inflateBackEnd() is then called to free the
+   allocated state.
+
+     A raw deflate stream is one with no zlib or gzip header or trailer.
+   This routine would normally be used in a utility that reads zip or gzip
+   files and writes out uncompressed files.  The utility would decode the
+   header and process the trailer on its own, hence this routine expects only
+   the raw deflate stream to decompress.  This is different from the default
+   behavior of inflate(), which expects a zlib header and trailer around the
+   deflate stream.
+
+     inflateBack() uses two subroutines supplied by the caller that are then
+   called by inflateBack() for input and output.  inflateBack() calls those
+   routines until it reads a complete deflate stream and writes out all of the
+   uncompressed data, or until it encounters an error.  The function's
+   parameters and return types are defined above in the in_func and out_func
+   typedefs.  inflateBack() will call in(in_desc, &buf) which should return the
+   number of bytes of provided input, and a pointer to that input in buf.  If
+   there is no input available, in() must return zero -- buf is ignored in that
+   case -- and inflateBack() will return a buffer error.  inflateBack() will
+   call out(out_desc, buf, len) to write the uncompressed data buf[0..len-1].
+   out() should return zero on success, or non-zero on failure.  If out()
+   returns non-zero, inflateBack() will return with an error.  Neither in() nor
+   out() are permitted to change the contents of the window provided to
+   inflateBackInit(), which is also the buffer that out() uses to write from.
+   The length written by out() will be at most the window size.  Any non-zero
+   amount of input may be provided by in().
+
+     For convenience, inflateBack() can be provided input on the first call by
+   setting strm->next_in and strm->avail_in.  If that input is exhausted, then
+   in() will be called.  Therefore strm->next_in must be initialized before
+   calling inflateBack().  If strm->next_in is Z_NULL, then in() will be called
+   immediately for input.  If strm->next_in is not Z_NULL, then strm->avail_in
+   must also be initialized, and then if strm->avail_in is not zero, input will
+   initially be taken from strm->next_in[0 ..  strm->avail_in - 1].
+
+     The in_desc and out_desc parameters of inflateBack() is passed as the
+   first parameter of in() and out() respectively when they are called.  These
+   descriptors can be optionally used to pass any information that the caller-
+   supplied in() and out() functions need to do their job.
+
+     On return, inflateBack() will set strm->next_in and strm->avail_in to
+   pass back any unused input that was provided by the last in() call.  The
+   return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
+   if in() or out() returned an error, Z_DATA_ERROR if there was a format error
+   in the deflate stream (in which case strm->msg is set to indicate the nature
+   of the error), or Z_STREAM_ERROR if the stream was not properly initialized.
+   In the case of Z_BUF_ERROR, an input or output error can be distinguished
+   using strm->next_in which will be Z_NULL only if in() returned an error.  If
+   strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning
+   non-zero.  (in() will always be called before out(), so strm->next_in is
+   assured to be defined if out() returns non-zero.)  Note that inflateBack()
+   cannot return Z_OK.
+*/
+
+ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
+/*
+     All memory allocated by inflateBackInit() is freed.
+
+     inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
+   state was inconsistent.
+*/
+
+ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
+/* Return flags indicating compile-time options.
+
+    Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
+     1.0: size of uInt
+     3.2: size of uLong
+     5.4: size of voidpf (pointer)
+     7.6: size of z_off_t
+
+    Compiler, assembler, and debug options:
+     8: ZLIB_DEBUG
+     9: ASMV or ASMINF -- use ASM code
+     10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
+     11: 0 (reserved)
+
+    One-time table building (smaller code, but not thread-safe if true):
+     12: BUILDFIXED -- build static block decoding tables when needed
+     13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
+     14,15: 0 (reserved)
+
+    Library content (indicates missing functionality):
+     16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
+                          deflate code when not needed)
+     17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
+                    and decode gzip streams (to avoid linking crc code)
+     18-19: 0 (reserved)
+
+    Operation variations (changes in library functionality):
+     20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
+     21: FASTEST -- deflate algorithm with only one, lowest compression level
+     22,23: 0 (reserved)
+
+    The sprintf variant used by gzprintf (zero is best):
+     24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
+     25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
+     26: 0 = returns value, 1 = void -- 1 means inferred string length returned
+
+    Remainder:
+     27-31: 0 (reserved)
+ */
+
+#ifndef Z_SOLO
+
+                        /* utility functions */
+
+/*
+     The following utility functions are implemented on top of the basic
+   stream-oriented functions.  To simplify the interface, some default options
+   are assumed (compression level and memory usage, standard memory allocation
+   functions).  The source code of these utility functions can be modified if
+   you need special options.
+*/
+
+ZEXTERN int ZEXPORT compress OF((Bytef *dest,   uLongf *destLen,
+                                 const Bytef *source, uLong sourceLen));
+/*
+     Compresses the source buffer into the destination buffer.  sourceLen is
+   the byte length of the source buffer.  Upon entry, destLen is the total size
+   of the destination buffer, which must be at least the value returned by
+   compressBound(sourceLen).  Upon exit, destLen is the actual size of the
+   compressed data.  compress() is equivalent to compress2() with a level
+   parameter of Z_DEFAULT_COMPRESSION.
+
+     compress returns Z_OK if success, Z_MEM_ERROR if there was not
+   enough memory, Z_BUF_ERROR if there was not enough room in the output
+   buffer.
+*/
+
+ZEXTERN int ZEXPORT compress2 OF((Bytef *dest,   uLongf *destLen,
+                                  const Bytef *source, uLong sourceLen,
+                                  int level));
+/*
+     Compresses the source buffer into the destination buffer.  The level
+   parameter has the same meaning as in deflateInit.  sourceLen is the byte
+   length of the source buffer.  Upon entry, destLen is the total size of the
+   destination buffer, which must be at least the value returned by
+   compressBound(sourceLen).  Upon exit, destLen is the actual size of the
+   compressed data.
+
+     compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_BUF_ERROR if there was not enough room in the output buffer,
+   Z_STREAM_ERROR if the level parameter is invalid.
+*/
+
+ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
+/*
+     compressBound() returns an upper bound on the compressed size after
+   compress() or compress2() on sourceLen bytes.  It would be used before a
+   compress() or compress2() call to allocate the destination buffer.
+*/
+
+ZEXTERN int ZEXPORT uncompress OF((Bytef *dest,   uLongf *destLen,
+                                   const Bytef *source, uLong sourceLen));
+/*
+     Decompresses the source buffer into the destination buffer.  sourceLen is
+   the byte length of the source buffer.  Upon entry, destLen is the total size
+   of the destination buffer, which must be large enough to hold the entire
+   uncompressed data.  (The size of the uncompressed data must have been saved
+   previously by the compressor and transmitted to the decompressor by some
+   mechanism outside the scope of this compression library.) Upon exit, destLen
+   is the actual size of the uncompressed data.
+
+     uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
+   enough memory, Z_BUF_ERROR if there was not enough room in the output
+   buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.  In
+   the case where there is not enough room, uncompress() will fill the output
+   buffer with the uncompressed data up to that point.
+*/
+
+ZEXTERN int ZEXPORT uncompress2 OF((Bytef *dest,   uLongf *destLen,
+                                    const Bytef *source, uLong *sourceLen));
+/*
+     Same as uncompress, except that sourceLen is a pointer, where the
+   length of the source is *sourceLen.  On return, *sourceLen is the number of
+   source bytes consumed.
+*/
+
+                        /* gzip file access functions */
+
+/*
+     This library supports reading and writing files in gzip (.gz) format with
+   an interface similar to that of stdio, using the functions that start with
+   "gz".  The gzip format is different from the zlib format.  gzip is a gzip
+   wrapper, documented in RFC 1952, wrapped around a deflate stream.
+*/
+
+typedef struct gzFile_s *gzFile;    /* semi-opaque gzip file descriptor */
+
+/*
+ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
+
+     Opens a gzip (.gz) file for reading or writing.  The mode parameter is as
+   in fopen ("rb" or "wb") but can also include a compression level ("wb9") or
+   a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only
+   compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F'
+   for fixed code compression as in "wb9F".  (See the description of
+   deflateInit2 for more information about the strategy parameter.)  'T' will
+   request transparent writing or appending with no compression and not using
+   the gzip format.
+
+     "a" can be used instead of "w" to request that the gzip stream that will
+   be written be appended to the file.  "+" will result in an error, since
+   reading and writing to the same gzip file is not supported.  The addition of
+   "x" when writing will create the file exclusively, which fails if the file
+   already exists.  On systems that support it, the addition of "e" when
+   reading or writing will set the flag to close the file on an execve() call.
+
+     These functions, as well as gzip, will read and decode a sequence of gzip
+   streams in a file.  The append function of gzopen() can be used to create
+   such a file.  (Also see gzflush() for another way to do this.)  When
+   appending, gzopen does not test whether the file begins with a gzip stream,
+   nor does it look for the end of the gzip streams to begin appending.  gzopen
+   will simply append a gzip stream to the existing file.
+
+     gzopen can be used to read a file which is not in gzip format; in this
+   case gzread will directly read from the file without decompression.  When
+   reading, this will be detected automatically by looking for the magic two-
+   byte gzip header.
+
+     gzopen returns NULL if the file could not be opened, if there was
+   insufficient memory to allocate the gzFile state, or if an invalid mode was
+   specified (an 'r', 'w', or 'a' was not provided, or '+' was provided).
+   errno can be checked to determine if the reason gzopen failed was that the
+   file could not be opened.
+*/
+
+ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
+/*
+     gzdopen associates a gzFile with the file descriptor fd.  File descriptors
+   are obtained from calls like open, dup, creat, pipe or fileno (if the file
+   has been previously opened with fopen).  The mode parameter is as in gzopen.
+
+     The next call of gzclose on the returned gzFile will also close the file
+   descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor
+   fd.  If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd,
+   mode);.  The duplicated descriptor should be saved to avoid a leak, since
+   gzdopen does not close fd if it fails.  If you are using fileno() to get the
+   file descriptor from a FILE *, then you will have to use dup() to avoid
+   double-close()ing the file descriptor.  Both gzclose() and fclose() will
+   close the associated file descriptor, so they need to have different file
+   descriptors.
+
+     gzdopen returns NULL if there was insufficient memory to allocate the
+   gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not
+   provided, or '+' was provided), or if fd is -1.  The file descriptor is not
+   used until the next gz* read, write, seek, or close operation, so gzdopen
+   will not detect if fd is invalid (unless fd is -1).
+*/
+
+ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size));
+/*
+     Set the internal buffer size used by this library's functions.  The
+   default buffer size is 8192 bytes.  This function must be called after
+   gzopen() or gzdopen(), and before any other calls that read or write the
+   file.  The buffer memory allocation is always deferred to the first read or
+   write.  Three times that size in buffer space is allocated.  A larger buffer
+   size of, for example, 64K or 128K bytes will noticeably increase the speed
+   of decompression (reading).
+
+     The new buffer size also affects the maximum length for gzprintf().
+
+     gzbuffer() returns 0 on success, or -1 on failure, such as being called
+   too late.
+*/
+
+ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
+/*
+     Dynamically update the compression level or strategy.  See the description
+   of deflateInit2 for the meaning of these parameters.  Previously provided
+   data is flushed before the parameter change.
+
+     gzsetparams returns Z_OK if success, Z_STREAM_ERROR if the file was not
+   opened for writing, Z_ERRNO if there is an error writing the flushed data,
+   or Z_MEM_ERROR if there is a memory allocation error.
+*/
+
+ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
+/*
+     Reads the given number of uncompressed bytes from the compressed file.  If
+   the input file is not in gzip format, gzread copies the given number of
+   bytes into the buffer directly from the file.
+
+     After reaching the end of a gzip stream in the input, gzread will continue
+   to read, looking for another gzip stream.  Any number of gzip streams may be
+   concatenated in the input file, and will all be decompressed by gzread().
+   If something other than a gzip stream is encountered after a gzip stream,
+   that remaining trailing garbage is ignored (and no error is returned).
+
+     gzread can be used to read a gzip file that is being concurrently written.
+   Upon reaching the end of the input, gzread will return with the available
+   data.  If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then
+   gzclearerr can be used to clear the end of file indicator in order to permit
+   gzread to be tried again.  Z_OK indicates that a gzip stream was completed
+   on the last gzread.  Z_BUF_ERROR indicates that the input file ended in the
+   middle of a gzip stream.  Note that gzread does not return -1 in the event
+   of an incomplete gzip stream.  This error is deferred until gzclose(), which
+   will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip
+   stream.  Alternatively, gzerror can be used before gzclose to detect this
+   case.
+
+     gzread returns the number of uncompressed bytes actually read, less than
+   len for end of file, or -1 for error.  If len is too large to fit in an int,
+   then nothing is read, -1 is returned, and the error state is set to
+   Z_STREAM_ERROR.
+*/
+
+ZEXTERN z_size_t ZEXPORT gzfread OF((voidp buf, z_size_t size, z_size_t nitems,
+                                     gzFile file));
+/*
+     Read up to nitems items of size size from file to buf, otherwise operating
+   as gzread() does.  This duplicates the interface of stdio's fread(), with
+   size_t request and return types.  If the library defines size_t, then
+   z_size_t is identical to size_t.  If not, then z_size_t is an unsigned
+   integer type that can contain a pointer.
+
+     gzfread() returns the number of full items read of size size, or zero if
+   the end of the file was reached and a full item could not be read, or if
+   there was an error.  gzerror() must be consulted if zero is returned in
+   order to determine if there was an error.  If the multiplication of size and
+   nitems overflows, i.e. the product does not fit in a z_size_t, then nothing
+   is read, zero is returned, and the error state is set to Z_STREAM_ERROR.
+
+     In the event that the end of file is reached and only a partial item is
+   available at the end, i.e. the remaining uncompressed data length is not a
+   multiple of size, then the final partial item is nevetheless read into buf
+   and the end-of-file flag is set.  The length of the partial item read is not
+   provided, but could be inferred from the result of gztell().  This behavior
+   is the same as the behavior of fread() implementations in common libraries,
+   but it prevents the direct use of gzfread() to read a concurrently written
+   file, reseting and retrying on end-of-file, when size is not 1.
+*/
+
+ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
+                                voidpc buf, unsigned len));
+/*
+     Writes the given number of uncompressed bytes into the compressed file.
+   gzwrite returns the number of uncompressed bytes written or 0 in case of
+   error.
+*/
+
+ZEXTERN z_size_t ZEXPORT gzfwrite OF((voidpc buf, z_size_t size,
+                                      z_size_t nitems, gzFile file));
+/*
+     gzfwrite() writes nitems items of size size from buf to file, duplicating
+   the interface of stdio's fwrite(), with size_t request and return types.  If
+   the library defines size_t, then z_size_t is identical to size_t.  If not,
+   then z_size_t is an unsigned integer type that can contain a pointer.
+
+     gzfwrite() returns the number of full items written of size size, or zero
+   if there was an error.  If the multiplication of size and nitems overflows,
+   i.e. the product does not fit in a z_size_t, then nothing is written, zero
+   is returned, and the error state is set to Z_STREAM_ERROR.
+*/
+
+ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...));
+/*
+     Converts, formats, and writes the arguments to the compressed file under
+   control of the format string, as in fprintf.  gzprintf returns the number of
+   uncompressed bytes actually written, or a negative zlib error code in case
+   of error.  The number of uncompressed bytes written is limited to 8191, or
+   one less than the buffer size given to gzbuffer().  The caller should assure
+   that this limit is not exceeded.  If it is exceeded, then gzprintf() will
+   return an error (0) with nothing written.  In this case, there may also be a
+   buffer overflow with unpredictable consequences, which is possible only if
+   zlib was compiled with the insecure functions sprintf() or vsprintf()
+   because the secure snprintf() or vsnprintf() functions were not available.
+   This can be determined using zlibCompileFlags().
+*/
+
+ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
+/*
+     Writes the given null-terminated string to the compressed file, excluding
+   the terminating null character.
+
+     gzputs returns the number of characters written, or -1 in case of error.
+*/
+
+ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
+/*
+     Reads bytes from the compressed file until len-1 characters are read, or a
+   newline character is read and transferred to buf, or an end-of-file
+   condition is encountered.  If any characters are read or if len == 1, the
+   string is terminated with a null character.  If no characters are read due
+   to an end-of-file or len < 1, then the buffer is left untouched.
+
+     gzgets returns buf which is a null-terminated string, or it returns NULL
+   for end-of-file or in case of error.  If there was an error, the contents at
+   buf are indeterminate.
+*/
+
+ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
+/*
+     Writes c, converted to an unsigned char, into the compressed file.  gzputc
+   returns the value that was written, or -1 in case of error.
+*/
+
+ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
+/*
+     Reads one byte from the compressed file.  gzgetc returns this byte or -1
+   in case of end of file or error.  This is implemented as a macro for speed.
+   As such, it does not do all of the checking the other functions do.  I.e.
+   it does not check to see if file is NULL, nor whether the structure file
+   points to has been clobbered or not.
+*/
+
+ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
+/*
+     Push one character back onto the stream to be read as the first character
+   on the next read.  At least one character of push-back is allowed.
+   gzungetc() returns the character pushed, or -1 on failure.  gzungetc() will
+   fail if c is -1, and may fail if a character has been pushed but not read
+   yet.  If gzungetc is used immediately after gzopen or gzdopen, at least the
+   output buffer size of pushed characters is allowed.  (See gzbuffer above.)
+   The pushed character will be discarded if the stream is repositioned with
+   gzseek() or gzrewind().
+*/
+
+ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
+/*
+     Flushes all pending output into the compressed file.  The parameter flush
+   is as in the deflate() function.  The return value is the zlib error number
+   (see function gzerror below).  gzflush is only permitted when writing.
+
+     If the flush parameter is Z_FINISH, the remaining data is written and the
+   gzip stream is completed in the output.  If gzwrite() is called again, a new
+   gzip stream will be started in the output.  gzread() is able to read such
+   concatenated gzip streams.
+
+     gzflush should be called only when strictly necessary because it will
+   degrade compression if called too often.
+*/
+
+/*
+ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
+                                   z_off_t offset, int whence));
+
+     Sets the starting position for the next gzread or gzwrite on the given
+   compressed file.  The offset represents a number of bytes in the
+   uncompressed data stream.  The whence parameter is defined as in lseek(2);
+   the value SEEK_END is not supported.
+
+     If the file is opened for reading, this function is emulated but can be
+   extremely slow.  If the file is opened for writing, only forward seeks are
+   supported; gzseek then compresses a sequence of zeroes up to the new
+   starting position.
+
+     gzseek returns the resulting offset location as measured in bytes from
+   the beginning of the uncompressed stream, or -1 in case of error, in
+   particular if the file is opened for writing and the new starting position
+   would be before the current position.
+*/
+
+ZEXTERN int ZEXPORT    gzrewind OF((gzFile file));
+/*
+     Rewinds the given file. This function is supported only for reading.
+
+     gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
+*/
+
+/*
+ZEXTERN z_off_t ZEXPORT    gztell OF((gzFile file));
+
+     Returns the starting position for the next gzread or gzwrite on the given
+   compressed file.  This position represents a number of bytes in the
+   uncompressed data stream, and is zero when starting, even if appending or
+   reading a gzip stream from the middle of a file using gzdopen().
+
+     gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
+*/
+
+/*
+ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file));
+
+     Returns the current offset in the file being read or written.  This offset
+   includes the count of bytes that precede the gzip stream, for example when
+   appending or when using gzdopen() for reading.  When reading, the offset
+   does not include as yet unused buffered input.  This information can be used
+   for a progress indicator.  On error, gzoffset() returns -1.
+*/
+
+ZEXTERN int ZEXPORT gzeof OF((gzFile file));
+/*
+     Returns true (1) if the end-of-file indicator has been set while reading,
+   false (0) otherwise.  Note that the end-of-file indicator is set only if the
+   read tried to go past the end of the input, but came up short.  Therefore,
+   just like feof(), gzeof() may return false even if there is no more data to
+   read, in the event that the last read request was for the exact number of
+   bytes remaining in the input file.  This will happen if the input file size
+   is an exact multiple of the buffer size.
+
+     If gzeof() returns true, then the read functions will return no more data,
+   unless the end-of-file indicator is reset by gzclearerr() and the input file
+   has grown since the previous end of file was detected.
+*/
+
+ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
+/*
+     Returns true (1) if file is being copied directly while reading, or false
+   (0) if file is a gzip stream being decompressed.
+
+     If the input file is empty, gzdirect() will return true, since the input
+   does not contain a gzip stream.
+
+     If gzdirect() is used immediately after gzopen() or gzdopen() it will
+   cause buffers to be allocated to allow reading the file to determine if it
+   is a gzip file.  Therefore if gzbuffer() is used, it should be called before
+   gzdirect().
+
+     When writing, gzdirect() returns true (1) if transparent writing was
+   requested ("wT" for the gzopen() mode), or false (0) otherwise.  (Note:
+   gzdirect() is not needed when writing.  Transparent writing must be
+   explicitly requested, so the application already knows the answer.  When
+   linking statically, using gzdirect() will include all of the zlib code for
+   gzip file reading and decompression, which may not be desired.)
+*/
+
+ZEXTERN int ZEXPORT    gzclose OF((gzFile file));
+/*
+     Flushes all pending output if necessary, closes the compressed file and
+   deallocates the (de)compression state.  Note that once file is closed, you
+   cannot call gzerror with file, since its structures have been deallocated.
+   gzclose must not be called more than once on the same file, just as free
+   must not be called more than once on the same allocation.
+
+     gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a
+   file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the
+   last read ended in the middle of a gzip stream, or Z_OK on success.
+*/
+
+ZEXTERN int ZEXPORT gzclose_r OF((gzFile file));
+ZEXTERN int ZEXPORT gzclose_w OF((gzFile file));
+/*
+     Same as gzclose(), but gzclose_r() is only for use when reading, and
+   gzclose_w() is only for use when writing or appending.  The advantage to
+   using these instead of gzclose() is that they avoid linking in zlib
+   compression or decompression code that is not used when only reading or only
+   writing respectively.  If gzclose() is used, then both compression and
+   decompression code will be included the application when linking to a static
+   zlib library.
+*/
+
+ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
+/*
+     Returns the error message for the last error which occurred on the given
+   compressed file.  errnum is set to zlib error number.  If an error occurred
+   in the file system and not in the compression library, errnum is set to
+   Z_ERRNO and the application may consult errno to get the exact error code.
+
+     The application must not modify the returned string.  Future calls to
+   this function may invalidate the previously returned string.  If file is
+   closed, then the string previously returned by gzerror will no longer be
+   available.
+
+     gzerror() should be used to distinguish errors from end-of-file for those
+   functions above that do not distinguish those cases in their return values.
+*/
+
+ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
+/*
+     Clears the error and end-of-file flags for file.  This is analogous to the
+   clearerr() function in stdio.  This is useful for continuing to read a gzip
+   file that is being written concurrently.
+*/
+
+#endif /* !Z_SOLO */
+
+                        /* checksum functions */
+
+/*
+     These functions are not related to compression but are exported
+   anyway because they might be useful in applications using the compression
+   library.
+*/
+
+ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
+/*
+     Update a running Adler-32 checksum with the bytes buf[0..len-1] and
+   return the updated checksum.  If buf is Z_NULL, this function returns the
+   required initial value for the checksum.
+
+     An Adler-32 checksum is almost as reliable as a CRC-32 but can be computed
+   much faster.
+
+   Usage example:
+
+     uLong adler = adler32(0L, Z_NULL, 0);
+
+     while (read_buffer(buffer, length) != EOF) {
+       adler = adler32(adler, buffer, length);
+     }
+     if (adler != original_adler) error();
+*/
+
+ZEXTERN uLong ZEXPORT adler32_z OF((uLong adler, const Bytef *buf,
+                                    z_size_t len));
+/*
+     Same as adler32(), but with a size_t length.
+*/
+
+/*
+ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
+                                          z_off_t len2));
+
+     Combine two Adler-32 checksums into one.  For two sequences of bytes, seq1
+   and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
+   each, adler1 and adler2.  adler32_combine() returns the Adler-32 checksum of
+   seq1 and seq2 concatenated, requiring only adler1, adler2, and len2.  Note
+   that the z_off_t type (like off_t) is a signed integer.  If len2 is
+   negative, the result has no meaning or utility.
+*/
+
+ZEXTERN uLong ZEXPORT crc32   OF((uLong crc, const Bytef *buf, uInt len));
+/*
+     Update a running CRC-32 with the bytes buf[0..len-1] and return the
+   updated CRC-32.  If buf is Z_NULL, this function returns the required
+   initial value for the crc.  Pre- and post-conditioning (one's complement) is
+   performed within this function so it shouldn't be done by the application.
+
+   Usage example:
+
+     uLong crc = crc32(0L, Z_NULL, 0);
+
+     while (read_buffer(buffer, length) != EOF) {
+       crc = crc32(crc, buffer, length);
+     }
+     if (crc != original_crc) error();
+*/
+
+ZEXTERN uLong ZEXPORT crc32_z OF((uLong adler, const Bytef *buf,
+                                  z_size_t len));
+/*
+     Same as crc32(), but with a size_t length.
+*/
+
+/*
+ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
+
+     Combine two CRC-32 check values into one.  For two sequences of bytes,
+   seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
+   calculated for each, crc1 and crc2.  crc32_combine() returns the CRC-32
+   check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
+   len2.
+*/
+
+
+                        /* various hacks, don't look :) */
+
+/* deflateInit and inflateInit are macros to allow checking the zlib version
+ * and the compiler's view of z_stream:
+ */
+ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
+                                     const char *version, int stream_size));
+ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
+                                     const char *version, int stream_size));
+ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int  level, int  method,
+                                      int windowBits, int memLevel,
+                                      int strategy, const char *version,
+                                      int stream_size));
+ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int  windowBits,
+                                      const char *version, int stream_size));
+ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
+                                         unsigned char FAR *window,
+                                         const char *version,
+                                         int stream_size));
+#ifdef Z_PREFIX_SET
+#  define z_deflateInit(strm, level) \
+          deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define z_inflateInit(strm) \
+          inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define z_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
+          deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
+                        (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define z_inflateInit2(strm, windowBits) \
+          inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
+                        (int)sizeof(z_stream))
+#  define z_inflateBackInit(strm, windowBits, window) \
+          inflateBackInit_((strm), (windowBits), (window), \
+                           ZLIB_VERSION, (int)sizeof(z_stream))
+#else
+#  define deflateInit(strm, level) \
+          deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define inflateInit(strm) \
+          inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
+          deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
+                        (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
+#  define inflateInit2(strm, windowBits) \
+          inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
+                        (int)sizeof(z_stream))
+#  define inflateBackInit(strm, windowBits, window) \
+          inflateBackInit_((strm), (windowBits), (window), \
+                           ZLIB_VERSION, (int)sizeof(z_stream))
+#endif
+
+#ifndef Z_SOLO
+
+/* gzgetc() macro and its supporting function and exposed data structure.  Note
+ * that the real internal state is much larger than the exposed structure.
+ * This abbreviated structure exposes just enough for the gzgetc() macro.  The
+ * user should not mess with these exposed elements, since their names or
+ * behavior could change in the future, perhaps even capriciously.  They can
+ * only be used by the gzgetc() macro.  You have been warned.
+ */
+struct gzFile_s {
+    unsigned have;
+    unsigned char *next;
+    z_off64_t pos;
+};
+ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file));  /* backward compatibility */
+#ifdef Z_PREFIX_SET
+#  undef z_gzgetc
+#  define z_gzgetc(g) \
+          ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
+#else
+#  define gzgetc(g) \
+          ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
+#endif
+
+/* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
+ * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
+ * both are true, the application gets the *64 functions, and the regular
+ * functions are changed to 64 bits) -- in case these are set on systems
+ * without large file support, _LFS64_LARGEFILE must also be true
+ */
+#ifdef Z_LARGE64
+   ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
+   ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
+   ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
+   ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
+   ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t));
+   ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t));
+#endif
+
+#if !defined(ZLIB_INTERNAL) && defined(Z_WANT64)
+#  ifdef Z_PREFIX_SET
+#    define z_gzopen z_gzopen64
+#    define z_gzseek z_gzseek64
+#    define z_gztell z_gztell64
+#    define z_gzoffset z_gzoffset64
+#    define z_adler32_combine z_adler32_combine64
+#    define z_crc32_combine z_crc32_combine64
+#  else
+#    define gzopen gzopen64
+#    define gzseek gzseek64
+#    define gztell gztell64
+#    define gzoffset gzoffset64
+#    define adler32_combine adler32_combine64
+#    define crc32_combine crc32_combine64
+#  endif
+#  ifndef Z_LARGE64
+     ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
+     ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int));
+     ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile));
+     ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile));
+     ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t));
+     ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t));
+#  endif
+#else
+   ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *));
+   ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int));
+   ZEXTERN z_off_t ZEXPORT gztell OF((gzFile));
+   ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile));
+   ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
+   ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
+#endif
+
+#else /* Z_SOLO */
+
+   ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
+   ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
+
+#endif /* !Z_SOLO */
+
+/* undocumented functions */
+ZEXTERN const char   * ZEXPORT zError           OF((int));
+ZEXTERN int            ZEXPORT inflateSyncPoint OF((z_streamp));
+ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table    OF((void));
+ZEXTERN int            ZEXPORT inflateUndermine OF((z_streamp, int));
+ZEXTERN int            ZEXPORT inflateValidate OF((z_streamp, int));
+ZEXTERN unsigned long  ZEXPORT inflateCodesUsed OF ((z_streamp));
+ZEXTERN int            ZEXPORT inflateResetKeep OF((z_streamp));
+ZEXTERN int            ZEXPORT deflateResetKeep OF((z_streamp));
+#if (defined(_WIN32) || defined(__CYGWIN__)) && !defined(Z_SOLO)
+ZEXTERN gzFile         ZEXPORT gzopen_w OF((const wchar_t *path,
+                                            const char *mode));
+#endif
+#if defined(STDC) || defined(Z_HAVE_STDARG_H)
+#  ifndef Z_SOLO
+ZEXTERN int            ZEXPORTVA gzvprintf Z_ARG((gzFile file,
+                                                  const char *format,
+                                                  va_list va));
+#  endif
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ZLIB_H */
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/ChangeLog
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/ChangeLog	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,1515 @@
+
+                ChangeLog file for zlib
+
+Changes in 1.2.11 (15 Jan 2017)
+- Fix deflate stored bug when pulling last block from window
+- Permit immediate deflateParams changes before any deflate input
+
+Changes in 1.2.10 (2 Jan 2017)
+- Avoid warnings on snprintf() return value
+- Fix bug in deflate_stored() for zero-length input
+- Fix bug in gzwrite.c that produced corrupt gzip files
+- Remove files to be installed before copying them in Makefile.in
+- Add warnings when compiling with assembler code
+
+Changes in 1.2.9 (31 Dec 2016)
+- Fix contrib/minizip to permit unzipping with desktop API [Zouzou]
+- Improve contrib/blast to return unused bytes
+- Assure that gzoffset() is correct when appending
+- Improve compress() and uncompress() to support large lengths
+- Fix bug in test/example.c where error code not saved
+- Remedy Coverity warning [Randers-Pehrson]
+- Improve speed of gzprintf() in transparent mode
+- Fix inflateInit2() bug when windowBits is 16 or 32
+- Change DEBUG macro to ZLIB_DEBUG
+- Avoid uninitialized access by gzclose_w()
+- Allow building zlib outside of the source directory
+- Fix bug that accepted invalid zlib header when windowBits is zero
+- Fix gzseek() problem on MinGW due to buggy _lseeki64 there
+- Loop on write() calls in gzwrite.c in case of non-blocking I/O
+- Add --warn (-w) option to ./configure for more compiler warnings
+- Reject a window size of 256 bytes if not using the zlib wrapper
+- Fix bug when level 0 used with Z_HUFFMAN or Z_RLE
+- Add --debug (-d) option to ./configure to define ZLIB_DEBUG
+- Fix bugs in creating a very large gzip header
+- Add uncompress2() function, which returns the input size used
+- Assure that deflateParams() will not switch functions mid-block
+- Dramatically speed up deflation for level 0 (storing)
+- Add gzfread(), duplicating the interface of fread()
+- Add gzfwrite(), duplicating the interface of fwrite()
+- Add deflateGetDictionary() function
+- Use snprintf() for later versions of Microsoft C
+- Fix *Init macros to use z_ prefix when requested
+- Replace as400 with os400 for OS/400 support [Monnerat]
+- Add crc32_z() and adler32_z() functions with size_t lengths
+- Update Visual Studio project files [AraHaan]
+
+Changes in 1.2.8 (28 Apr 2013)
+- Update contrib/minizip/iowin32.c for Windows RT [Vollant]
+- Do not force Z_CONST for C++
+- Clean up contrib/vstudio [Roß]
+- Correct spelling error in zlib.h
+- Fix mixed line endings in contrib/vstudio
+
+Changes in 1.2.7.3 (13 Apr 2013)
+- Fix version numbers and DLL names in contrib/vstudio/*/zlib.rc
+
+Changes in 1.2.7.2 (13 Apr 2013)
+- Change check for a four-byte type back to hexadecimal
+- Fix typo in win32/Makefile.msc
+- Add casts in gzwrite.c for pointer differences
+
+Changes in 1.2.7.1 (24 Mar 2013)
+- Replace use of unsafe string functions with snprintf if available
+- Avoid including stddef.h on Windows for Z_SOLO compile [Niessink]
+- Fix gzgetc undefine when Z_PREFIX set [Turk]
+- Eliminate use of mktemp in Makefile (not always available)
+- Fix bug in 'F' mode for gzopen()
+- Add inflateGetDictionary() function
+- Correct comment in deflate.h
+- Use _snprintf for snprintf in Microsoft C
+- On Darwin, only use /usr/bin/libtool if libtool is not Apple
+- Delete "--version" file if created by "ar --version" [Richard G.]
+- Fix configure check for veracity of compiler error return codes
+- Fix CMake compilation of static lib for MSVC2010 x64
+- Remove unused variable in infback9.c
+- Fix argument checks in gzlog_compress() and gzlog_write()
+- Clean up the usage of z_const and respect const usage within zlib
+- Clean up examples/gzlog.[ch] comparisons of different types
+- Avoid shift equal to bits in type (caused endless loop)
+- Fix uninitialized value bug in gzputc() introduced by const patches
+- Fix memory allocation error in examples/zran.c [Nor]
+- Fix bug where gzopen(), gzclose() would write an empty file
+- Fix bug in gzclose() when gzwrite() runs out of memory
+- Check for input buffer malloc failure in examples/gzappend.c
+- Add note to contrib/blast to use binary mode in stdio
+- Fix comparisons of differently signed integers in contrib/blast
+- Check for invalid code length codes in contrib/puff
+- Fix serious but very rare decompression bug in inftrees.c
+- Update inflateBack() comments, since inflate() can be faster
+- Use underscored I/O function names for WINAPI_FAMILY
+- Add _tr_flush_bits to the external symbols prefixed by --zprefix
+- Add contrib/vstudio/vc10 pre-build step for static only
+- Quote --version-script argument in CMakeLists.txt
+- Don't specify --version-script on Apple platforms in CMakeLists.txt
+- Fix casting error in contrib/testzlib/testzlib.c
+- Fix types in contrib/minizip to match result of get_crc_table()
+- Simplify contrib/vstudio/vc10 with 'd' suffix
+- Add TOP support to win32/Makefile.msc
+- Suport i686 and amd64 assembler builds in CMakeLists.txt
+- Fix typos in the use of _LARGEFILE64_SOURCE in zconf.h
+- Add vc11 and vc12 build files to contrib/vstudio
+- Add gzvprintf() as an undocumented function in zlib
+- Fix configure for Sun shell
+- Remove runtime check in configure for four-byte integer type
+- Add casts and consts to ease user conversion to C++
+- Add man pages for minizip and miniunzip
+- In Makefile uninstall, don't rm if preceding cd fails
+- Do not return Z_BUF_ERROR if deflateParam() has nothing to write
+
+Changes in 1.2.7 (2 May 2012)
+- Replace use of memmove() with a simple copy for portability
+- Test for existence of strerror
+- Restore gzgetc_ for backward compatibility with 1.2.6
+- Fix build with non-GNU make on Solaris
+- Require gcc 4.0 or later on Mac OS X to use the hidden attribute
+- Include unistd.h for Watcom C
+- Use __WATCOMC__ instead of __WATCOM__
+- Do not use the visibility attribute if NO_VIZ defined
+- Improve the detection of no hidden visibility attribute
+- Avoid using __int64 for gcc or solo compilation
+- Cast to char * in gzprintf to avoid warnings [Zinser]
+- Fix make_vms.com for VAX [Zinser]
+- Don't use library or built-in byte swaps
+- Simplify test and use of gcc hidden attribute
+- Fix bug in gzclose_w() when gzwrite() fails to allocate memory
+- Add "x" (O_EXCL) and "e" (O_CLOEXEC) modes support to gzopen()
+- Fix bug in test/minigzip.c for configure --solo
+- Fix contrib/vstudio project link errors [Mohanathas]
+- Add ability to choose the builder in make_vms.com [Schweda]
+- Add DESTDIR support to mingw32 win32/Makefile.gcc
+- Fix comments in win32/Makefile.gcc for proper usage
+- Allow overriding the default install locations for cmake
+- Generate and install the pkg-config file with cmake
+- Build both a static and a shared version of zlib with cmake
+- Include version symbols for cmake builds
+- If using cmake with MSVC, add the source directory to the includes
+- Remove unneeded EXTRA_CFLAGS from win32/Makefile.gcc [Truta]
+- Move obsolete emx makefile to old [Truta]
+- Allow the use of -Wundef when compiling or using zlib
+- Avoid the use of the -u option with mktemp
+- Improve inflate() documentation on the use of Z_FINISH
+- Recognize clang as gcc
+- Add gzopen_w() in Windows for wide character path names
+- Rename zconf.h in CMakeLists.txt to move it out of the way
+- Add source directory in CMakeLists.txt for building examples
+- Look in build directory for zlib.pc in CMakeLists.txt
+- Remove gzflags from zlibvc.def in vc9 and vc10
+- Fix contrib/minizip compilation in the MinGW environment
+- Update ./configure for Solaris, support --64 [Mooney]
+- Remove -R. from Solaris shared build (possible security issue)
+- Avoid race condition for parallel make (-j) running example
+- Fix type mismatch between get_crc_table() and crc_table
+- Fix parsing of version with "-" in CMakeLists.txt [Snider, Ziegler]
+- Fix the path to zlib.map in CMakeLists.txt
+- Force the native libtool in Mac OS X to avoid GNU libtool [Beebe]
+- Add instructions to win32/Makefile.gcc for shared install [Torri]
+
+Changes in 1.2.6.1 (12 Feb 2012)
+- Avoid the use of the Objective-C reserved name "id"
+- Include io.h in gzguts.h for Microsoft compilers
+- Fix problem with ./configure --prefix and gzgetc macro
+- Include gz_header definition when compiling zlib solo
+- Put gzflags() functionality back in zutil.c
+- Avoid library header include in crc32.c for Z_SOLO
+- Use name in GCC_CLASSIC as C compiler for coverage testing, if set
+- Minor cleanup in contrib/minizip/zip.c [Vollant]
+- Update make_vms.com [Zinser]
+- Remove unnecessary gzgetc_ function
+- Use optimized byte swap operations for Microsoft and GNU [Snyder]
+- Fix minor typo in zlib.h comments [Rzesniowiecki]
+
+Changes in 1.2.6 (29 Jan 2012)
+- Update the Pascal interface in contrib/pascal
+- Fix function numbers for gzgetc_ in zlibvc.def files
+- Fix configure.ac for contrib/minizip [Schiffer]
+- Fix large-entry detection in minizip on 64-bit systems [Schiffer]
+- Have ./configure use the compiler return code for error indication
+- Fix CMakeLists.txt for cross compilation [McClure]
+- Fix contrib/minizip/zip.c for 64-bit architectures [Dalsnes]
+- Fix compilation of contrib/minizip on FreeBSD [Marquez]
+- Correct suggested usages in win32/Makefile.msc [Shachar, Horvath]
+- Include io.h for Turbo C / Borland C on all platforms [Truta]
+- Make version explicit in contrib/minizip/configure.ac [Bosmans]
+- Avoid warning for no encryption in contrib/minizip/zip.c [Vollant]
+- Minor cleanup up contrib/minizip/unzip.c [Vollant]
+- Fix bug when compiling minizip with C++ [Vollant]
+- Protect for long name and extra fields in contrib/minizip [Vollant]
+- Avoid some warnings in contrib/minizip [Vollant]
+- Add -I../.. -L../.. to CFLAGS for minizip and miniunzip
+- Add missing libs to minizip linker command
+- Add support for VPATH builds in contrib/minizip
+- Add an --enable-demos option to contrib/minizip/configure
+- Add the generation of configure.log by ./configure
+- Exit when required parameters not provided to win32/Makefile.gcc
+- Have gzputc return the character written instead of the argument
+- Use the -m option on ldconfig for BSD systems [Tobias]
+- Correct in zlib.map when deflateResetKeep was added
+
+Changes in 1.2.5.3 (15 Jan 2012)
+- Restore gzgetc function for binary compatibility
+- Do not use _lseeki64 under Borland C++ [Truta]
+- Update win32/Makefile.msc to build test/*.c [Truta]
+- Remove old/visualc6 given CMakefile and other alternatives
+- Update AS400 build files and documentation [Monnerat]
+- Update win32/Makefile.gcc to build test/*.c [Truta]
+- Permit stronger flushes after Z_BLOCK flushes
+- Avoid extraneous empty blocks when doing empty flushes
+- Permit Z_NULL arguments to deflatePending
+- Allow deflatePrime() to insert bits in the middle of a stream
+- Remove second empty static block for Z_PARTIAL_FLUSH
+- Write out all of the available bits when using Z_BLOCK
+- Insert the first two strings in the hash table after a flush
+
+Changes in 1.2.5.2 (17 Dec 2011)
+- fix ld error: unable to find version dependency 'ZLIB_1.2.5'
+- use relative symlinks for shared libs
+- Avoid searching past window for Z_RLE strategy
+- Assure that high-water mark initialization is always applied in deflate
+- Add assertions to fill_window() in deflate.c to match comments
+- Update python link in README
+- Correct spelling error in gzread.c
+- Fix bug in gzgets() for a concatenated empty gzip stream
+- Correct error in comment for gz_make()
+- Change gzread() and related to ignore junk after gzip streams
+- Allow gzread() and related to continue after gzclearerr()
+- Allow gzrewind() and gzseek() after a premature end-of-file
+- Simplify gzseek() now that raw after gzip is ignored
+- Change gzgetc() to a macro for speed (~40% speedup in testing)
+- Fix gzclose() to return the actual error last encountered
+- Always add large file support for windows
+- Include zconf.h for windows large file support
+- Include zconf.h.cmakein for windows large file support
+- Update zconf.h.cmakein on make distclean
+- Merge vestigial vsnprintf determination from zutil.h to gzguts.h
+- Clarify how gzopen() appends in zlib.h comments
+- Correct documentation of gzdirect() since junk at end now ignored
+- Add a transparent write mode to gzopen() when 'T' is in the mode
+- Update python link in zlib man page
+- Get inffixed.h and MAKEFIXED result to match
+- Add a ./config --solo option to make zlib subset with no library use
+- Add undocumented inflateResetKeep() function for CAB file decoding
+- Add --cover option to ./configure for gcc coverage testing
+- Add #define ZLIB_CONST option to use const in the z_stream interface
+- Add comment to gzdopen() in zlib.h to use dup() when using fileno()
+- Note behavior of uncompress() to provide as much data as it can
+- Add files in contrib/minizip to aid in building libminizip
+- Split off AR options in Makefile.in and configure
+- Change ON macro to Z_ARG to avoid application conflicts
+- Facilitate compilation with Borland C++ for pragmas and vsnprintf
+- Include io.h for Turbo C / Borland C++
+- Move example.c and minigzip.c to test/
+- Simplify incomplete code table filling in inflate_table()
+- Remove code from inflate.c and infback.c that is impossible to execute
+- Test the inflate code with full coverage
+- Allow deflateSetDictionary, inflateSetDictionary at any time (in raw)
+- Add deflateResetKeep and fix inflateResetKeep to retain dictionary
+- Fix gzwrite.c to accommodate reduced memory zlib compilation
+- Have inflate() with Z_FINISH avoid the allocation of a window
+- Do not set strm->adler when doing raw inflate
+- Fix gzeof() to behave just like feof() when read is not past end of file
+- Fix bug in gzread.c when end-of-file is reached
+- Avoid use of Z_BUF_ERROR in gz* functions except for premature EOF
+- Document gzread() capability to read concurrently written files
+- Remove hard-coding of resource compiler in CMakeLists.txt [Blammo]
+
+Changes in 1.2.5.1 (10 Sep 2011)
+- Update FAQ entry on shared builds (#13)
+- Avoid symbolic argument to chmod in Makefile.in
+- Fix bug and add consts in contrib/puff [Oberhumer]
+- Update contrib/puff/zeros.raw test file to have all block types
+- Add full coverage test for puff in contrib/puff/Makefile
+- Fix static-only-build install in Makefile.in
+- Fix bug in unzGetCurrentFileInfo() in contrib/minizip [Kuno]
+- Add libz.a dependency to shared in Makefile.in for parallel builds
+- Spell out "number" (instead of "nb") in zlib.h for total_in, total_out
+- Replace $(...) with `...` in configure for non-bash sh [Bowler]
+- Add darwin* to Darwin* and solaris* to SunOS\ 5* in configure [Groffen]
+- Add solaris* to Linux* in configure to allow gcc use [Groffen]
+- Add *bsd* to Linux* case in configure [Bar-Lev]
+- Add inffast.obj to dependencies in win32/Makefile.msc
+- Correct spelling error in deflate.h [Kohler]
+- Change libzdll.a again to libz.dll.a (!) in win32/Makefile.gcc
+- Add test to configure for GNU C looking for gcc in output of $cc -v
+- Add zlib.pc generation to win32/Makefile.gcc [Weigelt]
+- Fix bug in zlib.h for _FILE_OFFSET_BITS set and _LARGEFILE64_SOURCE not
+- Add comment in zlib.h that adler32_combine with len2 < 0 makes no sense
+- Make NO_DIVIDE option in adler32.c much faster (thanks to John Reiser)
+- Make stronger test in zconf.h to include unistd.h for LFS
+- Apply Darwin patches for 64-bit file offsets to contrib/minizip [Slack]
+- Fix zlib.h LFS support when Z_PREFIX used
+- Add updated as400 support (removed from old) [Monnerat]
+- Avoid deflate sensitivity to volatile input data
+- Avoid division in adler32_combine for NO_DIVIDE
+- Clarify the use of Z_FINISH with deflateBound() amount of space
+- Set binary for output file in puff.c
+- Use u4 type for crc_table to avoid conversion warnings
+- Apply casts in zlib.h to avoid conversion warnings
+- Add OF to prototypes for adler32_combine_ and crc32_combine_ [Miller]
+- Improve inflateSync() documentation to note indeterminancy
+- Add deflatePending() function to return the amount of pending output
+- Correct the spelling of "specification" in FAQ [Randers-Pehrson]
+- Add a check in configure for stdarg.h, use for gzprintf()
+- Check that pointers fit in ints when gzprint() compiled old style
+- Add dummy name before $(SHAREDLIBV) in Makefile [Bar-Lev, Bowler]
+- Delete line in configure that adds -L. libz.a to LDFLAGS [Weigelt]
+- Add debug records in assmebler code [Londer]
+- Update RFC references to use http://tools.ietf.org/html/... [Li]
+- Add --archs option, use of libtool to configure for Mac OS X [Borstel]
+
+Changes in 1.2.5 (19 Apr 2010)
+- Disable visibility attribute in win32/Makefile.gcc [Bar-Lev]
+- Default to libdir as sharedlibdir in configure [Nieder]
+- Update copyright dates on modified source files
+- Update trees.c to be able to generate modified trees.h
+- Exit configure for MinGW, suggesting win32/Makefile.gcc
+- Check for NULL path in gz_open [Homurlu]
+
+Changes in 1.2.4.5 (18 Apr 2010)
+- Set sharedlibdir in configure [Torok]
+- Set LDFLAGS in Makefile.in [Bar-Lev]
+- Avoid mkdir objs race condition in Makefile.in [Bowler]
+- Add ZLIB_INTERNAL in front of internal inter-module functions and arrays
+- Define ZLIB_INTERNAL to hide internal functions and arrays for GNU C
+- Don't use hidden attribute when it is a warning generator (e.g. Solaris)
+
+Changes in 1.2.4.4 (18 Apr 2010)
+- Fix CROSS_PREFIX executable testing, CHOST extract, mingw* [Torok]
+- Undefine _LARGEFILE64_SOURCE in zconf.h if it is zero, but not if empty
+- Try to use bash or ksh regardless of functionality of /bin/sh
+- Fix configure incompatibility with NetBSD sh
+- Remove attempt to run under bash or ksh since have better NetBSD fix
+- Fix win32/Makefile.gcc for MinGW [Bar-Lev]
+- Add diagnostic messages when using CROSS_PREFIX in configure
+- Added --sharedlibdir option to configure [Weigelt]
+- Use hidden visibility attribute when available [Frysinger]
+
+Changes in 1.2.4.3 (10 Apr 2010)
+- Only use CROSS_PREFIX in configure for ar and ranlib if they exist
+- Use CROSS_PREFIX for nm [Bar-Lev]
+- Assume _LARGEFILE64_SOURCE defined is equivalent to true
+- Avoid use of undefined symbols in #if with && and ||
+- Make *64 prototypes in gzguts.h consistent with functions
+- Add -shared load option for MinGW in configure [Bowler]
+- Move z_off64_t to public interface, use instead of off64_t
+- Remove ! from shell test in configure (not portable to Solaris)
+- Change +0 macro tests to -0 for possibly increased portability
+
+Changes in 1.2.4.2 (9 Apr 2010)
+- Add consistent carriage returns to readme.txt's in masmx86 and masmx64
+- Really provide prototypes for *64 functions when building without LFS
+- Only define unlink() in minigzip.c if unistd.h not included
+- Update README to point to contrib/vstudio project files
+- Move projects/vc6 to old/ and remove projects/
+- Include stdlib.h in minigzip.c for setmode() definition under WinCE
+- Clean up assembler builds in win32/Makefile.msc [Rowe]
+- Include sys/types.h for Microsoft for off_t definition
+- Fix memory leak on error in gz_open()
+- Symbolize nm as $NM in configure [Weigelt]
+- Use TEST_LDSHARED instead of LDSHARED to link test programs [Weigelt]
+- Add +0 to _FILE_OFFSET_BITS and _LFS64_LARGEFILE in case not defined
+- Fix bug in gzeof() to take into account unused input data
+- Avoid initialization of structures with variables in puff.c
+- Updated win32/README-WIN32.txt [Rowe]
+
+Changes in 1.2.4.1 (28 Mar 2010)
+- Remove the use of [a-z] constructs for sed in configure [gentoo 310225]
+- Remove $(SHAREDLIB) from LIBS in Makefile.in [Creech]
+- Restore "for debugging" comment on sprintf() in gzlib.c
+- Remove fdopen for MVS from gzguts.h
+- Put new README-WIN32.txt in win32 [Rowe]
+- Add check for shell to configure and invoke another shell if needed
+- Fix big fat stinking bug in gzseek() on uncompressed files
+- Remove vestigial F_OPEN64 define in zutil.h
+- Set and check the value of _LARGEFILE_SOURCE and _LARGEFILE64_SOURCE
+- Avoid errors on non-LFS systems when applications define LFS macros
+- Set EXE to ".exe" in configure for MINGW [Kahle]
+- Match crc32() in crc32.c exactly to the prototype in zlib.h [Sherrill]
+- Add prefix for cross-compilation in win32/makefile.gcc [Bar-Lev]
+- Add DLL install in win32/makefile.gcc [Bar-Lev]
+- Allow Linux* or linux* from uname in configure [Bar-Lev]
+- Allow ldconfig to be redefined in configure and Makefile.in [Bar-Lev]
+- Add cross-compilation prefixes to configure [Bar-Lev]
+- Match type exactly in gz_load() invocation in gzread.c
+- Match type exactly of zcalloc() in zutil.c to zlib.h alloc_func
+- Provide prototypes for *64 functions when building zlib without LFS
+- Don't use -lc when linking shared library on MinGW
+- Remove errno.h check in configure and vestigial errno code in zutil.h
+
+Changes in 1.2.4 (14 Mar 2010)
+- Fix VER3 extraction in configure for no fourth subversion
+- Update zlib.3, add docs to Makefile.in to make .pdf out of it
+- Add zlib.3.pdf to distribution
+- Don't set error code in gzerror() if passed pointer is NULL
+- Apply destination directory fixes to CMakeLists.txt [Lowman]
+- Move #cmakedefine's to a new zconf.in.cmakein
+- Restore zconf.h for builds that don't use configure or cmake
+- Add distclean to dummy Makefile for convenience
+- Update and improve INDEX, README, and FAQ
+- Update CMakeLists.txt for the return of zconf.h [Lowman]
+- Update contrib/vstudio/vc9 and vc10 [Vollant]
+- Change libz.dll.a back to libzdll.a in win32/Makefile.gcc
+- Apply license and readme changes to contrib/asm686 [Raiter]
+- Check file name lengths and add -c option in minigzip.c [Li]
+- Update contrib/amd64 and contrib/masmx86/ [Vollant]
+- Avoid use of "eof" parameter in trees.c to not shadow library variable
+- Update make_vms.com for removal of zlibdefs.h [Zinser]
+- Update assembler code and vstudio projects in contrib [Vollant]
+- Remove outdated assembler code contrib/masm686 and contrib/asm586
+- Remove old vc7 and vc8 from contrib/vstudio
+- Update win32/Makefile.msc, add ZLIB_VER_SUBREVISION [Rowe]
+- Fix memory leaks in gzclose_r() and gzclose_w(), file leak in gz_open()
+- Add contrib/gcc_gvmat64 for longest_match and inflate_fast [Vollant]
+- Remove *64 functions from win32/zlib.def (they're not 64-bit yet)
+- Fix bug in void-returning vsprintf() case in gzwrite.c
+- Fix name change from inflate.h in contrib/inflate86/inffas86.c
+- Check if temporary file exists before removing in make_vms.com [Zinser]
+- Fix make install and uninstall for --static option
+- Fix usage of _MSC_VER in gzguts.h and zutil.h [Truta]
+- Update readme.txt in contrib/masmx64 and masmx86 to assemble
+
+Changes in 1.2.3.9 (21 Feb 2010)
+- Expunge gzio.c
+- Move as400 build information to old
+- Fix updates in contrib/minizip and contrib/vstudio
+- Add const to vsnprintf test in configure to avoid warnings [Weigelt]
+- Delete zconf.h (made by configure) [Weigelt]
+- Change zconf.in.h to zconf.h.in per convention [Weigelt]
+- Check for NULL buf in gzgets()
+- Return empty string for gzgets() with len == 1 (like fgets())
+- Fix description of gzgets() in zlib.h for end-of-file, NULL return
+- Update minizip to 1.1 [Vollant]
+- Avoid MSVC loss of data warnings in gzread.c, gzwrite.c
+- Note in zlib.h that gzerror() should be used to distinguish from EOF
+- Remove use of snprintf() from gzlib.c
+- Fix bug in gzseek()
+- Update contrib/vstudio, adding vc9 and vc10 [Kuno, Vollant]
+- Fix zconf.h generation in CMakeLists.txt [Lowman]
+- Improve comments in zconf.h where modified by configure
+
+Changes in 1.2.3.8 (13 Feb 2010)
+- Clean up text files (tabs, trailing whitespace, etc.) [Oberhumer]
+- Use z_off64_t in gz_zero() and gz_skip() to match state->skip
+- Avoid comparison problem when sizeof(int) == sizeof(z_off64_t)
+- Revert to Makefile.in from 1.2.3.6 (live with the clutter)
+- Fix missing error return in gzflush(), add zlib.h note
+- Add *64 functions to zlib.map [Levin]
+- Fix signed/unsigned comparison in gz_comp()
+- Use SFLAGS when testing shared linking in configure
+- Add --64 option to ./configure to use -m64 with gcc
+- Fix ./configure --help to correctly name options
+- Have make fail if a test fails [Levin]
+- Avoid buffer overrun in contrib/masmx64/gvmat64.asm [Simpson]
+- Remove assembler object files from contrib
+
+Changes in 1.2.3.7 (24 Jan 2010)
+- Always gzopen() with O_LARGEFILE if available
+- Fix gzdirect() to work immediately after gzopen() or gzdopen()
+- Make gzdirect() more precise when the state changes while reading
+- Improve zlib.h documentation in many places
+- Catch memory allocation failure in gz_open()
+- Complete close operation if seek forward in gzclose_w() fails
+- Return Z_ERRNO from gzclose_r() if close() fails
+- Return Z_STREAM_ERROR instead of EOF for gzclose() being passed NULL
+- Return zero for gzwrite() errors to match zlib.h description
+- Return -1 on gzputs() error to match zlib.h description
+- Add zconf.in.h to allow recovery from configure modification [Weigelt]
+- Fix static library permissions in Makefile.in [Weigelt]
+- Avoid warnings in configure tests that hide functionality [Weigelt]
+- Add *BSD and DragonFly to Linux case in configure [gentoo 123571]
+- Change libzdll.a to libz.dll.a in win32/Makefile.gcc [gentoo 288212]
+- Avoid access of uninitialized data for first inflateReset2 call [Gomes]
+- Keep object files in subdirectories to reduce the clutter somewhat
+- Remove default Makefile and zlibdefs.h, add dummy Makefile
+- Add new external functions to Z_PREFIX, remove duplicates, z_z_ -> z_
+- Remove zlibdefs.h completely -- modify zconf.h instead
+
+Changes in 1.2.3.6 (17 Jan 2010)
+- Avoid void * arithmetic in gzread.c and gzwrite.c
+- Make compilers happier with const char * for gz_error message
+- Avoid unused parameter warning in inflate.c
+- Avoid signed-unsigned comparison warning in inflate.c
+- Indent #pragma's for traditional C
+- Fix usage of strwinerror() in glib.c, change to gz_strwinerror()
+- Correct email address in configure for system options
+- Update make_vms.com and add make_vms.com to contrib/minizip [Zinser]
+- Update zlib.map [Brown]
+- Fix Makefile.in for Solaris 10 make of example64 and minizip64 [Torok]
+- Apply various fixes to CMakeLists.txt [Lowman]
+- Add checks on len in gzread() and gzwrite()
+- Add error message for no more room for gzungetc()
+- Remove zlib version check in gzwrite()
+- Defer compression of gzprintf() result until need to
+- Use snprintf() in gzdopen() if available
+- Remove USE_MMAP configuration determination (only used by minigzip)
+- Remove examples/pigz.c (available separately)
+- Update examples/gun.c to 1.6
+
+Changes in 1.2.3.5 (8 Jan 2010)
+- Add space after #if in zutil.h for some compilers
+- Fix relatively harmless bug in deflate_fast() [Exarevsky]
+- Fix same problem in deflate_slow()
+- Add $(SHAREDLIBV) to LIBS in Makefile.in [Brown]
+- Add deflate_rle() for faster Z_RLE strategy run-length encoding
+- Add deflate_huff() for faster Z_HUFFMAN_ONLY encoding
+- Change name of "write" variable in inffast.c to avoid library collisions
+- Fix premature EOF from gzread() in gzio.c [Brown]
+- Use zlib header window size if windowBits is 0 in inflateInit2()
+- Remove compressBound() call in deflate.c to avoid linking compress.o
+- Replace use of errno in gz* with functions, support WinCE [Alves]
+- Provide alternative to perror() in minigzip.c for WinCE [Alves]
+- Don't use _vsnprintf on later versions of MSVC [Lowman]
+- Add CMake build script and input file [Lowman]
+- Update contrib/minizip to 1.1 [Svensson, Vollant]
+- Moved nintendods directory from contrib to .
+- Replace gzio.c with a new set of routines with the same functionality
+- Add gzbuffer(), gzoffset(), gzclose_r(), gzclose_w() as part of above
+- Update contrib/minizip to 1.1b
+- Change gzeof() to return 0 on error instead of -1 to agree with zlib.h
+
+Changes in 1.2.3.4 (21 Dec 2009)
+- Use old school .SUFFIXES in Makefile.in for FreeBSD compatibility
+- Update comments in configure and Makefile.in for default --shared
+- Fix test -z's in configure [Marquess]
+- Build examplesh and minigzipsh when not testing
+- Change NULL's to Z_NULL's in deflate.c and in comments in zlib.h
+- Import LDFLAGS from the environment in configure
+- Fix configure to populate SFLAGS with discovered CFLAGS options
+- Adapt make_vms.com to the new Makefile.in [Zinser]
+- Add zlib2ansi script for C++ compilation [Marquess]
+- Add _FILE_OFFSET_BITS=64 test to make test (when applicable)
+- Add AMD64 assembler code for longest match to contrib [Teterin]
+- Include options from $SFLAGS when doing $LDSHARED
+- Simplify 64-bit file support by introducing z_off64_t type
+- Make shared object files in objs directory to work around old Sun cc
+- Use only three-part version number for Darwin shared compiles
+- Add rc option to ar in Makefile.in for when ./configure not run
+- Add -WI,-rpath,. to LDFLAGS for OSF 1 V4*
+- Set LD_LIBRARYN32_PATH for SGI IRIX shared compile
+- Protect against _FILE_OFFSET_BITS being defined when compiling zlib
+- Rename Makefile.in targets allstatic to static and allshared to shared
+- Fix static and shared Makefile.in targets to be independent
+- Correct error return bug in gz_open() by setting state [Brown]
+- Put spaces before ;;'s in configure for better sh compatibility
+- Add pigz.c (parallel implementation of gzip) to examples/
+- Correct constant in crc32.c to UL [Leventhal]
+- Reject negative lengths in crc32_combine()
+- Add inflateReset2() function to work like inflateEnd()/inflateInit2()
+- Include sys/types.h for _LARGEFILE64_SOURCE [Brown]
+- Correct typo in doc/algorithm.txt [Janik]
+- Fix bug in adler32_combine() [Zhu]
+- Catch missing-end-of-block-code error in all inflates and in puff
+    Assures that random input to inflate eventually results in an error
+- Added enough.c (calculation of ENOUGH for inftrees.h) to examples/
+- Update ENOUGH and its usage to reflect discovered bounds
+- Fix gzerror() error report on empty input file [Brown]
+- Add ush casts in trees.c to avoid pedantic runtime errors
+- Fix typo in zlib.h uncompress() description [Reiss]
+- Correct inflate() comments with regard to automatic header detection
+- Remove deprecation comment on Z_PARTIAL_FLUSH (it stays)
+- Put new version of gzlog (2.0) in examples with interruption recovery
+- Add puff compile option to permit invalid distance-too-far streams
+- Add puff TEST command options, ability to read piped input
+- Prototype the *64 functions in zlib.h when _FILE_OFFSET_BITS == 64, but
+  _LARGEFILE64_SOURCE not defined
+- Fix Z_FULL_FLUSH to truly erase the past by resetting s->strstart
+- Fix deflateSetDictionary() to use all 32K for output consistency
+- Remove extraneous #define MIN_LOOKAHEAD in deflate.c (in deflate.h)
+- Clear bytes after deflate lookahead to avoid use of uninitialized data
+- Change a limit in inftrees.c to be more transparent to Coverity Prevent
+- Update win32/zlib.def with exported symbols from zlib.h
+- Correct spelling errors in zlib.h [Willem, Sobrado]
+- Allow Z_BLOCK for deflate() to force a new block
+- Allow negative bits in inflatePrime() to delete existing bit buffer
+- Add Z_TREES flush option to inflate() to return at end of trees
+- Add inflateMark() to return current state information for random access
+- Add Makefile for NintendoDS to contrib [Costa]
+- Add -w in configure compile tests to avoid spurious warnings [Beucler]
+- Fix typos in zlib.h comments for deflateSetDictionary()
+- Fix EOF detection in transparent gzread() [Maier]
+
+Changes in 1.2.3.3 (2 October 2006)
+- Make --shared the default for configure, add a --static option
+- Add compile option to permit invalid distance-too-far streams
+- Add inflateUndermine() function which is required to enable above
+- Remove use of "this" variable name for C++ compatibility [Marquess]
+- Add testing of shared library in make test, if shared library built
+- Use ftello() and fseeko() if available instead of ftell() and fseek()
+- Provide two versions of all functions that use the z_off_t type for
+  binary compatibility -- a normal version and a 64-bit offset version,
+  per the Large File Support Extension when _LARGEFILE64_SOURCE is
+  defined; use the 64-bit versions by default when _FILE_OFFSET_BITS
+  is defined to be 64
+- Add a --uname= option to configure to perhaps help with cross-compiling
+
+Changes in 1.2.3.2 (3 September 2006)
+- Turn off silly Borland warnings [Hay]
+- Use off64_t and define _LARGEFILE64_SOURCE when present
+- Fix missing dependency on inffixed.h in Makefile.in
+- Rig configure --shared to build both shared and static [Teredesai, Truta]
+- Remove zconf.in.h and instead create a new zlibdefs.h file
+- Fix contrib/minizip/unzip.c non-encrypted after encrypted [Vollant]
+- Add treebuild.xml (see http://treebuild.metux.de/) [Weigelt]
+
+Changes in 1.2.3.1 (16 August 2006)
+- Add watcom directory with OpenWatcom make files [Daniel]
+- Remove #undef of FAR in zconf.in.h for MVS [Fedtke]
+- Update make_vms.com [Zinser]
+- Use -fPIC for shared build in configure [Teredesai, Nicholson]
+- Use only major version number for libz.so on IRIX and OSF1 [Reinholdtsen]
+- Use fdopen() (not _fdopen()) for Interix in zutil.h [Bäck]
+- Add some FAQ entries about the contrib directory
+- Update the MVS question in the FAQ
+- Avoid extraneous reads after EOF in gzio.c [Brown]
+- Correct spelling of "successfully" in gzio.c [Randers-Pehrson]
+- Add comments to zlib.h about gzerror() usage [Brown]
+- Set extra flags in gzip header in gzopen() like deflate() does
+- Make configure options more compatible with double-dash conventions
+  [Weigelt]
+- Clean up compilation under Solaris SunStudio cc [Rowe, Reinholdtsen]
+- Fix uninstall target in Makefile.in [Truta]
+- Add pkgconfig support [Weigelt]
+- Use $(DESTDIR) macro in Makefile.in [Reinholdtsen, Weigelt]
+- Replace set_data_type() with a more accurate detect_data_type() in
+  trees.c, according to the txtvsbin.txt document [Truta]
+- Swap the order of #include <stdio.h> and #include "zlib.h" in
+  gzio.c, example.c and minigzip.c [Truta]
+- Shut up annoying VS2005 warnings about standard C deprecation [Rowe,
+  Truta] (where?)
+- Fix target "clean" from win32/Makefile.bor [Truta]
+- Create .pdb and .manifest files in win32/makefile.msc [Ziegler, Rowe]
+- Update zlib www home address in win32/DLL_FAQ.txt [Truta]
+- Update contrib/masmx86/inffas32.asm for VS2005 [Vollant, Van Wassenhove]
+- Enable browse info in the "Debug" and "ASM Debug" configurations in
+  the Visual C++ 6 project, and set (non-ASM) "Debug" as default [Truta]
+- Add pkgconfig support [Weigelt]
+- Add ZLIB_VER_MAJOR, ZLIB_VER_MINOR and ZLIB_VER_REVISION in zlib.h,
+  for use in win32/zlib1.rc [Polushin, Rowe, Truta]
+- Add a document that explains the new text detection scheme to
+  doc/txtvsbin.txt [Truta]
+- Add rfc1950.txt, rfc1951.txt and rfc1952.txt to doc/ [Truta]
+- Move algorithm.txt into doc/ [Truta]
+- Synchronize FAQ with website
+- Fix compressBound(), was low for some pathological cases [Fearnley]
+- Take into account wrapper variations in deflateBound()
+- Set examples/zpipe.c input and output to binary mode for Windows
+- Update examples/zlib_how.html with new zpipe.c (also web site)
+- Fix some warnings in examples/gzlog.c and examples/zran.c (it seems
+  that gcc became pickier in 4.0)
+- Add zlib.map for Linux: "All symbols from zlib-1.1.4 remain
+  un-versioned, the patch adds versioning only for symbols introduced in
+  zlib-1.2.0 or later.  It also declares as local those symbols which are
+  not designed to be exported." [Levin]
+- Update Z_PREFIX list in zconf.in.h, add --zprefix option to configure
+- Do not initialize global static by default in trees.c, add a response
+  NO_INIT_GLOBAL_POINTERS to initialize them if needed [Marquess]
+- Don't use strerror() in gzio.c under WinCE [Yakimov]
+- Don't use errno.h in zutil.h under WinCE [Yakimov]
+- Move arguments for AR to its usage to allow replacing ar [Marot]
+- Add HAVE_VISIBILITY_PRAGMA in zconf.in.h for Mozilla [Randers-Pehrson]
+- Improve inflateInit() and inflateInit2() documentation
+- Fix structure size comment in inflate.h
+- Change configure help option from --h* to --help [Santos]
+
+Changes in 1.2.3 (18 July 2005)
+- Apply security vulnerability fixes to contrib/infback9 as well
+- Clean up some text files (carriage returns, trailing space)
+- Update testzlib, vstudio, masmx64, and masmx86 in contrib [Vollant]
+
+Changes in 1.2.2.4 (11 July 2005)
+- Add inflatePrime() function for starting inflation at bit boundary
+- Avoid some Visual C warnings in deflate.c
+- Avoid more silly Visual C warnings in inflate.c and inftrees.c for 64-bit
+  compile
+- Fix some spelling errors in comments [Betts]
+- Correct inflateInit2() error return documentation in zlib.h
+- Add zran.c example of compressed data random access to examples
+  directory, shows use of inflatePrime()
+- Fix cast for assignments to strm->state in inflate.c and infback.c
+- Fix zlibCompileFlags() in zutil.c to use 1L for long shifts [Oberhumer]
+- Move declarations of gf2 functions to right place in crc32.c [Oberhumer]
+- Add cast in trees.c t avoid a warning [Oberhumer]
+- Avoid some warnings in fitblk.c, gun.c, gzjoin.c in examples [Oberhumer]
+- Update make_vms.com [Zinser]
+- Initialize state->write in inflateReset() since copied in inflate_fast()
+- Be more strict on incomplete code sets in inflate_table() and increase
+  ENOUGH and MAXD -- this repairs a possible security vulnerability for
+  invalid inflate input.  Thanks to Tavis Ormandy and Markus Oberhumer for
+  discovering the vulnerability and providing test cases.
+- Add ia64 support to configure for HP-UX [Smith]
+- Add error return to gzread() for format or i/o error [Levin]
+- Use malloc.h for OS/2 [Necasek]
+
+Changes in 1.2.2.3 (27 May 2005)
+- Replace 1U constants in inflate.c and inftrees.c for 64-bit compile
+- Typecast fread() return values in gzio.c [Vollant]
+- Remove trailing space in minigzip.c outmode (VC++ can't deal with it)
+- Fix crc check bug in gzread() after gzungetc() [Heiner]
+- Add the deflateTune() function to adjust internal compression parameters
+- Add a fast gzip decompressor, gun.c, to examples (use of inflateBack)
+- Remove an incorrect assertion in examples/zpipe.c
+- Add C++ wrapper in infback9.h [Donais]
+- Fix bug in inflateCopy() when decoding fixed codes
+- Note in zlib.h how much deflateSetDictionary() actually uses
+- Remove USE_DICT_HEAD in deflate.c (would mess up inflate if used)
+- Add _WIN32_WCE to define WIN32 in zconf.in.h [Spencer]
+- Don't include stderr.h or errno.h for _WIN32_WCE in zutil.h [Spencer]
+- Add gzdirect() function to indicate transparent reads
+- Update contrib/minizip [Vollant]
+- Fix compilation of deflate.c when both ASMV and FASTEST [Oberhumer]
+- Add casts in crc32.c to avoid warnings [Oberhumer]
+- Add contrib/masmx64 [Vollant]
+- Update contrib/asm586, asm686, masmx86, testzlib, vstudio [Vollant]
+
+Changes in 1.2.2.2 (30 December 2004)
+- Replace structure assignments in deflate.c and inflate.c with zmemcpy to
+  avoid implicit memcpy calls (portability for no-library compilation)
+- Increase sprintf() buffer size in gzdopen() to allow for large numbers
+- Add INFLATE_STRICT to check distances against zlib header
+- Improve WinCE errno handling and comments [Chang]
+- Remove comment about no gzip header processing in FAQ
+- Add Z_FIXED strategy option to deflateInit2() to force fixed trees
+- Add updated make_vms.com [Coghlan], update README
+- Create a new "examples" directory, move gzappend.c there, add zpipe.c,
+  fitblk.c, gzlog.[ch], gzjoin.c, and zlib_how.html.
+- Add FAQ entry and comments in deflate.c on uninitialized memory access
+- Add Solaris 9 make options in configure [Gilbert]
+- Allow strerror() usage in gzio.c for STDC
+- Fix DecompressBuf in contrib/delphi/ZLib.pas [ManChesTer]
+- Update contrib/masmx86/inffas32.asm and gvmat32.asm [Vollant]
+- Use z_off_t for adler32_combine() and crc32_combine() lengths
+- Make adler32() much faster for small len
+- Use OS_CODE in deflate() default gzip header
+
+Changes in 1.2.2.1 (31 October 2004)
+- Allow inflateSetDictionary() call for raw inflate
+- Fix inflate header crc check bug for file names and comments
+- Add deflateSetHeader() and gz_header structure for custom gzip headers
+- Add inflateGetheader() to retrieve gzip headers
+- Add crc32_combine() and adler32_combine() functions
+- Add alloc_func, free_func, in_func, out_func to Z_PREFIX list
+- Use zstreamp consistently in zlib.h (inflate_back functions)
+- Remove GUNZIP condition from definition of inflate_mode in inflate.h
+  and in contrib/inflate86/inffast.S [Truta, Anderson]
+- Add support for AMD64 in contrib/inflate86/inffas86.c [Anderson]
+- Update projects/README.projects and projects/visualc6 [Truta]
+- Update win32/DLL_FAQ.txt [Truta]
+- Avoid warning under NO_GZCOMPRESS in gzio.c; fix typo [Truta]
+- Deprecate Z_ASCII; use Z_TEXT instead [Truta]
+- Use a new algorithm for setting strm->data_type in trees.c [Truta]
+- Do not define an exit() prototype in zutil.c unless DEBUG defined
+- Remove prototype of exit() from zutil.c, example.c, minigzip.c [Truta]
+- Add comment in zlib.h for Z_NO_FLUSH parameter to deflate()
+- Fix Darwin build version identification [Peterson]
+
+Changes in 1.2.2 (3 October 2004)
+- Update zlib.h comments on gzip in-memory processing
+- Set adler to 1 in inflateReset() to support Java test suite [Walles]
+- Add contrib/dotzlib [Ravn]
+- Update win32/DLL_FAQ.txt [Truta]
+- Update contrib/minizip [Vollant]
+- Move contrib/visual-basic.txt to old/ [Truta]
+- Fix assembler builds in projects/visualc6/ [Truta]
+
+Changes in 1.2.1.2 (9 September 2004)
+- Update INDEX file
+- Fix trees.c to update strm->data_type (no one ever noticed!)
+- Fix bug in error case in inflate.c, infback.c, and infback9.c [Brown]
+- Add "volatile" to crc table flag declaration (for DYNAMIC_CRC_TABLE)
+- Add limited multitasking protection to DYNAMIC_CRC_TABLE
+- Add NO_vsnprintf for VMS in zutil.h [Mozilla]
+- Don't declare strerror() under VMS [Mozilla]
+- Add comment to DYNAMIC_CRC_TABLE to use get_crc_table() to initialize
+- Update contrib/ada [Anisimkov]
+- Update contrib/minizip [Vollant]
+- Fix configure to not hardcode directories for Darwin [Peterson]
+- Fix gzio.c to not return error on empty files [Brown]
+- Fix indentation; update version in contrib/delphi/ZLib.pas and
+  contrib/pascal/zlibpas.pas [Truta]
+- Update mkasm.bat in contrib/masmx86 [Truta]
+- Update contrib/untgz [Truta]
+- Add projects/README.projects [Truta]
+- Add project for MS Visual C++ 6.0 in projects/visualc6 [Cadieux, Truta]
+- Update win32/DLL_FAQ.txt [Truta]
+- Update list of Z_PREFIX symbols in zconf.h [Randers-Pehrson, Truta]
+- Remove an unnecessary assignment to curr in inftrees.c [Truta]
+- Add OS/2 to exe builds in configure [Poltorak]
+- Remove err dummy parameter in zlib.h [Kientzle]
+
+Changes in 1.2.1.1 (9 January 2004)
+- Update email address in README
+- Several FAQ updates
+- Fix a big fat bug in inftrees.c that prevented decoding valid
+  dynamic blocks with only literals and no distance codes --
+  Thanks to "Hot Emu" for the bug report and sample file
+- Add a note to puff.c on no distance codes case.
+
+Changes in 1.2.1 (17 November 2003)
+- Remove a tab in contrib/gzappend/gzappend.c
+- Update some interfaces in contrib for new zlib functions
+- Update zlib version number in some contrib entries
+- Add Windows CE definition for ptrdiff_t in zutil.h [Mai, Truta]
+- Support shared libraries on Hurd and KFreeBSD [Brown]
+- Fix error in NO_DIVIDE option of adler32.c
+
+Changes in 1.2.0.8 (4 November 2003)
+- Update version in contrib/delphi/ZLib.pas and contrib/pascal/zlibpas.pas
+- Add experimental NO_DIVIDE #define in adler32.c
+    - Possibly faster on some processors (let me know if it is)
+- Correct Z_BLOCK to not return on first inflate call if no wrap
+- Fix strm->data_type on inflate() return to correctly indicate EOB
+- Add deflatePrime() function for appending in the middle of a byte
+- Add contrib/gzappend for an example of appending to a stream
+- Update win32/DLL_FAQ.txt [Truta]
+- Delete Turbo C comment in README [Truta]
+- Improve some indentation in zconf.h [Truta]
+- Fix infinite loop on bad input in configure script [Church]
+- Fix gzeof() for concatenated gzip files [Johnson]
+- Add example to contrib/visual-basic.txt [Michael B.]
+- Add -p to mkdir's in Makefile.in [vda]
+- Fix configure to properly detect presence or lack of printf functions
+- Add AS400 support [Monnerat]
+- Add a little Cygwin support [Wilson]
+
+Changes in 1.2.0.7 (21 September 2003)
+- Correct some debug formats in contrib/infback9
+- Cast a type in a debug statement in trees.c
+- Change search and replace delimiter in configure from % to # [Beebe]
+- Update contrib/untgz to 0.2 with various fixes [Truta]
+- Add build support for Amiga [Nikl]
+- Remove some directories in old that have been updated to 1.2
+- Add dylib building for Mac OS X in configure and Makefile.in
+- Remove old distribution stuff from Makefile
+- Update README to point to DLL_FAQ.txt, and add comment on Mac OS X
+- Update links in README
+
+Changes in 1.2.0.6 (13 September 2003)
+- Minor FAQ updates
+- Update contrib/minizip to 1.00 [Vollant]
+- Remove test of gz functions in example.c when GZ_COMPRESS defined [Truta]
+- Update POSTINC comment for 68060 [Nikl]
+- Add contrib/infback9 with deflate64 decoding (unsupported)
+- For MVS define NO_vsnprintf and undefine FAR [van Burik]
+- Add pragma for fdopen on MVS [van Burik]
+
+Changes in 1.2.0.5 (8 September 2003)
+- Add OF to inflateBackEnd() declaration in zlib.h
+- Remember start when using gzdopen in the middle of a file
+- Use internal off_t counters in gz* functions to properly handle seeks
+- Perform more rigorous check for distance-too-far in inffast.c
+- Add Z_BLOCK flush option to return from inflate at block boundary
+- Set strm->data_type on return from inflate
+    - Indicate bits unused, if at block boundary, and if in last block
+- Replace size_t with ptrdiff_t in crc32.c, and check for correct size
+- Add condition so old NO_DEFLATE define still works for compatibility
+- FAQ update regarding the Windows DLL [Truta]
+- INDEX update: add qnx entry, remove aix entry [Truta]
+- Install zlib.3 into mandir [Wilson]
+- Move contrib/zlib_dll_FAQ.txt to win32/DLL_FAQ.txt; update [Truta]
+- Adapt the zlib interface to the new DLL convention guidelines [Truta]
+- Introduce ZLIB_WINAPI macro to allow the export of functions using
+  the WINAPI calling convention, for Visual Basic [Vollant, Truta]
+- Update msdos and win32 scripts and makefiles [Truta]
+- Export symbols by name, not by ordinal, in win32/zlib.def [Truta]
+- Add contrib/ada [Anisimkov]
+- Move asm files from contrib/vstudio/vc70_32 to contrib/asm386 [Truta]
+- Rename contrib/asm386 to contrib/masmx86 [Truta, Vollant]
+- Add contrib/masm686 [Truta]
+- Fix offsets in contrib/inflate86 and contrib/masmx86/inffas32.asm
+  [Truta, Vollant]
+- Update contrib/delphi; rename to contrib/pascal; add example [Truta]
+- Remove contrib/delphi2; add a new contrib/delphi [Truta]
+- Avoid inclusion of the nonstandard <memory.h> in contrib/iostream,
+  and fix some method prototypes [Truta]
+- Fix the ZCR_SEED2 constant to avoid warnings in contrib/minizip
+  [Truta]
+- Avoid the use of backslash (\) in contrib/minizip [Vollant]
+- Fix file time handling in contrib/untgz; update makefiles [Truta]
+- Update contrib/vstudio/vc70_32 to comply with the new DLL guidelines
+  [Vollant]
+- Remove contrib/vstudio/vc15_16 [Vollant]
+- Rename contrib/vstudio/vc70_32 to contrib/vstudio/vc7 [Truta]
+- Update README.contrib [Truta]
+- Invert the assignment order of match_head and s->prev[...] in
+  INSERT_STRING [Truta]
+- Compare TOO_FAR with 32767 instead of 32768, to avoid 16-bit warnings
+  [Truta]
+- Compare function pointers with 0, not with NULL or Z_NULL [Truta]
+- Fix prototype of syncsearch in inflate.c [Truta]
+- Introduce ASMINF macro to be enabled when using an ASM implementation
+  of inflate_fast [Truta]
+- Change NO_DEFLATE to NO_GZCOMPRESS [Truta]
+- Modify test_gzio in example.c to take a single file name as a
+  parameter [Truta]
+- Exit the example.c program if gzopen fails [Truta]
+- Add type casts around strlen in example.c [Truta]
+- Remove casting to sizeof in minigzip.c; give a proper type
+  to the variable compared with SUFFIX_LEN [Truta]
+- Update definitions of STDC and STDC99 in zconf.h [Truta]
+- Synchronize zconf.h with the new Windows DLL interface [Truta]
+- Use SYS16BIT instead of __32BIT__ to distinguish between
+  16- and 32-bit platforms [Truta]
+- Use far memory allocators in small 16-bit memory models for
+  Turbo C [Truta]
+- Add info about the use of ASMV, ASMINF and ZLIB_WINAPI in
+  zlibCompileFlags [Truta]
+- Cygwin has vsnprintf [Wilson]
+- In Windows16, OS_CODE is 0, as in MSDOS [Truta]
+- In Cygwin, OS_CODE is 3 (Unix), not 11 (Windows32) [Wilson]
+
+Changes in 1.2.0.4 (10 August 2003)
+- Minor FAQ updates
+- Be more strict when checking inflateInit2's windowBits parameter
+- Change NO_GUNZIP compile option to NO_GZIP to cover deflate as well
+- Add gzip wrapper option to deflateInit2 using windowBits
+- Add updated QNX rule in configure and qnx directory [Bonnefoy]
+- Make inflate distance-too-far checks more rigorous
+- Clean up FAR usage in inflate
+- Add casting to sizeof() in gzio.c and minigzip.c
+
+Changes in 1.2.0.3 (19 July 2003)
+- Fix silly error in gzungetc() implementation [Vollant]
+- Update contrib/minizip and contrib/vstudio [Vollant]
+- Fix printf format in example.c
+- Correct cdecl support in zconf.in.h [Anisimkov]
+- Minor FAQ updates
+
+Changes in 1.2.0.2 (13 July 2003)
+- Add ZLIB_VERNUM in zlib.h for numerical preprocessor comparisons
+- Attempt to avoid warnings in crc32.c for pointer-int conversion
+- Add AIX to configure, remove aix directory [Bakker]
+- Add some casts to minigzip.c
+- Improve checking after insecure sprintf() or vsprintf() calls
+- Remove #elif's from crc32.c
+- Change leave label to inf_leave in inflate.c and infback.c to avoid
+  library conflicts
+- Remove inflate gzip decoding by default--only enable gzip decoding by
+  special request for stricter backward compatibility
+- Add zlibCompileFlags() function to return compilation information
+- More typecasting in deflate.c to avoid warnings
+- Remove leading underscore from _Capital #defines [Truta]
+- Fix configure to link shared library when testing
+- Add some Windows CE target adjustments [Mai]
+- Remove #define ZLIB_DLL in zconf.h [Vollant]
+- Add zlib.3 [Rodgers]
+- Update RFC URL in deflate.c and algorithm.txt [Mai]
+- Add zlib_dll_FAQ.txt to contrib [Truta]
+- Add UL to some constants [Truta]
+- Update minizip and vstudio [Vollant]
+- Remove vestigial NEED_DUMMY_RETURN from zconf.in.h
+- Expand use of NO_DUMMY_DECL to avoid all dummy structures
+- Added iostream3 to contrib [Schwardt]
+- Replace rewind() with fseek() for WinCE [Truta]
+- Improve setting of zlib format compression level flags
+    - Report 0 for huffman and rle strategies and for level == 0 or 1
+    - Report 2 only for level == 6
+- Only deal with 64K limit when necessary at compile time [Truta]
+- Allow TOO_FAR check to be turned off at compile time [Truta]
+- Add gzclearerr() function [Souza]
+- Add gzungetc() function
+
+Changes in 1.2.0.1 (17 March 2003)
+- Add Z_RLE strategy for run-length encoding [Truta]
+    - When Z_RLE requested, restrict matches to distance one
+    - Update zlib.h, minigzip.c, gzopen(), gzdopen() for Z_RLE
+- Correct FASTEST compilation to allow level == 0
+- Clean up what gets compiled for FASTEST
+- Incorporate changes to zconf.in.h [Vollant]
+    - Refine detection of Turbo C need for dummy returns
+    - Refine ZLIB_DLL compilation
+    - Include additional header file on VMS for off_t typedef
+- Try to use _vsnprintf where it supplants vsprintf [Vollant]
+- Add some casts in inffast.c
+- Enchance comments in zlib.h on what happens if gzprintf() tries to
+  write more than 4095 bytes before compression
+- Remove unused state from inflateBackEnd()
+- Remove exit(0) from minigzip.c, example.c
+- Get rid of all those darn tabs
+- Add "check" target to Makefile.in that does the same thing as "test"
+- Add "mostlyclean" and "maintainer-clean" targets to Makefile.in
+- Update contrib/inflate86 [Anderson]
+- Update contrib/testzlib, contrib/vstudio, contrib/minizip [Vollant]
+- Add msdos and win32 directories with makefiles [Truta]
+- More additions and improvements to the FAQ
+
+Changes in 1.2.0 (9 March 2003)
+- New and improved inflate code
+    - About 20% faster
+    - Does not allocate 32K window unless and until needed
+    - Automatically detects and decompresses gzip streams
+    - Raw inflate no longer needs an extra dummy byte at end
+    - Added inflateBack functions using a callback interface--even faster
+      than inflate, useful for file utilities (gzip, zip)
+    - Added inflateCopy() function to record state for random access on
+      externally generated deflate streams (e.g. in gzip files)
+    - More readable code (I hope)
+- New and improved crc32()
+    - About 50% faster, thanks to suggestions from Rodney Brown
+- Add deflateBound() and compressBound() functions
+- Fix memory leak in deflateInit2()
+- Permit setting dictionary for raw deflate (for parallel deflate)
+- Fix const declaration for gzwrite()
+- Check for some malloc() failures in gzio.c
+- Fix bug in gzopen() on single-byte file 0x1f
+- Fix bug in gzread() on concatenated file with 0x1f at end of buffer
+  and next buffer doesn't start with 0x8b
+- Fix uncompress() to return Z_DATA_ERROR on truncated input
+- Free memory at end of example.c
+- Remove MAX #define in trees.c (conflicted with some libraries)
+- Fix static const's in deflate.c, gzio.c, and zutil.[ch]
+- Declare malloc() and free() in gzio.c if STDC not defined
+- Use malloc() instead of calloc() in zutil.c if int big enough
+- Define STDC for AIX
+- Add aix/ with approach for compiling shared library on AIX
+- Add HP-UX support for shared libraries in configure
+- Add OpenUNIX support for shared libraries in configure
+- Use $cc instead of gcc to build shared library
+- Make prefix directory if needed when installing
+- Correct Macintosh avoidance of typedef Byte in zconf.h
+- Correct Turbo C memory allocation when under Linux
+- Use libz.a instead of -lz in Makefile (assure use of compiled library)
+- Update configure to check for snprintf or vsnprintf functions and their
+  return value, warn during make if using an insecure function
+- Fix configure problem with compile-time knowledge of HAVE_UNISTD_H that
+  is lost when library is used--resolution is to build new zconf.h
+- Documentation improvements (in zlib.h):
+    - Document raw deflate and inflate
+    - Update RFCs URL
+    - Point out that zlib and gzip formats are different
+    - Note that Z_BUF_ERROR is not fatal
+    - Document string limit for gzprintf() and possible buffer overflow
+    - Note requirement on avail_out when flushing
+    - Note permitted values of flush parameter of inflate()
+- Add some FAQs (and even answers) to the FAQ
+- Add contrib/inflate86/ for x86 faster inflate
+- Add contrib/blast/ for PKWare Data Compression Library decompression
+- Add contrib/puff/ simple inflate for deflate format description
+
+Changes in 1.1.4 (11 March 2002)
+- ZFREE was repeated on same allocation on some error conditions.
+  This creates a security problem described in
+  http://www.zlib.org/advisory-2002-03-11.txt
+- Returned incorrect error (Z_MEM_ERROR) on some invalid data
+- Avoid accesses before window for invalid distances with inflate window
+  less than 32K.
+- force windowBits > 8 to avoid a bug in the encoder for a window size
+  of 256 bytes. (A complete fix will be available in 1.1.5).
+
+Changes in 1.1.3 (9 July 1998)
+- fix "an inflate input buffer bug that shows up on rare but persistent
+  occasions" (Mark)
+- fix gzread and gztell for concatenated .gz files (Didier Le Botlan)
+- fix gzseek(..., SEEK_SET) in write mode
+- fix crc check after a gzeek (Frank Faubert)
+- fix miniunzip when the last entry in a zip file is itself a zip file
+  (J Lillge)
+- add contrib/asm586 and contrib/asm686 (Brian Raiter)
+  See http://www.muppetlabs.com/~breadbox/software/assembly.html
+- add support for Delphi 3 in contrib/delphi (Bob Dellaca)
+- add support for C++Builder 3 and Delphi 3 in contrib/delphi2 (Davide Moretti)
+- do not exit prematurely in untgz if 0 at start of block (Magnus Holmgren)
+- use macro EXTERN instead of extern to support DLL for BeOS (Sander Stoks)
+- added a FAQ file
+
+- Support gzdopen on Mac with Metrowerks (Jason Linhart)
+- Do not redefine Byte on Mac (Brad Pettit & Jason Linhart)
+- define SEEK_END too if SEEK_SET is not defined (Albert Chin-A-Young)
+- avoid some warnings with Borland C (Tom Tanner)
+- fix a problem in contrib/minizip/zip.c for 16-bit MSDOS (Gilles Vollant)
+- emulate utime() for WIN32 in contrib/untgz  (Gilles Vollant)
+- allow several arguments to configure (Tim Mooney, Frodo Looijaard)
+- use libdir and includedir in Makefile.in (Tim Mooney)
+- support shared libraries on OSF1 V4 (Tim Mooney)
+- remove so_locations in "make clean"  (Tim Mooney)
+- fix maketree.c compilation error (Glenn, Mark)
+- Python interface to zlib now in Python 1.5 (Jeremy Hylton)
+- new Makefile.riscos (Rich Walker)
+- initialize static descriptors in trees.c for embedded targets (Nick Smith)
+- use "foo-gz" in example.c for RISCOS and VMS (Nick Smith)
+- add the OS/2 files in Makefile.in too (Andrew Zabolotny)
+- fix fdopen and halloc macros for Microsoft C 6.0 (Tom Lane)
+- fix maketree.c to allow clean compilation of inffixed.h (Mark)
+- fix parameter check in deflateCopy (Gunther Nikl)
+- cleanup trees.c, use compressed_len only in debug mode (Christian Spieler)
+- Many portability patches by Christian Spieler:
+  . zutil.c, zutil.h: added "const" for zmem*
+  . Make_vms.com: fixed some typos
+  . Make_vms.com: msdos/Makefile.*: removed zutil.h from some dependency lists
+  . msdos/Makefile.msc: remove "default rtl link library" info from obj files
+  . msdos/Makefile.*: use model-dependent name for the built zlib library
+  . msdos/Makefile.emx, nt/Makefile.emx, nt/Makefile.gcc:
+     new makefiles, for emx (DOS/OS2), emx&rsxnt and mingw32 (Windows 9x / NT)
+- use define instead of typedef for Bytef also for MSC small/medium (Tom Lane)
+- replace __far with _far for better portability (Christian Spieler, Tom Lane)
+- fix test for errno.h in configure (Tim Newsham)
+
+Changes in 1.1.2 (19 March 98)
+- added contrib/minzip, mini zip and unzip based on zlib (Gilles Vollant)
+  See http://www.winimage.com/zLibDll/unzip.html
+- preinitialize the inflate tables for fixed codes, to make the code
+  completely thread safe (Mark)
+- some simplifications and slight speed-up to the inflate code (Mark)
+- fix gzeof on non-compressed files (Allan Schrum)
+- add -std1 option in configure for OSF1 to fix gzprintf (Martin Mokrejs)
+- use default value of 4K for Z_BUFSIZE for 16-bit MSDOS (Tim Wegner + Glenn)
+- added os2/Makefile.def and os2/zlib.def (Andrew Zabolotny)
+- add shared lib support for UNIX_SV4.2MP (MATSUURA Takanori)
+- do not wrap extern "C" around system includes (Tom Lane)
+- mention zlib binding for TCL in README (Andreas Kupries)
+- added amiga/Makefile.pup for Amiga powerUP SAS/C PPC (Andreas Kleinert)
+- allow "make install prefix=..." even after configure (Glenn Randers-Pehrson)
+- allow "configure --prefix $HOME" (Tim Mooney)
+- remove warnings in example.c and gzio.c (Glenn Randers-Pehrson)
+- move Makefile.sas to amiga/Makefile.sas
+
+Changes in 1.1.1 (27 Feb 98)
+- fix macros _tr_tally_* in deflate.h for debug mode  (Glenn Randers-Pehrson)
+- remove block truncation heuristic which had very marginal effect for zlib
+  (smaller lit_bufsize than in gzip 1.2.4) and degraded a little the
+  compression ratio on some files. This also allows inlining _tr_tally for
+  matches in deflate_slow.
+- added msdos/Makefile.w32 for WIN32 Microsoft Visual C++ (Bob Frazier)
+
+Changes in 1.1.0 (24 Feb 98)
+- do not return STREAM_END prematurely in inflate (John Bowler)
+- revert to the zlib 1.0.8 inflate to avoid the gcc 2.8.0 bug (Jeremy Buhler)
+- compile with -DFASTEST to get compression code optimized for speed only
+- in minigzip, try mmap'ing the input file first (Miguel Albrecht)
+- increase size of I/O buffers in minigzip.c and gzio.c (not a big gain
+  on Sun but significant on HP)
+
+- add a pointer to experimental unzip library in README (Gilles Vollant)
+- initialize variable gcc in configure (Chris Herborth)
+
+Changes in 1.0.9 (17 Feb 1998)
+- added gzputs and gzgets functions
+- do not clear eof flag in gzseek (Mark Diekhans)
+- fix gzseek for files in transparent mode (Mark Diekhans)
+- do not assume that vsprintf returns the number of bytes written (Jens Krinke)
+- replace EXPORT with ZEXPORT to avoid conflict with other programs
+- added compress2 in zconf.h, zlib.def, zlib.dnt
+- new asm code from Gilles Vollant in contrib/asm386
+- simplify the inflate code (Mark):
+ . Replace ZALLOC's in huft_build() with single ZALLOC in inflate_blocks_new()
+ . ZALLOC the length list in inflate_trees_fixed() instead of using stack
+ . ZALLOC the value area for huft_build() instead of using stack
+ . Simplify Z_FINISH check in inflate()
+
+- Avoid gcc 2.8.0 comparison bug a little differently than zlib 1.0.8
+- in inftrees.c, avoid cc -O bug on HP (Farshid Elahi)
+- in zconf.h move the ZLIB_DLL stuff earlier to avoid problems with
+  the declaration of FAR (Gilles VOllant)
+- install libz.so* with mode 755 (executable) instead of 644 (Marc Lehmann)
+- read_buf buf parameter of type Bytef* instead of charf*
+- zmemcpy parameters are of type Bytef*, not charf* (Joseph Strout)
+- do not redeclare unlink in minigzip.c for WIN32 (John Bowler)
+- fix check for presence of directories in "make install" (Ian Willis)
+
+Changes in 1.0.8 (27 Jan 1998)
+- fixed offsets in contrib/asm386/gvmat32.asm (Gilles Vollant)
+- fix gzgetc and gzputc for big endian systems (Markus Oberhumer)
+- added compress2() to allow setting the compression level
+- include sys/types.h to get off_t on some systems (Marc Lehmann & QingLong)
+- use constant arrays for the static trees in trees.c instead of computing
+  them at run time (thanks to Ken Raeburn for this suggestion). To create
+  trees.h, compile with GEN_TREES_H and run "make test".
+- check return code of example in "make test" and display result
+- pass minigzip command line options to file_compress
+- simplifying code of inflateSync to avoid gcc 2.8 bug
+
+- support CC="gcc -Wall" in configure -s (QingLong)
+- avoid a flush caused by ftell in gzopen for write mode (Ken Raeburn)
+- fix test for shared library support to avoid compiler warnings
+- zlib.lib -> zlib.dll in msdos/zlib.rc (Gilles Vollant)
+- check for TARGET_OS_MAC in addition to MACOS (Brad Pettit)
+- do not use fdopen for Metrowerks on Mac (Brad Pettit))
+- add checks for gzputc and gzputc in example.c
+- avoid warnings in gzio.c and deflate.c (Andreas Kleinert)
+- use const for the CRC table (Ken Raeburn)
+- fixed "make uninstall" for shared libraries
+- use Tracev instead of Trace in infblock.c
+- in example.c use correct compressed length for test_sync
+- suppress +vnocompatwarnings in configure for HPUX (not always supported)
+
+Changes in 1.0.7 (20 Jan 1998)
+- fix gzseek which was broken in write mode
+- return error for gzseek to negative absolute position
+- fix configure for Linux (Chun-Chung Chen)
+- increase stack space for MSC (Tim Wegner)
+- get_crc_table and inflateSyncPoint are EXPORTed (Gilles Vollant)
+- define EXPORTVA for gzprintf (Gilles Vollant)
+- added man page zlib.3 (Rick Rodgers)
+- for contrib/untgz, fix makedir() and improve Makefile
+
+- check gzseek in write mode in example.c
+- allocate extra buffer for seeks only if gzseek is actually called
+- avoid signed/unsigned comparisons (Tim Wegner, Gilles Vollant)
+- add inflateSyncPoint in zconf.h
+- fix list of exported functions in nt/zlib.dnt and mdsos/zlib.def
+
+Changes in 1.0.6 (19 Jan 1998)
+- add functions gzprintf, gzputc, gzgetc, gztell, gzeof, gzseek, gzrewind and
+  gzsetparams (thanks to Roland Giersig and Kevin Ruland for some of this code)
+- Fix a deflate bug occurring only with compression level 0 (thanks to
+  Andy Buckler for finding this one).
+- In minigzip, pass transparently also the first byte for .Z files.
+- return Z_BUF_ERROR instead of Z_OK if output buffer full in uncompress()
+- check Z_FINISH in inflate (thanks to Marc Schluper)
+- Implement deflateCopy (thanks to Adam Costello)
+- make static libraries by default in configure, add --shared option.
+- move MSDOS or Windows specific files to directory msdos
+- suppress the notion of partial flush to simplify the interface
+  (but the symbol Z_PARTIAL_FLUSH is kept for compatibility with 1.0.4)
+- suppress history buffer provided by application to simplify the interface
+  (this feature was not implemented anyway in 1.0.4)
+- next_in and avail_in must be initialized before calling inflateInit or
+  inflateInit2
+- add EXPORT in all exported functions (for Windows DLL)
+- added Makefile.nt (thanks to Stephen Williams)
+- added the unsupported "contrib" directory:
+   contrib/asm386/ by Gilles Vollant <info@winimage.com>
+        386 asm code replacing longest_match().
+   contrib/iostream/ by Kevin Ruland <kevin@rodin.wustl.edu>
+        A C++ I/O streams interface to the zlib gz* functions
+   contrib/iostream2/  by Tyge Løvset <Tyge.Lovset@cmr.no>
+        Another C++ I/O streams interface
+   contrib/untgz/  by "Pedro A. Aranda Guti\irrez" <paag@tid.es>
+        A very simple tar.gz file extractor using zlib
+   contrib/visual-basic.txt by Carlos Rios <c_rios@sonda.cl>
+        How to use compress(), uncompress() and the gz* functions from VB.
+- pass params -f (filtered data), -h (huffman only), -1 to -9 (compression
+  level) in minigzip (thanks to Tom Lane)
+
+- use const for rommable constants in deflate
+- added test for gzseek and gztell in example.c
+- add undocumented function inflateSyncPoint() (hack for Paul Mackerras)
+- add undocumented function zError to convert error code to string
+  (for Tim Smithers)
+- Allow compilation of gzio with -DNO_DEFLATE to avoid the compression code.
+- Use default memcpy for Symantec MSDOS compiler.
+- Add EXPORT keyword for check_func (needed for Windows DLL)
+- add current directory to LD_LIBRARY_PATH for "make test"
+- create also a link for libz.so.1
+- added support for FUJITSU UXP/DS (thanks to Toshiaki Nomura)
+- use $(SHAREDLIB) instead of libz.so in Makefile.in (for HPUX)
+- added -soname for Linux in configure (Chun-Chung Chen,
+- assign numbers to the exported functions in zlib.def (for Windows DLL)
+- add advice in zlib.h for best usage of deflateSetDictionary
+- work around compiler bug on Atari (cast Z_NULL in call of s->checkfn)
+- allow compilation with ANSI keywords only enabled for TurboC in large model
+- avoid "versionString"[0] (Borland bug)
+- add NEED_DUMMY_RETURN for Borland
+- use variable z_verbose for tracing in debug mode (L. Peter Deutsch).
+- allow compilation with CC
+- defined STDC for OS/2 (David Charlap)
+- limit external names to 8 chars for MVS (Thomas Lund)
+- in minigzip.c, use static buffers only for 16-bit systems
+- fix suffix check for "minigzip -d foo.gz"
+- do not return an error for the 2nd of two consecutive gzflush() (Felix Lee)
+- use _fdopen instead of fdopen for MSC >= 6.0 (Thomas Fanslau)
+- added makelcc.bat for lcc-win32 (Tom St Denis)
+- in Makefile.dj2, use copy and del instead of install and rm (Frank Donahoe)
+- Avoid expanded $Id$. Use "rcs -kb" or "cvs admin -kb" to avoid Id expansion.
+- check for unistd.h in configure (for off_t)
+- remove useless check parameter in inflate_blocks_free
+- avoid useless assignment of s->check to itself in inflate_blocks_new
+- do not flush twice in gzclose (thanks to Ken Raeburn)
+- rename FOPEN as F_OPEN to avoid clash with /usr/include/sys/file.h
+- use NO_ERRNO_H instead of enumeration of operating systems with errno.h
+- work around buggy fclose on pipes for HP/UX
+- support zlib DLL with BORLAND C++ 5.0 (thanks to Glenn Randers-Pehrson)
+- fix configure if CC is already equal to gcc
+
+Changes in 1.0.5 (3 Jan 98)
+- Fix inflate to terminate gracefully when fed corrupted or invalid data
+- Use const for rommable constants in inflate
+- Eliminate memory leaks on error conditions in inflate
+- Removed some vestigial code in inflate
+- Update web address in README
+
+Changes in 1.0.4 (24 Jul 96)
+- In very rare conditions, deflate(s, Z_FINISH) could fail to produce an EOF
+  bit, so the decompressor could decompress all the correct data but went
+  on to attempt decompressing extra garbage data. This affected minigzip too.
+- zlibVersion and gzerror return const char* (needed for DLL)
+- port to RISCOS (no fdopen, no multiple dots, no unlink, no fileno)
+- use z_error only for DEBUG (avoid problem with DLLs)
+
+Changes in 1.0.3 (2 Jul 96)
+- use z_streamp instead of z_stream *, which is now a far pointer in MSDOS
+  small and medium models; this makes the library incompatible with previous
+  versions for these models. (No effect in large model or on other systems.)
+- return OK instead of BUF_ERROR if previous deflate call returned with
+  avail_out as zero but there is nothing to do
+- added memcmp for non STDC compilers
+- define NO_DUMMY_DECL for more Mac compilers (.h files merged incorrectly)
+- define __32BIT__ if __386__ or i386 is defined (pb. with Watcom and SCO)
+- better check for 16-bit mode MSC (avoids problem with Symantec)
+
+Changes in 1.0.2 (23 May 96)
+- added Windows DLL support
+- added a function zlibVersion (for the DLL support)
+- fixed declarations using Bytef in infutil.c (pb with MSDOS medium model)
+- Bytef is define's instead of typedef'd only for Borland C
+- avoid reading uninitialized memory in example.c
+- mention in README that the zlib format is now RFC1950
+- updated Makefile.dj2
+- added algorithm.doc
+
+Changes in 1.0.1 (20 May 96) [1.0 skipped to avoid confusion]
+- fix array overlay in deflate.c which sometimes caused bad compressed data
+- fix inflate bug with empty stored block
+- fix MSDOS medium model which was broken in 0.99
+- fix deflateParams() which could generate bad compressed data.
+- Bytef is define'd instead of typedef'ed (work around Borland bug)
+- added an INDEX file
+- new makefiles for DJGPP (Makefile.dj2), 32-bit Borland (Makefile.b32),
+  Watcom (Makefile.wat), Amiga SAS/C (Makefile.sas)
+- speed up adler32 for modern machines without auto-increment
+- added -ansi for IRIX in configure
+- static_init_done in trees.c is an int
+- define unlink as delete for VMS
+- fix configure for QNX
+- add configure branch for SCO and HPUX
+- avoid many warnings (unused variables, dead assignments, etc...)
+- no fdopen for BeOS
+- fix the Watcom fix for 32 bit mode (define FAR as empty)
+- removed redefinition of Byte for MKWERKS
+- work around an MWKERKS bug (incorrect merge of all .h files)
+
+Changes in 0.99 (27 Jan 96)
+- allow preset dictionary shared between compressor and decompressor
+- allow compression level 0 (no compression)
+- add deflateParams in zlib.h: allow dynamic change of compression level
+  and compression strategy.
+- test large buffers and deflateParams in example.c
+- add optional "configure" to build zlib as a shared library
+- suppress Makefile.qnx, use configure instead
+- fixed deflate for 64-bit systems (detected on Cray)
+- fixed inflate_blocks for 64-bit systems (detected on Alpha)
+- declare Z_DEFLATED in zlib.h (possible parameter for deflateInit2)
+- always return Z_BUF_ERROR when deflate() has nothing to do
+- deflateInit and inflateInit are now macros to allow version checking
+- prefix all global functions and types with z_ with -DZ_PREFIX
+- make falloc completely reentrant (inftrees.c)
+- fixed very unlikely race condition in ct_static_init
+- free in reverse order of allocation to help memory manager
+- use zlib-1.0/* instead of zlib/* inside the tar.gz
+- make zlib warning-free with "gcc -O3 -Wall -Wwrite-strings -Wpointer-arith
+  -Wconversion -Wstrict-prototypes -Wmissing-prototypes"
+- allow gzread on concatenated .gz files
+- deflateEnd now returns Z_DATA_ERROR if it was premature
+- deflate is finally (?) fully deterministic (no matches beyond end of input)
+- Document Z_SYNC_FLUSH
+- add uninstall in Makefile
+- Check for __cpluplus in zlib.h
+- Better test in ct_align for partial flush
+- avoid harmless warnings for Borland C++
+- initialize hash_head in deflate.c
+- avoid warning on fdopen (gzio.c) for HP cc -Aa
+- include stdlib.h for STDC compilers
+- include errno.h for Cray
+- ignore error if ranlib doesn't exist
+- call ranlib twice for NeXTSTEP
+- use exec_prefix instead of prefix for libz.a
+- renamed ct_* as _tr_* to avoid conflict with applications
+- clear z->msg in inflateInit2 before any error return
+- initialize opaque in example.c, gzio.c, deflate.c and inflate.c
+- fixed typo in zconf.h (_GNUC__ => __GNUC__)
+- check for WIN32 in zconf.h and zutil.c (avoid farmalloc in 32-bit mode)
+- fix typo in Make_vms.com (f$trnlnm -> f$getsyi)
+- in fcalloc, normalize pointer if size > 65520 bytes
+- don't use special fcalloc for 32 bit Borland C++
+- use STDC instead of __GO32__ to avoid redeclaring exit, calloc, etc...
+- use Z_BINARY instead of BINARY
+- document that gzclose after gzdopen will close the file
+- allow "a" as mode in gzopen.
+- fix error checking in gzread
+- allow skipping .gz extra-field on pipes
+- added reference to Perl interface in README
+- put the crc table in FAR data (I dislike more and more the medium model :)
+- added get_crc_table
+- added a dimension to all arrays (Borland C can't count).
+- workaround Borland C bug in declaration of inflate_codes_new & inflate_fast
+- guard against multiple inclusion of *.h (for precompiled header on Mac)
+- Watcom C pretends to be Microsoft C small model even in 32 bit mode.
+- don't use unsized arrays to avoid silly warnings by Visual C++:
+     warning C4746: 'inflate_mask' : unsized array treated as  '__far'
+     (what's wrong with far data in far model?).
+- define enum out of inflate_blocks_state to allow compilation with C++
+
+Changes in 0.95 (16 Aug 95)
+- fix MSDOS small and medium model (now easier to adapt to any compiler)
+- inlined send_bits
+- fix the final (:-) bug for deflate with flush (output was correct but
+  not completely flushed in rare occasions).
+- default window size is same for compression and decompression
+  (it's now sufficient to set MAX_WBITS in zconf.h).
+- voidp -> voidpf and voidnp -> voidp (for consistency with other
+  typedefs and because voidnp was not near in large model).
+
+Changes in 0.94 (13 Aug 95)
+- support MSDOS medium model
+- fix deflate with flush (could sometimes generate bad output)
+- fix deflateReset (zlib header was incorrectly suppressed)
+- added support for VMS
+- allow a compression level in gzopen()
+- gzflush now calls fflush
+- For deflate with flush, flush even if no more input is provided.
+- rename libgz.a as libz.a
+- avoid complex expression in infcodes.c triggering Turbo C bug
+- work around a problem with gcc on Alpha (in INSERT_STRING)
+- don't use inline functions (problem with some gcc versions)
+- allow renaming of Byte, uInt, etc... with #define.
+- avoid warning about (unused) pointer before start of array in deflate.c
+- avoid various warnings in gzio.c, example.c, infblock.c, adler32.c, zutil.c
+- avoid reserved word 'new' in trees.c
+
+Changes in 0.93 (25 June 95)
+- temporarily disable inline functions
+- make deflate deterministic
+- give enough lookahead for PARTIAL_FLUSH
+- Set binary mode for stdin/stdout in minigzip.c for OS/2
+- don't even use signed char in inflate (not portable enough)
+- fix inflate memory leak for segmented architectures
+
+Changes in 0.92 (3 May 95)
+- don't assume that char is signed (problem on SGI)
+- Clear bit buffer when starting a stored block
+- no memcpy on Pyramid
+- suppressed inftest.c
+- optimized fill_window, put longest_match inline for gcc
+- optimized inflate on stored blocks.
+- untabify all sources to simplify patches
+
+Changes in 0.91 (2 May 95)
+- Default MEM_LEVEL is 8 (not 9 for Unix) as documented in zlib.h
+- Document the memory requirements in zconf.h
+- added "make install"
+- fix sync search logic in inflateSync
+- deflate(Z_FULL_FLUSH) now works even if output buffer too short
+- after inflateSync, don't scare people with just "lo world"
+- added support for DJGPP
+
+Changes in 0.9 (1 May 95)
+- don't assume that zalloc clears the allocated memory (the TurboC bug
+  was Mark's bug after all :)
+- let again gzread copy uncompressed data unchanged (was working in 0.71)
+- deflate(Z_FULL_FLUSH), inflateReset and inflateSync are now fully implemented
+- added a test of inflateSync in example.c
+- moved MAX_WBITS to zconf.h because users might want to change that.
+- document explicitly that zalloc(64K) on MSDOS must return a normalized
+  pointer (zero offset)
+- added Makefiles for Microsoft C, Turbo C, Borland C++
+- faster crc32()
+
+Changes in 0.8 (29 April 95)
+- added fast inflate (inffast.c)
+- deflate(Z_FINISH) now returns Z_STREAM_END when done. Warning: this
+  is incompatible with previous versions of zlib which returned Z_OK.
+- work around a TurboC compiler bug (bad code for b << 0, see infutil.h)
+  (actually that was not a compiler bug, see 0.81 above)
+- gzread no longer reads one extra byte in certain cases
+- In gzio destroy(), don't reference a freed structure
+- avoid many warnings for MSDOS
+- avoid the ERROR symbol which is used by MS Windows
+
+Changes in 0.71 (14 April 95)
+- Fixed more MSDOS compilation problems :( There is still a bug with
+  TurboC large model.
+
+Changes in 0.7 (14 April 95)
+- Added full inflate support.
+- Simplified the crc32() interface. The pre- and post-conditioning
+  (one's complement) is now done inside crc32(). WARNING: this is
+  incompatible with previous versions; see zlib.h for the new usage.
+
+Changes in 0.61 (12 April 95)
+- workaround for a bug in TurboC. example and minigzip now work on MSDOS.
+
+Changes in 0.6 (11 April 95)
+- added minigzip.c
+- added gzdopen to reopen a file descriptor as gzFile
+- added transparent reading of non-gziped files in gzread.
+- fixed bug in gzread (don't read crc as data)
+- fixed bug in destroy (gzio.c) (don't return Z_STREAM_END for gzclose).
+- don't allocate big arrays in the stack (for MSDOS)
+- fix some MSDOS compilation problems
+
+Changes in 0.5:
+- do real compression in deflate.c. Z_PARTIAL_FLUSH is supported but
+  not yet Z_FULL_FLUSH.
+- support decompression but only in a single step (forced Z_FINISH)
+- added opaque object for zalloc and zfree.
+- added deflateReset and inflateReset
+- added a variable zlib_version for consistency checking.
+- renamed the 'filter' parameter of deflateInit2 as 'strategy'.
+  Added Z_FILTERED and Z_HUFFMAN_ONLY constants.
+
+Changes in 0.4:
+- avoid "zip" everywhere, use zlib instead of ziplib.
+- suppress Z_BLOCK_FLUSH, interpret Z_PARTIAL_FLUSH as block flush
+  if compression method == 8.
+- added adler32 and crc32
+- renamed deflateOptions as deflateInit2, call one or the other but not both
+- added the method parameter for deflateInit2.
+- added inflateInit2
+- simplied considerably deflateInit and inflateInit by not supporting
+  user-provided history buffer. This is supported only in deflateInit2
+  and inflateInit2.
+
+Changes in 0.3:
+- prefix all macro names with Z_
+- use Z_FINISH instead of deflateEnd to finish compression.
+- added Z_HUFFMAN_ONLY
+- added gzerror()
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/FAQ
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/FAQ	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,368 @@
+
+                Frequently Asked Questions about zlib
+
+
+If your question is not there, please check the zlib home page
+http://zlib.net/ which may have more recent information.
+The lastest zlib FAQ is at http://zlib.net/zlib_faq.html
+
+
+ 1. Is zlib Y2K-compliant?
+
+    Yes. zlib doesn't handle dates.
+
+ 2. Where can I get a Windows DLL version?
+
+    The zlib sources can be compiled without change to produce a DLL.  See the
+    file win32/DLL_FAQ.txt in the zlib distribution.  Pointers to the
+    precompiled DLL are found in the zlib web site at http://zlib.net/ .
+
+ 3. Where can I get a Visual Basic interface to zlib?
+
+    See
+        * http://marknelson.us/1997/01/01/zlib-engine/
+        * win32/DLL_FAQ.txt in the zlib distribution
+
+ 4. compress() returns Z_BUF_ERROR.
+
+    Make sure that before the call of compress(), the length of the compressed
+    buffer is equal to the available size of the compressed buffer and not
+    zero.  For Visual Basic, check that this parameter is passed by reference
+    ("as any"), not by value ("as long").
+
+ 5. deflate() or inflate() returns Z_BUF_ERROR.
+
+    Before making the call, make sure that avail_in and avail_out are not zero.
+    When setting the parameter flush equal to Z_FINISH, also make sure that
+    avail_out is big enough to allow processing all pending input.  Note that a
+    Z_BUF_ERROR is not fatal--another call to deflate() or inflate() can be
+    made with more input or output space.  A Z_BUF_ERROR may in fact be
+    unavoidable depending on how the functions are used, since it is not
+    possible to tell whether or not there is more output pending when
+    strm.avail_out returns with zero.  See http://zlib.net/zlib_how.html for a
+    heavily annotated example.
+
+ 6. Where's the zlib documentation (man pages, etc.)?
+
+    It's in zlib.h .  Examples of zlib usage are in the files test/example.c
+    and test/minigzip.c, with more in examples/ .
+
+ 7. Why don't you use GNU autoconf or libtool or ...?
+
+    Because we would like to keep zlib as a very small and simple package.
+    zlib is rather portable and doesn't need much configuration.
+
+ 8. I found a bug in zlib.
+
+    Most of the time, such problems are due to an incorrect usage of zlib.
+    Please try to reproduce the problem with a small program and send the
+    corresponding source to us at zlib@gzip.org .  Do not send multi-megabyte
+    data files without prior agreement.
+
+ 9. Why do I get "undefined reference to gzputc"?
+
+    If "make test" produces something like
+
+       example.o(.text+0x154): undefined reference to `gzputc'
+
+    check that you don't have old files libz.* in /usr/lib, /usr/local/lib or
+    /usr/X11R6/lib. Remove any old versions, then do "make install".
+
+10. I need a Delphi interface to zlib.
+
+    See the contrib/delphi directory in the zlib distribution.
+
+11. Can zlib handle .zip archives?
+
+    Not by itself, no.  See the directory contrib/minizip in the zlib
+    distribution.
+
+12. Can zlib handle .Z files?
+
+    No, sorry.  You have to spawn an uncompress or gunzip subprocess, or adapt
+    the code of uncompress on your own.
+
+13. How can I make a Unix shared library?
+
+    By default a shared (and a static) library is built for Unix.  So:
+
+    make distclean
+    ./configure
+    make
+
+14. How do I install a shared zlib library on Unix?
+
+    After the above, then:
+
+    make install
+
+    However, many flavors of Unix come with a shared zlib already installed.
+    Before going to the trouble of compiling a shared version of zlib and
+    trying to install it, you may want to check if it's already there!  If you
+    can #include <zlib.h>, it's there.  The -lz option will probably link to
+    it.  You can check the version at the top of zlib.h or with the
+    ZLIB_VERSION symbol defined in zlib.h .
+
+15. I have a question about OttoPDF.
+
+    We are not the authors of OttoPDF. The real author is on the OttoPDF web
+    site: Joel Hainley, jhainley@myndkryme.com.
+
+16. Can zlib decode Flate data in an Adobe PDF file?
+
+    Yes. See http://www.pdflib.com/ . To modify PDF forms, see
+    http://sourceforge.net/projects/acroformtool/ .
+
+17. Why am I getting this "register_frame_info not found" error on Solaris?
+
+    After installing zlib 1.1.4 on Solaris 2.6, running applications using zlib
+    generates an error such as:
+
+        ld.so.1: rpm: fatal: relocation error: file /usr/local/lib/libz.so:
+        symbol __register_frame_info: referenced symbol not found
+
+    The symbol __register_frame_info is not part of zlib, it is generated by
+    the C compiler (cc or gcc).  You must recompile applications using zlib
+    which have this problem.  This problem is specific to Solaris.  See
+    http://www.sunfreeware.com for Solaris versions of zlib and applications
+    using zlib.
+
+18. Why does gzip give an error on a file I make with compress/deflate?
+
+    The compress and deflate functions produce data in the zlib format, which
+    is different and incompatible with the gzip format.  The gz* functions in
+    zlib on the other hand use the gzip format.  Both the zlib and gzip formats
+    use the same compressed data format internally, but have different headers
+    and trailers around the compressed data.
+
+19. Ok, so why are there two different formats?
+
+    The gzip format was designed to retain the directory information about a
+    single file, such as the name and last modification date.  The zlib format
+    on the other hand was designed for in-memory and communication channel
+    applications, and has a much more compact header and trailer and uses a
+    faster integrity check than gzip.
+
+20. Well that's nice, but how do I make a gzip file in memory?
+
+    You can request that deflate write the gzip format instead of the zlib
+    format using deflateInit2().  You can also request that inflate decode the
+    gzip format using inflateInit2().  Read zlib.h for more details.
+
+21. Is zlib thread-safe?
+
+    Yes.  However any library routines that zlib uses and any application-
+    provided memory allocation routines must also be thread-safe.  zlib's gz*
+    functions use stdio library routines, and most of zlib's functions use the
+    library memory allocation routines by default.  zlib's *Init* functions
+    allow for the application to provide custom memory allocation routines.
+
+    Of course, you should only operate on any given zlib or gzip stream from a
+    single thread at a time.
+
+22. Can I use zlib in my commercial application?
+
+    Yes.  Please read the license in zlib.h.
+
+23. Is zlib under the GNU license?
+
+    No.  Please read the license in zlib.h.
+
+24. The license says that altered source versions must be "plainly marked". So
+    what exactly do I need to do to meet that requirement?
+
+    You need to change the ZLIB_VERSION and ZLIB_VERNUM #defines in zlib.h.  In
+    particular, the final version number needs to be changed to "f", and an
+    identification string should be appended to ZLIB_VERSION.  Version numbers
+    x.x.x.f are reserved for modifications to zlib by others than the zlib
+    maintainers.  For example, if the version of the base zlib you are altering
+    is "1.2.3.4", then in zlib.h you should change ZLIB_VERNUM to 0x123f, and
+    ZLIB_VERSION to something like "1.2.3.f-zachary-mods-v3".  You can also
+    update the version strings in deflate.c and inftrees.c.
+
+    For altered source distributions, you should also note the origin and
+    nature of the changes in zlib.h, as well as in ChangeLog and README, along
+    with the dates of the alterations.  The origin should include at least your
+    name (or your company's name), and an email address to contact for help or
+    issues with the library.
+
+    Note that distributing a compiled zlib library along with zlib.h and
+    zconf.h is also a source distribution, and so you should change
+    ZLIB_VERSION and ZLIB_VERNUM and note the origin and nature of the changes
+    in zlib.h as you would for a full source distribution.
+
+25. Will zlib work on a big-endian or little-endian architecture, and can I
+    exchange compressed data between them?
+
+    Yes and yes.
+
+26. Will zlib work on a 64-bit machine?
+
+    Yes.  It has been tested on 64-bit machines, and has no dependence on any
+    data types being limited to 32-bits in length.  If you have any
+    difficulties, please provide a complete problem report to zlib@gzip.org
+
+27. Will zlib decompress data from the PKWare Data Compression Library?
+
+    No.  The PKWare DCL uses a completely different compressed data format than
+    does PKZIP and zlib.  However, you can look in zlib's contrib/blast
+    directory for a possible solution to your problem.
+
+28. Can I access data randomly in a compressed stream?
+
+    No, not without some preparation.  If when compressing you periodically use
+    Z_FULL_FLUSH, carefully write all the pending data at those points, and
+    keep an index of those locations, then you can start decompression at those
+    points.  You have to be careful to not use Z_FULL_FLUSH too often, since it
+    can significantly degrade compression.  Alternatively, you can scan a
+    deflate stream once to generate an index, and then use that index for
+    random access.  See examples/zran.c .
+
+29. Does zlib work on MVS, OS/390, CICS, etc.?
+
+    It has in the past, but we have not heard of any recent evidence.  There
+    were working ports of zlib 1.1.4 to MVS, but those links no longer work.
+    If you know of recent, successful applications of zlib on these operating
+    systems, please let us know.  Thanks.
+
+30. Is there some simpler, easier to read version of inflate I can look at to
+    understand the deflate format?
+
+    First off, you should read RFC 1951.  Second, yes.  Look in zlib's
+    contrib/puff directory.
+
+31. Does zlib infringe on any patents?
+
+    As far as we know, no.  In fact, that was originally the whole point behind
+    zlib.  Look here for some more information:
+
+    http://www.gzip.org/#faq11
+
+32. Can zlib work with greater than 4 GB of data?
+
+    Yes.  inflate() and deflate() will process any amount of data correctly.
+    Each call of inflate() or deflate() is limited to input and output chunks
+    of the maximum value that can be stored in the compiler's "unsigned int"
+    type, but there is no limit to the number of chunks.  Note however that the
+    strm.total_in and strm_total_out counters may be limited to 4 GB.  These
+    counters are provided as a convenience and are not used internally by
+    inflate() or deflate().  The application can easily set up its own counters
+    updated after each call of inflate() or deflate() to count beyond 4 GB.
+    compress() and uncompress() may be limited to 4 GB, since they operate in a
+    single call.  gzseek() and gztell() may be limited to 4 GB depending on how
+    zlib is compiled.  See the zlibCompileFlags() function in zlib.h.
+
+    The word "may" appears several times above since there is a 4 GB limit only
+    if the compiler's "long" type is 32 bits.  If the compiler's "long" type is
+    64 bits, then the limit is 16 exabytes.
+
+33. Does zlib have any security vulnerabilities?
+
+    The only one that we are aware of is potentially in gzprintf().  If zlib is
+    compiled to use sprintf() or vsprintf(), then there is no protection
+    against a buffer overflow of an 8K string space (or other value as set by
+    gzbuffer()), other than the caller of gzprintf() assuring that the output
+    will not exceed 8K.  On the other hand, if zlib is compiled to use
+    snprintf() or vsnprintf(), which should normally be the case, then there is
+    no vulnerability.  The ./configure script will display warnings if an
+    insecure variation of sprintf() will be used by gzprintf().  Also the
+    zlibCompileFlags() function will return information on what variant of
+    sprintf() is used by gzprintf().
+
+    If you don't have snprintf() or vsnprintf() and would like one, you can
+    find a portable implementation here:
+
+        http://www.ijs.si/software/snprintf/
+
+    Note that you should be using the most recent version of zlib.  Versions
+    1.1.3 and before were subject to a double-free vulnerability, and versions
+    1.2.1 and 1.2.2 were subject to an access exception when decompressing
+    invalid compressed data.
+
+34. Is there a Java version of zlib?
+
+    Probably what you want is to use zlib in Java. zlib is already included
+    as part of the Java SDK in the java.util.zip package. If you really want
+    a version of zlib written in the Java language, look on the zlib home
+    page for links: http://zlib.net/ .
+
+35. I get this or that compiler or source-code scanner warning when I crank it
+    up to maximally-pedantic. Can't you guys write proper code?
+
+    Many years ago, we gave up attempting to avoid warnings on every compiler
+    in the universe.  It just got to be a waste of time, and some compilers
+    were downright silly as well as contradicted each other.  So now, we simply
+    make sure that the code always works.
+
+36. Valgrind (or some similar memory access checker) says that deflate is
+    performing a conditional jump that depends on an uninitialized value.
+    Isn't that a bug?
+
+    No.  That is intentional for performance reasons, and the output of deflate
+    is not affected.  This only started showing up recently since zlib 1.2.x
+    uses malloc() by default for allocations, whereas earlier versions used
+    calloc(), which zeros out the allocated memory.  Even though the code was
+    correct, versions 1.2.4 and later was changed to not stimulate these
+    checkers.
+
+37. Will zlib read the (insert any ancient or arcane format here) compressed
+    data format?
+
+    Probably not. Look in the comp.compression FAQ for pointers to various
+    formats and associated software.
+
+38. How can I encrypt/decrypt zip files with zlib?
+
+    zlib doesn't support encryption.  The original PKZIP encryption is very
+    weak and can be broken with freely available programs.  To get strong
+    encryption, use GnuPG, http://www.gnupg.org/ , which already includes zlib
+    compression.  For PKZIP compatible "encryption", look at
+    http://www.info-zip.org/
+
+39. What's the difference between the "gzip" and "deflate" HTTP 1.1 encodings?
+
+    "gzip" is the gzip format, and "deflate" is the zlib format.  They should
+    probably have called the second one "zlib" instead to avoid confusion with
+    the raw deflate compressed data format.  While the HTTP 1.1 RFC 2616
+    correctly points to the zlib specification in RFC 1950 for the "deflate"
+    transfer encoding, there have been reports of servers and browsers that
+    incorrectly produce or expect raw deflate data per the deflate
+    specification in RFC 1951, most notably Microsoft.  So even though the
+    "deflate" transfer encoding using the zlib format would be the more
+    efficient approach (and in fact exactly what the zlib format was designed
+    for), using the "gzip" transfer encoding is probably more reliable due to
+    an unfortunate choice of name on the part of the HTTP 1.1 authors.
+
+    Bottom line: use the gzip format for HTTP 1.1 encoding.
+
+40. Does zlib support the new "Deflate64" format introduced by PKWare?
+
+    No.  PKWare has apparently decided to keep that format proprietary, since
+    they have not documented it as they have previous compression formats.  In
+    any case, the compression improvements are so modest compared to other more
+    modern approaches, that it's not worth the effort to implement.
+
+41. I'm having a problem with the zip functions in zlib, can you help?
+
+    There are no zip functions in zlib.  You are probably using minizip by
+    Giles Vollant, which is found in the contrib directory of zlib.  It is not
+    part of zlib.  In fact none of the stuff in contrib is part of zlib.  The
+    files in there are not supported by the zlib authors.  You need to contact
+    the authors of the respective contribution for help.
+
+42. The match.asm code in contrib is under the GNU General Public License.
+    Since it's part of zlib, doesn't that mean that all of zlib falls under the
+    GNU GPL?
+
+    No.  The files in contrib are not part of zlib.  They were contributed by
+    other authors and are provided as a convenience to the user within the zlib
+    distribution.  Each item in contrib has its own license.
+
+43. Is zlib subject to export controls?  What is its ECCN?
+
+    zlib is not subject to export controls, and so is classified as EAR99.
+
+44. Can you please sign these lengthy legal documents and fax them back to us
+    so that we can use your software in our product?
+
+    No. Go away. Shoo.
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/INDEX
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/INDEX	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,68 @@
+CMakeLists.txt  cmake build file
+ChangeLog       history of changes
+FAQ             Frequently Asked Questions about zlib
+INDEX           this file
+Makefile        dummy Makefile that tells you to ./configure
+Makefile.in     template for Unix Makefile
+README          guess what
+configure       configure script for Unix
+make_vms.com    makefile for VMS
+test/example.c  zlib usages examples for build testing
+test/minigzip.c minimal gzip-like functionality for build testing
+test/infcover.c inf*.c code coverage for build coverage testing
+treebuild.xml   XML description of source file dependencies
+zconf.h.cmakein zconf.h template for cmake
+zconf.h.in      zconf.h template for configure
+zlib.3          Man page for zlib
+zlib.3.pdf      Man page in PDF format
+zlib.map        Linux symbol information
+zlib.pc.in      Template for pkg-config descriptor
+zlib.pc.cmakein zlib.pc template for cmake
+zlib2ansi       perl script to convert source files for C++ compilation
+
+amiga/          makefiles for Amiga SAS C
+as400/          makefiles for AS/400
+doc/            documentation for formats and algorithms
+msdos/          makefiles for MSDOS
+nintendods/     makefile for Nintendo DS
+old/            makefiles for various architectures and zlib documentation
+                files that have not yet been updated for zlib 1.2.x
+qnx/            makefiles for QNX
+watcom/         makefiles for OpenWatcom
+win32/          makefiles for Windows
+
+                zlib public header files (required for library use):
+zconf.h
+zlib.h
+
+                private source files used to build the zlib library:
+adler32.c
+compress.c
+crc32.c
+crc32.h
+deflate.c
+deflate.h
+gzclose.c
+gzguts.h
+gzlib.c
+gzread.c
+gzwrite.c
+infback.c
+inffast.c
+inffast.h
+inffixed.h
+inflate.c
+inflate.h
+inftrees.c
+inftrees.h
+trees.c
+trees.h
+uncompr.c
+zutil.c
+zutil.h
+
+                source files for sample programs
+See examples/README.examples
+
+                unsupported contributions by third parties
+See contrib/README.contrib
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/README
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/README	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,115 @@
+ZLIB DATA COMPRESSION LIBRARY
+
+zlib 1.2.11 is a general purpose data compression library.  All the code is
+thread safe.  The data format used by the zlib library is described by RFCs
+(Request for Comments) 1950 to 1952 in the files
+http://tools.ietf.org/html/rfc1950 (zlib format), rfc1951 (deflate format) and
+rfc1952 (gzip format).
+
+All functions of the compression library are documented in the file zlib.h
+(volunteer to write man pages welcome, contact zlib@gzip.org).  A usage example
+of the library is given in the file test/example.c which also tests that
+the library is working correctly.  Another example is given in the file
+test/minigzip.c.  The compression library itself is composed of all source
+files in the root directory.
+
+To compile all files and run the test program, follow the instructions given at
+the top of Makefile.in.  In short "./configure; make test", and if that goes
+well, "make install" should work for most flavors of Unix.  For Windows, use
+one of the special makefiles in win32/ or contrib/vstudio/ .  For VMS, use
+make_vms.com.
+
+Questions about zlib should be sent to <zlib@gzip.org>, or to Gilles Vollant
+<info@winimage.com> for the Windows DLL version.  The zlib home page is
+http://zlib.net/ .  Before reporting a problem, please check this site to
+verify that you have the latest version of zlib; otherwise get the latest
+version and check whether the problem still exists or not.
+
+PLEASE read the zlib FAQ http://zlib.net/zlib_faq.html before asking for help.
+
+Mark Nelson <markn@ieee.org> wrote an article about zlib for the Jan.  1997
+issue of Dr.  Dobb's Journal; a copy of the article is available at
+http://marknelson.us/1997/01/01/zlib-engine/ .
+
+The changes made in version 1.2.11 are documented in the file ChangeLog.
+
+Unsupported third party contributions are provided in directory contrib/ .
+
+zlib is available in Java using the java.util.zip package, documented at
+http://java.sun.com/developer/technicalArticles/Programming/compression/ .
+
+A Perl interface to zlib written by Paul Marquess <pmqs@cpan.org> is available
+at CPAN (Comprehensive Perl Archive Network) sites, including
+http://search.cpan.org/~pmqs/IO-Compress-Zlib/ .
+
+A Python interface to zlib written by A.M. Kuchling <amk@amk.ca> is
+available in Python 1.5 and later versions, see
+http://docs.python.org/library/zlib.html .
+
+zlib is built into tcl: http://wiki.tcl.tk/4610 .
+
+An experimental package to read and write files in .zip format, written on top
+of zlib by Gilles Vollant <info@winimage.com>, is available in the
+contrib/minizip directory of zlib.
+
+
+Notes for some targets:
+
+- For Windows DLL versions, please see win32/DLL_FAQ.txt
+
+- For 64-bit Irix, deflate.c must be compiled without any optimization. With
+  -O, one libpng test fails. The test works in 32 bit mode (with the -n32
+  compiler flag). The compiler bug has been reported to SGI.
+
+- zlib doesn't work with gcc 2.6.3 on a DEC 3000/300LX under OSF/1 2.1 it works
+  when compiled with cc.
+
+- On Digital Unix 4.0D (formely OSF/1) on AlphaServer, the cc option -std1 is
+  necessary to get gzprintf working correctly. This is done by configure.
+
+- zlib doesn't work on HP-UX 9.05 with some versions of /bin/cc. It works with
+  other compilers. Use "make test" to check your compiler.
+
+- gzdopen is not supported on RISCOS or BEOS.
+
+- For PalmOs, see http://palmzlib.sourceforge.net/
+
+
+Acknowledgments:
+
+  The deflate format used by zlib was defined by Phil Katz.  The deflate and
+  zlib specifications were written by L.  Peter Deutsch.  Thanks to all the
+  people who reported problems and suggested various improvements in zlib; they
+  are too numerous to cite here.
+
+Copyright notice:
+
+ (C) 1995-2017 Jean-loup Gailly and Mark Adler
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  Jean-loup Gailly        Mark Adler
+  jloup@gzip.org          madler@alumni.caltech.edu
+
+If you use the zlib library in a product, we would appreciate *not* receiving
+lengthy legal documents to sign.  The sources are provided for free but without
+warranty of any kind.  The library has been entirely written by Jean-loup
+Gailly and Mark Adler; it does not include third-party code.
+
+If you redistribute modified sources, we would appreciate that you include in
+the file ChangeLog history information documenting your changes.  Please read
+the FAQ for more information on the distribution of modified source versions.
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/README.9front
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/README.9front	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,1 @@
+This is Zlib 1.2.11 for 9front, with other platform files removed, keep in mind contrib/ is unsupported neither by 9front nor by upstream, and we dont do the test
\ No newline at end of file
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/adler32.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/adler32.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,186 @@
+/* adler32.c -- compute the Adler-32 checksum of a data stream
+ * Copyright (C) 1995-2011, 2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* @(#) $Id$ */
+
+#include "zutil.h"
+
+local uLong adler32_combine_ OF((uLong adler1, uLong adler2, z_off64_t len2));
+
+#define BASE 65521U     /* largest prime smaller than 65536 */
+#define NMAX 5552
+/* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
+
+#define DO1(buf,i)  {adler += (buf)[i]; sum2 += adler;}
+#define DO2(buf,i)  DO1(buf,i); DO1(buf,i+1);
+#define DO4(buf,i)  DO2(buf,i); DO2(buf,i+2);
+#define DO8(buf,i)  DO4(buf,i); DO4(buf,i+4);
+#define DO16(buf)   DO8(buf,0); DO8(buf,8);
+
+/* use NO_DIVIDE if your processor does not do division in hardware --
+   try it both ways to see which is faster */
+#ifdef NO_DIVIDE
+/* note that this assumes BASE is 65521, where 65536 % 65521 == 15
+   (thank you to John Reiser for pointing this out) */
+#  define CHOP(a) \
+    do { \
+        unsigned long tmp = a >> 16; \
+        a &= 0xffffUL; \
+        a += (tmp << 4) - tmp; \
+    } while (0)
+#  define MOD28(a) \
+    do { \
+        CHOP(a); \
+        if (a >= BASE) a -= BASE; \
+    } while (0)
+#  define MOD(a) \
+    do { \
+        CHOP(a); \
+        MOD28(a); \
+    } while (0)
+#  define MOD63(a) \
+    do { /* this assumes a is not negative */ \
+        z_off64_t tmp = a >> 32; \
+        a &= 0xffffffffL; \
+        a += (tmp << 8) - (tmp << 5) + tmp; \
+        tmp = a >> 16; \
+        a &= 0xffffL; \
+        a += (tmp << 4) - tmp; \
+        tmp = a >> 16; \
+        a &= 0xffffL; \
+        a += (tmp << 4) - tmp; \
+        if (a >= BASE) a -= BASE; \
+    } while (0)
+#else
+#  define MOD(a) a %= BASE
+#  define MOD28(a) a %= BASE
+#  define MOD63(a) a %= BASE
+#endif
+
+/* ========================================================================= */
+uLong ZEXPORT adler32_z(adler, buf, len)
+    uLong adler;
+    const Bytef *buf;
+    z_size_t len;
+{
+    unsigned long sum2;
+    unsigned n;
+
+    /* split Adler-32 into component sums */
+    sum2 = (adler >> 16) & 0xffff;
+    adler &= 0xffff;
+
+    /* in case user likes doing a byte at a time, keep it fast */
+    if (len == 1) {
+        adler += buf[0];
+        if (adler >= BASE)
+            adler -= BASE;
+        sum2 += adler;
+        if (sum2 >= BASE)
+            sum2 -= BASE;
+        return adler | (sum2 << 16);
+    }
+
+    /* initial Adler-32 value (deferred check for len == 1 speed) */
+    if (buf == Z_NULL)
+        return 1L;
+
+    /* in case short lengths are provided, keep it somewhat fast */
+    if (len < 16) {
+        while (len--) {
+            adler += *buf++;
+            sum2 += adler;
+        }
+        if (adler >= BASE)
+            adler -= BASE;
+        MOD28(sum2);            /* only added so many BASE's */
+        return adler | (sum2 << 16);
+    }
+
+    /* do length NMAX blocks -- requires just one modulo operation */
+    while (len >= NMAX) {
+        len -= NMAX;
+        n = NMAX / 16;          /* NMAX is divisible by 16 */
+        do {
+            DO16(buf);          /* 16 sums unrolled */
+            buf += 16;
+        } while (--n);
+        MOD(adler);
+        MOD(sum2);
+    }
+
+    /* do remaining bytes (less than NMAX, still just one modulo) */
+    if (len) {                  /* avoid modulos if none remaining */
+        while (len >= 16) {
+            len -= 16;
+            DO16(buf);
+            buf += 16;
+        }
+        while (len--) {
+            adler += *buf++;
+            sum2 += adler;
+        }
+        MOD(adler);
+        MOD(sum2);
+    }
+
+    /* return recombined sums */
+    return adler | (sum2 << 16);
+}
+
+/* ========================================================================= */
+uLong ZEXPORT adler32(adler, buf, len)
+    uLong adler;
+    const Bytef *buf;
+    uInt len;
+{
+    return adler32_z(adler, buf, len);
+}
+
+/* ========================================================================= */
+local uLong adler32_combine_(adler1, adler2, len2)
+    uLong adler1;
+    uLong adler2;
+    z_off64_t len2;
+{
+    unsigned long sum1;
+    unsigned long sum2;
+    unsigned rem;
+
+    /* for negative len, return invalid adler32 as a clue for debugging */
+    if (len2 < 0)
+        return 0xffffffffUL;
+
+    /* the derivation of this formula is left as an exercise for the reader */
+    MOD63(len2);                /* assumes len2 >= 0 */
+    rem = (unsigned)len2;
+    sum1 = adler1 & 0xffff;
+    sum2 = rem * sum1;
+    MOD(sum2);
+    sum1 += (adler2 & 0xffff) + BASE - 1;
+    sum2 += ((adler1 >> 16) & 0xffff) + ((adler2 >> 16) & 0xffff) + BASE - rem;
+    if (sum1 >= BASE) sum1 -= BASE;
+    if (sum1 >= BASE) sum1 -= BASE;
+    if (sum2 >= ((unsigned long)BASE << 1)) sum2 -= ((unsigned long)BASE << 1);
+    if (sum2 >= BASE) sum2 -= BASE;
+    return sum1 | (sum2 << 16);
+}
+
+/* ========================================================================= */
+uLong ZEXPORT adler32_combine(adler1, adler2, len2)
+    uLong adler1;
+    uLong adler2;
+    z_off_t len2;
+{
+    return adler32_combine_(adler1, adler2, len2);
+}
+
+uLong ZEXPORT adler32_combine64(adler1, adler2, len2)
+    uLong adler1;
+    uLong adler2;
+    z_off64_t len2;
+{
+    return adler32_combine_(adler1, adler2, len2);
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/compress.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/compress.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,86 @@
+/* compress.c -- compress a memory buffer
+ * Copyright (C) 1995-2005, 2014, 2016 Jean-loup Gailly, Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* @(#) $Id$ */
+
+#define ZLIB_INTERNAL
+#include "zlib.h"
+
+/* ===========================================================================
+     Compresses the source buffer into the destination buffer. The level
+   parameter has the same meaning as in deflateInit.  sourceLen is the byte
+   length of the source buffer. Upon entry, destLen is the total size of the
+   destination buffer, which must be at least 0.1% larger than sourceLen plus
+   12 bytes. Upon exit, destLen is the actual size of the compressed buffer.
+
+     compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_BUF_ERROR if there was not enough room in the output buffer,
+   Z_STREAM_ERROR if the level parameter is invalid.
+*/
+int ZEXPORT compress2 (dest, destLen, source, sourceLen, level)
+    Bytef *dest;
+    uLongf *destLen;
+    const Bytef *source;
+    uLong sourceLen;
+    int level;
+{
+    z_stream stream;
+    int err;
+    const uInt max = (uInt)-1;
+    uLong left;
+
+    left = *destLen;
+    *destLen = 0;
+
+    stream.zalloc = (alloc_func)0;
+    stream.zfree = (free_func)0;
+    stream.opaque = (voidpf)0;
+
+    err = deflateInit(&stream, level);
+    if (err != Z_OK) return err;
+
+    stream.next_out = dest;
+    stream.avail_out = 0;
+    stream.next_in = (z_const Bytef *)source;
+    stream.avail_in = 0;
+
+    do {
+        if (stream.avail_out == 0) {
+            stream.avail_out = left > (uLong)max ? max : (uInt)left;
+            left -= stream.avail_out;
+        }
+        if (stream.avail_in == 0) {
+            stream.avail_in = sourceLen > (uLong)max ? max : (uInt)sourceLen;
+            sourceLen -= stream.avail_in;
+        }
+        err = deflate(&stream, sourceLen ? Z_NO_FLUSH : Z_FINISH);
+    } while (err == Z_OK);
+
+    *destLen = stream.total_out;
+    deflateEnd(&stream);
+    return err == Z_STREAM_END ? Z_OK : err;
+}
+
+/* ===========================================================================
+ */
+int ZEXPORT compress (dest, destLen, source, sourceLen)
+    Bytef *dest;
+    uLongf *destLen;
+    const Bytef *source;
+    uLong sourceLen;
+{
+    return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION);
+}
+
+/* ===========================================================================
+     If the default memLevel or windowBits for deflateInit() is changed, then
+   this function needs to be updated.
+ */
+uLong ZEXPORT compressBound (sourceLen)
+    uLong sourceLen;
+{
+    return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) +
+           (sourceLen >> 25) + 13;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/README.contrib
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/README.contrib	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,51 @@
+All files under this contrib directory are UNSUPPORTED. There were
+provided by users of zlib and were not tested by the authors of zlib.
+Use at your own risk. Please contact the authors of the contributions
+for help about these, not the zlib authors. Thanks.
+
+
+ada/        by Dmitriy Anisimkov <anisimkov@yahoo.com>
+        Support for Ada
+        See http://zlib-ada.sourceforge.net/
+
+amd64/      by Mikhail Teterin <mi@ALDAN.algebra.com>
+        asm code for AMD64
+        See patch at http://www.freebsd.org/cgi/query-pr.cgi?pr=bin/96393
+
+blast/      by Mark Adler <madler@alumni.caltech.edu>
+        Decompressor for output of PKWare Data Compression Library (DCL)
+
+delphi/     by Cosmin Truta <cosmint@cs.ubbcluj.ro>
+        Support for Delphi and C++ Builder
+
+infback9/   by Mark Adler <madler@alumni.caltech.edu>
+        Unsupported diffs to infback to decode the deflate64 format
+
+masmx64/    by Gilles Vollant <info@winimage.com>
+        x86 64-bit (AMD64 and Intel EM64t) code for x64 assembler to
+        replace longest_match() and inflate_fast(),  also masm x86
+        64-bits translation of Chris Anderson inflate_fast()
+
+masmx86/    by Gilles Vollant <info@winimage.com>
+        x86 asm code to replace longest_match() and inflate_fast(),
+        for Visual C++ and MASM (32 bits).
+        Based on Brian Raiter (asm686) and Chris Anderson (inflate86)
+
+minizip/    by Gilles Vollant <info@winimage.com>
+        Mini zip and unzip based on zlib
+        Includes Zip64 support by Mathias Svensson <mathias@result42.com>
+        See http://www.winimage.com/zLibDll/minizip.html
+
+pascal/     by Bob Dellaca <bobdl@xtra.co.nz> et al.
+        Support for Pascal
+
+puff/       by Mark Adler <madler@alumni.caltech.edu>
+        Small, low memory usage inflate.  Also serves to provide an
+        unambiguous description of the deflate format.
+
+testzlib/   by Gilles Vollant <info@winimage.com>
+        Example of the use of zlib
+
+untgz/      by Pedro A. Aranda Gutierrez <paag@tid.es>
+        A very simple tar.gz file extractor using zlib
+
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/ada/buffer_demo.adb
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/ada/buffer_demo.adb	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,106 @@
+----------------------------------------------------------------
+--  ZLib for Ada thick binding.                               --
+--                                                            --
+--  Copyright (C) 2002-2004 Dmitriy Anisimkov                 --
+--                                                            --
+--  Open source license information is in the zlib.ads file.  --
+----------------------------------------------------------------
+--
+--  $Id: buffer_demo.adb,v 1.3 2004/09/06 06:55:35 vagul Exp $
+
+--  This demo program provided by Dr Steve Sangwine <sjs@essex.ac.uk>
+--
+--  Demonstration of a problem with Zlib-Ada (already fixed) when a buffer
+--  of exactly the correct size is used for decompressed data, and the last
+--  few bytes passed in to Zlib are checksum bytes.
+
+--  This program compresses a string of text, and then decompresses the
+--  compressed text into a buffer of the same size as the original text.
+
+with Ada.Streams; use Ada.Streams;
+with Ada.Text_IO;
+
+with ZLib; use ZLib;
+
+procedure Buffer_Demo is
+   EOL  : Character renames ASCII.LF;
+   Text : constant String
+     := "Four score and seven years ago our fathers brought forth," & EOL &
+        "upon this continent, a new nation, conceived in liberty," & EOL &
+        "and dedicated to the proposition that `all men are created equal'.";
+
+   Source : Stream_Element_Array (1 .. Text'Length);
+   for Source'Address use Text'Address;
+
+begin
+   Ada.Text_IO.Put (Text);
+   Ada.Text_IO.New_Line;
+   Ada.Text_IO.Put_Line
+     ("Uncompressed size : " & Positive'Image (Text'Length) & " bytes");
+
+   declare
+      Compressed_Data : Stream_Element_Array (1 .. Text'Length);
+      L               : Stream_Element_Offset;
+   begin
+      Compress : declare
+         Compressor : Filter_Type;
+         I : Stream_Element_Offset;
+      begin
+         Deflate_Init (Compressor);
+
+         --  Compress the whole of T at once.
+
+         Translate (Compressor, Source, I, Compressed_Data, L, Finish);
+         pragma Assert (I = Source'Last);
+
+         Close (Compressor);
+
+         Ada.Text_IO.Put_Line
+           ("Compressed size :   "
+            & Stream_Element_Offset'Image (L) & " bytes");
+      end Compress;
+
+      --  Now we decompress the data, passing short blocks of data to Zlib
+      --  (because this demonstrates the problem - the last block passed will
+      --  contain checksum information and there will be no output, only a
+      --  check inside Zlib that the checksum is correct).
+
+      Decompress : declare
+         Decompressor : Filter_Type;
+
+         Uncompressed_Data : Stream_Element_Array (1 .. Text'Length);
+
+         Block_Size : constant := 4;
+         --  This makes sure that the last block contains
+         --  only Adler checksum data.
+
+         P : Stream_Element_Offset := Compressed_Data'First - 1;
+         O : Stream_Element_Offset;
+      begin
+         Inflate_Init (Decompressor);
+
+         loop
+            Translate
+              (Decompressor,
+               Compressed_Data
+                 (P + 1 .. Stream_Element_Offset'Min (P + Block_Size, L)),
+               P,
+               Uncompressed_Data
+                 (Total_Out (Decompressor) + 1 .. Uncompressed_Data'Last),
+               O,
+               No_Flush);
+
+               Ada.Text_IO.Put_Line
+                 ("Total in : " & Count'Image (Total_In (Decompressor)) &
+                  ", out : " & Count'Image (Total_Out (Decompressor)));
+
+               exit when P = L;
+         end loop;
+
+         Ada.Text_IO.New_Line;
+         Ada.Text_IO.Put_Line
+           ("Decompressed text matches original text : "
+             & Boolean'Image (Uncompressed_Data = Source));
+      end Decompress;
+   end;
+end Buffer_Demo;
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/ada/mtest.adb
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/ada/mtest.adb	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,156 @@
+----------------------------------------------------------------
+--  ZLib for Ada thick binding.                               --
+--                                                            --
+--  Copyright (C) 2002-2003 Dmitriy Anisimkov                 --
+--                                                            --
+--  Open source license information is in the zlib.ads file.  --
+----------------------------------------------------------------
+--  Continuous test for ZLib multithreading. If the test would fail
+--  we should provide thread safe allocation routines for the Z_Stream.
+--
+--  $Id: mtest.adb,v 1.4 2004/07/23 07:49:54 vagul Exp $
+
+with ZLib;
+with Ada.Streams;
+with Ada.Numerics.Discrete_Random;
+with Ada.Text_IO;
+with Ada.Exceptions;
+with Ada.Task_Identification;
+
+procedure MTest is
+   use Ada.Streams;
+   use ZLib;
+
+   Stop : Boolean := False;
+
+   pragma Atomic (Stop);
+
+   subtype Visible_Symbols is Stream_Element range 16#20# .. 16#7E#;
+
+   package Random_Elements is
+      new Ada.Numerics.Discrete_Random (Visible_Symbols);
+
+   task type Test_Task;
+
+   task body Test_Task is
+      Buffer : Stream_Element_Array (1 .. 100_000);
+      Gen : Random_Elements.Generator;
+
+      Buffer_First  : Stream_Element_Offset;
+      Compare_First : Stream_Element_Offset;
+
+      Deflate : Filter_Type;
+      Inflate : Filter_Type;
+
+      procedure Further (Item : in Stream_Element_Array);
+
+      procedure Read_Buffer
+        (Item : out Ada.Streams.Stream_Element_Array;
+         Last : out Ada.Streams.Stream_Element_Offset);
+
+      -------------
+      -- Further --
+      -------------
+
+      procedure Further (Item : in Stream_Element_Array) is
+
+         procedure Compare (Item : in Stream_Element_Array);
+
+         -------------
+         -- Compare --
+         -------------
+
+         procedure Compare (Item : in Stream_Element_Array) is
+            Next_First : Stream_Element_Offset := Compare_First + Item'Length;
+         begin
+            if Buffer (Compare_First .. Next_First - 1) /= Item then
+               raise Program_Error;
+            end if;
+
+            Compare_First := Next_First;
+         end Compare;
+
+         procedure Compare_Write is new ZLib.Write (Write => Compare);
+      begin
+         Compare_Write (Inflate, Item, No_Flush);
+      end Further;
+
+      -----------------
+      -- Read_Buffer --
+      -----------------
+
+      procedure Read_Buffer
+        (Item : out Ada.Streams.Stream_Element_Array;
+         Last : out Ada.Streams.Stream_Element_Offset)
+      is
+         Buff_Diff   : Stream_Element_Offset := Buffer'Last - Buffer_First;
+         Next_First : Stream_Element_Offset;
+      begin
+         if Item'Length <= Buff_Diff then
+            Last := Item'Last;
+
+            Next_First := Buffer_First + Item'Length;
+
+            Item := Buffer (Buffer_First .. Next_First - 1);
+
+            Buffer_First := Next_First;
+         else
+            Last := Item'First + Buff_Diff;
+            Item (Item'First .. Last) := Buffer (Buffer_First .. Buffer'Last);
+            Buffer_First := Buffer'Last + 1;
+         end if;
+      end Read_Buffer;
+
+      procedure Translate is new Generic_Translate
+                                   (Data_In  => Read_Buffer,
+                                    Data_Out => Further);
+
+   begin
+      Random_Elements.Reset (Gen);
+
+      Buffer := (others => 20);
+
+      Main : loop
+         for J in Buffer'Range loop
+            Buffer (J) := Random_Elements.Random (Gen);
+
+            Deflate_Init (Deflate);
+            Inflate_Init (Inflate);
+
+            Buffer_First  := Buffer'First;
+            Compare_First := Buffer'First;
+
+            Translate (Deflate);
+
+            if Compare_First /= Buffer'Last + 1 then
+               raise Program_Error;
+            end if;
+
+            Ada.Text_IO.Put_Line
+              (Ada.Task_Identification.Image
+                 (Ada.Task_Identification.Current_Task)
+               & Stream_Element_Offset'Image (J)
+               & ZLib.Count'Image (Total_Out (Deflate)));
+
+            Close (Deflate);
+            Close (Inflate);
+
+            exit Main when Stop;
+         end loop;
+      end loop Main;
+   exception
+      when E : others =>
+         Ada.Text_IO.Put_Line (Ada.Exceptions.Exception_Information (E));
+         Stop := True;
+   end Test_Task;
+
+   Test : array (1 .. 4) of Test_Task;
+
+   pragma Unreferenced (Test);
+
+   Dummy : Character;
+
+begin
+   Ada.Text_IO.Get_Immediate (Dummy);
+   Stop := True;
+end MTest;
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/ada/read.adb
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/ada/read.adb	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,156 @@
+----------------------------------------------------------------
+--  ZLib for Ada thick binding.                               --
+--                                                            --
+--  Copyright (C) 2002-2003 Dmitriy Anisimkov                 --
+--                                                            --
+--  Open source license information is in the zlib.ads file.  --
+----------------------------------------------------------------
+
+--  $Id: read.adb,v 1.8 2004/05/31 10:53:40 vagul Exp $
+
+--  Test/demo program for the generic read interface.
+
+with Ada.Numerics.Discrete_Random;
+with Ada.Streams;
+with Ada.Text_IO;
+
+with ZLib;
+
+procedure Read is
+
+   use Ada.Streams;
+
+   ------------------------------------
+   --  Test configuration parameters --
+   ------------------------------------
+
+   File_Size   : Stream_Element_Offset := 100_000;
+
+   Continuous  : constant Boolean          := False;
+   --  If this constant is True, the test would be repeated again and again,
+   --  with increment File_Size for every iteration.
+
+   Header      : constant ZLib.Header_Type := ZLib.Default;
+   --  Do not use Header other than Default in ZLib versions 1.1.4 and older.
+
+   Init_Random : constant := 8;
+   --  We are using the same random sequence, in case of we catch bug,
+   --  so we would be able to reproduce it.
+
+   -- End --
+
+   Pack_Size : Stream_Element_Offset;
+   Offset    : Stream_Element_Offset;
+
+   Filter     : ZLib.Filter_Type;
+
+   subtype Visible_Symbols
+      is Stream_Element range 16#20# .. 16#7E#;
+
+   package Random_Elements is new
+      Ada.Numerics.Discrete_Random (Visible_Symbols);
+
+   Gen : Random_Elements.Generator;
+   Period  : constant Stream_Element_Offset := 200;
+   --  Period constant variable for random generator not to be very random.
+   --  Bigger period, harder random.
+
+   Read_Buffer : Stream_Element_Array (1 .. 2048);
+   Read_First  : Stream_Element_Offset;
+   Read_Last   : Stream_Element_Offset;
+
+   procedure Reset;
+
+   procedure Read
+     (Item : out Stream_Element_Array;
+      Last : out Stream_Element_Offset);
+   --  this procedure is for generic instantiation of
+   --  ZLib.Read
+   --  reading data from the File_In.
+
+   procedure Read is new ZLib.Read
+                           (Read,
+                            Read_Buffer,
+                            Rest_First => Read_First,
+                            Rest_Last  => Read_Last);
+
+   ----------
+   -- Read --
+   ----------
+
+   procedure Read
+     (Item : out Stream_Element_Array;
+      Last : out Stream_Element_Offset) is
+   begin
+      Last := Stream_Element_Offset'Min
+               (Item'Last,
+                Item'First + File_Size - Offset);
+
+      for J in Item'First .. Last loop
+         if J < Item'First + Period then
+            Item (J) := Random_Elements.Random (Gen);
+         else
+            Item (J) := Item (J - Period);
+         end if;
+
+         Offset   := Offset + 1;
+      end loop;
+   end Read;
+
+   -----------
+   -- Reset --
+   -----------
+
+   procedure Reset is
+   begin
+      Random_Elements.Reset (Gen, Init_Random);
+      Pack_Size := 0;
+      Offset := 1;
+      Read_First := Read_Buffer'Last + 1;
+      Read_Last  := Read_Buffer'Last;
+   end Reset;
+
+begin
+   Ada.Text_IO.Put_Line ("ZLib " & ZLib.Version);
+
+   loop
+      for Level in ZLib.Compression_Level'Range loop
+
+         Ada.Text_IO.Put ("Level ="
+            & ZLib.Compression_Level'Image (Level));
+
+         --  Deflate using generic instantiation.
+
+         ZLib.Deflate_Init
+               (Filter,
+                Level,
+                Header => Header);
+
+         Reset;
+
+         Ada.Text_IO.Put
+           (Stream_Element_Offset'Image (File_Size) & " ->");
+
+         loop
+            declare
+               Buffer : Stream_Element_Array (1 .. 1024);
+               Last   : Stream_Element_Offset;
+            begin
+               Read (Filter, Buffer, Last);
+
+               Pack_Size := Pack_Size + Last - Buffer'First + 1;
+
+               exit when Last < Buffer'Last;
+            end;
+         end loop;
+
+         Ada.Text_IO.Put_Line (Stream_Element_Offset'Image (Pack_Size));
+
+         ZLib.Close (Filter);
+      end loop;
+
+      exit when not Continuous;
+
+      File_Size := File_Size + 1;
+   end loop;
+end Read;
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/ada/readme.txt
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/ada/readme.txt	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,65 @@
+                        ZLib for Ada thick binding (ZLib.Ada)
+                        Release 1.3
+
+ZLib.Ada is a thick binding interface to the popular ZLib data
+compression library, available at http://www.gzip.org/zlib/.
+It provides Ada-style access to the ZLib C library.
+
+
+        Here are the main changes since ZLib.Ada 1.2:
+
+- Attension: ZLib.Read generic routine have a initialization requirement
+  for Read_Last parameter now. It is a bit incompartible with previous version,
+  but extends functionality, we could use new parameters Allow_Read_Some and
+  Flush now.
+
+- Added Is_Open routines to ZLib and ZLib.Streams packages.
+
+- Add pragma Assert to check Stream_Element is 8 bit.
+
+- Fix extraction to buffer with exact known decompressed size. Error reported by
+  Steve Sangwine.
+
+- Fix definition of ULong (changed to unsigned_long), fix regression on 64 bits
+  computers. Patch provided by Pascal Obry.
+
+- Add Status_Error exception definition.
+
+- Add pragma Assertion that Ada.Streams.Stream_Element size is 8 bit.
+
+
+        How to build ZLib.Ada under GNAT
+
+You should have the ZLib library already build on your computer, before
+building ZLib.Ada. Make the directory of ZLib.Ada sources current and
+issue the command:
+
+  gnatmake test -largs -L<directory where libz.a is> -lz
+
+Or use the GNAT project file build for GNAT 3.15 or later:
+
+  gnatmake -Pzlib.gpr -L<directory where libz.a is>
+
+
+        How to build ZLib.Ada under Aonix ObjectAda for Win32 7.2.2
+
+1. Make a project with all *.ads and *.adb files from the distribution.
+2. Build the libz.a library from the ZLib C sources.
+3. Rename libz.a to z.lib.
+4. Add the library z.lib to the project.
+5. Add the libc.lib library from the ObjectAda distribution to the project.
+6. Build the executable using test.adb as a main procedure.
+
+
+        How to use ZLib.Ada
+
+The source files test.adb and read.adb are small demo programs that show
+the main functionality of ZLib.Ada.
+
+The routines from the package specifications are commented.
+
+
+Homepage: http://zlib-ada.sourceforge.net/
+Author: Dmitriy Anisimkov <anisimkov@yahoo.com>
+
+Contributors: Pascal Obry <pascal@obry.org>, Steve Sangwine <sjs@essex.ac.uk>
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/ada/test.adb
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/ada/test.adb	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,463 @@
+----------------------------------------------------------------
+--  ZLib for Ada thick binding.                               --
+--                                                            --
+--  Copyright (C) 2002-2003 Dmitriy Anisimkov                 --
+--                                                            --
+--  Open source license information is in the zlib.ads file.  --
+----------------------------------------------------------------
+
+--  $Id: test.adb,v 1.17 2003/08/12 12:13:30 vagul Exp $
+
+--  The program has a few aims.
+--  1. Test ZLib.Ada95 thick binding functionality.
+--  2. Show the example of use main functionality of the ZLib.Ada95 binding.
+--  3. Build this program automatically compile all ZLib.Ada95 packages under
+--     GNAT Ada95 compiler.
+
+with ZLib.Streams;
+with Ada.Streams.Stream_IO;
+with Ada.Numerics.Discrete_Random;
+
+with Ada.Text_IO;
+
+with Ada.Calendar;
+
+procedure Test is
+
+   use Ada.Streams;
+   use Stream_IO;
+
+   ------------------------------------
+   --  Test configuration parameters --
+   ------------------------------------
+
+   File_Size   : Count   := 100_000;
+   Continuous  : constant Boolean := False;
+
+   Header      : constant ZLib.Header_Type := ZLib.Default;
+                                              --  ZLib.None;
+                                              --  ZLib.Auto;
+                                              --  ZLib.GZip;
+   --  Do not use Header other then Default in ZLib versions 1.1.4
+   --  and older.
+
+   Strategy    : constant ZLib.Strategy_Type := ZLib.Default_Strategy;
+   Init_Random : constant := 10;
+
+   -- End --
+
+   In_File_Name  : constant String := "testzlib.in";
+   --  Name of the input file
+
+   Z_File_Name   : constant String := "testzlib.zlb";
+   --  Name of the compressed file.
+
+   Out_File_Name : constant String := "testzlib.out";
+   --  Name of the decompressed file.
+
+   File_In   : File_Type;
+   File_Out  : File_Type;
+   File_Back : File_Type;
+   File_Z    : ZLib.Streams.Stream_Type;
+
+   Filter : ZLib.Filter_Type;
+
+   Time_Stamp : Ada.Calendar.Time;
+
+   procedure Generate_File;
+   --  Generate file of spetsified size with some random data.
+   --  The random data is repeatable, for the good compression.
+
+   procedure Compare_Streams
+     (Left, Right : in out Root_Stream_Type'Class);
+   --  The procedure compearing data in 2 streams.
+   --  It is for compare data before and after compression/decompression.
+
+   procedure Compare_Files (Left, Right : String);
+   --  Compare files. Based on the Compare_Streams.
+
+   procedure Copy_Streams
+     (Source, Target : in out Root_Stream_Type'Class;
+      Buffer_Size    : in     Stream_Element_Offset := 1024);
+   --  Copying data from one stream to another. It is for test stream
+   --  interface of the library.
+
+   procedure Data_In
+     (Item : out Stream_Element_Array;
+      Last : out Stream_Element_Offset);
+   --  this procedure is for generic instantiation of
+   --  ZLib.Generic_Translate.
+   --  reading data from the File_In.
+
+   procedure Data_Out (Item : in Stream_Element_Array);
+   --  this procedure is for generic instantiation of
+   --  ZLib.Generic_Translate.
+   --  writing data to the File_Out.
+
+   procedure Stamp;
+   --  Store the timestamp to the local variable.
+
+   procedure Print_Statistic (Msg : String; Data_Size : ZLib.Count);
+   --  Print the time statistic with the message.
+
+   procedure Translate is new ZLib.Generic_Translate
+                                (Data_In  => Data_In,
+                                 Data_Out => Data_Out);
+   --  This procedure is moving data from File_In to File_Out
+   --  with compression or decompression, depend on initialization of
+   --  Filter parameter.
+
+   -------------------
+   -- Compare_Files --
+   -------------------
+
+   procedure Compare_Files (Left, Right : String) is
+      Left_File, Right_File : File_Type;
+   begin
+      Open (Left_File, In_File, Left);
+      Open (Right_File, In_File, Right);
+      Compare_Streams (Stream (Left_File).all, Stream (Right_File).all);
+      Close (Left_File);
+      Close (Right_File);
+   end Compare_Files;
+
+   ---------------------
+   -- Compare_Streams --
+   ---------------------
+
+   procedure Compare_Streams
+     (Left, Right : in out Ada.Streams.Root_Stream_Type'Class)
+   is
+      Left_Buffer, Right_Buffer : Stream_Element_Array (0 .. 16#FFF#);
+      Left_Last, Right_Last : Stream_Element_Offset;
+   begin
+      loop
+         Read (Left, Left_Buffer, Left_Last);
+         Read (Right, Right_Buffer, Right_Last);
+
+         if Left_Last /= Right_Last then
+            Ada.Text_IO.Put_Line ("Compare error :"
+              & Stream_Element_Offset'Image (Left_Last)
+              & " /= "
+              & Stream_Element_Offset'Image (Right_Last));
+
+            raise Constraint_Error;
+
+         elsif Left_Buffer (0 .. Left_Last)
+               /= Right_Buffer (0 .. Right_Last)
+         then
+            Ada.Text_IO.Put_Line ("ERROR: IN and OUT files is not equal.");
+            raise Constraint_Error;
+
+         end if;
+
+         exit when Left_Last < Left_Buffer'Last;
+      end loop;
+   end Compare_Streams;
+
+   ------------------
+   -- Copy_Streams --
+   ------------------
+
+   procedure Copy_Streams
+     (Source, Target : in out Ada.Streams.Root_Stream_Type'Class;
+      Buffer_Size    : in     Stream_Element_Offset := 1024)
+   is
+      Buffer : Stream_Element_Array (1 .. Buffer_Size);
+      Last   : Stream_Element_Offset;
+   begin
+      loop
+         Read  (Source, Buffer, Last);
+         Write (Target, Buffer (1 .. Last));
+
+         exit when Last < Buffer'Last;
+      end loop;
+   end Copy_Streams;
+
+   -------------
+   -- Data_In --
+   -------------
+
+   procedure Data_In
+     (Item : out Stream_Element_Array;
+      Last : out Stream_Element_Offset) is
+   begin
+      Read (File_In, Item, Last);
+   end Data_In;
+
+   --------------
+   -- Data_Out --
+   --------------
+
+   procedure Data_Out (Item : in Stream_Element_Array) is
+   begin
+      Write (File_Out, Item);
+   end Data_Out;
+
+   -------------------
+   -- Generate_File --
+   -------------------
+
+   procedure Generate_File is
+      subtype Visible_Symbols is Stream_Element range 16#20# .. 16#7E#;
+
+      package Random_Elements is
+         new Ada.Numerics.Discrete_Random (Visible_Symbols);
+
+      Gen    : Random_Elements.Generator;
+      Buffer : Stream_Element_Array := (1 .. 77 => 16#20#) & 10;
+
+      Buffer_Count : constant Count := File_Size / Buffer'Length;
+      --  Number of same buffers in the packet.
+
+      Density : constant Count := 30; --  from 0 to Buffer'Length - 2;
+
+      procedure Fill_Buffer (J, D : in Count);
+      --  Change the part of the buffer.
+
+      -----------------
+      -- Fill_Buffer --
+      -----------------
+
+      procedure Fill_Buffer (J, D : in Count) is
+      begin
+         for K in 0 .. D loop
+            Buffer
+              (Stream_Element_Offset ((J + K) mod (Buffer'Length - 1) + 1))
+             := Random_Elements.Random (Gen);
+
+         end loop;
+      end Fill_Buffer;
+
+   begin
+      Random_Elements.Reset (Gen, Init_Random);
+
+      Create (File_In, Out_File, In_File_Name);
+
+      Fill_Buffer (1, Buffer'Length - 2);
+
+      for J in 1 .. Buffer_Count loop
+         Write (File_In, Buffer);
+
+         Fill_Buffer (J, Density);
+      end loop;
+
+      --  fill remain size.
+
+      Write
+        (File_In,
+         Buffer
+           (1 .. Stream_Element_Offset
+                   (File_Size - Buffer'Length * Buffer_Count)));
+
+      Flush (File_In);
+      Close (File_In);
+   end Generate_File;
+
+   ---------------------
+   -- Print_Statistic --
+   ---------------------
+
+   procedure Print_Statistic (Msg : String; Data_Size : ZLib.Count) is
+      use Ada.Calendar;
+      use Ada.Text_IO;
+
+      package Count_IO is new Integer_IO (ZLib.Count);
+
+      Curr_Dur : Duration := Clock - Time_Stamp;
+   begin
+      Put (Msg);
+
+      Set_Col (20);
+      Ada.Text_IO.Put ("size =");
+
+      Count_IO.Put
+        (Data_Size,
+         Width => Stream_IO.Count'Image (File_Size)'Length);
+
+      Put_Line (" duration =" & Duration'Image (Curr_Dur));
+   end Print_Statistic;
+
+   -----------
+   -- Stamp --
+   -----------
+
+   procedure Stamp is
+   begin
+      Time_Stamp := Ada.Calendar.Clock;
+   end Stamp;
+
+begin
+   Ada.Text_IO.Put_Line ("ZLib " & ZLib.Version);
+
+   loop
+      Generate_File;
+
+      for Level in ZLib.Compression_Level'Range loop
+
+         Ada.Text_IO.Put_Line ("Level ="
+            & ZLib.Compression_Level'Image (Level));
+
+         --  Test generic interface.
+         Open   (File_In, In_File, In_File_Name);
+         Create (File_Out, Out_File, Z_File_Name);
+
+         Stamp;
+
+         --  Deflate using generic instantiation.
+
+         ZLib.Deflate_Init
+               (Filter   => Filter,
+                Level    => Level,
+                Strategy => Strategy,
+                Header   => Header);
+
+         Translate (Filter);
+         Print_Statistic ("Generic compress", ZLib.Total_Out (Filter));
+         ZLib.Close (Filter);
+
+         Close (File_In);
+         Close (File_Out);
+
+         Open   (File_In, In_File, Z_File_Name);
+         Create (File_Out, Out_File, Out_File_Name);
+
+         Stamp;
+
+         --  Inflate using generic instantiation.
+
+         ZLib.Inflate_Init (Filter, Header => Header);
+
+         Translate (Filter);
+         Print_Statistic ("Generic decompress", ZLib.Total_Out (Filter));
+
+         ZLib.Close (Filter);
+
+         Close (File_In);
+         Close (File_Out);
+
+         Compare_Files (In_File_Name, Out_File_Name);
+
+         --  Test stream interface.
+
+         --  Compress to the back stream.
+
+         Open   (File_In, In_File, In_File_Name);
+         Create (File_Back, Out_File, Z_File_Name);
+
+         Stamp;
+
+         ZLib.Streams.Create
+           (Stream          => File_Z,
+            Mode            => ZLib.Streams.Out_Stream,
+            Back            => ZLib.Streams.Stream_Access
+                                 (Stream (File_Back)),
+            Back_Compressed => True,
+            Level           => Level,
+            Strategy        => Strategy,
+            Header          => Header);
+
+         Copy_Streams
+           (Source => Stream (File_In).all,
+            Target => File_Z);
+
+         --  Flushing internal buffers to the back stream.
+
+         ZLib.Streams.Flush (File_Z, ZLib.Finish);
+
+         Print_Statistic ("Write compress",
+                          ZLib.Streams.Write_Total_Out (File_Z));
+
+         ZLib.Streams.Close (File_Z);
+
+         Close (File_In);
+         Close (File_Back);
+
+         --  Compare reading from original file and from
+         --  decompression stream.
+
+         Open (File_In,   In_File, In_File_Name);
+         Open (File_Back, In_File, Z_File_Name);
+
+         ZLib.Streams.Create
+           (Stream          => File_Z,
+            Mode            => ZLib.Streams.In_Stream,
+            Back            => ZLib.Streams.Stream_Access
+                                 (Stream (File_Back)),
+            Back_Compressed => True,
+            Header          => Header);
+
+         Stamp;
+         Compare_Streams (Stream (File_In).all, File_Z);
+
+         Print_Statistic ("Read decompress",
+                          ZLib.Streams.Read_Total_Out (File_Z));
+
+         ZLib.Streams.Close (File_Z);
+         Close (File_In);
+         Close (File_Back);
+
+         --  Compress by reading from compression stream.
+
+         Open (File_Back, In_File, In_File_Name);
+         Create (File_Out, Out_File, Z_File_Name);
+
+         ZLib.Streams.Create
+           (Stream          => File_Z,
+            Mode            => ZLib.Streams.In_Stream,
+            Back            => ZLib.Streams.Stream_Access
+                                 (Stream (File_Back)),
+            Back_Compressed => False,
+            Level           => Level,
+            Strategy        => Strategy,
+            Header          => Header);
+
+         Stamp;
+         Copy_Streams
+           (Source => File_Z,
+            Target => Stream (File_Out).all);
+
+         Print_Statistic ("Read compress",
+                          ZLib.Streams.Read_Total_Out (File_Z));
+
+         ZLib.Streams.Close (File_Z);
+
+         Close (File_Out);
+         Close (File_Back);
+
+         --  Decompress to decompression stream.
+
+         Open   (File_In,   In_File, Z_File_Name);
+         Create (File_Back, Out_File, Out_File_Name);
+
+         ZLib.Streams.Create
+           (Stream          => File_Z,
+            Mode            => ZLib.Streams.Out_Stream,
+            Back            => ZLib.Streams.Stream_Access
+                                 (Stream (File_Back)),
+            Back_Compressed => False,
+            Header          => Header);
+
+         Stamp;
+
+         Copy_Streams
+           (Source => Stream (File_In).all,
+            Target => File_Z);
+
+         Print_Statistic ("Write decompress",
+                          ZLib.Streams.Write_Total_Out (File_Z));
+
+         ZLib.Streams.Close (File_Z);
+         Close (File_In);
+         Close (File_Back);
+
+         Compare_Files (In_File_Name, Out_File_Name);
+      end loop;
+
+      Ada.Text_IO.Put_Line (Count'Image (File_Size) & " Ok.");
+
+      exit when not Continuous;
+
+      File_Size := File_Size + 1;
+   end loop;
+end Test;
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/ada/zlib-streams.adb
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/ada/zlib-streams.adb	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,225 @@
+----------------------------------------------------------------
+--  ZLib for Ada thick binding.                               --
+--                                                            --
+--  Copyright (C) 2002-2003 Dmitriy Anisimkov                 --
+--                                                            --
+--  Open source license information is in the zlib.ads file.  --
+----------------------------------------------------------------
+
+--  $Id: zlib-streams.adb,v 1.10 2004/05/31 10:53:40 vagul Exp $
+
+with Ada.Unchecked_Deallocation;
+
+package body ZLib.Streams is
+
+   -----------
+   -- Close --
+   -----------
+
+   procedure Close (Stream : in out Stream_Type) is
+      procedure Free is new Ada.Unchecked_Deallocation
+         (Stream_Element_Array, Buffer_Access);
+   begin
+      if Stream.Mode = Out_Stream or Stream.Mode = Duplex then
+         --  We should flush the data written by the writer.
+
+         Flush (Stream, Finish);
+
+         Close (Stream.Writer);
+      end if;
+
+      if Stream.Mode = In_Stream or Stream.Mode = Duplex then
+         Close (Stream.Reader);
+         Free (Stream.Buffer);
+      end if;
+   end Close;
+
+   ------------
+   -- Create --
+   ------------
+
+   procedure Create
+     (Stream            :    out Stream_Type;
+      Mode              : in     Stream_Mode;
+      Back              : in     Stream_Access;
+      Back_Compressed   : in     Boolean;
+      Level             : in     Compression_Level := Default_Compression;
+      Strategy          : in     Strategy_Type     := Default_Strategy;
+      Header            : in     Header_Type       := Default;
+      Read_Buffer_Size  : in     Ada.Streams.Stream_Element_Offset
+                                    := Default_Buffer_Size;
+      Write_Buffer_Size : in     Ada.Streams.Stream_Element_Offset
+                                    := Default_Buffer_Size)
+   is
+
+      subtype Buffer_Subtype is Stream_Element_Array (1 .. Read_Buffer_Size);
+
+      procedure Init_Filter
+         (Filter   : in out Filter_Type;
+          Compress : in     Boolean);
+
+      -----------------
+      -- Init_Filter --
+      -----------------
+
+      procedure Init_Filter
+         (Filter   : in out Filter_Type;
+          Compress : in     Boolean) is
+      begin
+         if Compress then
+            Deflate_Init
+              (Filter, Level, Strategy, Header => Header);
+         else
+            Inflate_Init (Filter, Header => Header);
+         end if;
+      end Init_Filter;
+
+   begin
+      Stream.Back := Back;
+      Stream.Mode := Mode;
+
+      if Mode = Out_Stream or Mode = Duplex then
+         Init_Filter (Stream.Writer, Back_Compressed);
+         Stream.Buffer_Size := Write_Buffer_Size;
+      else
+         Stream.Buffer_Size := 0;
+      end if;
+
+      if Mode = In_Stream or Mode = Duplex then
+         Init_Filter (Stream.Reader, not Back_Compressed);
+
+         Stream.Buffer     := new Buffer_Subtype;
+         Stream.Rest_First := Stream.Buffer'Last + 1;
+         Stream.Rest_Last  := Stream.Buffer'Last;
+      end if;
+   end Create;
+
+   -----------
+   -- Flush --
+   -----------
+
+   procedure Flush
+     (Stream : in out Stream_Type;
+      Mode   : in     Flush_Mode := Sync_Flush)
+   is
+      Buffer : Stream_Element_Array (1 .. Stream.Buffer_Size);
+      Last   : Stream_Element_Offset;
+   begin
+      loop
+         Flush (Stream.Writer, Buffer, Last, Mode);
+
+         Ada.Streams.Write (Stream.Back.all, Buffer (1 .. Last));
+
+         exit when Last < Buffer'Last;
+      end loop;
+   end Flush;
+
+   -------------
+   -- Is_Open --
+   -------------
+
+   function Is_Open (Stream : Stream_Type) return Boolean is
+   begin
+      return Is_Open (Stream.Reader) or else Is_Open (Stream.Writer);
+   end Is_Open;
+
+   ----------
+   -- Read --
+   ----------
+
+   procedure Read
+     (Stream : in out Stream_Type;
+      Item   :    out Stream_Element_Array;
+      Last   :    out Stream_Element_Offset)
+   is
+
+      procedure Read
+        (Item : out Stream_Element_Array;
+         Last : out Stream_Element_Offset);
+
+      ----------
+      -- Read --
+      ----------
+
+      procedure Read
+        (Item : out Stream_Element_Array;
+         Last : out Stream_Element_Offset) is
+      begin
+         Ada.Streams.Read (Stream.Back.all, Item, Last);
+      end Read;
+
+      procedure Read is new ZLib.Read
+         (Read       => Read,
+          Buffer     => Stream.Buffer.all,
+          Rest_First => Stream.Rest_First,
+          Rest_Last  => Stream.Rest_Last);
+
+   begin
+      Read (Stream.Reader, Item, Last);
+   end Read;
+
+   -------------------
+   -- Read_Total_In --
+   -------------------
+
+   function Read_Total_In (Stream : in Stream_Type) return Count is
+   begin
+      return Total_In (Stream.Reader);
+   end Read_Total_In;
+
+   --------------------
+   -- Read_Total_Out --
+   --------------------
+
+   function Read_Total_Out (Stream : in Stream_Type) return Count is
+   begin
+      return Total_Out (Stream.Reader);
+   end Read_Total_Out;
+
+   -----------
+   -- Write --
+   -----------
+
+   procedure Write
+     (Stream : in out Stream_Type;
+      Item   : in     Stream_Element_Array)
+   is
+
+      procedure Write (Item : in Stream_Element_Array);
+
+      -----------
+      -- Write --
+      -----------
+
+      procedure Write (Item : in Stream_Element_Array) is
+      begin
+         Ada.Streams.Write (Stream.Back.all, Item);
+      end Write;
+
+      procedure Write is new ZLib.Write
+         (Write       => Write,
+          Buffer_Size => Stream.Buffer_Size);
+
+   begin
+      Write (Stream.Writer, Item, No_Flush);
+   end Write;
+
+   --------------------
+   -- Write_Total_In --
+   --------------------
+
+   function Write_Total_In (Stream : in Stream_Type) return Count is
+   begin
+      return Total_In (Stream.Writer);
+   end Write_Total_In;
+
+   ---------------------
+   -- Write_Total_Out --
+   ---------------------
+
+   function Write_Total_Out (Stream : in Stream_Type) return Count is
+   begin
+      return Total_Out (Stream.Writer);
+   end Write_Total_Out;
+
+end ZLib.Streams;
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/ada/zlib-streams.ads
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/ada/zlib-streams.ads	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,114 @@
+----------------------------------------------------------------
+--  ZLib for Ada thick binding.                               --
+--                                                            --
+--  Copyright (C) 2002-2003 Dmitriy Anisimkov                 --
+--                                                            --
+--  Open source license information is in the zlib.ads file.  --
+----------------------------------------------------------------
+
+--  $Id: zlib-streams.ads,v 1.12 2004/05/31 10:53:40 vagul Exp $
+
+package ZLib.Streams is
+
+   type Stream_Mode is (In_Stream, Out_Stream, Duplex);
+
+   type Stream_Access is access all Ada.Streams.Root_Stream_Type'Class;
+
+   type Stream_Type is
+      new Ada.Streams.Root_Stream_Type with private;
+
+   procedure Read
+     (Stream : in out Stream_Type;
+      Item   :    out Ada.Streams.Stream_Element_Array;
+      Last   :    out Ada.Streams.Stream_Element_Offset);
+
+   procedure Write
+     (Stream : in out Stream_Type;
+      Item   : in     Ada.Streams.Stream_Element_Array);
+
+   procedure Flush
+     (Stream : in out Stream_Type;
+      Mode   : in     Flush_Mode := Sync_Flush);
+   --  Flush the written data to the back stream,
+   --  all data placed to the compressor is flushing to the Back stream.
+   --  Should not be used until necessary, because it is decreasing
+   --  compression.
+
+   function Read_Total_In (Stream : in Stream_Type) return Count;
+   pragma Inline (Read_Total_In);
+   --  Return total number of bytes read from back stream so far.
+
+   function Read_Total_Out (Stream : in Stream_Type) return Count;
+   pragma Inline (Read_Total_Out);
+   --  Return total number of bytes read so far.
+
+   function Write_Total_In (Stream : in Stream_Type) return Count;
+   pragma Inline (Write_Total_In);
+   --  Return total number of bytes written so far.
+
+   function Write_Total_Out (Stream : in Stream_Type) return Count;
+   pragma Inline (Write_Total_Out);
+   --  Return total number of bytes written to the back stream.
+
+   procedure Create
+     (Stream            :    out Stream_Type;
+      Mode              : in     Stream_Mode;
+      Back              : in     Stream_Access;
+      Back_Compressed   : in     Boolean;
+      Level             : in     Compression_Level := Default_Compression;
+      Strategy          : in     Strategy_Type     := Default_Strategy;
+      Header            : in     Header_Type       := Default;
+      Read_Buffer_Size  : in     Ada.Streams.Stream_Element_Offset
+                                    := Default_Buffer_Size;
+      Write_Buffer_Size : in     Ada.Streams.Stream_Element_Offset
+                                    := Default_Buffer_Size);
+   --  Create the Comression/Decompression stream.
+   --  If mode is In_Stream then Write operation is disabled.
+   --  If mode is Out_Stream then Read operation is disabled.
+
+   --  If Back_Compressed is true then
+   --  Data written to the Stream is compressing to the Back stream
+   --  and data read from the Stream is decompressed data from the Back stream.
+
+   --  If Back_Compressed is false then
+   --  Data written to the Stream is decompressing to the Back stream
+   --  and data read from the Stream is compressed data from the Back stream.
+
+   --  !!! When the Need_Header is False ZLib-Ada is using undocumented
+   --  ZLib 1.1.4 functionality to do not create/wait for ZLib headers.
+
+   function Is_Open (Stream : Stream_Type) return Boolean;
+
+   procedure Close (Stream : in out Stream_Type);
+
+private
+
+   use Ada.Streams;
+
+   type Buffer_Access is access all Stream_Element_Array;
+
+   type Stream_Type
+     is new Root_Stream_Type with
+   record
+      Mode       : Stream_Mode;
+
+      Buffer     : Buffer_Access;
+      Rest_First : Stream_Element_Offset;
+      Rest_Last  : Stream_Element_Offset;
+      --  Buffer for Read operation.
+      --  We need to have this buffer in the record
+      --  because not all read data from back stream
+      --  could be processed during the read operation.
+
+      Buffer_Size : Stream_Element_Offset;
+      --  Buffer size for write operation.
+      --  We do not need to have this buffer
+      --  in the record because all data could be
+      --  processed in the write operation.
+
+      Back       : Stream_Access;
+      Reader     : Filter_Type;
+      Writer     : Filter_Type;
+   end record;
+
+end ZLib.Streams;
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/ada/zlib-thin.adb
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/ada/zlib-thin.adb	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,141 @@
+----------------------------------------------------------------
+--  ZLib for Ada thick binding.                               --
+--                                                            --
+--  Copyright (C) 2002-2003 Dmitriy Anisimkov                 --
+--                                                            --
+--  Open source license information is in the zlib.ads file.  --
+----------------------------------------------------------------
+
+--  $Id: zlib-thin.adb,v 1.8 2003/12/14 18:27:31 vagul Exp $
+
+package body ZLib.Thin is
+
+   ZLIB_VERSION  : constant Chars_Ptr := zlibVersion;
+
+   Z_Stream_Size : constant Int := Z_Stream'Size / System.Storage_Unit;
+
+   --------------
+   -- Avail_In --
+   --------------
+
+   function Avail_In (Strm : in Z_Stream) return UInt is
+   begin
+      return Strm.Avail_In;
+   end Avail_In;
+
+   ---------------
+   -- Avail_Out --
+   ---------------
+
+   function Avail_Out (Strm : in Z_Stream) return UInt is
+   begin
+      return Strm.Avail_Out;
+   end Avail_Out;
+
+   ------------------
+   -- Deflate_Init --
+   ------------------
+
+   function Deflate_Init
+     (strm       : Z_Streamp;
+      level      : Int;
+      method     : Int;
+      windowBits : Int;
+      memLevel   : Int;
+      strategy   : Int)
+      return       Int is
+   begin
+      return deflateInit2
+               (strm,
+                level,
+                method,
+                windowBits,
+                memLevel,
+                strategy,
+                ZLIB_VERSION,
+                Z_Stream_Size);
+   end Deflate_Init;
+
+   ------------------
+   -- Inflate_Init --
+   ------------------
+
+   function Inflate_Init (strm : Z_Streamp; windowBits : Int) return Int is
+   begin
+      return inflateInit2 (strm, windowBits, ZLIB_VERSION, Z_Stream_Size);
+   end Inflate_Init;
+
+   ------------------------
+   -- Last_Error_Message --
+   ------------------------
+
+   function Last_Error_Message (Strm : in Z_Stream) return String is
+      use Interfaces.C.Strings;
+   begin
+      if Strm.msg = Null_Ptr then
+         return "";
+      else
+         return Value (Strm.msg);
+      end if;
+   end Last_Error_Message;
+
+   ------------
+   -- Set_In --
+   ------------
+
+   procedure Set_In
+     (Strm   : in out Z_Stream;
+      Buffer : in     Voidp;
+      Size   : in     UInt) is
+   begin
+      Strm.Next_In  := Buffer;
+      Strm.Avail_In := Size;
+   end Set_In;
+
+   ------------------
+   -- Set_Mem_Func --
+   ------------------
+
+   procedure Set_Mem_Func
+     (Strm   : in out Z_Stream;
+      Opaque : in     Voidp;
+      Alloc  : in     alloc_func;
+      Free   : in     free_func) is
+   begin
+      Strm.opaque := Opaque;
+      Strm.zalloc := Alloc;
+      Strm.zfree  := Free;
+   end Set_Mem_Func;
+
+   -------------
+   -- Set_Out --
+   -------------
+
+   procedure Set_Out
+     (Strm   : in out Z_Stream;
+      Buffer : in     Voidp;
+      Size   : in     UInt) is
+   begin
+      Strm.Next_Out  := Buffer;
+      Strm.Avail_Out := Size;
+   end Set_Out;
+
+   --------------
+   -- Total_In --
+   --------------
+
+   function Total_In (Strm : in Z_Stream) return ULong is
+   begin
+      return Strm.Total_In;
+   end Total_In;
+
+   ---------------
+   -- Total_Out --
+   ---------------
+
+   function Total_Out (Strm : in Z_Stream) return ULong is
+   begin
+      return Strm.Total_Out;
+   end Total_Out;
+
+end ZLib.Thin;
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/ada/zlib-thin.ads
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/ada/zlib-thin.ads	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,450 @@
+----------------------------------------------------------------
+--  ZLib for Ada thick binding.                               --
+--                                                            --
+--  Copyright (C) 2002-2003 Dmitriy Anisimkov                 --
+--                                                            --
+--  Open source license information is in the zlib.ads file.  --
+----------------------------------------------------------------
+
+--  $Id: zlib-thin.ads,v 1.11 2004/07/23 06:33:11 vagul Exp $
+
+with Interfaces.C.Strings;
+
+with System;
+
+private package ZLib.Thin is
+
+   --  From zconf.h
+
+   MAX_MEM_LEVEL : constant := 9;         --  zconf.h:105
+                                          --  zconf.h:105
+   MAX_WBITS : constant := 15;      --  zconf.h:115
+                                    --  32K LZ77 window
+                                    --  zconf.h:115
+   SEEK_SET : constant := 8#0000#;  --  zconf.h:244
+                                    --  Seek from beginning of file.
+                                    --  zconf.h:244
+   SEEK_CUR : constant := 1;        --  zconf.h:245
+                                    --  Seek from current position.
+                                    --  zconf.h:245
+   SEEK_END : constant := 2;        --  zconf.h:246
+                                    --  Set file pointer to EOF plus "offset"
+                                    --  zconf.h:246
+
+   type Byte is new Interfaces.C.unsigned_char; --  8 bits
+                                                --  zconf.h:214
+   type UInt is new Interfaces.C.unsigned;      --  16 bits or more
+                                                --  zconf.h:216
+   type Int is new Interfaces.C.int;
+
+   type ULong is new Interfaces.C.unsigned_long;     --  32 bits or more
+                                                     --  zconf.h:217
+   subtype Chars_Ptr is Interfaces.C.Strings.chars_ptr;
+
+   type ULong_Access is access ULong;
+   type Int_Access is access Int;
+
+   subtype Voidp is System.Address;            --  zconf.h:232
+
+   subtype Byte_Access is Voidp;
+
+   Nul : constant Voidp := System.Null_Address;
+   --  end from zconf
+
+   Z_NO_FLUSH : constant := 8#0000#;   --  zlib.h:125
+                                       --  zlib.h:125
+   Z_PARTIAL_FLUSH : constant := 1;       --  zlib.h:126
+                                          --  will be removed, use
+                                          --  Z_SYNC_FLUSH instead
+                                          --  zlib.h:126
+   Z_SYNC_FLUSH : constant := 2;       --  zlib.h:127
+                                       --  zlib.h:127
+   Z_FULL_FLUSH : constant := 3;       --  zlib.h:128
+                                       --  zlib.h:128
+   Z_FINISH : constant := 4;        --  zlib.h:129
+                                    --  zlib.h:129
+   Z_OK : constant := 8#0000#;   --  zlib.h:132
+                                 --  zlib.h:132
+   Z_STREAM_END : constant := 1;       --  zlib.h:133
+                                       --  zlib.h:133
+   Z_NEED_DICT : constant := 2;        --  zlib.h:134
+                                       --  zlib.h:134
+   Z_ERRNO : constant := -1;        --  zlib.h:135
+                                    --  zlib.h:135
+   Z_STREAM_ERROR : constant := -2;       --  zlib.h:136
+                                          --  zlib.h:136
+   Z_DATA_ERROR : constant := -3;      --  zlib.h:137
+                                       --  zlib.h:137
+   Z_MEM_ERROR : constant := -4;       --  zlib.h:138
+                                       --  zlib.h:138
+   Z_BUF_ERROR : constant := -5;       --  zlib.h:139
+                                       --  zlib.h:139
+   Z_VERSION_ERROR : constant := -6;      --  zlib.h:140
+                                          --  zlib.h:140
+   Z_NO_COMPRESSION : constant := 8#0000#;   --  zlib.h:145
+                                             --  zlib.h:145
+   Z_BEST_SPEED : constant := 1;       --  zlib.h:146
+                                       --  zlib.h:146
+   Z_BEST_COMPRESSION : constant := 9;       --  zlib.h:147
+                                             --  zlib.h:147
+   Z_DEFAULT_COMPRESSION : constant := -1;      --  zlib.h:148
+                                                --  zlib.h:148
+   Z_FILTERED : constant := 1;      --  zlib.h:151
+                                    --  zlib.h:151
+   Z_HUFFMAN_ONLY : constant := 2;        --  zlib.h:152
+                                          --  zlib.h:152
+   Z_DEFAULT_STRATEGY : constant := 8#0000#; --  zlib.h:153
+                                             --  zlib.h:153
+   Z_BINARY : constant := 8#0000#;  --  zlib.h:156
+                                    --  zlib.h:156
+   Z_ASCII : constant := 1;      --  zlib.h:157
+                                 --  zlib.h:157
+   Z_UNKNOWN : constant := 2;       --  zlib.h:158
+                                    --  zlib.h:158
+   Z_DEFLATED : constant := 8;      --  zlib.h:161
+                                    --  zlib.h:161
+   Z_NULL : constant := 8#0000#; --  zlib.h:164
+                                 --  for initializing zalloc, zfree, opaque
+                                 --  zlib.h:164
+   type gzFile is new Voidp;                  --  zlib.h:646
+
+   type Z_Stream is private;
+
+   type Z_Streamp is access all Z_Stream;     --  zlib.h:89
+
+   type alloc_func is access function
+     (Opaque : Voidp;
+      Items  : UInt;
+      Size   : UInt)
+      return Voidp; --  zlib.h:63
+
+   type free_func is access procedure (opaque : Voidp; address : Voidp);
+
+   function zlibVersion return Chars_Ptr;
+
+   function Deflate (strm : Z_Streamp; flush : Int) return Int;
+
+   function DeflateEnd (strm : Z_Streamp) return Int;
+
+   function Inflate (strm : Z_Streamp; flush : Int) return Int;
+
+   function InflateEnd (strm : Z_Streamp) return Int;
+
+   function deflateSetDictionary
+     (strm       : Z_Streamp;
+      dictionary : Byte_Access;
+      dictLength : UInt)
+      return       Int;
+
+   function deflateCopy (dest : Z_Streamp; source : Z_Streamp) return Int;
+   --  zlib.h:478
+
+   function deflateReset (strm : Z_Streamp) return Int; -- zlib.h:495
+
+   function deflateParams
+     (strm     : Z_Streamp;
+      level    : Int;
+      strategy : Int)
+      return     Int;       -- zlib.h:506
+
+   function inflateSetDictionary
+     (strm       : Z_Streamp;
+      dictionary : Byte_Access;
+      dictLength : UInt)
+      return       Int; --  zlib.h:548
+
+   function inflateSync (strm : Z_Streamp) return Int;  --  zlib.h:565
+
+   function inflateReset (strm : Z_Streamp) return Int; --  zlib.h:580
+
+   function compress
+     (dest      : Byte_Access;
+      destLen   : ULong_Access;
+      source    : Byte_Access;
+      sourceLen : ULong)
+      return      Int;           -- zlib.h:601
+
+   function compress2
+     (dest      : Byte_Access;
+      destLen   : ULong_Access;
+      source    : Byte_Access;
+      sourceLen : ULong;
+      level     : Int)
+      return      Int;          -- zlib.h:615
+
+   function uncompress
+     (dest      : Byte_Access;
+      destLen   : ULong_Access;
+      source    : Byte_Access;
+      sourceLen : ULong)
+      return      Int;
+
+   function gzopen (path : Chars_Ptr; mode : Chars_Ptr) return gzFile;
+
+   function gzdopen (fd : Int; mode : Chars_Ptr) return gzFile;
+
+   function gzsetparams
+     (file     : gzFile;
+      level    : Int;
+      strategy : Int)
+      return     Int;
+
+   function gzread
+     (file : gzFile;
+      buf  : Voidp;
+      len  : UInt)
+      return Int;
+
+   function gzwrite
+     (file : in gzFile;
+      buf  : in Voidp;
+      len  : in UInt)
+      return Int;
+
+   function gzprintf (file : in gzFile; format : in Chars_Ptr) return Int;
+
+   function gzputs (file : in gzFile; s : in Chars_Ptr) return Int;
+
+   function gzgets
+     (file : gzFile;
+      buf  : Chars_Ptr;
+      len  : Int)
+      return Chars_Ptr;
+
+   function gzputc (file : gzFile; char : Int) return Int;
+
+   function gzgetc (file : gzFile) return Int;
+
+   function gzflush (file : gzFile; flush : Int) return Int;
+
+   function gzseek
+     (file   : gzFile;
+      offset : Int;
+      whence : Int)
+      return   Int;
+
+   function gzrewind (file : gzFile) return Int;
+
+   function gztell (file : gzFile) return Int;
+
+   function gzeof (file : gzFile) return Int;
+
+   function gzclose (file : gzFile) return Int;
+
+   function gzerror (file : gzFile; errnum : Int_Access) return Chars_Ptr;
+
+   function adler32
+     (adler : ULong;
+      buf   : Byte_Access;
+      len   : UInt)
+      return  ULong;
+
+   function crc32
+     (crc  : ULong;
+      buf  : Byte_Access;
+      len  : UInt)
+      return ULong;
+
+   function deflateInit
+     (strm        : Z_Streamp;
+      level       : Int;
+      version     : Chars_Ptr;
+      stream_size : Int)
+      return        Int;
+
+   function deflateInit2
+     (strm        : Z_Streamp;
+      level       : Int;
+      method      : Int;
+      windowBits  : Int;
+      memLevel    : Int;
+      strategy    : Int;
+      version     : Chars_Ptr;
+      stream_size : Int)
+      return        Int;
+
+   function Deflate_Init
+     (strm       : Z_Streamp;
+      level      : Int;
+      method     : Int;
+      windowBits : Int;
+      memLevel   : Int;
+      strategy   : Int)
+      return       Int;
+   pragma Inline (Deflate_Init);
+
+   function inflateInit
+     (strm        : Z_Streamp;
+      version     : Chars_Ptr;
+      stream_size : Int)
+      return        Int;
+
+   function inflateInit2
+     (strm        : in Z_Streamp;
+      windowBits  : in Int;
+      version     : in Chars_Ptr;
+      stream_size : in Int)
+      return      Int;
+
+   function inflateBackInit
+     (strm        : in Z_Streamp;
+      windowBits  : in Int;
+      window      : in Byte_Access;
+      version     : in Chars_Ptr;
+      stream_size : in Int)
+      return      Int;
+   --  Size of window have to be 2**windowBits.
+
+   function Inflate_Init (strm : Z_Streamp; windowBits : Int) return Int;
+   pragma Inline (Inflate_Init);
+
+   function zError (err : Int) return Chars_Ptr;
+
+   function inflateSyncPoint (z : Z_Streamp) return Int;
+
+   function get_crc_table return ULong_Access;
+
+   --  Interface to the available fields of the z_stream structure.
+   --  The application must update next_in and avail_in when avail_in has
+   --  dropped to zero. It must update next_out and avail_out when avail_out
+   --  has dropped to zero. The application must initialize zalloc, zfree and
+   --  opaque before calling the init function.
+
+   procedure Set_In
+     (Strm   : in out Z_Stream;
+      Buffer : in Voidp;
+      Size   : in UInt);
+   pragma Inline (Set_In);
+
+   procedure Set_Out
+     (Strm   : in out Z_Stream;
+      Buffer : in Voidp;
+      Size   : in UInt);
+   pragma Inline (Set_Out);
+
+   procedure Set_Mem_Func
+     (Strm   : in out Z_Stream;
+      Opaque : in Voidp;
+      Alloc  : in alloc_func;
+      Free   : in free_func);
+   pragma Inline (Set_Mem_Func);
+
+   function Last_Error_Message (Strm : in Z_Stream) return String;
+   pragma Inline (Last_Error_Message);
+
+   function Avail_Out (Strm : in Z_Stream) return UInt;
+   pragma Inline (Avail_Out);
+
+   function Avail_In (Strm : in Z_Stream) return UInt;
+   pragma Inline (Avail_In);
+
+   function Total_In (Strm : in Z_Stream) return ULong;
+   pragma Inline (Total_In);
+
+   function Total_Out (Strm : in Z_Stream) return ULong;
+   pragma Inline (Total_Out);
+
+   function inflateCopy
+     (dest   : in Z_Streamp;
+      Source : in Z_Streamp)
+      return Int;
+
+   function compressBound (Source_Len : in ULong) return ULong;
+
+   function deflateBound
+     (Strm       : in Z_Streamp;
+      Source_Len : in ULong)
+      return     ULong;
+
+   function gzungetc (C : in Int; File : in  gzFile) return Int;
+
+   function zlibCompileFlags return ULong;
+
+private
+
+   type Z_Stream is record            -- zlib.h:68
+      Next_In   : Voidp      := Nul;  -- next input byte
+      Avail_In  : UInt       := 0;    -- number of bytes available at next_in
+      Total_In  : ULong      := 0;    -- total nb of input bytes read so far
+      Next_Out  : Voidp      := Nul;  -- next output byte should be put there
+      Avail_Out : UInt       := 0;    -- remaining free space at next_out
+      Total_Out : ULong      := 0;    -- total nb of bytes output so far
+      msg       : Chars_Ptr;          -- last error message, NULL if no error
+      state     : Voidp;              -- not visible by applications
+      zalloc    : alloc_func := null; -- used to allocate the internal state
+      zfree     : free_func  := null; -- used to free the internal state
+      opaque    : Voidp;              -- private data object passed to
+                                      --  zalloc and zfree
+      data_type : Int;                -- best guess about the data type:
+                                      --  ascii or binary
+      adler     : ULong;              -- adler32 value of the uncompressed
+                                      --  data
+      reserved  : ULong;              -- reserved for future use
+   end record;
+
+   pragma Convention (C, Z_Stream);
+
+   pragma Import (C, zlibVersion, "zlibVersion");
+   pragma Import (C, Deflate, "deflate");
+   pragma Import (C, DeflateEnd, "deflateEnd");
+   pragma Import (C, Inflate, "inflate");
+   pragma Import (C, InflateEnd, "inflateEnd");
+   pragma Import (C, deflateSetDictionary, "deflateSetDictionary");
+   pragma Import (C, deflateCopy, "deflateCopy");
+   pragma Import (C, deflateReset, "deflateReset");
+   pragma Import (C, deflateParams, "deflateParams");
+   pragma Import (C, inflateSetDictionary, "inflateSetDictionary");
+   pragma Import (C, inflateSync, "inflateSync");
+   pragma Import (C, inflateReset, "inflateReset");
+   pragma Import (C, compress, "compress");
+   pragma Import (C, compress2, "compress2");
+   pragma Import (C, uncompress, "uncompress");
+   pragma Import (C, gzopen, "gzopen");
+   pragma Import (C, gzdopen, "gzdopen");
+   pragma Import (C, gzsetparams, "gzsetparams");
+   pragma Import (C, gzread, "gzread");
+   pragma Import (C, gzwrite, "gzwrite");
+   pragma Import (C, gzprintf, "gzprintf");
+   pragma Import (C, gzputs, "gzputs");
+   pragma Import (C, gzgets, "gzgets");
+   pragma Import (C, gzputc, "gzputc");
+   pragma Import (C, gzgetc, "gzgetc");
+   pragma Import (C, gzflush, "gzflush");
+   pragma Import (C, gzseek, "gzseek");
+   pragma Import (C, gzrewind, "gzrewind");
+   pragma Import (C, gztell, "gztell");
+   pragma Import (C, gzeof, "gzeof");
+   pragma Import (C, gzclose, "gzclose");
+   pragma Import (C, gzerror, "gzerror");
+   pragma Import (C, adler32, "adler32");
+   pragma Import (C, crc32, "crc32");
+   pragma Import (C, deflateInit, "deflateInit_");
+   pragma Import (C, inflateInit, "inflateInit_");
+   pragma Import (C, deflateInit2, "deflateInit2_");
+   pragma Import (C, inflateInit2, "inflateInit2_");
+   pragma Import (C, zError, "zError");
+   pragma Import (C, inflateSyncPoint, "inflateSyncPoint");
+   pragma Import (C, get_crc_table, "get_crc_table");
+
+   --  since zlib 1.2.0:
+
+   pragma Import (C, inflateCopy, "inflateCopy");
+   pragma Import (C, compressBound, "compressBound");
+   pragma Import (C, deflateBound, "deflateBound");
+   pragma Import (C, gzungetc, "gzungetc");
+   pragma Import (C, zlibCompileFlags, "zlibCompileFlags");
+
+   pragma Import (C, inflateBackInit, "inflateBackInit_");
+
+   --  I stopped binding the inflateBack routines, because realize that
+   --  it does not support zlib and gzip headers for now, and have no
+   --  symmetric deflateBack routines.
+   --  ZLib-Ada is symmetric regarding deflate/inflate data transformation
+   --  and has a similar generic callback interface for the
+   --  deflate/inflate transformation based on the regular Deflate/Inflate
+   --  routines.
+
+   --  pragma Import (C, inflateBack, "inflateBack");
+   --  pragma Import (C, inflateBackEnd, "inflateBackEnd");
+
+end ZLib.Thin;
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/ada/zlib.adb
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/ada/zlib.adb	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,701 @@
+----------------------------------------------------------------
+--  ZLib for Ada thick binding.                               --
+--                                                            --
+--  Copyright (C) 2002-2004 Dmitriy Anisimkov                 --
+--                                                            --
+--  Open source license information is in the zlib.ads file.  --
+----------------------------------------------------------------
+
+--  $Id: zlib.adb,v 1.31 2004/09/06 06:53:19 vagul Exp $
+
+with Ada.Exceptions;
+with Ada.Unchecked_Conversion;
+with Ada.Unchecked_Deallocation;
+
+with Interfaces.C.Strings;
+
+with ZLib.Thin;
+
+package body ZLib is
+
+   use type Thin.Int;
+
+   type Z_Stream is new Thin.Z_Stream;
+
+   type Return_Code_Enum is
+      (OK,
+       STREAM_END,
+       NEED_DICT,
+       ERRNO,
+       STREAM_ERROR,
+       DATA_ERROR,
+       MEM_ERROR,
+       BUF_ERROR,
+       VERSION_ERROR);
+
+   type Flate_Step_Function is access
+     function (Strm : in Thin.Z_Streamp; Flush : in Thin.Int) return Thin.Int;
+   pragma Convention (C, Flate_Step_Function);
+
+   type Flate_End_Function is access
+      function (Ctrm : in Thin.Z_Streamp) return Thin.Int;
+   pragma Convention (C, Flate_End_Function);
+
+   type Flate_Type is record
+      Step : Flate_Step_Function;
+      Done : Flate_End_Function;
+   end record;
+
+   subtype Footer_Array is Stream_Element_Array (1 .. 8);
+
+   Simple_GZip_Header : constant Stream_Element_Array (1 .. 10)
+     := (16#1f#, 16#8b#,                 --  Magic header
+         16#08#,                         --  Z_DEFLATED
+         16#00#,                         --  Flags
+         16#00#, 16#00#, 16#00#, 16#00#, --  Time
+         16#00#,                         --  XFlags
+         16#03#                          --  OS code
+        );
+   --  The simplest gzip header is not for informational, but just for
+   --  gzip format compatibility.
+   --  Note that some code below is using assumption
+   --  Simple_GZip_Header'Last > Footer_Array'Last, so do not make
+   --  Simple_GZip_Header'Last <= Footer_Array'Last.
+
+   Return_Code : constant array (Thin.Int range <>) of Return_Code_Enum
+     := (0 => OK,
+         1 => STREAM_END,
+         2 => NEED_DICT,
+        -1 => ERRNO,
+        -2 => STREAM_ERROR,
+        -3 => DATA_ERROR,
+        -4 => MEM_ERROR,
+        -5 => BUF_ERROR,
+        -6 => VERSION_ERROR);
+
+   Flate : constant array (Boolean) of Flate_Type
+     := (True  => (Step => Thin.Deflate'Access,
+                   Done => Thin.DeflateEnd'Access),
+         False => (Step => Thin.Inflate'Access,
+                   Done => Thin.InflateEnd'Access));
+
+   Flush_Finish : constant array (Boolean) of Flush_Mode
+     := (True => Finish, False => No_Flush);
+
+   procedure Raise_Error (Stream : in Z_Stream);
+   pragma Inline (Raise_Error);
+
+   procedure Raise_Error (Message : in String);
+   pragma Inline (Raise_Error);
+
+   procedure Check_Error (Stream : in Z_Stream; Code : in Thin.Int);
+
+   procedure Free is new Ada.Unchecked_Deallocation
+      (Z_Stream, Z_Stream_Access);
+
+   function To_Thin_Access is new Ada.Unchecked_Conversion
+     (Z_Stream_Access, Thin.Z_Streamp);
+
+   procedure Translate_GZip
+     (Filter    : in out Filter_Type;
+      In_Data   : in     Ada.Streams.Stream_Element_Array;
+      In_Last   :    out Ada.Streams.Stream_Element_Offset;
+      Out_Data  :    out Ada.Streams.Stream_Element_Array;
+      Out_Last  :    out Ada.Streams.Stream_Element_Offset;
+      Flush     : in     Flush_Mode);
+   --  Separate translate routine for make gzip header.
+
+   procedure Translate_Auto
+     (Filter    : in out Filter_Type;
+      In_Data   : in     Ada.Streams.Stream_Element_Array;
+      In_Last   :    out Ada.Streams.Stream_Element_Offset;
+      Out_Data  :    out Ada.Streams.Stream_Element_Array;
+      Out_Last  :    out Ada.Streams.Stream_Element_Offset;
+      Flush     : in     Flush_Mode);
+   --  translate routine without additional headers.
+
+   -----------------
+   -- Check_Error --
+   -----------------
+
+   procedure Check_Error (Stream : in Z_Stream; Code : in Thin.Int) is
+      use type Thin.Int;
+   begin
+      if Code /= Thin.Z_OK then
+         Raise_Error
+            (Return_Code_Enum'Image (Return_Code (Code))
+              & ": " & Last_Error_Message (Stream));
+      end if;
+   end Check_Error;
+
+   -----------
+   -- Close --
+   -----------
+
+   procedure Close
+     (Filter       : in out Filter_Type;
+      Ignore_Error : in     Boolean := False)
+   is
+      Code : Thin.Int;
+   begin
+      if not Ignore_Error and then not Is_Open (Filter) then
+         raise Status_Error;
+      end if;
+
+      Code := Flate (Filter.Compression).Done (To_Thin_Access (Filter.Strm));
+
+      if Ignore_Error or else Code = Thin.Z_OK then
+         Free (Filter.Strm);
+      else
+         declare
+            Error_Message : constant String
+              := Last_Error_Message (Filter.Strm.all);
+         begin
+            Free (Filter.Strm);
+            Ada.Exceptions.Raise_Exception
+               (ZLib_Error'Identity,
+                Return_Code_Enum'Image (Return_Code (Code))
+                  & ": " & Error_Message);
+         end;
+      end if;
+   end Close;
+
+   -----------
+   -- CRC32 --
+   -----------
+
+   function CRC32
+     (CRC  : in Unsigned_32;
+      Data : in Ada.Streams.Stream_Element_Array)
+      return Unsigned_32
+   is
+      use Thin;
+   begin
+      return Unsigned_32 (crc32 (ULong (CRC),
+                                 Data'Address,
+                                 Data'Length));
+   end CRC32;
+
+   procedure CRC32
+     (CRC  : in out Unsigned_32;
+      Data : in     Ada.Streams.Stream_Element_Array) is
+   begin
+      CRC := CRC32 (CRC, Data);
+   end CRC32;
+
+   ------------------
+   -- Deflate_Init --
+   ------------------
+
+   procedure Deflate_Init
+     (Filter       : in out Filter_Type;
+      Level        : in     Compression_Level  := Default_Compression;
+      Strategy     : in     Strategy_Type      := Default_Strategy;
+      Method       : in     Compression_Method := Deflated;
+      Window_Bits  : in     Window_Bits_Type   := Default_Window_Bits;
+      Memory_Level : in     Memory_Level_Type  := Default_Memory_Level;
+      Header       : in     Header_Type        := Default)
+   is
+      use type Thin.Int;
+      Win_Bits : Thin.Int := Thin.Int (Window_Bits);
+   begin
+      if Is_Open (Filter) then
+         raise Status_Error;
+      end if;
+
+      --  We allow ZLib to make header only in case of default header type.
+      --  Otherwise we would either do header by ourselfs, or do not do
+      --  header at all.
+
+      if Header = None or else Header = GZip then
+         Win_Bits := -Win_Bits;
+      end if;
+
+      --  For the GZip CRC calculation and make headers.
+
+      if Header = GZip then
+         Filter.CRC    := 0;
+         Filter.Offset := Simple_GZip_Header'First;
+      else
+         Filter.Offset := Simple_GZip_Header'Last + 1;
+      end if;
+
+      Filter.Strm        := new Z_Stream;
+      Filter.Compression := True;
+      Filter.Stream_End  := False;
+      Filter.Header      := Header;
+
+      if Thin.Deflate_Init
+           (To_Thin_Access (Filter.Strm),
+            Level      => Thin.Int (Level),
+            method     => Thin.Int (Method),
+            windowBits => Win_Bits,
+            memLevel   => Thin.Int (Memory_Level),
+            strategy   => Thin.Int (Strategy)) /= Thin.Z_OK
+      then
+         Raise_Error (Filter.Strm.all);
+      end if;
+   end Deflate_Init;
+
+   -----------
+   -- Flush --
+   -----------
+
+   procedure Flush
+     (Filter    : in out Filter_Type;
+      Out_Data  :    out Ada.Streams.Stream_Element_Array;
+      Out_Last  :    out Ada.Streams.Stream_Element_Offset;
+      Flush     : in     Flush_Mode)
+   is
+      No_Data : Stream_Element_Array := (1 .. 0 => 0);
+      Last    : Stream_Element_Offset;
+   begin
+      Translate (Filter, No_Data, Last, Out_Data, Out_Last, Flush);
+   end Flush;
+
+   -----------------------
+   -- Generic_Translate --
+   -----------------------
+
+   procedure Generic_Translate
+     (Filter          : in out ZLib.Filter_Type;
+      In_Buffer_Size  : in     Integer := Default_Buffer_Size;
+      Out_Buffer_Size : in     Integer := Default_Buffer_Size)
+   is
+      In_Buffer  : Stream_Element_Array
+                     (1 .. Stream_Element_Offset (In_Buffer_Size));
+      Out_Buffer : Stream_Element_Array
+                     (1 .. Stream_Element_Offset (Out_Buffer_Size));
+      Last       : Stream_Element_Offset;
+      In_Last    : Stream_Element_Offset;
+      In_First   : Stream_Element_Offset;
+      Out_Last   : Stream_Element_Offset;
+   begin
+      Main : loop
+         Data_In (In_Buffer, Last);
+
+         In_First := In_Buffer'First;
+
+         loop
+            Translate
+              (Filter   => Filter,
+               In_Data  => In_Buffer (In_First .. Last),
+               In_Last  => In_Last,
+               Out_Data => Out_Buffer,
+               Out_Last => Out_Last,
+               Flush    => Flush_Finish (Last < In_Buffer'First));
+
+            if Out_Buffer'First <= Out_Last then
+               Data_Out (Out_Buffer (Out_Buffer'First .. Out_Last));
+            end if;
+
+            exit Main when Stream_End (Filter);
+
+            --  The end of in buffer.
+
+            exit when In_Last = Last;
+
+            In_First := In_Last + 1;
+         end loop;
+      end loop Main;
+
+   end Generic_Translate;
+
+   ------------------
+   -- Inflate_Init --
+   ------------------
+
+   procedure Inflate_Init
+     (Filter      : in out Filter_Type;
+      Window_Bits : in     Window_Bits_Type := Default_Window_Bits;
+      Header      : in     Header_Type      := Default)
+   is
+      use type Thin.Int;
+      Win_Bits : Thin.Int := Thin.Int (Window_Bits);
+
+      procedure Check_Version;
+      --  Check the latest header types compatibility.
+
+      procedure Check_Version is
+      begin
+         if Version <= "1.1.4" then
+            Raise_Error
+              ("Inflate header type " & Header_Type'Image (Header)
+               & " incompatible with ZLib version " & Version);
+         end if;
+      end Check_Version;
+
+   begin
+      if Is_Open (Filter) then
+         raise Status_Error;
+      end if;
+
+      case Header is
+         when None =>
+            Check_Version;
+
+            --  Inflate data without headers determined
+            --  by negative Win_Bits.
+
+            Win_Bits := -Win_Bits;
+         when GZip =>
+            Check_Version;
+
+            --  Inflate gzip data defined by flag 16.
+
+            Win_Bits := Win_Bits + 16;
+         when Auto =>
+            Check_Version;
+
+            --  Inflate with automatic detection
+            --  of gzip or native header defined by flag 32.
+
+            Win_Bits := Win_Bits + 32;
+         when Default => null;
+      end case;
+
+      Filter.Strm        := new Z_Stream;
+      Filter.Compression := False;
+      Filter.Stream_End  := False;
+      Filter.Header      := Header;
+
+      if Thin.Inflate_Init
+         (To_Thin_Access (Filter.Strm), Win_Bits) /= Thin.Z_OK
+      then
+         Raise_Error (Filter.Strm.all);
+      end if;
+   end Inflate_Init;
+
+   -------------
+   -- Is_Open --
+   -------------
+
+   function Is_Open (Filter : in Filter_Type) return Boolean is
+   begin
+      return Filter.Strm /= null;
+   end Is_Open;
+
+   -----------------
+   -- Raise_Error --
+   -----------------
+
+   procedure Raise_Error (Message : in String) is
+   begin
+      Ada.Exceptions.Raise_Exception (ZLib_Error'Identity, Message);
+   end Raise_Error;
+
+   procedure Raise_Error (Stream : in Z_Stream) is
+   begin
+      Raise_Error (Last_Error_Message (Stream));
+   end Raise_Error;
+
+   ----------
+   -- Read --
+   ----------
+
+   procedure Read
+     (Filter : in out Filter_Type;
+      Item   :    out Ada.Streams.Stream_Element_Array;
+      Last   :    out Ada.Streams.Stream_Element_Offset;
+      Flush  : in     Flush_Mode := No_Flush)
+   is
+      In_Last    : Stream_Element_Offset;
+      Item_First : Ada.Streams.Stream_Element_Offset := Item'First;
+      V_Flush    : Flush_Mode := Flush;
+
+   begin
+      pragma Assert (Rest_First in Buffer'First .. Buffer'Last + 1);
+      pragma Assert (Rest_Last in Buffer'First - 1 .. Buffer'Last);
+
+      loop
+         if Rest_Last = Buffer'First - 1 then
+            V_Flush := Finish;
+
+         elsif Rest_First > Rest_Last then
+            Read (Buffer, Rest_Last);
+            Rest_First := Buffer'First;
+
+            if Rest_Last < Buffer'First then
+               V_Flush := Finish;
+            end if;
+         end if;
+
+         Translate
+           (Filter   => Filter,
+            In_Data  => Buffer (Rest_First .. Rest_Last),
+            In_Last  => In_Last,
+            Out_Data => Item (Item_First .. Item'Last),
+            Out_Last => Last,
+            Flush    => V_Flush);
+
+         Rest_First := In_Last + 1;
+
+         exit when Stream_End (Filter)
+           or else Last = Item'Last
+           or else (Last >= Item'First and then Allow_Read_Some);
+
+         Item_First := Last + 1;
+      end loop;
+   end Read;
+
+   ----------------
+   -- Stream_End --
+   ----------------
+
+   function Stream_End (Filter : in Filter_Type) return Boolean is
+   begin
+      if Filter.Header = GZip and Filter.Compression then
+         return Filter.Stream_End
+            and then Filter.Offset = Footer_Array'Last + 1;
+      else
+         return Filter.Stream_End;
+      end if;
+   end Stream_End;
+
+   --------------
+   -- Total_In --
+   --------------
+
+   function Total_In (Filter : in Filter_Type) return Count is
+   begin
+      return Count (Thin.Total_In (To_Thin_Access (Filter.Strm).all));
+   end Total_In;
+
+   ---------------
+   -- Total_Out --
+   ---------------
+
+   function Total_Out (Filter : in Filter_Type) return Count is
+   begin
+      return Count (Thin.Total_Out (To_Thin_Access (Filter.Strm).all));
+   end Total_Out;
+
+   ---------------
+   -- Translate --
+   ---------------
+
+   procedure Translate
+     (Filter    : in out Filter_Type;
+      In_Data   : in     Ada.Streams.Stream_Element_Array;
+      In_Last   :    out Ada.Streams.Stream_Element_Offset;
+      Out_Data  :    out Ada.Streams.Stream_Element_Array;
+      Out_Last  :    out Ada.Streams.Stream_Element_Offset;
+      Flush     : in     Flush_Mode) is
+   begin
+      if Filter.Header = GZip and then Filter.Compression then
+         Translate_GZip
+           (Filter   => Filter,
+            In_Data  => In_Data,
+            In_Last  => In_Last,
+            Out_Data => Out_Data,
+            Out_Last => Out_Last,
+            Flush    => Flush);
+      else
+         Translate_Auto
+           (Filter   => Filter,
+            In_Data  => In_Data,
+            In_Last  => In_Last,
+            Out_Data => Out_Data,
+            Out_Last => Out_Last,
+            Flush    => Flush);
+      end if;
+   end Translate;
+
+   --------------------
+   -- Translate_Auto --
+   --------------------
+
+   procedure Translate_Auto
+     (Filter    : in out Filter_Type;
+      In_Data   : in     Ada.Streams.Stream_Element_Array;
+      In_Last   :    out Ada.Streams.Stream_Element_Offset;
+      Out_Data  :    out Ada.Streams.Stream_Element_Array;
+      Out_Last  :    out Ada.Streams.Stream_Element_Offset;
+      Flush     : in     Flush_Mode)
+   is
+      use type Thin.Int;
+      Code : Thin.Int;
+
+   begin
+      if not Is_Open (Filter) then
+         raise Status_Error;
+      end if;
+
+      if Out_Data'Length = 0 and then In_Data'Length = 0 then
+         raise Constraint_Error;
+      end if;
+
+      Set_Out (Filter.Strm.all, Out_Data'Address, Out_Data'Length);
+      Set_In  (Filter.Strm.all, In_Data'Address, In_Data'Length);
+
+      Code := Flate (Filter.Compression).Step
+        (To_Thin_Access (Filter.Strm),
+         Thin.Int (Flush));
+
+      if Code = Thin.Z_STREAM_END then
+         Filter.Stream_End := True;
+      else
+         Check_Error (Filter.Strm.all, Code);
+      end if;
+
+      In_Last  := In_Data'Last
+         - Stream_Element_Offset (Avail_In (Filter.Strm.all));
+      Out_Last := Out_Data'Last
+         - Stream_Element_Offset (Avail_Out (Filter.Strm.all));
+   end Translate_Auto;
+
+   --------------------
+   -- Translate_GZip --
+   --------------------
+
+   procedure Translate_GZip
+     (Filter    : in out Filter_Type;
+      In_Data   : in     Ada.Streams.Stream_Element_Array;
+      In_Last   :    out Ada.Streams.Stream_Element_Offset;
+      Out_Data  :    out Ada.Streams.Stream_Element_Array;
+      Out_Last  :    out Ada.Streams.Stream_Element_Offset;
+      Flush     : in     Flush_Mode)
+   is
+      Out_First : Stream_Element_Offset;
+
+      procedure Add_Data (Data : in Stream_Element_Array);
+      --  Add data to stream from the Filter.Offset till necessary,
+      --  used for add gzip headr/footer.
+
+      procedure Put_32
+        (Item : in out Stream_Element_Array;
+         Data : in     Unsigned_32);
+      pragma Inline (Put_32);
+
+      --------------
+      -- Add_Data --
+      --------------
+
+      procedure Add_Data (Data : in Stream_Element_Array) is
+         Data_First : Stream_Element_Offset renames Filter.Offset;
+         Data_Last  : Stream_Element_Offset;
+         Data_Len   : Stream_Element_Offset; --  -1
+         Out_Len    : Stream_Element_Offset; --  -1
+      begin
+         Out_First := Out_Last + 1;
+
+         if Data_First > Data'Last then
+            return;
+         end if;
+
+         Data_Len  := Data'Last     - Data_First;
+         Out_Len   := Out_Data'Last - Out_First;
+
+         if Data_Len <= Out_Len then
+            Out_Last  := Out_First  + Data_Len;
+            Data_Last := Data'Last;
+         else
+            Out_Last  := Out_Data'Last;
+            Data_Last := Data_First + Out_Len;
+         end if;
+
+         Out_Data (Out_First .. Out_Last) := Data (Data_First .. Data_Last);
+
+         Data_First := Data_Last + 1;
+         Out_First  := Out_Last + 1;
+      end Add_Data;
+
+      ------------
+      -- Put_32 --
+      ------------
+
+      procedure Put_32
+        (Item : in out Stream_Element_Array;
+         Data : in     Unsigned_32)
+      is
+         D : Unsigned_32 := Data;
+      begin
+         for J in Item'First .. Item'First + 3 loop
+            Item (J) := Stream_Element (D and 16#FF#);
+            D := Shift_Right (D, 8);
+         end loop;
+      end Put_32;
+
+   begin
+      Out_Last := Out_Data'First - 1;
+
+      if not Filter.Stream_End then
+         Add_Data (Simple_GZip_Header);
+
+         Translate_Auto
+           (Filter   => Filter,
+            In_Data  => In_Data,
+            In_Last  => In_Last,
+            Out_Data => Out_Data (Out_First .. Out_Data'Last),
+            Out_Last => Out_Last,
+            Flush    => Flush);
+
+         CRC32 (Filter.CRC, In_Data (In_Data'First .. In_Last));
+      end if;
+
+      if Filter.Stream_End and then Out_Last <= Out_Data'Last then
+         --  This detection method would work only when
+         --  Simple_GZip_Header'Last > Footer_Array'Last
+
+         if Filter.Offset = Simple_GZip_Header'Last + 1 then
+            Filter.Offset := Footer_Array'First;
+         end if;
+
+         declare
+            Footer : Footer_Array;
+         begin
+            Put_32 (Footer, Filter.CRC);
+            Put_32 (Footer (Footer'First + 4 .. Footer'Last),
+                    Unsigned_32 (Total_In (Filter)));
+            Add_Data (Footer);
+         end;
+      end if;
+   end Translate_GZip;
+
+   -------------
+   -- Version --
+   -------------
+
+   function Version return String is
+   begin
+      return Interfaces.C.Strings.Value (Thin.zlibVersion);
+   end Version;
+
+   -----------
+   -- Write --
+   -----------
+
+   procedure Write
+     (Filter : in out Filter_Type;
+      Item   : in     Ada.Streams.Stream_Element_Array;
+      Flush  : in     Flush_Mode := No_Flush)
+   is
+      Buffer   : Stream_Element_Array (1 .. Buffer_Size);
+      In_Last  : Stream_Element_Offset;
+      Out_Last : Stream_Element_Offset;
+      In_First : Stream_Element_Offset := Item'First;
+   begin
+      if Item'Length = 0 and Flush = No_Flush then
+         return;
+      end if;
+
+      loop
+         Translate
+           (Filter   => Filter,
+            In_Data  => Item (In_First .. Item'Last),
+            In_Last  => In_Last,
+            Out_Data => Buffer,
+            Out_Last => Out_Last,
+            Flush    => Flush);
+
+         if Out_Last >= Buffer'First then
+            Write (Buffer (1 .. Out_Last));
+         end if;
+
+         exit when In_Last = Item'Last or Stream_End (Filter);
+
+         In_First := In_Last + 1;
+      end loop;
+   end Write;
+
+end ZLib;
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/ada/zlib.ads
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/ada/zlib.ads	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,328 @@
+------------------------------------------------------------------------------
+--                      ZLib for Ada thick binding.                         --
+--                                                                          --
+--              Copyright (C) 2002-2004 Dmitriy Anisimkov                   --
+--                                                                          --
+--  This library is free software; you can redistribute it and/or modify    --
+--  it under the terms of the GNU General Public License as published by    --
+--  the Free Software Foundation; either version 2 of the License, or (at   --
+--  your option) any later version.                                         --
+--                                                                          --
+--  This library is distributed in the hope that it will be useful, but     --
+--  WITHOUT ANY WARRANTY; without even the implied warranty of              --
+--  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU       --
+--  General Public License for more details.                                --
+--                                                                          --
+--  You should have received a copy of the GNU General Public License       --
+--  along with this library; if not, write to the Free Software Foundation, --
+--  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.          --
+--                                                                          --
+--  As a special exception, if other files instantiate generics from this   --
+--  unit, or you link this unit with other files to produce an executable,  --
+--  this  unit  does not  by itself cause  the resulting executable to be   --
+--  covered by the GNU General Public License. This exception does not      --
+--  however invalidate any other reasons why the executable file  might be  --
+--  covered by the  GNU Public License.                                     --
+------------------------------------------------------------------------------
+
+--  $Id: zlib.ads,v 1.26 2004/09/06 06:53:19 vagul Exp $
+
+with Ada.Streams;
+
+with Interfaces;
+
+package ZLib is
+
+   ZLib_Error   : exception;
+   Status_Error : exception;
+
+   type Compression_Level is new Integer range -1 .. 9;
+
+   type Flush_Mode is private;
+
+   type Compression_Method is private;
+
+   type Window_Bits_Type is new Integer range 8 .. 15;
+
+   type Memory_Level_Type is new Integer range 1 .. 9;
+
+   type Unsigned_32 is new Interfaces.Unsigned_32;
+
+   type Strategy_Type is private;
+
+   type Header_Type is (None, Auto, Default, GZip);
+   --  Header type usage have a some limitation for inflate.
+   --  See comment for Inflate_Init.
+
+   subtype Count is Ada.Streams.Stream_Element_Count;
+
+   Default_Memory_Level : constant Memory_Level_Type := 8;
+   Default_Window_Bits  : constant Window_Bits_Type  := 15;
+
+   ----------------------------------
+   -- Compression method constants --
+   ----------------------------------
+
+   Deflated : constant Compression_Method;
+   --  Only one method allowed in this ZLib version
+
+   ---------------------------------
+   -- Compression level constants --
+   ---------------------------------
+
+   No_Compression      : constant Compression_Level := 0;
+   Best_Speed          : constant Compression_Level := 1;
+   Best_Compression    : constant Compression_Level := 9;
+   Default_Compression : constant Compression_Level := -1;
+
+   --------------------------
+   -- Flush mode constants --
+   --------------------------
+
+   No_Flush      : constant Flush_Mode;
+   --  Regular way for compression, no flush
+
+   Partial_Flush : constant Flush_Mode;
+   --  Will be removed, use Z_SYNC_FLUSH instead
+
+   Sync_Flush    : constant Flush_Mode;
+   --  All pending output is flushed to the output buffer and the output
+   --  is aligned on a byte boundary, so that the decompressor can get all
+   --  input data available so far. (In particular avail_in is zero after the
+   --  call if enough output space has been provided  before the call.)
+   --  Flushing may degrade compression for some compression algorithms and so
+   --  it should be used only when necessary.
+
+   Block_Flush   : constant Flush_Mode;
+   --  Z_BLOCK requests that inflate() stop
+   --  if and when it get to the next deflate block boundary. When decoding the
+   --  zlib or gzip format, this will cause inflate() to return immediately
+   --  after the header and before the first block. When doing a raw inflate,
+   --  inflate() will go ahead and process the first block, and will return
+   --  when it gets to the end of that block, or when it runs out of data.
+
+   Full_Flush    : constant Flush_Mode;
+   --  All output is flushed as with SYNC_FLUSH, and the compression state
+   --  is reset so that decompression can restart from this point if previous
+   --  compressed data has been damaged or if random access is desired. Using
+   --  Full_Flush too often can seriously degrade the compression.
+
+   Finish        : constant Flush_Mode;
+   --  Just for tell the compressor that input data is complete.
+
+   ------------------------------------
+   -- Compression strategy constants --
+   ------------------------------------
+
+   --  RLE stategy could be used only in version 1.2.0 and later.
+
+   Filtered         : constant Strategy_Type;
+   Huffman_Only     : constant Strategy_Type;
+   RLE              : constant Strategy_Type;
+   Default_Strategy : constant Strategy_Type;
+
+   Default_Buffer_Size : constant := 4096;
+
+   type Filter_Type is tagged limited private;
+   --  The filter is for compression and for decompression.
+   --  The usage of the type is depend of its initialization.
+
+   function Version return String;
+   pragma Inline (Version);
+   --  Return string representation of the ZLib version.
+
+   procedure Deflate_Init
+     (Filter       : in out Filter_Type;
+      Level        : in     Compression_Level  := Default_Compression;
+      Strategy     : in     Strategy_Type      := Default_Strategy;
+      Method       : in     Compression_Method := Deflated;
+      Window_Bits  : in     Window_Bits_Type   := Default_Window_Bits;
+      Memory_Level : in     Memory_Level_Type  := Default_Memory_Level;
+      Header       : in     Header_Type        := Default);
+   --  Compressor initialization.
+   --  When Header parameter is Auto or Default, then default zlib header
+   --  would be provided for compressed data.
+   --  When Header is GZip, then gzip header would be set instead of
+   --  default header.
+   --  When Header is None, no header would be set for compressed data.
+
+   procedure Inflate_Init
+     (Filter      : in out Filter_Type;
+      Window_Bits : in     Window_Bits_Type := Default_Window_Bits;
+      Header      : in     Header_Type      := Default);
+   --  Decompressor initialization.
+   --  Default header type mean that ZLib default header is expecting in the
+   --  input compressed stream.
+   --  Header type None mean that no header is expecting in the input stream.
+   --  GZip header type mean that GZip header is expecting in the
+   --  input compressed stream.
+   --  Auto header type mean that header type (GZip or Native) would be
+   --  detected automatically in the input stream.
+   --  Note that header types parameter values None, GZip and Auto are
+   --  supported for inflate routine only in ZLib versions 1.2.0.2 and later.
+   --  Deflate_Init is supporting all header types.
+
+   function Is_Open (Filter : in Filter_Type) return Boolean;
+   pragma Inline (Is_Open);
+   --  Is the filter opened for compression or decompression.
+
+   procedure Close
+     (Filter       : in out Filter_Type;
+      Ignore_Error : in     Boolean := False);
+   --  Closing the compression or decompressor.
+   --  If stream is closing before the complete and Ignore_Error is False,
+   --  The exception would be raised.
+
+   generic
+      with procedure Data_In
+        (Item : out Ada.Streams.Stream_Element_Array;
+         Last : out Ada.Streams.Stream_Element_Offset);
+      with procedure Data_Out
+        (Item : in Ada.Streams.Stream_Element_Array);
+   procedure Generic_Translate
+     (Filter          : in out Filter_Type;
+      In_Buffer_Size  : in     Integer := Default_Buffer_Size;
+      Out_Buffer_Size : in     Integer := Default_Buffer_Size);
+   --  Compress/decompress data fetch from Data_In routine and pass the result
+   --  to the Data_Out routine. User should provide Data_In and Data_Out
+   --  for compression/decompression data flow.
+   --  Compression or decompression depend on Filter initialization.
+
+   function Total_In (Filter : in Filter_Type) return Count;
+   pragma Inline (Total_In);
+   --  Returns total number of input bytes read so far
+
+   function Total_Out (Filter : in Filter_Type) return Count;
+   pragma Inline (Total_Out);
+   --  Returns total number of bytes output so far
+
+   function CRC32
+     (CRC    : in Unsigned_32;
+      Data   : in Ada.Streams.Stream_Element_Array)
+      return Unsigned_32;
+   pragma Inline (CRC32);
+   --  Compute CRC32, it could be necessary for make gzip format
+
+   procedure CRC32
+     (CRC  : in out Unsigned_32;
+      Data : in     Ada.Streams.Stream_Element_Array);
+   pragma Inline (CRC32);
+   --  Compute CRC32, it could be necessary for make gzip format
+
+   -------------------------------------------------
+   --  Below is more complex low level routines.  --
+   -------------------------------------------------
+
+   procedure Translate
+     (Filter    : in out Filter_Type;
+      In_Data   : in     Ada.Streams.Stream_Element_Array;
+      In_Last   :    out Ada.Streams.Stream_Element_Offset;
+      Out_Data  :    out Ada.Streams.Stream_Element_Array;
+      Out_Last  :    out Ada.Streams.Stream_Element_Offset;
+      Flush     : in     Flush_Mode);
+   --  Compress/decompress the In_Data buffer and place the result into
+   --  Out_Data. In_Last is the index of last element from In_Data accepted by
+   --  the Filter. Out_Last is the last element of the received data from
+   --  Filter. To tell the filter that incoming data are complete put the
+   --  Flush parameter to Finish.
+
+   function Stream_End (Filter : in Filter_Type) return Boolean;
+   pragma Inline (Stream_End);
+   --  Return the true when the stream is complete.
+
+   procedure Flush
+     (Filter    : in out Filter_Type;
+      Out_Data  :    out Ada.Streams.Stream_Element_Array;
+      Out_Last  :    out Ada.Streams.Stream_Element_Offset;
+      Flush     : in     Flush_Mode);
+   pragma Inline (Flush);
+   --  Flushing the data from the compressor.
+
+   generic
+      with procedure Write
+        (Item : in Ada.Streams.Stream_Element_Array);
+      --  User should provide this routine for accept
+      --  compressed/decompressed data.
+
+      Buffer_Size : in Ada.Streams.Stream_Element_Offset
+         := Default_Buffer_Size;
+      --  Buffer size for Write user routine.
+
+   procedure Write
+     (Filter  : in out Filter_Type;
+      Item    : in     Ada.Streams.Stream_Element_Array;
+      Flush   : in     Flush_Mode := No_Flush);
+   --  Compress/Decompress data from Item to the generic parameter procedure
+   --  Write. Output buffer size could be set in Buffer_Size generic parameter.
+
+   generic
+      with procedure Read
+        (Item : out Ada.Streams.Stream_Element_Array;
+         Last : out Ada.Streams.Stream_Element_Offset);
+      --  User should provide data for compression/decompression
+      --  thru this routine.
+
+      Buffer : in out Ada.Streams.Stream_Element_Array;
+      --  Buffer for keep remaining data from the previous
+      --  back read.
+
+      Rest_First, Rest_Last : in out Ada.Streams.Stream_Element_Offset;
+      --  Rest_First have to be initialized to Buffer'Last + 1
+      --  Rest_Last have to be initialized to Buffer'Last
+      --  before usage.
+
+      Allow_Read_Some : in Boolean := False;
+      --  Is it allowed to return Last < Item'Last before end of data.
+
+   procedure Read
+     (Filter : in out Filter_Type;
+      Item   :    out Ada.Streams.Stream_Element_Array;
+      Last   :    out Ada.Streams.Stream_Element_Offset;
+      Flush  : in     Flush_Mode := No_Flush);
+   --  Compress/Decompress data from generic parameter procedure Read to the
+   --  Item. User should provide Buffer and initialized Rest_First, Rest_Last
+   --  indicators. If Allow_Read_Some is True, Read routines could return
+   --  Last < Item'Last only at end of stream.
+
+private
+
+   use Ada.Streams;
+
+   pragma Assert (Ada.Streams.Stream_Element'Size    =    8);
+   pragma Assert (Ada.Streams.Stream_Element'Modulus = 2**8);
+
+   type Flush_Mode is new Integer range 0 .. 5;
+
+   type Compression_Method is new Integer range 8 .. 8;
+
+   type Strategy_Type is new Integer range 0 .. 3;
+
+   No_Flush      : constant Flush_Mode := 0;
+   Partial_Flush : constant Flush_Mode := 1;
+   Sync_Flush    : constant Flush_Mode := 2;
+   Full_Flush    : constant Flush_Mode := 3;
+   Finish        : constant Flush_Mode := 4;
+   Block_Flush   : constant Flush_Mode := 5;
+
+   Filtered         : constant Strategy_Type := 1;
+   Huffman_Only     : constant Strategy_Type := 2;
+   RLE              : constant Strategy_Type := 3;
+   Default_Strategy : constant Strategy_Type := 0;
+
+   Deflated : constant Compression_Method := 8;
+
+   type Z_Stream;
+
+   type Z_Stream_Access is access all Z_Stream;
+
+   type Filter_Type is tagged limited record
+      Strm        : Z_Stream_Access;
+      Compression : Boolean;
+      Stream_End  : Boolean;
+      Header      : Header_Type;
+      CRC         : Unsigned_32;
+      Offset      : Stream_Element_Offset;
+      --  Offset for gzip header/footer output.
+   end record;
+
+end ZLib;
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/ada/zlib.gpr
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/ada/zlib.gpr	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,20 @@
+project Zlib is
+
+   for Languages use ("Ada");
+   for Source_Dirs use (".");
+   for Object_Dir use ".";
+   for Main use ("test.adb", "mtest.adb", "read.adb", "buffer_demo");
+
+   package Compiler is
+      for Default_Switches ("ada") use ("-gnatwcfilopru", "-gnatVcdfimorst", "-gnatyabcefhiklmnoprst");
+   end Compiler;
+
+   package Linker is
+      for Default_Switches ("ada") use ("-lz");
+   end Linker;
+
+   package Builder is
+      for Default_Switches ("ada") use ("-s", "-gnatQ");
+   end Builder;
+
+end Zlib;
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/amd64/amd64-match.S
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/amd64/amd64-match.S	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,452 @@
+/*
+ * match.S -- optimized version of longest_match()
+ * based on the similar work by Gilles Vollant, and Brian Raiter, written 1998
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the BSD License. Use by owners of Che Guevarra
+ * parafernalia is prohibited, where possible, and highly discouraged
+ * elsewhere.
+ */
+
+#ifndef NO_UNDERLINE
+#	define	match_init	_match_init
+#	define	longest_match	_longest_match
+#endif
+
+#define	scanend		ebx
+#define	scanendw	bx
+#define	chainlenwmask	edx /* high word: current chain len low word: s->wmask */
+#define	curmatch	rsi
+#define	curmatchd	esi
+#define	windowbestlen	r8
+#define	scanalign	r9
+#define	scanalignd	r9d
+#define	window		r10
+#define	bestlen		r11
+#define	bestlend	r11d
+#define	scanstart	r12d
+#define	scanstartw	r12w
+#define scan		r13
+#define nicematch	r14d
+#define	limit		r15
+#define	limitd		r15d
+#define prev		rcx
+
+/*
+ * The 258 is a "magic number, not a parameter -- changing it
+ * breaks the hell loose
+ */
+#define	MAX_MATCH	(258)
+#define	MIN_MATCH	(3)
+#define	MIN_LOOKAHEAD	(MAX_MATCH + MIN_MATCH + 1)
+#define	MAX_MATCH_8	((MAX_MATCH + 7) & ~7)
+
+/* stack frame offsets */
+#define	LocalVarsSize	(112)
+#define _chainlenwmask	( 8-LocalVarsSize)(%rsp)
+#define _windowbestlen	(16-LocalVarsSize)(%rsp)
+#define save_r14        (24-LocalVarsSize)(%rsp)
+#define save_rsi        (32-LocalVarsSize)(%rsp)
+#define save_rbx        (40-LocalVarsSize)(%rsp)
+#define save_r12        (56-LocalVarsSize)(%rsp)
+#define save_r13        (64-LocalVarsSize)(%rsp)
+#define save_r15        (80-LocalVarsSize)(%rsp)
+
+
+.globl	match_init, longest_match
+
+/*
+ * On AMD64 the first argument of a function (in our case -- the pointer to
+ * deflate_state structure) is passed in %rdi, hence our offsets below are
+ * all off of that.
+ */
+
+/* you can check the structure offset by running
+
+#include <stdlib.h>
+#include <stdio.h>
+#include "deflate.h"
+
+void print_depl()
+{
+deflate_state ds;
+deflate_state *s=&ds;
+printf("size pointer=%u\n",(int)sizeof(void*));
+
+printf("#define dsWSize         (%3u)(%%rdi)\n",(int)(((char*)&(s->w_size))-((char*)s)));
+printf("#define dsWMask         (%3u)(%%rdi)\n",(int)(((char*)&(s->w_mask))-((char*)s)));
+printf("#define dsWindow        (%3u)(%%rdi)\n",(int)(((char*)&(s->window))-((char*)s)));
+printf("#define dsPrev          (%3u)(%%rdi)\n",(int)(((char*)&(s->prev))-((char*)s)));
+printf("#define dsMatchLen      (%3u)(%%rdi)\n",(int)(((char*)&(s->match_length))-((char*)s)));
+printf("#define dsPrevMatch     (%3u)(%%rdi)\n",(int)(((char*)&(s->prev_match))-((char*)s)));
+printf("#define dsStrStart      (%3u)(%%rdi)\n",(int)(((char*)&(s->strstart))-((char*)s)));
+printf("#define dsMatchStart    (%3u)(%%rdi)\n",(int)(((char*)&(s->match_start))-((char*)s)));
+printf("#define dsLookahead     (%3u)(%%rdi)\n",(int)(((char*)&(s->lookahead))-((char*)s)));
+printf("#define dsPrevLen       (%3u)(%%rdi)\n",(int)(((char*)&(s->prev_length))-((char*)s)));
+printf("#define dsMaxChainLen   (%3u)(%%rdi)\n",(int)(((char*)&(s->max_chain_length))-((char*)s)));
+printf("#define dsGoodMatch     (%3u)(%%rdi)\n",(int)(((char*)&(s->good_match))-((char*)s)));
+printf("#define dsNiceMatch     (%3u)(%%rdi)\n",(int)(((char*)&(s->nice_match))-((char*)s)));
+}
+
+*/
+
+
+/*
+  to compile for XCode 3.2 on MacOSX x86_64
+  - run "gcc -g -c -DXCODE_MAC_X64_STRUCTURE amd64-match.S"
+ */
+
+
+#ifndef CURRENT_LINX_XCODE_MAC_X64_STRUCTURE
+#define dsWSize		( 68)(%rdi)
+#define dsWMask		( 76)(%rdi)
+#define dsWindow	( 80)(%rdi)
+#define dsPrev		( 96)(%rdi)
+#define dsMatchLen	(144)(%rdi)
+#define dsPrevMatch	(148)(%rdi)
+#define dsStrStart	(156)(%rdi)
+#define dsMatchStart	(160)(%rdi)
+#define dsLookahead	(164)(%rdi)
+#define dsPrevLen	(168)(%rdi)
+#define dsMaxChainLen	(172)(%rdi)
+#define dsGoodMatch	(188)(%rdi)
+#define dsNiceMatch	(192)(%rdi)
+
+#else 
+
+#ifndef STRUCT_OFFSET
+#	define STRUCT_OFFSET	(0)
+#endif
+
+
+#define dsWSize		( 56 + STRUCT_OFFSET)(%rdi)
+#define dsWMask		( 64 + STRUCT_OFFSET)(%rdi)
+#define dsWindow	( 72 + STRUCT_OFFSET)(%rdi)
+#define dsPrev		( 88 + STRUCT_OFFSET)(%rdi)
+#define dsMatchLen	(136 + STRUCT_OFFSET)(%rdi)
+#define dsPrevMatch	(140 + STRUCT_OFFSET)(%rdi)
+#define dsStrStart	(148 + STRUCT_OFFSET)(%rdi)
+#define dsMatchStart	(152 + STRUCT_OFFSET)(%rdi)
+#define dsLookahead	(156 + STRUCT_OFFSET)(%rdi)
+#define dsPrevLen	(160 + STRUCT_OFFSET)(%rdi)
+#define dsMaxChainLen	(164 + STRUCT_OFFSET)(%rdi)
+#define dsGoodMatch	(180 + STRUCT_OFFSET)(%rdi)
+#define dsNiceMatch	(184 + STRUCT_OFFSET)(%rdi)
+
+#endif
+
+
+
+
+.text
+
+/* uInt longest_match(deflate_state *deflatestate, IPos curmatch) */
+
+longest_match:
+/*
+ * Retrieve the function arguments. %curmatch will hold cur_match
+ * throughout the entire function (passed via rsi on amd64).
+ * rdi will hold the pointer to the deflate_state (first arg on amd64)
+ */
+		mov     %rsi, save_rsi
+		mov     %rbx, save_rbx
+		mov	%r12, save_r12
+		mov     %r13, save_r13
+		mov     %r14, save_r14
+		mov     %r15, save_r15
+
+/* uInt wmask = s->w_mask;						*/
+/* unsigned chain_length = s->max_chain_length;				*/
+/* if (s->prev_length >= s->good_match) {				*/
+/*     chain_length >>= 2;						*/
+/* }									*/
+
+		movl	dsPrevLen, %eax
+		movl	dsGoodMatch, %ebx
+		cmpl	%ebx, %eax
+		movl	dsWMask, %eax
+		movl	dsMaxChainLen, %chainlenwmask
+		jl	LastMatchGood
+		shrl	$2, %chainlenwmask
+LastMatchGood:
+
+/* chainlen is decremented once beforehand so that the function can	*/
+/* use the sign flag instead of the zero flag for the exit test.	*/
+/* It is then shifted into the high word, to make room for the wmask	*/
+/* value, which it will always accompany.				*/
+
+		decl	%chainlenwmask
+		shll	$16, %chainlenwmask
+		orl	%eax, %chainlenwmask
+
+/* if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;	*/
+
+		movl	dsNiceMatch, %eax
+		movl	dsLookahead, %ebx
+		cmpl	%eax, %ebx
+		jl	LookaheadLess
+		movl	%eax, %ebx
+LookaheadLess:	movl	%ebx, %nicematch
+
+/* register Bytef *scan = s->window + s->strstart;			*/
+
+		mov	dsWindow, %window
+		movl	dsStrStart, %limitd
+		lea	(%limit, %window), %scan
+
+/* Determine how many bytes the scan ptr is off from being		*/
+/* dword-aligned.							*/
+
+		mov	%scan, %scanalign
+		negl	%scanalignd
+		andl	$3, %scanalignd
+
+/* IPos limit = s->strstart > (IPos)MAX_DIST(s) ?			*/
+/*     s->strstart - (IPos)MAX_DIST(s) : NIL;				*/
+
+		movl	dsWSize, %eax
+		subl	$MIN_LOOKAHEAD, %eax
+		xorl	%ecx, %ecx
+		subl	%eax, %limitd
+		cmovng	%ecx, %limitd
+
+/* int best_len = s->prev_length;					*/
+
+		movl	dsPrevLen, %bestlend
+
+/* Store the sum of s->window + best_len in %windowbestlen locally, and in memory.	*/
+
+		lea	(%window, %bestlen), %windowbestlen
+		mov	%windowbestlen, _windowbestlen
+
+/* register ush scan_start = *(ushf*)scan;				*/
+/* register ush scan_end   = *(ushf*)(scan+best_len-1);			*/
+/* Posf *prev = s->prev;						*/
+
+		movzwl	(%scan), %scanstart
+		movzwl	-1(%scan, %bestlen), %scanend
+		mov	dsPrev, %prev
+
+/* Jump into the main loop.						*/
+
+		movl	%chainlenwmask, _chainlenwmask
+		jmp	LoopEntry
+
+.balign 16
+
+/* do {
+ *     match = s->window + cur_match;
+ *     if (*(ushf*)(match+best_len-1) != scan_end ||
+ *         *(ushf*)match != scan_start) continue;
+ *     [...]
+ * } while ((cur_match = prev[cur_match & wmask]) > limit
+ *          && --chain_length != 0);
+ *
+ * Here is the inner loop of the function. The function will spend the
+ * majority of its time in this loop, and majority of that time will
+ * be spent in the first ten instructions.
+ */
+LookupLoop:
+		andl	%chainlenwmask, %curmatchd
+		movzwl	(%prev, %curmatch, 2), %curmatchd
+		cmpl	%limitd, %curmatchd
+		jbe	LeaveNow
+		subl	$0x00010000, %chainlenwmask
+		js	LeaveNow
+LoopEntry:	cmpw	-1(%windowbestlen, %curmatch), %scanendw
+		jne	LookupLoop
+		cmpw	%scanstartw, (%window, %curmatch)
+		jne	LookupLoop
+
+/* Store the current value of chainlen.					*/
+		movl	%chainlenwmask, _chainlenwmask
+
+/* %scan is the string under scrutiny, and %prev to the string we	*/
+/* are hoping to match it up with. In actuality, %esi and %edi are	*/
+/* both pointed (MAX_MATCH_8 - scanalign) bytes ahead, and %edx is	*/
+/* initialized to -(MAX_MATCH_8 - scanalign).				*/
+
+		mov	$(-MAX_MATCH_8), %rdx
+		lea	(%curmatch, %window), %windowbestlen
+		lea	MAX_MATCH_8(%windowbestlen, %scanalign), %windowbestlen
+		lea	MAX_MATCH_8(%scan, %scanalign), %prev
+
+/* the prefetching below makes very little difference... */
+		prefetcht1	(%windowbestlen, %rdx)
+		prefetcht1	(%prev, %rdx)
+
+/*
+ * Test the strings for equality, 8 bytes at a time. At the end,
+ * adjust %rdx so that it is offset to the exact byte that mismatched.
+ *
+ * It should be confessed that this loop usually does not represent
+ * much of the total running time. Replacing it with a more
+ * straightforward "rep cmpsb" would not drastically degrade
+ * performance -- unrolling it, for example, makes no difference.
+ */
+
+#undef USE_SSE	/* works, but is 6-7% slower, than non-SSE... */
+
+LoopCmps:
+#ifdef USE_SSE
+		/* Preload the SSE registers */
+		movdqu	  (%windowbestlen, %rdx), %xmm1
+		movdqu	  (%prev, %rdx), %xmm2
+		pcmpeqb	%xmm2, %xmm1
+		movdqu	16(%windowbestlen, %rdx), %xmm3
+		movdqu	16(%prev, %rdx), %xmm4
+		pcmpeqb	%xmm4, %xmm3
+		movdqu	32(%windowbestlen, %rdx), %xmm5
+		movdqu	32(%prev, %rdx), %xmm6
+		pcmpeqb	%xmm6, %xmm5
+		movdqu	48(%windowbestlen, %rdx), %xmm7
+		movdqu	48(%prev, %rdx), %xmm8
+		pcmpeqb	%xmm8, %xmm7
+
+		/* Check the comparisions' results */
+		pmovmskb %xmm1, %rax
+		notw	%ax
+		bsfw	%ax, %ax
+		jnz	LeaveLoopCmps
+		
+		/* this is the only iteration of the loop with a possibility of having
+		   incremented rdx by 0x108 (each loop iteration add 16*4 = 0x40 
+		   and (0x40*4)+8=0x108 */
+		add	$8, %rdx
+		jz LenMaximum
+		add	$8, %rdx
+
+		
+		pmovmskb %xmm3, %rax
+		notw	%ax
+		bsfw	%ax, %ax
+		jnz	LeaveLoopCmps
+		
+		
+		add	$16, %rdx
+
+
+		pmovmskb %xmm5, %rax
+		notw	%ax
+		bsfw	%ax, %ax
+		jnz	LeaveLoopCmps
+		
+		add	$16, %rdx
+
+
+		pmovmskb %xmm7, %rax
+		notw	%ax
+		bsfw	%ax, %ax
+		jnz	LeaveLoopCmps
+		
+		add	$16, %rdx
+		
+		jmp	LoopCmps
+LeaveLoopCmps:	add	%rax, %rdx
+#else
+		mov	(%windowbestlen, %rdx), %rax
+		xor	(%prev, %rdx), %rax
+		jnz	LeaveLoopCmps
+		
+		mov	8(%windowbestlen, %rdx), %rax
+		xor	8(%prev, %rdx), %rax
+		jnz	LeaveLoopCmps8
+
+		mov	16(%windowbestlen, %rdx), %rax
+		xor	16(%prev, %rdx), %rax
+		jnz	LeaveLoopCmps16
+				
+		add	$24, %rdx
+		jnz	LoopCmps
+		jmp	LenMaximum
+#	if 0
+/*
+ * This three-liner is tantalizingly simple, but bsf is a slow instruction,
+ * and the complicated alternative down below is quite a bit faster. Sad...
+ */
+
+LeaveLoopCmps:	bsf	%rax, %rax /* find the first non-zero bit */
+		shrl	$3, %eax /* divide by 8 to get the byte */
+		add	%rax, %rdx
+#	else
+LeaveLoopCmps16:
+		add	$8, %rdx
+LeaveLoopCmps8:
+		add	$8, %rdx
+LeaveLoopCmps:	testl   $0xFFFFFFFF, %eax /* Check the first 4 bytes */
+		jnz     Check16
+		add     $4, %rdx
+		shr     $32, %rax
+Check16:        testw   $0xFFFF, %ax
+		jnz     LenLower
+		add	$2, %rdx
+		shrl	$16, %eax
+LenLower:	subb	$1, %al
+		adc	$0, %rdx
+#	endif
+#endif
+
+/* Calculate the length of the match. If it is longer than MAX_MATCH,	*/
+/* then automatically accept it as the best possible match and leave.	*/
+
+		lea	(%prev, %rdx), %rax
+		sub	%scan, %rax
+		cmpl	$MAX_MATCH, %eax
+		jge	LenMaximum
+
+/* If the length of the match is not longer than the best match we	*/
+/* have so far, then forget it and return to the lookup loop.		*/
+
+		cmpl	%bestlend, %eax
+		jg	LongerMatch
+		mov	_windowbestlen, %windowbestlen
+		mov	dsPrev, %prev
+		movl	_chainlenwmask, %edx
+		jmp	LookupLoop
+
+/*         s->match_start = cur_match;					*/
+/*         best_len = len;						*/
+/*         if (len >= nice_match) break;				*/
+/*         scan_end = *(ushf*)(scan+best_len-1);			*/
+
+LongerMatch:
+		movl	%eax, %bestlend
+		movl	%curmatchd, dsMatchStart
+		cmpl	%nicematch, %eax
+		jge	LeaveNow
+
+		lea	(%window, %bestlen), %windowbestlen
+		mov	%windowbestlen, _windowbestlen
+
+		movzwl	-1(%scan, %rax), %scanend
+		mov	dsPrev, %prev
+		movl	_chainlenwmask, %chainlenwmask
+		jmp	LookupLoop
+
+/* Accept the current string, with the maximum possible length.		*/
+
+LenMaximum:
+		movl	$MAX_MATCH, %bestlend
+		movl	%curmatchd, dsMatchStart
+
+/* if ((uInt)best_len <= s->lookahead) return (uInt)best_len;		*/
+/* return s->lookahead;							*/
+
+LeaveNow:
+		movl	dsLookahead, %eax
+		cmpl	%eax, %bestlend
+		cmovngl	%bestlend, %eax
+LookaheadRet:
+
+/* Restore the registers and return from whence we came.			*/
+
+	mov	save_rsi, %rsi
+	mov	save_rbx, %rbx
+	mov	save_r12, %r12
+	mov	save_r13, %r13
+	mov	save_r14, %r14
+	mov	save_r15, %r15
+
+	ret
+
+match_init:	ret
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/blast/Makefile
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/blast/Makefile	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,8 @@
+blast: blast.c blast.h
+	cc -DTEST -o blast blast.c
+
+test: blast
+	blast < test.pk | cmp - test.txt
+
+clean:
+	rm -f blast blast.o
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/blast/README
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/blast/README	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,4 @@
+Read blast.h for purpose and usage.
+
+Mark Adler
+madler@alumni.caltech.edu
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/blast/blast.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/blast/blast.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,466 @@
+/* blast.c
+ * Copyright (C) 2003, 2012, 2013 Mark Adler
+ * For conditions of distribution and use, see copyright notice in blast.h
+ * version 1.3, 24 Aug 2013
+ *
+ * blast.c decompresses data compressed by the PKWare Compression Library.
+ * This function provides functionality similar to the explode() function of
+ * the PKWare library, hence the name "blast".
+ *
+ * This decompressor is based on the excellent format description provided by
+ * Ben Rudiak-Gould in comp.compression on August 13, 2001.  Interestingly, the
+ * example Ben provided in the post is incorrect.  The distance 110001 should
+ * instead be 111000.  When corrected, the example byte stream becomes:
+ *
+ *    00 04 82 24 25 8f 80 7f
+ *
+ * which decompresses to "AIAIAIAIAIAIA" (without the quotes).
+ */
+
+/*
+ * Change history:
+ *
+ * 1.0  12 Feb 2003     - First version
+ * 1.1  16 Feb 2003     - Fixed distance check for > 4 GB uncompressed data
+ * 1.2  24 Oct 2012     - Add note about using binary mode in stdio
+ *                      - Fix comparisons of differently signed integers
+ * 1.3  24 Aug 2013     - Return unused input from blast()
+ *                      - Fix test code to correctly report unused input
+ *                      - Enable the provision of initial input to blast()
+ */
+
+#include <stddef.h>             /* for NULL */
+#include <setjmp.h>             /* for setjmp(), longjmp(), and jmp_buf */
+#include "blast.h"              /* prototype for blast() */
+
+#define local static            /* for local function definitions */
+#define MAXBITS 13              /* maximum code length */
+#define MAXWIN 4096             /* maximum window size */
+
+/* input and output state */
+struct state {
+    /* input state */
+    blast_in infun;             /* input function provided by user */
+    void *inhow;                /* opaque information passed to infun() */
+    unsigned char *in;          /* next input location */
+    unsigned left;              /* available input at in */
+    int bitbuf;                 /* bit buffer */
+    int bitcnt;                 /* number of bits in bit buffer */
+
+    /* input limit error return state for bits() and decode() */
+    jmp_buf env;
+
+    /* output state */
+    blast_out outfun;           /* output function provided by user */
+    void *outhow;               /* opaque information passed to outfun() */
+    unsigned next;              /* index of next write location in out[] */
+    int first;                  /* true to check distances (for first 4K) */
+    unsigned char out[MAXWIN];  /* output buffer and sliding window */
+};
+
+/*
+ * Return need bits from the input stream.  This always leaves less than
+ * eight bits in the buffer.  bits() works properly for need == 0.
+ *
+ * Format notes:
+ *
+ * - Bits are stored in bytes from the least significant bit to the most
+ *   significant bit.  Therefore bits are dropped from the bottom of the bit
+ *   buffer, using shift right, and new bytes are appended to the top of the
+ *   bit buffer, using shift left.
+ */
+local int bits(struct state *s, int need)
+{
+    int val;            /* bit accumulator */
+
+    /* load at least need bits into val */
+    val = s->bitbuf;
+    while (s->bitcnt < need) {
+        if (s->left == 0) {
+            s->left = s->infun(s->inhow, &(s->in));
+            if (s->left == 0) longjmp(s->env, 1);       /* out of input */
+        }
+        val |= (int)(*(s->in)++) << s->bitcnt;          /* load eight bits */
+        s->left--;
+        s->bitcnt += 8;
+    }
+
+    /* drop need bits and update buffer, always zero to seven bits left */
+    s->bitbuf = val >> need;
+    s->bitcnt -= need;
+
+    /* return need bits, zeroing the bits above that */
+    return val & ((1 << need) - 1);
+}
+
+/*
+ * Huffman code decoding tables.  count[1..MAXBITS] is the number of symbols of
+ * each length, which for a canonical code are stepped through in order.
+ * symbol[] are the symbol values in canonical order, where the number of
+ * entries is the sum of the counts in count[].  The decoding process can be
+ * seen in the function decode() below.
+ */
+struct huffman {
+    short *count;       /* number of symbols of each length */
+    short *symbol;      /* canonically ordered symbols */
+};
+
+/*
+ * Decode a code from the stream s using huffman table h.  Return the symbol or
+ * a negative value if there is an error.  If all of the lengths are zero, i.e.
+ * an empty code, or if the code is incomplete and an invalid code is received,
+ * then -9 is returned after reading MAXBITS bits.
+ *
+ * Format notes:
+ *
+ * - The codes as stored in the compressed data are bit-reversed relative to
+ *   a simple integer ordering of codes of the same lengths.  Hence below the
+ *   bits are pulled from the compressed data one at a time and used to
+ *   build the code value reversed from what is in the stream in order to
+ *   permit simple integer comparisons for decoding.
+ *
+ * - The first code for the shortest length is all ones.  Subsequent codes of
+ *   the same length are simply integer decrements of the previous code.  When
+ *   moving up a length, a one bit is appended to the code.  For a complete
+ *   code, the last code of the longest length will be all zeros.  To support
+ *   this ordering, the bits pulled during decoding are inverted to apply the
+ *   more "natural" ordering starting with all zeros and incrementing.
+ */
+local int decode(struct state *s, struct huffman *h)
+{
+    int len;            /* current number of bits in code */
+    int code;           /* len bits being decoded */
+    int first;          /* first code of length len */
+    int count;          /* number of codes of length len */
+    int index;          /* index of first code of length len in symbol table */
+    int bitbuf;         /* bits from stream */
+    int left;           /* bits left in next or left to process */
+    short *next;        /* next number of codes */
+
+    bitbuf = s->bitbuf;
+    left = s->bitcnt;
+    code = first = index = 0;
+    len = 1;
+    next = h->count + 1;
+    while (1) {
+        while (left--) {
+            code |= (bitbuf & 1) ^ 1;   /* invert code */
+            bitbuf >>= 1;
+            count = *next++;
+            if (code < first + count) { /* if length len, return symbol */
+                s->bitbuf = bitbuf;
+                s->bitcnt = (s->bitcnt - len) & 7;
+                return h->symbol[index + (code - first)];
+            }
+            index += count;             /* else update for next length */
+            first += count;
+            first <<= 1;
+            code <<= 1;
+            len++;
+        }
+        left = (MAXBITS+1) - len;
+        if (left == 0) break;
+        if (s->left == 0) {
+            s->left = s->infun(s->inhow, &(s->in));
+            if (s->left == 0) longjmp(s->env, 1);       /* out of input */
+        }
+        bitbuf = *(s->in)++;
+        s->left--;
+        if (left > 8) left = 8;
+    }
+    return -9;                          /* ran out of codes */
+}
+
+/*
+ * Given a list of repeated code lengths rep[0..n-1], where each byte is a
+ * count (high four bits + 1) and a code length (low four bits), generate the
+ * list of code lengths.  This compaction reduces the size of the object code.
+ * Then given the list of code lengths length[0..n-1] representing a canonical
+ * Huffman code for n symbols, construct the tables required to decode those
+ * codes.  Those tables are the number of codes of each length, and the symbols
+ * sorted by length, retaining their original order within each length.  The
+ * return value is zero for a complete code set, negative for an over-
+ * subscribed code set, and positive for an incomplete code set.  The tables
+ * can be used if the return value is zero or positive, but they cannot be used
+ * if the return value is negative.  If the return value is zero, it is not
+ * possible for decode() using that table to return an error--any stream of
+ * enough bits will resolve to a symbol.  If the return value is positive, then
+ * it is possible for decode() using that table to return an error for received
+ * codes past the end of the incomplete lengths.
+ */
+local int construct(struct huffman *h, const unsigned char *rep, int n)
+{
+    int symbol;         /* current symbol when stepping through length[] */
+    int len;            /* current length when stepping through h->count[] */
+    int left;           /* number of possible codes left of current length */
+    short offs[MAXBITS+1];      /* offsets in symbol table for each length */
+    short length[256];  /* code lengths */
+
+    /* convert compact repeat counts into symbol bit length list */
+    symbol = 0;
+    do {
+        len = *rep++;
+        left = (len >> 4) + 1;
+        len &= 15;
+        do {
+            length[symbol++] = len;
+        } while (--left);
+    } while (--n);
+    n = symbol;
+
+    /* count number of codes of each length */
+    for (len = 0; len <= MAXBITS; len++)
+        h->count[len] = 0;
+    for (symbol = 0; symbol < n; symbol++)
+        (h->count[length[symbol]])++;   /* assumes lengths are within bounds */
+    if (h->count[0] == n)               /* no codes! */
+        return 0;                       /* complete, but decode() will fail */
+
+    /* check for an over-subscribed or incomplete set of lengths */
+    left = 1;                           /* one possible code of zero length */
+    for (len = 1; len <= MAXBITS; len++) {
+        left <<= 1;                     /* one more bit, double codes left */
+        left -= h->count[len];          /* deduct count from possible codes */
+        if (left < 0) return left;      /* over-subscribed--return negative */
+    }                                   /* left > 0 means incomplete */
+
+    /* generate offsets into symbol table for each length for sorting */
+    offs[1] = 0;
+    for (len = 1; len < MAXBITS; len++)
+        offs[len + 1] = offs[len] + h->count[len];
+
+    /*
+     * put symbols in table sorted by length, by symbol order within each
+     * length
+     */
+    for (symbol = 0; symbol < n; symbol++)
+        if (length[symbol] != 0)
+            h->symbol[offs[length[symbol]]++] = symbol;
+
+    /* return zero for complete set, positive for incomplete set */
+    return left;
+}
+
+/*
+ * Decode PKWare Compression Library stream.
+ *
+ * Format notes:
+ *
+ * - First byte is 0 if literals are uncoded or 1 if they are coded.  Second
+ *   byte is 4, 5, or 6 for the number of extra bits in the distance code.
+ *   This is the base-2 logarithm of the dictionary size minus six.
+ *
+ * - Compressed data is a combination of literals and length/distance pairs
+ *   terminated by an end code.  Literals are either Huffman coded or
+ *   uncoded bytes.  A length/distance pair is a coded length followed by a
+ *   coded distance to represent a string that occurs earlier in the
+ *   uncompressed data that occurs again at the current location.
+ *
+ * - A bit preceding a literal or length/distance pair indicates which comes
+ *   next, 0 for literals, 1 for length/distance.
+ *
+ * - If literals are uncoded, then the next eight bits are the literal, in the
+ *   normal bit order in the stream, i.e. no bit-reversal is needed. Similarly,
+ *   no bit reversal is needed for either the length extra bits or the distance
+ *   extra bits.
+ *
+ * - Literal bytes are simply written to the output.  A length/distance pair is
+ *   an instruction to copy previously uncompressed bytes to the output.  The
+ *   copy is from distance bytes back in the output stream, copying for length
+ *   bytes.
+ *
+ * - Distances pointing before the beginning of the output data are not
+ *   permitted.
+ *
+ * - Overlapped copies, where the length is greater than the distance, are
+ *   allowed and common.  For example, a distance of one and a length of 518
+ *   simply copies the last byte 518 times.  A distance of four and a length of
+ *   twelve copies the last four bytes three times.  A simple forward copy
+ *   ignoring whether the length is greater than the distance or not implements
+ *   this correctly.
+ */
+local int decomp(struct state *s)
+{
+    int lit;            /* true if literals are coded */
+    int dict;           /* log2(dictionary size) - 6 */
+    int symbol;         /* decoded symbol, extra bits for distance */
+    int len;            /* length for copy */
+    unsigned dist;      /* distance for copy */
+    int copy;           /* copy counter */
+    unsigned char *from, *to;   /* copy pointers */
+    static int virgin = 1;                              /* build tables once */
+    static short litcnt[MAXBITS+1], litsym[256];        /* litcode memory */
+    static short lencnt[MAXBITS+1], lensym[16];         /* lencode memory */
+    static short distcnt[MAXBITS+1], distsym[64];       /* distcode memory */
+    static struct huffman litcode = {litcnt, litsym};   /* length code */
+    static struct huffman lencode = {lencnt, lensym};   /* length code */
+    static struct huffman distcode = {distcnt, distsym};/* distance code */
+        /* bit lengths of literal codes */
+    static const unsigned char litlen[] = {
+        11, 124, 8, 7, 28, 7, 188, 13, 76, 4, 10, 8, 12, 10, 12, 10, 8, 23, 8,
+        9, 7, 6, 7, 8, 7, 6, 55, 8, 23, 24, 12, 11, 7, 9, 11, 12, 6, 7, 22, 5,
+        7, 24, 6, 11, 9, 6, 7, 22, 7, 11, 38, 7, 9, 8, 25, 11, 8, 11, 9, 12,
+        8, 12, 5, 38, 5, 38, 5, 11, 7, 5, 6, 21, 6, 10, 53, 8, 7, 24, 10, 27,
+        44, 253, 253, 253, 252, 252, 252, 13, 12, 45, 12, 45, 12, 61, 12, 45,
+        44, 173};
+        /* bit lengths of length codes 0..15 */
+    static const unsigned char lenlen[] = {2, 35, 36, 53, 38, 23};
+        /* bit lengths of distance codes 0..63 */
+    static const unsigned char distlen[] = {2, 20, 53, 230, 247, 151, 248};
+    static const short base[16] = {     /* base for length codes */
+        3, 2, 4, 5, 6, 7, 8, 9, 10, 12, 16, 24, 40, 72, 136, 264};
+    static const char extra[16] = {     /* extra bits for length codes */
+        0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8};
+
+    /* set up decoding tables (once--might not be thread-safe) */
+    if (virgin) {
+        construct(&litcode, litlen, sizeof(litlen));
+        construct(&lencode, lenlen, sizeof(lenlen));
+        construct(&distcode, distlen, sizeof(distlen));
+        virgin = 0;
+    }
+
+    /* read header */
+    lit = bits(s, 8);
+    if (lit > 1) return -1;
+    dict = bits(s, 8);
+    if (dict < 4 || dict > 6) return -2;
+
+    /* decode literals and length/distance pairs */
+    do {
+        if (bits(s, 1)) {
+            /* get length */
+            symbol = decode(s, &lencode);
+            len = base[symbol] + bits(s, extra[symbol]);
+            if (len == 519) break;              /* end code */
+
+            /* get distance */
+            symbol = len == 2 ? 2 : dict;
+            dist = decode(s, &distcode) << symbol;
+            dist += bits(s, symbol);
+            dist++;
+            if (s->first && dist > s->next)
+                return -3;              /* distance too far back */
+
+            /* copy length bytes from distance bytes back */
+            do {
+                to = s->out + s->next;
+                from = to - dist;
+                copy = MAXWIN;
+                if (s->next < dist) {
+                    from += copy;
+                    copy = dist;
+                }
+                copy -= s->next;
+                if (copy > len) copy = len;
+                len -= copy;
+                s->next += copy;
+                do {
+                    *to++ = *from++;
+                } while (--copy);
+                if (s->next == MAXWIN) {
+                    if (s->outfun(s->outhow, s->out, s->next)) return 1;
+                    s->next = 0;
+                    s->first = 0;
+                }
+            } while (len != 0);
+        }
+        else {
+            /* get literal and write it */
+            symbol = lit ? decode(s, &litcode) : bits(s, 8);
+            s->out[s->next++] = symbol;
+            if (s->next == MAXWIN) {
+                if (s->outfun(s->outhow, s->out, s->next)) return 1;
+                s->next = 0;
+                s->first = 0;
+            }
+        }
+    } while (1);
+    return 0;
+}
+
+/* See comments in blast.h */
+int blast(blast_in infun, void *inhow, blast_out outfun, void *outhow,
+          unsigned *left, unsigned char **in)
+{
+    struct state s;             /* input/output state */
+    int err;                    /* return value */
+
+    /* initialize input state */
+    s.infun = infun;
+    s.inhow = inhow;
+    if (left != NULL && *left) {
+        s.left = *left;
+        s.in = *in;
+    }
+    else
+        s.left = 0;
+    s.bitbuf = 0;
+    s.bitcnt = 0;
+
+    /* initialize output state */
+    s.outfun = outfun;
+    s.outhow = outhow;
+    s.next = 0;
+    s.first = 1;
+
+    /* return if bits() or decode() tries to read past available input */
+    if (setjmp(s.env) != 0)             /* if came back here via longjmp(), */
+        err = 2;                        /*  then skip decomp(), return error */
+    else
+        err = decomp(&s);               /* decompress */
+
+    /* return unused input */
+    if (left != NULL)
+        *left = s.left;
+    if (in != NULL)
+        *in = s.left ? s.in : NULL;
+
+    /* write any leftover output and update the error code if needed */
+    if (err != 1 && s.next && s.outfun(s.outhow, s.out, s.next) && err == 0)
+        err = 1;
+    return err;
+}
+
+#ifdef TEST
+/* Example of how to use blast() */
+#include <stdio.h>
+#include <stdlib.h>
+
+#define CHUNK 16384
+
+local unsigned inf(void *how, unsigned char **buf)
+{
+    static unsigned char hold[CHUNK];
+
+    *buf = hold;
+    return fread(hold, 1, CHUNK, (FILE *)how);
+}
+
+local int outf(void *how, unsigned char *buf, unsigned len)
+{
+    return fwrite(buf, 1, len, (FILE *)how) != len;
+}
+
+/* Decompress a PKWare Compression Library stream from stdin to stdout */
+int main(void)
+{
+    int ret;
+    unsigned left;
+
+    /* decompress to stdout */
+    left = 0;
+    ret = blast(inf, stdin, outf, stdout, &left, NULL);
+    if (ret != 0)
+        fprintf(stderr, "blast error: %d\n", ret);
+
+    /* count any leftover bytes */
+    while (getchar() != EOF)
+        left++;
+    if (left)
+        fprintf(stderr, "blast warning: %u unused bytes of input\n", left);
+
+    /* return blast() error code */
+    return ret;
+}
+#endif
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/blast/blast.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/blast/blast.h	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,83 @@
+/* blast.h -- interface for blast.c
+  Copyright (C) 2003, 2012, 2013 Mark Adler
+  version 1.3, 24 Aug 2013
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the author be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  Mark Adler    madler@alumni.caltech.edu
+ */
+
+
+/*
+ * blast() decompresses the PKWare Data Compression Library (DCL) compressed
+ * format.  It provides the same functionality as the explode() function in
+ * that library.  (Note: PKWare overused the "implode" verb, and the format
+ * used by their library implode() function is completely different and
+ * incompatible with the implode compression method supported by PKZIP.)
+ *
+ * The binary mode for stdio functions should be used to assure that the
+ * compressed data is not corrupted when read or written.  For example:
+ * fopen(..., "rb") and fopen(..., "wb").
+ */
+
+
+typedef unsigned (*blast_in)(void *how, unsigned char **buf);
+typedef int (*blast_out)(void *how, unsigned char *buf, unsigned len);
+/* Definitions for input/output functions passed to blast().  See below for
+ * what the provided functions need to do.
+ */
+
+
+int blast(blast_in infun, void *inhow, blast_out outfun, void *outhow,
+          unsigned *left, unsigned char **in);
+/* Decompress input to output using the provided infun() and outfun() calls.
+ * On success, the return value of blast() is zero.  If there is an error in
+ * the source data, i.e. it is not in the proper format, then a negative value
+ * is returned.  If there is not enough input available or there is not enough
+ * output space, then a positive error is returned.
+ *
+ * The input function is invoked: len = infun(how, &buf), where buf is set by
+ * infun() to point to the input buffer, and infun() returns the number of
+ * available bytes there.  If infun() returns zero, then blast() returns with
+ * an input error.  (blast() only asks for input if it needs it.)  inhow is for
+ * use by the application to pass an input descriptor to infun(), if desired.
+ *
+ * If left and in are not NULL and *left is not zero when blast() is called,
+ * then the *left bytes are *in are consumed for input before infun() is used.
+ *
+ * The output function is invoked: err = outfun(how, buf, len), where the bytes
+ * to be written are buf[0..len-1].  If err is not zero, then blast() returns
+ * with an output error.  outfun() is always called with len <= 4096.  outhow
+ * is for use by the application to pass an output descriptor to outfun(), if
+ * desired.
+ *
+ * If there is any unused input, *left is set to the number of bytes that were
+ * read and *in points to them.  Otherwise *left is set to zero and *in is set
+ * to NULL.  If left or in are NULL, then they are not set.
+ *
+ * The return codes are:
+ *
+ *   2:  ran out of input before completing decompression
+ *   1:  output error before completing decompression
+ *   0:  successful decompression
+ *  -1:  literal flag not zero or one
+ *  -2:  dictionary size not in 4..6
+ *  -3:  distance is too far back
+ *
+ * At the bottom of blast.c is an example program that uses blast() that can be
+ * compiled to produce a command-line decompression filter by defining TEST.
+ */
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/blast/test.pk
Binary file sys/src/ape/lib/z/contrib/blast/test.pk has changed
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/blast/test.txt
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/blast/test.txt	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,1 @@
+AIAIAIAIAIAIA
\ No newline at end of file
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/delphi/ZLib.pas
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/delphi/ZLib.pas	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,557 @@
+{*******************************************************}
+{                                                       }
+{       Borland Delphi Supplemental Components          }
+{       ZLIB Data Compression Interface Unit            }
+{                                                       }
+{       Copyright (c) 1997,99 Borland Corporation       }
+{                                                       }
+{*******************************************************}
+
+{ Updated for zlib 1.2.x by Cosmin Truta <cosmint@cs.ubbcluj.ro> }
+
+unit ZLib;
+
+interface
+
+uses SysUtils, Classes;
+
+type
+  TAlloc = function (AppData: Pointer; Items, Size: Integer): Pointer; cdecl;
+  TFree = procedure (AppData, Block: Pointer); cdecl;
+
+  // Internal structure.  Ignore.
+  TZStreamRec = packed record
+    next_in: PChar;       // next input byte
+    avail_in: Integer;    // number of bytes available at next_in
+    total_in: Longint;    // total nb of input bytes read so far
+
+    next_out: PChar;      // next output byte should be put here
+    avail_out: Integer;   // remaining free space at next_out
+    total_out: Longint;   // total nb of bytes output so far
+
+    msg: PChar;           // last error message, NULL if no error
+    internal: Pointer;    // not visible by applications
+
+    zalloc: TAlloc;       // used to allocate the internal state
+    zfree: TFree;         // used to free the internal state
+    AppData: Pointer;     // private data object passed to zalloc and zfree
+
+    data_type: Integer;   // best guess about the data type: ascii or binary
+    adler: Longint;       // adler32 value of the uncompressed data
+    reserved: Longint;    // reserved for future use
+  end;
+
+  // Abstract ancestor class
+  TCustomZlibStream = class(TStream)
+  private
+    FStrm: TStream;
+    FStrmPos: Integer;
+    FOnProgress: TNotifyEvent;
+    FZRec: TZStreamRec;
+    FBuffer: array [Word] of Char;
+  protected
+    procedure Progress(Sender: TObject); dynamic;
+    property OnProgress: TNotifyEvent read FOnProgress write FOnProgress;
+    constructor Create(Strm: TStream);
+  end;
+
+{ TCompressionStream compresses data on the fly as data is written to it, and
+  stores the compressed data to another stream.
+
+  TCompressionStream is write-only and strictly sequential. Reading from the
+  stream will raise an exception. Using Seek to move the stream pointer
+  will raise an exception.
+
+  Output data is cached internally, written to the output stream only when
+  the internal output buffer is full.  All pending output data is flushed
+  when the stream is destroyed.
+
+  The Position property returns the number of uncompressed bytes of
+  data that have been written to the stream so far.
+
+  CompressionRate returns the on-the-fly percentage by which the original
+  data has been compressed:  (1 - (CompressedBytes / UncompressedBytes)) * 100
+  If raw data size = 100 and compressed data size = 25, the CompressionRate
+  is 75%
+
+  The OnProgress event is called each time the output buffer is filled and
+  written to the output stream.  This is useful for updating a progress
+  indicator when you are writing a large chunk of data to the compression
+  stream in a single call.}
+
+
+  TCompressionLevel = (clNone, clFastest, clDefault, clMax);
+
+  TCompressionStream = class(TCustomZlibStream)
+  private
+    function GetCompressionRate: Single;
+  public
+    constructor Create(CompressionLevel: TCompressionLevel; Dest: TStream);
+    destructor Destroy; override;
+    function Read(var Buffer; Count: Longint): Longint; override;
+    function Write(const Buffer; Count: Longint): Longint; override;
+    function Seek(Offset: Longint; Origin: Word): Longint; override;
+    property CompressionRate: Single read GetCompressionRate;
+    property OnProgress;
+  end;
+
+{ TDecompressionStream decompresses data on the fly as data is read from it.
+
+  Compressed data comes from a separate source stream.  TDecompressionStream
+  is read-only and unidirectional; you can seek forward in the stream, but not
+  backwards.  The special case of setting the stream position to zero is
+  allowed.  Seeking forward decompresses data until the requested position in
+  the uncompressed data has been reached.  Seeking backwards, seeking relative
+  to the end of the stream, requesting the size of the stream, and writing to
+  the stream will raise an exception.
+
+  The Position property returns the number of bytes of uncompressed data that
+  have been read from the stream so far.
+
+  The OnProgress event is called each time the internal input buffer of
+  compressed data is exhausted and the next block is read from the input stream.
+  This is useful for updating a progress indicator when you are reading a
+  large chunk of data from the decompression stream in a single call.}
+
+  TDecompressionStream = class(TCustomZlibStream)
+  public
+    constructor Create(Source: TStream);
+    destructor Destroy; override;
+    function Read(var Buffer; Count: Longint): Longint; override;
+    function Write(const Buffer; Count: Longint): Longint; override;
+    function Seek(Offset: Longint; Origin: Word): Longint; override;
+    property OnProgress;
+  end;
+
+
+
+{ CompressBuf compresses data, buffer to buffer, in one call.
+   In: InBuf = ptr to compressed data
+       InBytes = number of bytes in InBuf
+  Out: OutBuf = ptr to newly allocated buffer containing decompressed data
+       OutBytes = number of bytes in OutBuf   }
+procedure CompressBuf(const InBuf: Pointer; InBytes: Integer;
+                      out OutBuf: Pointer; out OutBytes: Integer);
+
+
+{ DecompressBuf decompresses data, buffer to buffer, in one call.
+   In: InBuf = ptr to compressed data
+       InBytes = number of bytes in InBuf
+       OutEstimate = zero, or est. size of the decompressed data
+  Out: OutBuf = ptr to newly allocated buffer containing decompressed data
+       OutBytes = number of bytes in OutBuf   }
+procedure DecompressBuf(const InBuf: Pointer; InBytes: Integer;
+ OutEstimate: Integer; out OutBuf: Pointer; out OutBytes: Integer);
+
+{ DecompressToUserBuf decompresses data, buffer to buffer, in one call.
+   In: InBuf = ptr to compressed data
+       InBytes = number of bytes in InBuf
+  Out: OutBuf = ptr to user-allocated buffer to contain decompressed data
+       BufSize = number of bytes in OutBuf   }
+procedure DecompressToUserBuf(const InBuf: Pointer; InBytes: Integer;
+  const OutBuf: Pointer; BufSize: Integer);
+
+const
+  zlib_version = '1.2.11';
+
+type
+  EZlibError = class(Exception);
+  ECompressionError = class(EZlibError);
+  EDecompressionError = class(EZlibError);
+
+implementation
+
+uses ZLibConst;
+
+const
+  Z_NO_FLUSH      = 0;
+  Z_PARTIAL_FLUSH = 1;
+  Z_SYNC_FLUSH    = 2;
+  Z_FULL_FLUSH    = 3;
+  Z_FINISH        = 4;
+
+  Z_OK            = 0;
+  Z_STREAM_END    = 1;
+  Z_NEED_DICT     = 2;
+  Z_ERRNO         = (-1);
+  Z_STREAM_ERROR  = (-2);
+  Z_DATA_ERROR    = (-3);
+  Z_MEM_ERROR     = (-4);
+  Z_BUF_ERROR     = (-5);
+  Z_VERSION_ERROR = (-6);
+
+  Z_NO_COMPRESSION       =   0;
+  Z_BEST_SPEED           =   1;
+  Z_BEST_COMPRESSION     =   9;
+  Z_DEFAULT_COMPRESSION  = (-1);
+
+  Z_FILTERED            = 1;
+  Z_HUFFMAN_ONLY        = 2;
+  Z_RLE                 = 3;
+  Z_DEFAULT_STRATEGY    = 0;
+
+  Z_BINARY   = 0;
+  Z_ASCII    = 1;
+  Z_UNKNOWN  = 2;
+
+  Z_DEFLATED = 8;
+
+
+{$L adler32.obj}
+{$L compress.obj}
+{$L crc32.obj}
+{$L deflate.obj}
+{$L infback.obj}
+{$L inffast.obj}
+{$L inflate.obj}
+{$L inftrees.obj}
+{$L trees.obj}
+{$L uncompr.obj}
+{$L zutil.obj}
+
+procedure adler32; external;
+procedure compressBound; external;
+procedure crc32; external;
+procedure deflateInit2_; external;
+procedure deflateParams; external;
+
+function _malloc(Size: Integer): Pointer; cdecl;
+begin
+  Result := AllocMem(Size);
+end;
+
+procedure _free(Block: Pointer); cdecl;
+begin
+  FreeMem(Block);
+end;
+
+procedure _memset(P: Pointer; B: Byte; count: Integer); cdecl;
+begin
+  FillChar(P^, count, B);
+end;
+
+procedure _memcpy(dest, source: Pointer; count: Integer); cdecl;
+begin
+  Move(source^, dest^, count);
+end;
+
+
+
+// deflate compresses data
+function deflateInit_(var strm: TZStreamRec; level: Integer; version: PChar;
+  recsize: Integer): Integer; external;
+function deflate(var strm: TZStreamRec; flush: Integer): Integer; external;
+function deflateEnd(var strm: TZStreamRec): Integer; external;
+
+// inflate decompresses data
+function inflateInit_(var strm: TZStreamRec; version: PChar;
+  recsize: Integer): Integer; external;
+function inflate(var strm: TZStreamRec; flush: Integer): Integer; external;
+function inflateEnd(var strm: TZStreamRec): Integer; external;
+function inflateReset(var strm: TZStreamRec): Integer; external;
+
+
+function zlibAllocMem(AppData: Pointer; Items, Size: Integer): Pointer; cdecl;
+begin
+//  GetMem(Result, Items*Size);
+  Result := AllocMem(Items * Size);
+end;
+
+procedure zlibFreeMem(AppData, Block: Pointer); cdecl;
+begin
+  FreeMem(Block);
+end;
+
+{function zlibCheck(code: Integer): Integer;
+begin
+  Result := code;
+  if code < 0 then
+    raise EZlibError.Create('error');    //!!
+end;}
+
+function CCheck(code: Integer): Integer;
+begin
+  Result := code;
+  if code < 0 then
+    raise ECompressionError.Create('error'); //!!
+end;
+
+function DCheck(code: Integer): Integer;
+begin
+  Result := code;
+  if code < 0 then
+    raise EDecompressionError.Create('error');  //!!
+end;
+
+procedure CompressBuf(const InBuf: Pointer; InBytes: Integer;
+                      out OutBuf: Pointer; out OutBytes: Integer);
+var
+  strm: TZStreamRec;
+  P: Pointer;
+begin
+  FillChar(strm, sizeof(strm), 0);
+  strm.zalloc := zlibAllocMem;
+  strm.zfree := zlibFreeMem;
+  OutBytes := ((InBytes + (InBytes div 10) + 12) + 255) and not 255;
+  GetMem(OutBuf, OutBytes);
+  try
+    strm.next_in := InBuf;
+    strm.avail_in := InBytes;
+    strm.next_out := OutBuf;
+    strm.avail_out := OutBytes;
+    CCheck(deflateInit_(strm, Z_BEST_COMPRESSION, zlib_version, sizeof(strm)));
+    try
+      while CCheck(deflate(strm, Z_FINISH)) <> Z_STREAM_END do
+      begin
+        P := OutBuf;
+        Inc(OutBytes, 256);
+        ReallocMem(OutBuf, OutBytes);
+        strm.next_out := PChar(Integer(OutBuf) + (Integer(strm.next_out) - Integer(P)));
+        strm.avail_out := 256;
+      end;
+    finally
+      CCheck(deflateEnd(strm));
+    end;
+    ReallocMem(OutBuf, strm.total_out);
+    OutBytes := strm.total_out;
+  except
+    FreeMem(OutBuf);
+    raise
+  end;
+end;
+
+
+procedure DecompressBuf(const InBuf: Pointer; InBytes: Integer;
+  OutEstimate: Integer; out OutBuf: Pointer; out OutBytes: Integer);
+var
+  strm: TZStreamRec;
+  P: Pointer;
+  BufInc: Integer;
+begin
+  FillChar(strm, sizeof(strm), 0);
+  strm.zalloc := zlibAllocMem;
+  strm.zfree := zlibFreeMem;
+  BufInc := (InBytes + 255) and not 255;
+  if OutEstimate = 0 then
+    OutBytes := BufInc
+  else
+    OutBytes := OutEstimate;
+  GetMem(OutBuf, OutBytes);
+  try
+    strm.next_in := InBuf;
+    strm.avail_in := InBytes;
+    strm.next_out := OutBuf;
+    strm.avail_out := OutBytes;
+    DCheck(inflateInit_(strm, zlib_version, sizeof(strm)));
+    try
+      while DCheck(inflate(strm, Z_NO_FLUSH)) <> Z_STREAM_END do
+      begin
+        P := OutBuf;
+        Inc(OutBytes, BufInc);
+        ReallocMem(OutBuf, OutBytes);
+        strm.next_out := PChar(Integer(OutBuf) + (Integer(strm.next_out) - Integer(P)));
+        strm.avail_out := BufInc;
+      end;
+    finally
+      DCheck(inflateEnd(strm));
+    end;
+    ReallocMem(OutBuf, strm.total_out);
+    OutBytes := strm.total_out;
+  except
+    FreeMem(OutBuf);
+    raise
+  end;
+end;
+
+procedure DecompressToUserBuf(const InBuf: Pointer; InBytes: Integer;
+  const OutBuf: Pointer; BufSize: Integer);
+var
+  strm: TZStreamRec;
+begin
+  FillChar(strm, sizeof(strm), 0);
+  strm.zalloc := zlibAllocMem;
+  strm.zfree := zlibFreeMem;
+  strm.next_in := InBuf;
+  strm.avail_in := InBytes;
+  strm.next_out := OutBuf;
+  strm.avail_out := BufSize;
+  DCheck(inflateInit_(strm, zlib_version, sizeof(strm)));
+  try
+    if DCheck(inflate(strm, Z_FINISH)) <> Z_STREAM_END then
+      raise EZlibError.CreateRes(@sTargetBufferTooSmall);
+  finally
+    DCheck(inflateEnd(strm));
+  end;
+end;
+
+// TCustomZlibStream
+
+constructor TCustomZLibStream.Create(Strm: TStream);
+begin
+  inherited Create;
+  FStrm := Strm;
+  FStrmPos := Strm.Position;
+  FZRec.zalloc := zlibAllocMem;
+  FZRec.zfree := zlibFreeMem;
+end;
+
+procedure TCustomZLibStream.Progress(Sender: TObject);
+begin
+  if Assigned(FOnProgress) then FOnProgress(Sender);
+end;
+
+
+// TCompressionStream
+
+constructor TCompressionStream.Create(CompressionLevel: TCompressionLevel;
+  Dest: TStream);
+const
+  Levels: array [TCompressionLevel] of ShortInt =
+    (Z_NO_COMPRESSION, Z_BEST_SPEED, Z_DEFAULT_COMPRESSION, Z_BEST_COMPRESSION);
+begin
+  inherited Create(Dest);
+  FZRec.next_out := FBuffer;
+  FZRec.avail_out := sizeof(FBuffer);
+  CCheck(deflateInit_(FZRec, Levels[CompressionLevel], zlib_version, sizeof(FZRec)));
+end;
+
+destructor TCompressionStream.Destroy;
+begin
+  FZRec.next_in := nil;
+  FZRec.avail_in := 0;
+  try
+    if FStrm.Position <> FStrmPos then FStrm.Position := FStrmPos;
+    while (CCheck(deflate(FZRec, Z_FINISH)) <> Z_STREAM_END)
+      and (FZRec.avail_out = 0) do
+    begin
+      FStrm.WriteBuffer(FBuffer, sizeof(FBuffer));
+      FZRec.next_out := FBuffer;
+      FZRec.avail_out := sizeof(FBuffer);
+    end;
+    if FZRec.avail_out < sizeof(FBuffer) then
+      FStrm.WriteBuffer(FBuffer, sizeof(FBuffer) - FZRec.avail_out);
+  finally
+    deflateEnd(FZRec);
+  end;
+  inherited Destroy;
+end;
+
+function TCompressionStream.Read(var Buffer; Count: Longint): Longint;
+begin
+  raise ECompressionError.CreateRes(@sInvalidStreamOp);
+end;
+
+function TCompressionStream.Write(const Buffer; Count: Longint): Longint;
+begin
+  FZRec.next_in := @Buffer;
+  FZRec.avail_in := Count;
+  if FStrm.Position <> FStrmPos then FStrm.Position := FStrmPos;
+  while (FZRec.avail_in > 0) do
+  begin
+    CCheck(deflate(FZRec, 0));
+    if FZRec.avail_out = 0 then
+    begin
+      FStrm.WriteBuffer(FBuffer, sizeof(FBuffer));
+      FZRec.next_out := FBuffer;
+      FZRec.avail_out := sizeof(FBuffer);
+      FStrmPos := FStrm.Position;
+      Progress(Self);
+    end;
+  end;
+  Result := Count;
+end;
+
+function TCompressionStream.Seek(Offset: Longint; Origin: Word): Longint;
+begin
+  if (Offset = 0) and (Origin = soFromCurrent) then
+    Result := FZRec.total_in
+  else
+    raise ECompressionError.CreateRes(@sInvalidStreamOp);
+end;
+
+function TCompressionStream.GetCompressionRate: Single;
+begin
+  if FZRec.total_in = 0 then
+    Result := 0
+  else
+    Result := (1.0 - (FZRec.total_out / FZRec.total_in)) * 100.0;
+end;
+
+
+// TDecompressionStream
+
+constructor TDecompressionStream.Create(Source: TStream);
+begin
+  inherited Create(Source);
+  FZRec.next_in := FBuffer;
+  FZRec.avail_in := 0;
+  DCheck(inflateInit_(FZRec, zlib_version, sizeof(FZRec)));
+end;
+
+destructor TDecompressionStream.Destroy;
+begin
+  FStrm.Seek(-FZRec.avail_in, 1);
+  inflateEnd(FZRec);
+  inherited Destroy;
+end;
+
+function TDecompressionStream.Read(var Buffer; Count: Longint): Longint;
+begin
+  FZRec.next_out := @Buffer;
+  FZRec.avail_out := Count;
+  if FStrm.Position <> FStrmPos then FStrm.Position := FStrmPos;
+  while (FZRec.avail_out > 0) do
+  begin
+    if FZRec.avail_in = 0 then
+    begin
+      FZRec.avail_in := FStrm.Read(FBuffer, sizeof(FBuffer));
+      if FZRec.avail_in = 0 then
+      begin
+        Result := Count - FZRec.avail_out;
+        Exit;
+      end;
+      FZRec.next_in := FBuffer;
+      FStrmPos := FStrm.Position;
+      Progress(Self);
+    end;
+    CCheck(inflate(FZRec, 0));
+  end;
+  Result := Count;
+end;
+
+function TDecompressionStream.Write(const Buffer; Count: Longint): Longint;
+begin
+  raise EDecompressionError.CreateRes(@sInvalidStreamOp);
+end;
+
+function TDecompressionStream.Seek(Offset: Longint; Origin: Word): Longint;
+var
+  I: Integer;
+  Buf: array [0..4095] of Char;
+begin
+  if (Offset = 0) and (Origin = soFromBeginning) then
+  begin
+    DCheck(inflateReset(FZRec));
+    FZRec.next_in := FBuffer;
+    FZRec.avail_in := 0;
+    FStrm.Position := 0;
+    FStrmPos := 0;
+  end
+  else if ( (Offset >= 0) and (Origin = soFromCurrent)) or
+          ( ((Offset - FZRec.total_out) > 0) and (Origin = soFromBeginning)) then
+  begin
+    if Origin = soFromBeginning then Dec(Offset, FZRec.total_out);
+    if Offset > 0 then
+    begin
+      for I := 1 to Offset div sizeof(Buf) do
+        ReadBuffer(Buf, sizeof(Buf));
+      ReadBuffer(Buf, Offset mod sizeof(Buf));
+    end;
+  end
+  else
+    raise EDecompressionError.CreateRes(@sInvalidStreamOp);
+  Result := FZRec.total_out;
+end;
+
+
+end.
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/delphi/ZLibConst.pas
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/delphi/ZLibConst.pas	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,11 @@
+unit ZLibConst;
+
+interface
+
+resourcestring
+  sTargetBufferTooSmall = 'ZLib error: target buffer may be too small';
+  sInvalidStreamOp = 'Invalid stream operation';
+
+implementation
+
+end.
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/delphi/readme.txt
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/delphi/readme.txt	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,76 @@
+
+Overview
+========
+
+This directory contains an update to the ZLib interface unit,
+distributed by Borland as a Delphi supplemental component.
+
+The original ZLib unit is Copyright (c) 1997,99 Borland Corp.,
+and is based on zlib version 1.0.4.  There are a series of bugs
+and security problems associated with that old zlib version, and
+we recommend the users to update their ZLib unit.
+
+
+Summary of modifications
+========================
+
+- Improved makefile, adapted to zlib version 1.2.1.
+
+- Some field types from TZStreamRec are changed from Integer to
+  Longint, for consistency with the zlib.h header, and for 64-bit
+  readiness.
+
+- The zlib_version constant is updated.
+
+- The new Z_RLE strategy has its corresponding symbolic constant.
+
+- The allocation and deallocation functions and function types
+  (TAlloc, TFree, zlibAllocMem and zlibFreeMem) are now cdecl,
+  and _malloc and _free are added as C RTL stubs.  As a result,
+  the original C sources of zlib can be compiled out of the box,
+  and linked to the ZLib unit.
+
+
+Suggestions for improvements
+============================
+
+Currently, the ZLib unit provides only a limited wrapper around
+the zlib library, and much of the original zlib functionality is
+missing.  Handling compressed file formats like ZIP/GZIP or PNG
+cannot be implemented without having this functionality.
+Applications that handle these formats are either using their own,
+duplicated code, or not using the ZLib unit at all.
+
+Here are a few suggestions:
+
+- Checksum class wrappers around adler32() and crc32(), similar
+  to the Java classes that implement the java.util.zip.Checksum
+  interface.
+
+- The ability to read and write raw deflate streams, without the
+  zlib stream header and trailer.  Raw deflate streams are used
+  in the ZIP file format.
+
+- The ability to read and write gzip streams, used in the GZIP
+  file format, and normally produced by the gzip program.
+
+- The ability to select a different compression strategy, useful
+  to PNG and MNG image compression, and to multimedia compression
+  in general.  Besides the compression level
+
+    TCompressionLevel = (clNone, clFastest, clDefault, clMax);
+
+  which, in fact, could have used the 'z' prefix and avoided
+  TColor-like symbols
+
+    TCompressionLevel = (zcNone, zcFastest, zcDefault, zcMax);
+
+  there could be a compression strategy
+
+    TCompressionStrategy = (zsDefault, zsFiltered, zsHuffmanOnly, zsRle);
+
+- ZIP and GZIP stream handling via TStreams.
+
+
+--
+Cosmin Truta <cosmint@cs.ubbcluj.ro>
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/delphi/zlibd32.mak
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/delphi/zlibd32.mak	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,99 @@
+# Makefile for zlib
+# For use with Delphi and C++ Builder under Win32
+# Updated for zlib 1.2.x by Cosmin Truta
+
+# ------------ Borland C++ ------------
+
+# This project uses the Delphi (fastcall/register) calling convention:
+LOC = -DZEXPORT=__fastcall -DZEXPORTVA=__cdecl
+
+CC = bcc32
+LD = bcc32
+AR = tlib
+# do not use "-pr" in CFLAGS
+CFLAGS = -a -d -k- -O2 $(LOC)
+LDFLAGS =
+
+
+# variables
+ZLIB_LIB = zlib.lib
+
+OBJ1 = adler32.obj compress.obj crc32.obj deflate.obj gzclose.obj gzlib.obj gzread.obj
+OBJ2 = gzwrite.obj infback.obj inffast.obj inflate.obj inftrees.obj trees.obj uncompr.obj zutil.obj
+OBJP1 = +adler32.obj+compress.obj+crc32.obj+deflate.obj+gzclose.obj+gzlib.obj+gzread.obj
+OBJP2 = +gzwrite.obj+infback.obj+inffast.obj+inflate.obj+inftrees.obj+trees.obj+uncompr.obj+zutil.obj
+
+
+# targets
+all: $(ZLIB_LIB) example.exe minigzip.exe
+
+.c.obj:
+	$(CC) -c $(CFLAGS) $*.c
+
+adler32.obj: adler32.c zlib.h zconf.h
+
+compress.obj: compress.c zlib.h zconf.h
+
+crc32.obj: crc32.c zlib.h zconf.h crc32.h
+
+deflate.obj: deflate.c deflate.h zutil.h zlib.h zconf.h
+
+gzclose.obj: gzclose.c zlib.h zconf.h gzguts.h
+
+gzlib.obj: gzlib.c zlib.h zconf.h gzguts.h
+
+gzread.obj: gzread.c zlib.h zconf.h gzguts.h
+
+gzwrite.obj: gzwrite.c zlib.h zconf.h gzguts.h
+
+infback.obj: infback.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h inffixed.h
+
+inffast.obj: inffast.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h
+
+inflate.obj: inflate.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h inffixed.h
+
+inftrees.obj: inftrees.c zutil.h zlib.h zconf.h inftrees.h
+
+trees.obj: trees.c zutil.h zlib.h zconf.h deflate.h trees.h
+
+uncompr.obj: uncompr.c zlib.h zconf.h
+
+zutil.obj: zutil.c zutil.h zlib.h zconf.h
+
+example.obj: test/example.c zlib.h zconf.h
+
+minigzip.obj: test/minigzip.c zlib.h zconf.h
+
+
+# For the sake of the old Borland make,
+# the command line is cut to fit in the MS-DOS 128 byte limit:
+$(ZLIB_LIB): $(OBJ1) $(OBJ2)
+	-del $(ZLIB_LIB)
+	$(AR) $(ZLIB_LIB) $(OBJP1)
+	$(AR) $(ZLIB_LIB) $(OBJP2)
+
+
+# testing
+test: example.exe minigzip.exe
+	example
+	echo hello world | minigzip | minigzip -d
+
+example.exe: example.obj $(ZLIB_LIB)
+	$(LD) $(LDFLAGS) example.obj $(ZLIB_LIB)
+
+minigzip.exe: minigzip.obj $(ZLIB_LIB)
+	$(LD) $(LDFLAGS) minigzip.obj $(ZLIB_LIB)
+
+
+# cleanup
+clean:
+	-del *.obj
+	-del *.exe
+	-del *.lib
+	-del *.tds
+	-del zlib.bak
+	-del foo.gz
+
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/infback9/README
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/infback9/README	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,1 @@
+See infback9.h for what this is and how to use it.
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/infback9/infback9.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/infback9/infback9.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,615 @@
+/* infback9.c -- inflate deflate64 data using a call-back interface
+ * Copyright (C) 1995-2008 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "zutil.h"
+#include "infback9.h"
+#include "inftree9.h"
+#include "inflate9.h"
+
+#define WSIZE 65536UL
+
+/*
+   strm provides memory allocation functions in zalloc and zfree, or
+   Z_NULL to use the library memory allocation functions.
+
+   window is a user-supplied window and output buffer that is 64K bytes.
+ */
+int ZEXPORT inflateBack9Init_(strm, window, version, stream_size)
+z_stream FAR *strm;
+unsigned char FAR *window;
+const char *version;
+int stream_size;
+{
+    struct inflate_state FAR *state;
+
+    if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
+        stream_size != (int)(sizeof(z_stream)))
+        return Z_VERSION_ERROR;
+    if (strm == Z_NULL || window == Z_NULL)
+        return Z_STREAM_ERROR;
+    strm->msg = Z_NULL;                 /* in case we return an error */
+    if (strm->zalloc == (alloc_func)0) {
+        strm->zalloc = zcalloc;
+        strm->opaque = (voidpf)0;
+    }
+    if (strm->zfree == (free_func)0) strm->zfree = zcfree;
+    state = (struct inflate_state FAR *)ZALLOC(strm, 1,
+                                               sizeof(struct inflate_state));
+    if (state == Z_NULL) return Z_MEM_ERROR;
+    Tracev((stderr, "inflate: allocated\n"));
+    strm->state = (voidpf)state;
+    state->window = window;
+    return Z_OK;
+}
+
+/*
+   Build and output length and distance decoding tables for fixed code
+   decoding.
+ */
+#ifdef MAKEFIXED
+#include <stdio.h>
+
+void makefixed9(void)
+{
+    unsigned sym, bits, low, size;
+    code *next, *lenfix, *distfix;
+    struct inflate_state state;
+    code fixed[544];
+
+    /* literal/length table */
+    sym = 0;
+    while (sym < 144) state.lens[sym++] = 8;
+    while (sym < 256) state.lens[sym++] = 9;
+    while (sym < 280) state.lens[sym++] = 7;
+    while (sym < 288) state.lens[sym++] = 8;
+    next = fixed;
+    lenfix = next;
+    bits = 9;
+    inflate_table9(LENS, state.lens, 288, &(next), &(bits), state.work);
+
+    /* distance table */
+    sym = 0;
+    while (sym < 32) state.lens[sym++] = 5;
+    distfix = next;
+    bits = 5;
+    inflate_table9(DISTS, state.lens, 32, &(next), &(bits), state.work);
+
+    /* write tables */
+    puts("    /* inffix9.h -- table for decoding deflate64 fixed codes");
+    puts("     * Generated automatically by makefixed9().");
+    puts("     */");
+    puts("");
+    puts("    /* WARNING: this file should *not* be used by applications.");
+    puts("       It is part of the implementation of this library and is");
+    puts("       subject to change. Applications should only use zlib.h.");
+    puts("     */");
+    puts("");
+    size = 1U << 9;
+    printf("    static const code lenfix[%u] = {", size);
+    low = 0;
+    for (;;) {
+        if ((low % 6) == 0) printf("\n        ");
+        printf("{%u,%u,%d}", lenfix[low].op, lenfix[low].bits,
+               lenfix[low].val);
+        if (++low == size) break;
+        putchar(',');
+    }
+    puts("\n    };");
+    size = 1U << 5;
+    printf("\n    static const code distfix[%u] = {", size);
+    low = 0;
+    for (;;) {
+        if ((low % 5) == 0) printf("\n        ");
+        printf("{%u,%u,%d}", distfix[low].op, distfix[low].bits,
+               distfix[low].val);
+        if (++low == size) break;
+        putchar(',');
+    }
+    puts("\n    };");
+}
+#endif /* MAKEFIXED */
+
+/* Macros for inflateBack(): */
+
+/* Clear the input bit accumulator */
+#define INITBITS() \
+    do { \
+        hold = 0; \
+        bits = 0; \
+    } while (0)
+
+/* Assure that some input is available.  If input is requested, but denied,
+   then return a Z_BUF_ERROR from inflateBack(). */
+#define PULL() \
+    do { \
+        if (have == 0) { \
+            have = in(in_desc, &next); \
+            if (have == 0) { \
+                next = Z_NULL; \
+                ret = Z_BUF_ERROR; \
+                goto inf_leave; \
+            } \
+        } \
+    } while (0)
+
+/* Get a byte of input into the bit accumulator, or return from inflateBack()
+   with an error if there is no input available. */
+#define PULLBYTE() \
+    do { \
+        PULL(); \
+        have--; \
+        hold += (unsigned long)(*next++) << bits; \
+        bits += 8; \
+    } while (0)
+
+/* Assure that there are at least n bits in the bit accumulator.  If there is
+   not enough available input to do that, then return from inflateBack() with
+   an error. */
+#define NEEDBITS(n) \
+    do { \
+        while (bits < (unsigned)(n)) \
+            PULLBYTE(); \
+    } while (0)
+
+/* Return the low n bits of the bit accumulator (n <= 16) */
+#define BITS(n) \
+    ((unsigned)hold & ((1U << (n)) - 1))
+
+/* Remove n bits from the bit accumulator */
+#define DROPBITS(n) \
+    do { \
+        hold >>= (n); \
+        bits -= (unsigned)(n); \
+    } while (0)
+
+/* Remove zero to seven bits as needed to go to a byte boundary */
+#define BYTEBITS() \
+    do { \
+        hold >>= bits & 7; \
+        bits -= bits & 7; \
+    } while (0)
+
+/* Assure that some output space is available, by writing out the window
+   if it's full.  If the write fails, return from inflateBack() with a
+   Z_BUF_ERROR. */
+#define ROOM() \
+    do { \
+        if (left == 0) { \
+            put = window; \
+            left = WSIZE; \
+            wrap = 1; \
+            if (out(out_desc, put, (unsigned)left)) { \
+                ret = Z_BUF_ERROR; \
+                goto inf_leave; \
+            } \
+        } \
+    } while (0)
+
+/*
+   strm provides the memory allocation functions and window buffer on input,
+   and provides information on the unused input on return.  For Z_DATA_ERROR
+   returns, strm will also provide an error message.
+
+   in() and out() are the call-back input and output functions.  When
+   inflateBack() needs more input, it calls in().  When inflateBack() has
+   filled the window with output, or when it completes with data in the
+   window, it calls out() to write out the data.  The application must not
+   change the provided input until in() is called again or inflateBack()
+   returns.  The application must not change the window/output buffer until
+   inflateBack() returns.
+
+   in() and out() are called with a descriptor parameter provided in the
+   inflateBack() call.  This parameter can be a structure that provides the
+   information required to do the read or write, as well as accumulated
+   information on the input and output such as totals and check values.
+
+   in() should return zero on failure.  out() should return non-zero on
+   failure.  If either in() or out() fails, than inflateBack() returns a
+   Z_BUF_ERROR.  strm->next_in can be checked for Z_NULL to see whether it
+   was in() or out() that caused in the error.  Otherwise,  inflateBack()
+   returns Z_STREAM_END on success, Z_DATA_ERROR for an deflate format
+   error, or Z_MEM_ERROR if it could not allocate memory for the state.
+   inflateBack() can also return Z_STREAM_ERROR if the input parameters
+   are not correct, i.e. strm is Z_NULL or the state was not initialized.
+ */
+int ZEXPORT inflateBack9(strm, in, in_desc, out, out_desc)
+z_stream FAR *strm;
+in_func in;
+void FAR *in_desc;
+out_func out;
+void FAR *out_desc;
+{
+    struct inflate_state FAR *state;
+    z_const unsigned char FAR *next;    /* next input */
+    unsigned char FAR *put;     /* next output */
+    unsigned have;              /* available input */
+    unsigned long left;         /* available output */
+    inflate_mode mode;          /* current inflate mode */
+    int lastblock;              /* true if processing last block */
+    int wrap;                   /* true if the window has wrapped */
+    unsigned char FAR *window;  /* allocated sliding window, if needed */
+    unsigned long hold;         /* bit buffer */
+    unsigned bits;              /* bits in bit buffer */
+    unsigned extra;             /* extra bits needed */
+    unsigned long length;       /* literal or length of data to copy */
+    unsigned long offset;       /* distance back to copy string from */
+    unsigned long copy;         /* number of stored or match bytes to copy */
+    unsigned char FAR *from;    /* where to copy match bytes from */
+    code const FAR *lencode;    /* starting table for length/literal codes */
+    code const FAR *distcode;   /* starting table for distance codes */
+    unsigned lenbits;           /* index bits for lencode */
+    unsigned distbits;          /* index bits for distcode */
+    code here;                  /* current decoding table entry */
+    code last;                  /* parent table entry */
+    unsigned len;               /* length to copy for repeats, bits to drop */
+    int ret;                    /* return code */
+    static const unsigned short order[19] = /* permutation of code lengths */
+        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+#include "inffix9.h"
+
+    /* Check that the strm exists and that the state was initialized */
+    if (strm == Z_NULL || strm->state == Z_NULL)
+        return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+
+    /* Reset the state */
+    strm->msg = Z_NULL;
+    mode = TYPE;
+    lastblock = 0;
+    wrap = 0;
+    window = state->window;
+    next = strm->next_in;
+    have = next != Z_NULL ? strm->avail_in : 0;
+    hold = 0;
+    bits = 0;
+    put = window;
+    left = WSIZE;
+    lencode = Z_NULL;
+    distcode = Z_NULL;
+
+    /* Inflate until end of block marked as last */
+    for (;;)
+        switch (mode) {
+        case TYPE:
+            /* determine and dispatch block type */
+            if (lastblock) {
+                BYTEBITS();
+                mode = DONE;
+                break;
+            }
+            NEEDBITS(3);
+            lastblock = BITS(1);
+            DROPBITS(1);
+            switch (BITS(2)) {
+            case 0:                             /* stored block */
+                Tracev((stderr, "inflate:     stored block%s\n",
+                        lastblock ? " (last)" : ""));
+                mode = STORED;
+                break;
+            case 1:                             /* fixed block */
+                lencode = lenfix;
+                lenbits = 9;
+                distcode = distfix;
+                distbits = 5;
+                Tracev((stderr, "inflate:     fixed codes block%s\n",
+                        lastblock ? " (last)" : ""));
+                mode = LEN;                     /* decode codes */
+                break;
+            case 2:                             /* dynamic block */
+                Tracev((stderr, "inflate:     dynamic codes block%s\n",
+                        lastblock ? " (last)" : ""));
+                mode = TABLE;
+                break;
+            case 3:
+                strm->msg = (char *)"invalid block type";
+                mode = BAD;
+            }
+            DROPBITS(2);
+            break;
+
+        case STORED:
+            /* get and verify stored block length */
+            BYTEBITS();                         /* go to byte boundary */
+            NEEDBITS(32);
+            if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
+                strm->msg = (char *)"invalid stored block lengths";
+                mode = BAD;
+                break;
+            }
+            length = (unsigned)hold & 0xffff;
+            Tracev((stderr, "inflate:       stored length %lu\n",
+                    length));
+            INITBITS();
+
+            /* copy stored block from input to output */
+            while (length != 0) {
+                copy = length;
+                PULL();
+                ROOM();
+                if (copy > have) copy = have;
+                if (copy > left) copy = left;
+                zmemcpy(put, next, copy);
+                have -= copy;
+                next += copy;
+                left -= copy;
+                put += copy;
+                length -= copy;
+            }
+            Tracev((stderr, "inflate:       stored end\n"));
+            mode = TYPE;
+            break;
+
+        case TABLE:
+            /* get dynamic table entries descriptor */
+            NEEDBITS(14);
+            state->nlen = BITS(5) + 257;
+            DROPBITS(5);
+            state->ndist = BITS(5) + 1;
+            DROPBITS(5);
+            state->ncode = BITS(4) + 4;
+            DROPBITS(4);
+            if (state->nlen > 286) {
+                strm->msg = (char *)"too many length symbols";
+                mode = BAD;
+                break;
+            }
+            Tracev((stderr, "inflate:       table sizes ok\n"));
+
+            /* get code length code lengths (not a typo) */
+            state->have = 0;
+            while (state->have < state->ncode) {
+                NEEDBITS(3);
+                state->lens[order[state->have++]] = (unsigned short)BITS(3);
+                DROPBITS(3);
+            }
+            while (state->have < 19)
+                state->lens[order[state->have++]] = 0;
+            state->next = state->codes;
+            lencode = (code const FAR *)(state->next);
+            lenbits = 7;
+            ret = inflate_table9(CODES, state->lens, 19, &(state->next),
+                                &(lenbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid code lengths set";
+                mode = BAD;
+                break;
+            }
+            Tracev((stderr, "inflate:       code lengths ok\n"));
+
+            /* get length and distance code code lengths */
+            state->have = 0;
+            while (state->have < state->nlen + state->ndist) {
+                for (;;) {
+                    here = lencode[BITS(lenbits)];
+                    if ((unsigned)(here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                if (here.val < 16) {
+                    NEEDBITS(here.bits);
+                    DROPBITS(here.bits);
+                    state->lens[state->have++] = here.val;
+                }
+                else {
+                    if (here.val == 16) {
+                        NEEDBITS(here.bits + 2);
+                        DROPBITS(here.bits);
+                        if (state->have == 0) {
+                            strm->msg = (char *)"invalid bit length repeat";
+                            mode = BAD;
+                            break;
+                        }
+                        len = (unsigned)(state->lens[state->have - 1]);
+                        copy = 3 + BITS(2);
+                        DROPBITS(2);
+                    }
+                    else if (here.val == 17) {
+                        NEEDBITS(here.bits + 3);
+                        DROPBITS(here.bits);
+                        len = 0;
+                        copy = 3 + BITS(3);
+                        DROPBITS(3);
+                    }
+                    else {
+                        NEEDBITS(here.bits + 7);
+                        DROPBITS(here.bits);
+                        len = 0;
+                        copy = 11 + BITS(7);
+                        DROPBITS(7);
+                    }
+                    if (state->have + copy > state->nlen + state->ndist) {
+                        strm->msg = (char *)"invalid bit length repeat";
+                        mode = BAD;
+                        break;
+                    }
+                    while (copy--)
+                        state->lens[state->have++] = (unsigned short)len;
+                }
+            }
+
+            /* handle error breaks in while */
+            if (mode == BAD) break;
+
+            /* check for end-of-block code (better have one) */
+            if (state->lens[256] == 0) {
+                strm->msg = (char *)"invalid code -- missing end-of-block";
+                mode = BAD;
+                break;
+            }
+
+            /* build code tables -- note: do not change the lenbits or distbits
+               values here (9 and 6) without reading the comments in inftree9.h
+               concerning the ENOUGH constants, which depend on those values */
+            state->next = state->codes;
+            lencode = (code const FAR *)(state->next);
+            lenbits = 9;
+            ret = inflate_table9(LENS, state->lens, state->nlen,
+                            &(state->next), &(lenbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid literal/lengths set";
+                mode = BAD;
+                break;
+            }
+            distcode = (code const FAR *)(state->next);
+            distbits = 6;
+            ret = inflate_table9(DISTS, state->lens + state->nlen,
+                            state->ndist, &(state->next), &(distbits),
+                            state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid distances set";
+                mode = BAD;
+                break;
+            }
+            Tracev((stderr, "inflate:       codes ok\n"));
+            mode = LEN;
+
+        case LEN:
+            /* get a literal, length, or end-of-block code */
+            for (;;) {
+                here = lencode[BITS(lenbits)];
+                if ((unsigned)(here.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if (here.op && (here.op & 0xf0) == 0) {
+                last = here;
+                for (;;) {
+                    here = lencode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+            }
+            DROPBITS(here.bits);
+            length = (unsigned)here.val;
+
+            /* process literal */
+            if (here.op == 0) {
+                Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
+                        "inflate:         literal '%c'\n" :
+                        "inflate:         literal 0x%02x\n", here.val));
+                ROOM();
+                *put++ = (unsigned char)(length);
+                left--;
+                mode = LEN;
+                break;
+            }
+
+            /* process end of block */
+            if (here.op & 32) {
+                Tracevv((stderr, "inflate:         end of block\n"));
+                mode = TYPE;
+                break;
+            }
+
+            /* invalid code */
+            if (here.op & 64) {
+                strm->msg = (char *)"invalid literal/length code";
+                mode = BAD;
+                break;
+            }
+
+            /* length code -- get extra bits, if any */
+            extra = (unsigned)(here.op) & 31;
+            if (extra != 0) {
+                NEEDBITS(extra);
+                length += BITS(extra);
+                DROPBITS(extra);
+            }
+            Tracevv((stderr, "inflate:         length %lu\n", length));
+
+            /* get distance code */
+            for (;;) {
+                here = distcode[BITS(distbits)];
+                if ((unsigned)(here.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if ((here.op & 0xf0) == 0) {
+                last = here;
+                for (;;) {
+                    here = distcode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+            }
+            DROPBITS(here.bits);
+            if (here.op & 64) {
+                strm->msg = (char *)"invalid distance code";
+                mode = BAD;
+                break;
+            }
+            offset = (unsigned)here.val;
+
+            /* get distance extra bits, if any */
+            extra = (unsigned)(here.op) & 15;
+            if (extra != 0) {
+                NEEDBITS(extra);
+                offset += BITS(extra);
+                DROPBITS(extra);
+            }
+            if (offset > WSIZE - (wrap ? 0: left)) {
+                strm->msg = (char *)"invalid distance too far back";
+                mode = BAD;
+                break;
+            }
+            Tracevv((stderr, "inflate:         distance %lu\n", offset));
+
+            /* copy match from window to output */
+            do {
+                ROOM();
+                copy = WSIZE - offset;
+                if (copy < left) {
+                    from = put + copy;
+                    copy = left - copy;
+                }
+                else {
+                    from = put - offset;
+                    copy = left;
+                }
+                if (copy > length) copy = length;
+                length -= copy;
+                left -= copy;
+                do {
+                    *put++ = *from++;
+                } while (--copy);
+            } while (length != 0);
+            break;
+
+        case DONE:
+            /* inflate stream terminated properly -- write leftover output */
+            ret = Z_STREAM_END;
+            if (left < WSIZE) {
+                if (out(out_desc, window, (unsigned)(WSIZE - left)))
+                    ret = Z_BUF_ERROR;
+            }
+            goto inf_leave;
+
+        case BAD:
+            ret = Z_DATA_ERROR;
+            goto inf_leave;
+
+        default:                /* can't happen, but makes compilers happy */
+            ret = Z_STREAM_ERROR;
+            goto inf_leave;
+        }
+
+    /* Return unused input */
+  inf_leave:
+    strm->next_in = next;
+    strm->avail_in = have;
+    return ret;
+}
+
+int ZEXPORT inflateBack9End(strm)
+z_stream FAR *strm;
+{
+    if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
+        return Z_STREAM_ERROR;
+    ZFREE(strm, strm->state);
+    strm->state = Z_NULL;
+    Tracev((stderr, "inflate: end\n"));
+    return Z_OK;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/infback9/infback9.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/infback9/infback9.h	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,37 @@
+/* infback9.h -- header for using inflateBack9 functions
+ * Copyright (C) 2003 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/*
+ * This header file and associated patches provide a decoder for PKWare's
+ * undocumented deflate64 compression method (method 9).  Use with infback9.c,
+ * inftree9.h, inftree9.c, and inffix9.h.  These patches are not supported.
+ * This should be compiled with zlib, since it uses zutil.h and zutil.o.
+ * This code has not yet been tested on 16-bit architectures.  See the
+ * comments in zlib.h for inflateBack() usage.  These functions are used
+ * identically, except that there is no windowBits parameter, and a 64K
+ * window must be provided.  Also if int's are 16 bits, then a zero for
+ * the third parameter of the "out" function actually means 65536UL.
+ * zlib.h must be included before this header file.
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+ZEXTERN int ZEXPORT inflateBack9 OF((z_stream FAR *strm,
+                                    in_func in, void FAR *in_desc,
+                                    out_func out, void FAR *out_desc));
+ZEXTERN int ZEXPORT inflateBack9End OF((z_stream FAR *strm));
+ZEXTERN int ZEXPORT inflateBack9Init_ OF((z_stream FAR *strm,
+                                         unsigned char FAR *window,
+                                         const char *version,
+                                         int stream_size));
+#define inflateBack9Init(strm, window) \
+        inflateBack9Init_((strm), (window), \
+        ZLIB_VERSION, sizeof(z_stream))
+
+#ifdef __cplusplus
+}
+#endif
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/infback9/inffix9.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/infback9/inffix9.h	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,107 @@
+    /* inffix9.h -- table for decoding deflate64 fixed codes
+     * Generated automatically by makefixed9().
+     */
+
+    /* WARNING: this file should *not* be used by applications.
+       It is part of the implementation of this library and is
+       subject to change. Applications should only use zlib.h.
+     */
+
+    static const code lenfix[512] = {
+        {96,7,0},{0,8,80},{0,8,16},{132,8,115},{130,7,31},{0,8,112},
+        {0,8,48},{0,9,192},{128,7,10},{0,8,96},{0,8,32},{0,9,160},
+        {0,8,0},{0,8,128},{0,8,64},{0,9,224},{128,7,6},{0,8,88},
+        {0,8,24},{0,9,144},{131,7,59},{0,8,120},{0,8,56},{0,9,208},
+        {129,7,17},{0,8,104},{0,8,40},{0,9,176},{0,8,8},{0,8,136},
+        {0,8,72},{0,9,240},{128,7,4},{0,8,84},{0,8,20},{133,8,227},
+        {131,7,43},{0,8,116},{0,8,52},{0,9,200},{129,7,13},{0,8,100},
+        {0,8,36},{0,9,168},{0,8,4},{0,8,132},{0,8,68},{0,9,232},
+        {128,7,8},{0,8,92},{0,8,28},{0,9,152},{132,7,83},{0,8,124},
+        {0,8,60},{0,9,216},{130,7,23},{0,8,108},{0,8,44},{0,9,184},
+        {0,8,12},{0,8,140},{0,8,76},{0,9,248},{128,7,3},{0,8,82},
+        {0,8,18},{133,8,163},{131,7,35},{0,8,114},{0,8,50},{0,9,196},
+        {129,7,11},{0,8,98},{0,8,34},{0,9,164},{0,8,2},{0,8,130},
+        {0,8,66},{0,9,228},{128,7,7},{0,8,90},{0,8,26},{0,9,148},
+        {132,7,67},{0,8,122},{0,8,58},{0,9,212},{130,7,19},{0,8,106},
+        {0,8,42},{0,9,180},{0,8,10},{0,8,138},{0,8,74},{0,9,244},
+        {128,7,5},{0,8,86},{0,8,22},{65,8,0},{131,7,51},{0,8,118},
+        {0,8,54},{0,9,204},{129,7,15},{0,8,102},{0,8,38},{0,9,172},
+        {0,8,6},{0,8,134},{0,8,70},{0,9,236},{128,7,9},{0,8,94},
+        {0,8,30},{0,9,156},{132,7,99},{0,8,126},{0,8,62},{0,9,220},
+        {130,7,27},{0,8,110},{0,8,46},{0,9,188},{0,8,14},{0,8,142},
+        {0,8,78},{0,9,252},{96,7,0},{0,8,81},{0,8,17},{133,8,131},
+        {130,7,31},{0,8,113},{0,8,49},{0,9,194},{128,7,10},{0,8,97},
+        {0,8,33},{0,9,162},{0,8,1},{0,8,129},{0,8,65},{0,9,226},
+        {128,7,6},{0,8,89},{0,8,25},{0,9,146},{131,7,59},{0,8,121},
+        {0,8,57},{0,9,210},{129,7,17},{0,8,105},{0,8,41},{0,9,178},
+        {0,8,9},{0,8,137},{0,8,73},{0,9,242},{128,7,4},{0,8,85},
+        {0,8,21},{144,8,3},{131,7,43},{0,8,117},{0,8,53},{0,9,202},
+        {129,7,13},{0,8,101},{0,8,37},{0,9,170},{0,8,5},{0,8,133},
+        {0,8,69},{0,9,234},{128,7,8},{0,8,93},{0,8,29},{0,9,154},
+        {132,7,83},{0,8,125},{0,8,61},{0,9,218},{130,7,23},{0,8,109},
+        {0,8,45},{0,9,186},{0,8,13},{0,8,141},{0,8,77},{0,9,250},
+        {128,7,3},{0,8,83},{0,8,19},{133,8,195},{131,7,35},{0,8,115},
+        {0,8,51},{0,9,198},{129,7,11},{0,8,99},{0,8,35},{0,9,166},
+        {0,8,3},{0,8,131},{0,8,67},{0,9,230},{128,7,7},{0,8,91},
+        {0,8,27},{0,9,150},{132,7,67},{0,8,123},{0,8,59},{0,9,214},
+        {130,7,19},{0,8,107},{0,8,43},{0,9,182},{0,8,11},{0,8,139},
+        {0,8,75},{0,9,246},{128,7,5},{0,8,87},{0,8,23},{77,8,0},
+        {131,7,51},{0,8,119},{0,8,55},{0,9,206},{129,7,15},{0,8,103},
+        {0,8,39},{0,9,174},{0,8,7},{0,8,135},{0,8,71},{0,9,238},
+        {128,7,9},{0,8,95},{0,8,31},{0,9,158},{132,7,99},{0,8,127},
+        {0,8,63},{0,9,222},{130,7,27},{0,8,111},{0,8,47},{0,9,190},
+        {0,8,15},{0,8,143},{0,8,79},{0,9,254},{96,7,0},{0,8,80},
+        {0,8,16},{132,8,115},{130,7,31},{0,8,112},{0,8,48},{0,9,193},
+        {128,7,10},{0,8,96},{0,8,32},{0,9,161},{0,8,0},{0,8,128},
+        {0,8,64},{0,9,225},{128,7,6},{0,8,88},{0,8,24},{0,9,145},
+        {131,7,59},{0,8,120},{0,8,56},{0,9,209},{129,7,17},{0,8,104},
+        {0,8,40},{0,9,177},{0,8,8},{0,8,136},{0,8,72},{0,9,241},
+        {128,7,4},{0,8,84},{0,8,20},{133,8,227},{131,7,43},{0,8,116},
+        {0,8,52},{0,9,201},{129,7,13},{0,8,100},{0,8,36},{0,9,169},
+        {0,8,4},{0,8,132},{0,8,68},{0,9,233},{128,7,8},{0,8,92},
+        {0,8,28},{0,9,153},{132,7,83},{0,8,124},{0,8,60},{0,9,217},
+        {130,7,23},{0,8,108},{0,8,44},{0,9,185},{0,8,12},{0,8,140},
+        {0,8,76},{0,9,249},{128,7,3},{0,8,82},{0,8,18},{133,8,163},
+        {131,7,35},{0,8,114},{0,8,50},{0,9,197},{129,7,11},{0,8,98},
+        {0,8,34},{0,9,165},{0,8,2},{0,8,130},{0,8,66},{0,9,229},
+        {128,7,7},{0,8,90},{0,8,26},{0,9,149},{132,7,67},{0,8,122},
+        {0,8,58},{0,9,213},{130,7,19},{0,8,106},{0,8,42},{0,9,181},
+        {0,8,10},{0,8,138},{0,8,74},{0,9,245},{128,7,5},{0,8,86},
+        {0,8,22},{65,8,0},{131,7,51},{0,8,118},{0,8,54},{0,9,205},
+        {129,7,15},{0,8,102},{0,8,38},{0,9,173},{0,8,6},{0,8,134},
+        {0,8,70},{0,9,237},{128,7,9},{0,8,94},{0,8,30},{0,9,157},
+        {132,7,99},{0,8,126},{0,8,62},{0,9,221},{130,7,27},{0,8,110},
+        {0,8,46},{0,9,189},{0,8,14},{0,8,142},{0,8,78},{0,9,253},
+        {96,7,0},{0,8,81},{0,8,17},{133,8,131},{130,7,31},{0,8,113},
+        {0,8,49},{0,9,195},{128,7,10},{0,8,97},{0,8,33},{0,9,163},
+        {0,8,1},{0,8,129},{0,8,65},{0,9,227},{128,7,6},{0,8,89},
+        {0,8,25},{0,9,147},{131,7,59},{0,8,121},{0,8,57},{0,9,211},
+        {129,7,17},{0,8,105},{0,8,41},{0,9,179},{0,8,9},{0,8,137},
+        {0,8,73},{0,9,243},{128,7,4},{0,8,85},{0,8,21},{144,8,3},
+        {131,7,43},{0,8,117},{0,8,53},{0,9,203},{129,7,13},{0,8,101},
+        {0,8,37},{0,9,171},{0,8,5},{0,8,133},{0,8,69},{0,9,235},
+        {128,7,8},{0,8,93},{0,8,29},{0,9,155},{132,7,83},{0,8,125},
+        {0,8,61},{0,9,219},{130,7,23},{0,8,109},{0,8,45},{0,9,187},
+        {0,8,13},{0,8,141},{0,8,77},{0,9,251},{128,7,3},{0,8,83},
+        {0,8,19},{133,8,195},{131,7,35},{0,8,115},{0,8,51},{0,9,199},
+        {129,7,11},{0,8,99},{0,8,35},{0,9,167},{0,8,3},{0,8,131},
+        {0,8,67},{0,9,231},{128,7,7},{0,8,91},{0,8,27},{0,9,151},
+        {132,7,67},{0,8,123},{0,8,59},{0,9,215},{130,7,19},{0,8,107},
+        {0,8,43},{0,9,183},{0,8,11},{0,8,139},{0,8,75},{0,9,247},
+        {128,7,5},{0,8,87},{0,8,23},{77,8,0},{131,7,51},{0,8,119},
+        {0,8,55},{0,9,207},{129,7,15},{0,8,103},{0,8,39},{0,9,175},
+        {0,8,7},{0,8,135},{0,8,71},{0,9,239},{128,7,9},{0,8,95},
+        {0,8,31},{0,9,159},{132,7,99},{0,8,127},{0,8,63},{0,9,223},
+        {130,7,27},{0,8,111},{0,8,47},{0,9,191},{0,8,15},{0,8,143},
+        {0,8,79},{0,9,255}
+    };
+
+    static const code distfix[32] = {
+        {128,5,1},{135,5,257},{131,5,17},{139,5,4097},{129,5,5},
+        {137,5,1025},{133,5,65},{141,5,16385},{128,5,3},{136,5,513},
+        {132,5,33},{140,5,8193},{130,5,9},{138,5,2049},{134,5,129},
+        {142,5,32769},{128,5,2},{135,5,385},{131,5,25},{139,5,6145},
+        {129,5,7},{137,5,1537},{133,5,97},{141,5,24577},{128,5,4},
+        {136,5,769},{132,5,49},{140,5,12289},{130,5,13},{138,5,3073},
+        {134,5,193},{142,5,49153}
+    };
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/infback9/inflate9.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/infback9/inflate9.h	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,47 @@
+/* inflate9.h -- internal inflate state definition
+ * Copyright (C) 1995-2003 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+/* Possible inflate modes between inflate() calls */
+typedef enum {
+        TYPE,       /* i: waiting for type bits, including last-flag bit */
+        STORED,     /* i: waiting for stored size (length and complement) */
+        TABLE,      /* i: waiting for dynamic block table lengths */
+            LEN,        /* i: waiting for length/lit code */
+    DONE,       /* finished check, done -- remain here until reset */
+    BAD         /* got a data error -- remain here until reset */
+} inflate_mode;
+
+/*
+    State transitions between above modes -
+
+    (most modes can go to the BAD mode -- not shown for clarity)
+
+    Read deflate blocks:
+            TYPE -> STORED or TABLE or LEN or DONE
+            STORED -> TYPE
+            TABLE -> LENLENS -> CODELENS -> LEN
+    Read deflate codes:
+                LEN -> LEN or TYPE
+ */
+
+/* state maintained between inflate() calls.  Approximately 7K bytes. */
+struct inflate_state {
+        /* sliding window */
+    unsigned char FAR *window;  /* allocated sliding window, if needed */
+        /* dynamic table building */
+    unsigned ncode;             /* number of code length code lengths */
+    unsigned nlen;              /* number of length code lengths */
+    unsigned ndist;             /* number of distance code lengths */
+    unsigned have;              /* number of code lengths in lens[] */
+    code FAR *next;             /* next available space in codes[] */
+    unsigned short lens[320];   /* temporary storage for code lengths */
+    unsigned short work[288];   /* work area for code table building */
+    code codes[ENOUGH];         /* space for code tables */
+};
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/infback9/inftree9.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/infback9/inftree9.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,324 @@
+/* inftree9.c -- generate Huffman trees for efficient decoding
+ * Copyright (C) 1995-2017 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "zutil.h"
+#include "inftree9.h"
+
+#define MAXBITS 15
+
+const char inflate9_copyright[] =
+   " inflate9 1.2.11 Copyright 1995-2017 Mark Adler ";
+/*
+  If you use the zlib library in a product, an acknowledgment is welcome
+  in the documentation of your product. If for some reason you cannot
+  include such an acknowledgment, I would appreciate that you keep this
+  copyright string in the executable of your product.
+ */
+
+/*
+   Build a set of tables to decode the provided canonical Huffman code.
+   The code lengths are lens[0..codes-1].  The result starts at *table,
+   whose indices are 0..2^bits-1.  work is a writable array of at least
+   lens shorts, which is used as a work area.  type is the type of code
+   to be generated, CODES, LENS, or DISTS.  On return, zero is success,
+   -1 is an invalid code, and +1 means that ENOUGH isn't enough.  table
+   on return points to the next available entry's address.  bits is the
+   requested root table index bits, and on return it is the actual root
+   table index bits.  It will differ if the request is greater than the
+   longest code or if it is less than the shortest code.
+ */
+int inflate_table9(type, lens, codes, table, bits, work)
+codetype type;
+unsigned short FAR *lens;
+unsigned codes;
+code FAR * FAR *table;
+unsigned FAR *bits;
+unsigned short FAR *work;
+{
+    unsigned len;               /* a code's length in bits */
+    unsigned sym;               /* index of code symbols */
+    unsigned min, max;          /* minimum and maximum code lengths */
+    unsigned root;              /* number of index bits for root table */
+    unsigned curr;              /* number of index bits for current table */
+    unsigned drop;              /* code bits to drop for sub-table */
+    int left;                   /* number of prefix codes available */
+    unsigned used;              /* code entries in table used */
+    unsigned huff;              /* Huffman code */
+    unsigned incr;              /* for incrementing code, index */
+    unsigned fill;              /* index for replicating entries */
+    unsigned low;               /* low bits for current root entry */
+    unsigned mask;              /* mask for low root bits */
+    code this;                  /* table entry for duplication */
+    code FAR *next;             /* next available space in table */
+    const unsigned short FAR *base;     /* base value table to use */
+    const unsigned short FAR *extra;    /* extra bits table to use */
+    int end;                    /* use base and extra for symbol > end */
+    unsigned short count[MAXBITS+1];    /* number of codes of each length */
+    unsigned short offs[MAXBITS+1];     /* offsets in table for each length */
+    static const unsigned short lbase[31] = { /* Length codes 257..285 base */
+        3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17,
+        19, 23, 27, 31, 35, 43, 51, 59, 67, 83, 99, 115,
+        131, 163, 195, 227, 3, 0, 0};
+    static const unsigned short lext[31] = { /* Length codes 257..285 extra */
+        128, 128, 128, 128, 128, 128, 128, 128, 129, 129, 129, 129,
+        130, 130, 130, 130, 131, 131, 131, 131, 132, 132, 132, 132,
+        133, 133, 133, 133, 144, 77, 202};
+    static const unsigned short dbase[32] = { /* Distance codes 0..31 base */
+        1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49,
+        65, 97, 129, 193, 257, 385, 513, 769, 1025, 1537, 2049, 3073,
+        4097, 6145, 8193, 12289, 16385, 24577, 32769, 49153};
+    static const unsigned short dext[32] = { /* Distance codes 0..31 extra */
+        128, 128, 128, 128, 129, 129, 130, 130, 131, 131, 132, 132,
+        133, 133, 134, 134, 135, 135, 136, 136, 137, 137, 138, 138,
+        139, 139, 140, 140, 141, 141, 142, 142};
+
+    /*
+       Process a set of code lengths to create a canonical Huffman code.  The
+       code lengths are lens[0..codes-1].  Each length corresponds to the
+       symbols 0..codes-1.  The Huffman code is generated by first sorting the
+       symbols by length from short to long, and retaining the symbol order
+       for codes with equal lengths.  Then the code starts with all zero bits
+       for the first code of the shortest length, and the codes are integer
+       increments for the same length, and zeros are appended as the length
+       increases.  For the deflate format, these bits are stored backwards
+       from their more natural integer increment ordering, and so when the
+       decoding tables are built in the large loop below, the integer codes
+       are incremented backwards.
+
+       This routine assumes, but does not check, that all of the entries in
+       lens[] are in the range 0..MAXBITS.  The caller must assure this.
+       1..MAXBITS is interpreted as that code length.  zero means that that
+       symbol does not occur in this code.
+
+       The codes are sorted by computing a count of codes for each length,
+       creating from that a table of starting indices for each length in the
+       sorted table, and then entering the symbols in order in the sorted
+       table.  The sorted table is work[], with that space being provided by
+       the caller.
+
+       The length counts are used for other purposes as well, i.e. finding
+       the minimum and maximum length codes, determining if there are any
+       codes at all, checking for a valid set of lengths, and looking ahead
+       at length counts to determine sub-table sizes when building the
+       decoding tables.
+     */
+
+    /* accumulate lengths for codes (assumes lens[] all in 0..MAXBITS) */
+    for (len = 0; len <= MAXBITS; len++)
+        count[len] = 0;
+    for (sym = 0; sym < codes; sym++)
+        count[lens[sym]]++;
+
+    /* bound code lengths, force root to be within code lengths */
+    root = *bits;
+    for (max = MAXBITS; max >= 1; max--)
+        if (count[max] != 0) break;
+    if (root > max) root = max;
+    if (max == 0) return -1;            /* no codes! */
+    for (min = 1; min <= MAXBITS; min++)
+        if (count[min] != 0) break;
+    if (root < min) root = min;
+
+    /* check for an over-subscribed or incomplete set of lengths */
+    left = 1;
+    for (len = 1; len <= MAXBITS; len++) {
+        left <<= 1;
+        left -= count[len];
+        if (left < 0) return -1;        /* over-subscribed */
+    }
+    if (left > 0 && (type == CODES || max != 1))
+        return -1;                      /* incomplete set */
+
+    /* generate offsets into symbol table for each length for sorting */
+    offs[1] = 0;
+    for (len = 1; len < MAXBITS; len++)
+        offs[len + 1] = offs[len] + count[len];
+
+    /* sort symbols by length, by symbol order within each length */
+    for (sym = 0; sym < codes; sym++)
+        if (lens[sym] != 0) work[offs[lens[sym]]++] = (unsigned short)sym;
+
+    /*
+       Create and fill in decoding tables.  In this loop, the table being
+       filled is at next and has curr index bits.  The code being used is huff
+       with length len.  That code is converted to an index by dropping drop
+       bits off of the bottom.  For codes where len is less than drop + curr,
+       those top drop + curr - len bits are incremented through all values to
+       fill the table with replicated entries.
+
+       root is the number of index bits for the root table.  When len exceeds
+       root, sub-tables are created pointed to by the root entry with an index
+       of the low root bits of huff.  This is saved in low to check for when a
+       new sub-table should be started.  drop is zero when the root table is
+       being filled, and drop is root when sub-tables are being filled.
+
+       When a new sub-table is needed, it is necessary to look ahead in the
+       code lengths to determine what size sub-table is needed.  The length
+       counts are used for this, and so count[] is decremented as codes are
+       entered in the tables.
+
+       used keeps track of how many table entries have been allocated from the
+       provided *table space.  It is checked for LENS and DIST tables against
+       the constants ENOUGH_LENS and ENOUGH_DISTS to guard against changes in
+       the initial root table size constants.  See the comments in inftree9.h
+       for more information.
+
+       sym increments through all symbols, and the loop terminates when
+       all codes of length max, i.e. all codes, have been processed.  This
+       routine permits incomplete codes, so another loop after this one fills
+       in the rest of the decoding tables with invalid code markers.
+     */
+
+    /* set up for code type */
+    switch (type) {
+    case CODES:
+        base = extra = work;    /* dummy value--not used */
+        end = 19;
+        break;
+    case LENS:
+        base = lbase;
+        base -= 257;
+        extra = lext;
+        extra -= 257;
+        end = 256;
+        break;
+    default:            /* DISTS */
+        base = dbase;
+        extra = dext;
+        end = -1;
+    }
+
+    /* initialize state for loop */
+    huff = 0;                   /* starting code */
+    sym = 0;                    /* starting code symbol */
+    len = min;                  /* starting code length */
+    next = *table;              /* current table to fill in */
+    curr = root;                /* current table index bits */
+    drop = 0;                   /* current bits to drop from code for index */
+    low = (unsigned)(-1);       /* trigger new sub-table when len > root */
+    used = 1U << root;          /* use root table entries */
+    mask = used - 1;            /* mask for comparing low */
+
+    /* check available table space */
+    if ((type == LENS && used >= ENOUGH_LENS) ||
+        (type == DISTS && used >= ENOUGH_DISTS))
+        return 1;
+
+    /* process all codes and make table entries */
+    for (;;) {
+        /* create table entry */
+        this.bits = (unsigned char)(len - drop);
+        if ((int)(work[sym]) < end) {
+            this.op = (unsigned char)0;
+            this.val = work[sym];
+        }
+        else if ((int)(work[sym]) > end) {
+            this.op = (unsigned char)(extra[work[sym]]);
+            this.val = base[work[sym]];
+        }
+        else {
+            this.op = (unsigned char)(32 + 64);         /* end of block */
+            this.val = 0;
+        }
+
+        /* replicate for those indices with low len bits equal to huff */
+        incr = 1U << (len - drop);
+        fill = 1U << curr;
+        do {
+            fill -= incr;
+            next[(huff >> drop) + fill] = this;
+        } while (fill != 0);
+
+        /* backwards increment the len-bit code huff */
+        incr = 1U << (len - 1);
+        while (huff & incr)
+            incr >>= 1;
+        if (incr != 0) {
+            huff &= incr - 1;
+            huff += incr;
+        }
+        else
+            huff = 0;
+
+        /* go to next symbol, update count, len */
+        sym++;
+        if (--(count[len]) == 0) {
+            if (len == max) break;
+            len = lens[work[sym]];
+        }
+
+        /* create new sub-table if needed */
+        if (len > root && (huff & mask) != low) {
+            /* if first time, transition to sub-tables */
+            if (drop == 0)
+                drop = root;
+
+            /* increment past last table */
+            next += 1U << curr;
+
+            /* determine length of next table */
+            curr = len - drop;
+            left = (int)(1 << curr);
+            while (curr + drop < max) {
+                left -= count[curr + drop];
+                if (left <= 0) break;
+                curr++;
+                left <<= 1;
+            }
+
+            /* check for enough space */
+            used += 1U << curr;
+            if ((type == LENS && used >= ENOUGH_LENS) ||
+                (type == DISTS && used >= ENOUGH_DISTS))
+                return 1;
+
+            /* point entry in root table to sub-table */
+            low = huff & mask;
+            (*table)[low].op = (unsigned char)curr;
+            (*table)[low].bits = (unsigned char)root;
+            (*table)[low].val = (unsigned short)(next - *table);
+        }
+    }
+
+    /*
+       Fill in rest of table for incomplete codes.  This loop is similar to the
+       loop above in incrementing huff for table indices.  It is assumed that
+       len is equal to curr + drop, so there is no loop needed to increment
+       through high index bits.  When the current sub-table is filled, the loop
+       drops back to the root table to fill in any remaining entries there.
+     */
+    this.op = (unsigned char)64;                /* invalid code marker */
+    this.bits = (unsigned char)(len - drop);
+    this.val = (unsigned short)0;
+    while (huff != 0) {
+        /* when done with sub-table, drop back to root table */
+        if (drop != 0 && (huff & mask) != low) {
+            drop = 0;
+            len = root;
+            next = *table;
+            curr = root;
+            this.bits = (unsigned char)len;
+        }
+
+        /* put invalid code marker in table */
+        next[huff >> drop] = this;
+
+        /* backwards increment the len-bit code huff */
+        incr = 1U << (len - 1);
+        while (huff & incr)
+            incr >>= 1;
+        if (incr != 0) {
+            huff &= incr - 1;
+            huff += incr;
+        }
+        else
+            huff = 0;
+    }
+
+    /* set return parameters */
+    *table += used;
+    *bits = root;
+    return 0;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/infback9/inftree9.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/infback9/inftree9.h	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,61 @@
+/* inftree9.h -- header to use inftree9.c
+ * Copyright (C) 1995-2008 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+/* Structure for decoding tables.  Each entry provides either the
+   information needed to do the operation requested by the code that
+   indexed that table entry, or it provides a pointer to another
+   table that indexes more bits of the code.  op indicates whether
+   the entry is a pointer to another table, a literal, a length or
+   distance, an end-of-block, or an invalid code.  For a table
+   pointer, the low four bits of op is the number of index bits of
+   that table.  For a length or distance, the low four bits of op
+   is the number of extra bits to get after the code.  bits is
+   the number of bits in this code or part of the code to drop off
+   of the bit buffer.  val is the actual byte to output in the case
+   of a literal, the base length or distance, or the offset from
+   the current table to the next table.  Each entry is four bytes. */
+typedef struct {
+    unsigned char op;           /* operation, extra bits, table bits */
+    unsigned char bits;         /* bits in this part of the code */
+    unsigned short val;         /* offset in table or code value */
+} code;
+
+/* op values as set by inflate_table():
+    00000000 - literal
+    0000tttt - table link, tttt != 0 is the number of table index bits
+    100eeeee - length or distance, eeee is the number of extra bits
+    01100000 - end of block
+    01000000 - invalid code
+ */
+
+/* Maximum size of the dynamic table.  The maximum number of code structures is
+   1446, which is the sum of 852 for literal/length codes and 594 for distance
+   codes.  These values were found by exhaustive searches using the program
+   examples/enough.c found in the zlib distribtution.  The arguments to that
+   program are the number of symbols, the initial root table size, and the
+   maximum bit length of a code.  "enough 286 9 15" for literal/length codes
+   returns returns 852, and "enough 32 6 15" for distance codes returns 594.
+   The initial root table size (9 or 6) is found in the fifth argument of the
+   inflate_table() calls in infback9.c.  If the root table size is changed,
+   then these maximum sizes would be need to be recalculated and updated. */
+#define ENOUGH_LENS 852
+#define ENOUGH_DISTS 594
+#define ENOUGH (ENOUGH_LENS+ENOUGH_DISTS)
+
+/* Type of code to build for inflate_table9() */
+typedef enum {
+    CODES,
+    LENS,
+    DISTS
+} codetype;
+
+extern int inflate_table9 OF((codetype type, unsigned short FAR *lens,
+                             unsigned codes, code FAR * FAR *table,
+                             unsigned FAR *bits, unsigned short FAR *work));
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/masmx64/bld_ml64.bat
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/masmx64/bld_ml64.bat	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,2 @@
+ml64.exe /Flinffasx64 /c /Zi inffasx64.asm
+ml64.exe /Flgvmat64   /c /Zi gvmat64.asm
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/masmx64/gvmat64.asm
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/masmx64/gvmat64.asm	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,553 @@
+;uInt longest_match_x64(
+;    deflate_state *s,
+;    IPos cur_match);                             /* current match */
+
+; gvmat64.asm -- Asm portion of the optimized longest_match for 32 bits x86_64
+;  (AMD64 on Athlon 64, Opteron, Phenom
+;     and Intel EM64T on Pentium 4 with EM64T, Pentium D, Core 2 Duo, Core I5/I7)
+; Copyright (C) 1995-2010 Jean-loup Gailly, Brian Raiter and Gilles Vollant.
+;
+; File written by Gilles Vollant, by converting to assembly the longest_match
+;  from Jean-loup Gailly in deflate.c of zLib and infoZip zip.
+;
+;  and by taking inspiration on asm686 with masm, optimised assembly code
+;        from Brian Raiter, written 1998
+;
+;  This software is provided 'as-is', without any express or implied
+;  warranty.  In no event will the authors be held liable for any damages
+;  arising from the use of this software.
+;
+;  Permission is granted to anyone to use this software for any purpose,
+;  including commercial applications, and to alter it and redistribute it
+;  freely, subject to the following restrictions:
+;
+;  1. The origin of this software must not be misrepresented; you must not
+;     claim that you wrote the original software. If you use this software
+;     in a product, an acknowledgment in the product documentation would be
+;     appreciated but is not required.
+;  2. Altered source versions must be plainly marked as such, and must not be
+;     misrepresented as being the original software
+;  3. This notice may not be removed or altered from any source distribution.
+;
+;
+;
+;         http://www.zlib.net
+;         http://www.winimage.com/zLibDll
+;         http://www.muppetlabs.com/~breadbox/software/assembly.html
+;
+; to compile this file for infozip Zip, I use option:
+;   ml64.exe /Flgvmat64 /c /Zi /DINFOZIP gvmat64.asm
+;
+; to compile this file for zLib, I use option:
+;   ml64.exe /Flgvmat64 /c /Zi gvmat64.asm
+; Be carrefull to adapt zlib1222add below to your version of zLib
+;   (if you use a version of zLib before 1.0.4 or after 1.2.2.2, change
+;    value of zlib1222add later)
+;
+; This file compile with Microsoft Macro Assembler (x64) for AMD64
+;
+;   ml64.exe is given with Visual Studio 2005/2008/2010 and Windows WDK
+;
+;   (you can get Windows WDK with ml64 for AMD64 from
+;      http://www.microsoft.com/whdc/Devtools/wdk/default.mspx for low price)
+;
+
+
+;uInt longest_match(s, cur_match)
+;    deflate_state *s;
+;    IPos cur_match;                             /* current match */
+.code
+longest_match PROC
+
+
+;LocalVarsSize   equ 88
+ LocalVarsSize   equ 72
+
+; register used : rax,rbx,rcx,rdx,rsi,rdi,r8,r9,r10,r11,r12
+; free register :  r14,r15
+; register can be saved : rsp
+
+ chainlenwmask   equ  rsp + 8 - LocalVarsSize    ; high word: current chain len
+                                                 ; low word: s->wmask
+;window          equ  rsp + xx - LocalVarsSize   ; local copy of s->window ; stored in r10
+;windowbestlen   equ  rsp + xx - LocalVarsSize   ; s->window + bestlen , use r10+r11
+;scanstart       equ  rsp + xx - LocalVarsSize   ; first two bytes of string ; stored in r12w
+;scanend         equ  rsp + xx - LocalVarsSize   ; last two bytes of string use ebx
+;scanalign       equ  rsp + xx - LocalVarsSize   ; dword-misalignment of string r13
+;bestlen         equ  rsp + xx - LocalVarsSize   ; size of best match so far -> r11d
+;scan            equ  rsp + xx - LocalVarsSize   ; ptr to string wanting match -> r9
+IFDEF INFOZIP
+ELSE
+ nicematch       equ  (rsp + 16 - LocalVarsSize) ; a good enough match size
+ENDIF
+
+save_rdi        equ  rsp + 24 - LocalVarsSize
+save_rsi        equ  rsp + 32 - LocalVarsSize
+save_rbx        equ  rsp + 40 - LocalVarsSize
+save_rbp        equ  rsp + 48 - LocalVarsSize
+save_r12        equ  rsp + 56 - LocalVarsSize
+save_r13        equ  rsp + 64 - LocalVarsSize
+;save_r14        equ  rsp + 72 - LocalVarsSize
+;save_r15        equ  rsp + 80 - LocalVarsSize
+
+
+; summary of register usage
+; scanend     ebx
+; scanendw    bx
+; chainlenwmask   edx
+; curmatch    rsi
+; curmatchd   esi
+; windowbestlen   r8
+; scanalign   r9
+; scanalignd  r9d
+; window      r10
+; bestlen     r11
+; bestlend    r11d
+; scanstart   r12d
+; scanstartw  r12w
+; scan        r13
+; nicematch   r14d
+; limit       r15
+; limitd      r15d
+; prev        rcx
+
+;  all the +4 offsets are due to the addition of pending_buf_size (in zlib
+;  in the deflate_state structure since the asm code was first written
+;  (if you compile with zlib 1.0.4 or older, remove the +4).
+;  Note : these value are good with a 8 bytes boundary pack structure
+
+
+    MAX_MATCH           equ     258
+    MIN_MATCH           equ     3
+    MIN_LOOKAHEAD       equ     (MAX_MATCH+MIN_MATCH+1)
+
+
+;;; Offsets for fields in the deflate_state structure. These numbers
+;;; are calculated from the definition of deflate_state, with the
+;;; assumption that the compiler will dword-align the fields. (Thus,
+;;; changing the definition of deflate_state could easily cause this
+;;; program to crash horribly, without so much as a warning at
+;;; compile time. Sigh.)
+
+;  all the +zlib1222add offsets are due to the addition of fields
+;  in zlib in the deflate_state structure since the asm code was first written
+;  (if you compile with zlib 1.0.4 or older, use "zlib1222add equ (-4)").
+;  (if you compile with zlib between 1.0.5 and 1.2.2.1, use "zlib1222add equ 0").
+;  if you compile with zlib 1.2.2.2 or later , use "zlib1222add equ 8").
+
+
+IFDEF INFOZIP
+
+_DATA   SEGMENT
+COMM    window_size:DWORD
+; WMask ; 7fff
+COMM    window:BYTE:010040H
+COMM    prev:WORD:08000H
+; MatchLen : unused
+; PrevMatch : unused
+COMM    strstart:DWORD
+COMM    match_start:DWORD
+; Lookahead : ignore
+COMM    prev_length:DWORD ; PrevLen
+COMM    max_chain_length:DWORD
+COMM    good_match:DWORD
+COMM    nice_match:DWORD
+prev_ad equ OFFSET prev
+window_ad equ OFFSET window
+nicematch equ nice_match
+_DATA ENDS
+WMask equ 07fffh
+
+ELSE
+
+  IFNDEF zlib1222add
+    zlib1222add equ 8
+  ENDIF
+dsWSize         equ 56+zlib1222add+(zlib1222add/2)
+dsWMask         equ 64+zlib1222add+(zlib1222add/2)
+dsWindow        equ 72+zlib1222add
+dsPrev          equ 88+zlib1222add
+dsMatchLen      equ 128+zlib1222add
+dsPrevMatch     equ 132+zlib1222add
+dsStrStart      equ 140+zlib1222add
+dsMatchStart    equ 144+zlib1222add
+dsLookahead     equ 148+zlib1222add
+dsPrevLen       equ 152+zlib1222add
+dsMaxChainLen   equ 156+zlib1222add
+dsGoodMatch     equ 172+zlib1222add
+dsNiceMatch     equ 176+zlib1222add
+
+window_size     equ [ rcx + dsWSize]
+WMask           equ [ rcx + dsWMask]
+window_ad       equ [ rcx + dsWindow]
+prev_ad         equ [ rcx + dsPrev]
+strstart        equ [ rcx + dsStrStart]
+match_start     equ [ rcx + dsMatchStart]
+Lookahead       equ [ rcx + dsLookahead] ; 0ffffffffh on infozip
+prev_length     equ [ rcx + dsPrevLen]
+max_chain_length equ [ rcx + dsMaxChainLen]
+good_match      equ [ rcx + dsGoodMatch]
+nice_match      equ [ rcx + dsNiceMatch]
+ENDIF
+
+; parameter 1 in r8(deflate state s), param 2 in rdx (cur match)
+
+; see http://weblogs.asp.net/oldnewthing/archive/2004/01/14/58579.aspx and
+; http://msdn.microsoft.com/library/en-us/kmarch/hh/kmarch/64bitAMD_8e951dd2-ee77-4728-8702-55ce4b5dd24a.xml.asp
+;
+; All registers must be preserved across the call, except for
+;   rax, rcx, rdx, r8, r9, r10, and r11, which are scratch.
+
+
+
+;;; Save registers that the compiler may be using, and adjust esp to
+;;; make room for our stack frame.
+
+
+;;; Retrieve the function arguments. r8d will hold cur_match
+;;; throughout the entire function. edx will hold the pointer to the
+;;; deflate_state structure during the function's setup (before
+;;; entering the main loop.
+
+; parameter 1 in rcx (deflate_state* s), param 2 in edx -> r8 (cur match)
+
+; this clear high 32 bits of r8, which can be garbage in both r8 and rdx
+
+        mov [save_rdi],rdi
+        mov [save_rsi],rsi
+        mov [save_rbx],rbx
+        mov [save_rbp],rbp
+IFDEF INFOZIP
+        mov r8d,ecx
+ELSE
+        mov r8d,edx
+ENDIF
+        mov [save_r12],r12
+        mov [save_r13],r13
+;        mov [save_r14],r14
+;        mov [save_r15],r15
+
+
+;;; uInt wmask = s->w_mask;
+;;; unsigned chain_length = s->max_chain_length;
+;;; if (s->prev_length >= s->good_match) {
+;;;     chain_length >>= 2;
+;;; }
+
+        mov edi, prev_length
+        mov esi, good_match
+        mov eax, WMask
+        mov ebx, max_chain_length
+        cmp edi, esi
+        jl  LastMatchGood
+        shr ebx, 2
+LastMatchGood:
+
+;;; chainlen is decremented once beforehand so that the function can
+;;; use the sign flag instead of the zero flag for the exit test.
+;;; It is then shifted into the high word, to make room for the wmask
+;;; value, which it will always accompany.
+
+        dec ebx
+        shl ebx, 16
+        or  ebx, eax
+
+;;; on zlib only
+;;; if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
+
+IFDEF INFOZIP
+        mov [chainlenwmask], ebx
+; on infozip nice_match = [nice_match]
+ELSE
+        mov eax, nice_match
+        mov [chainlenwmask], ebx
+        mov r10d, Lookahead
+        cmp r10d, eax
+        cmovnl r10d, eax
+        mov [nicematch],r10d
+ENDIF
+
+;;; register Bytef *scan = s->window + s->strstart;
+        mov r10, window_ad
+        mov ebp, strstart
+        lea r13, [r10 + rbp]
+
+;;; Determine how many bytes the scan ptr is off from being
+;;; dword-aligned.
+
+         mov r9,r13
+         neg r13
+         and r13,3
+
+;;; IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
+;;;     s->strstart - (IPos)MAX_DIST(s) : NIL;
+IFDEF INFOZIP
+        mov eax,07efah ; MAX_DIST = (WSIZE-MIN_LOOKAHEAD) (0x8000-(3+8+1))
+ELSE
+        mov eax, window_size
+        sub eax, MIN_LOOKAHEAD
+ENDIF
+        xor edi,edi
+        sub ebp, eax
+
+        mov r11d, prev_length
+
+        cmovng ebp,edi
+
+;;; int best_len = s->prev_length;
+
+
+;;; Store the sum of s->window + best_len in esi locally, and in esi.
+
+       lea  rsi,[r10+r11]
+
+;;; register ush scan_start = *(ushf*)scan;
+;;; register ush scan_end   = *(ushf*)(scan+best_len-1);
+;;; Posf *prev = s->prev;
+
+        movzx r12d,word ptr [r9]
+        movzx ebx, word ptr [r9 + r11 - 1]
+
+        mov rdi, prev_ad
+
+;;; Jump into the main loop.
+
+        mov edx, [chainlenwmask]
+
+        cmp bx,word ptr [rsi + r8 - 1]
+        jz  LookupLoopIsZero
+
+LookupLoop1:
+        and r8d, edx
+
+        movzx   r8d, word ptr [rdi + r8*2]
+        cmp r8d, ebp
+        jbe LeaveNow
+        sub edx, 00010000h
+        js  LeaveNow
+
+LoopEntry1:
+        cmp bx,word ptr [rsi + r8 - 1]
+        jz  LookupLoopIsZero
+
+LookupLoop2:
+        and r8d, edx
+
+        movzx   r8d, word ptr [rdi + r8*2]
+        cmp r8d, ebp
+        jbe LeaveNow
+        sub edx, 00010000h
+        js  LeaveNow
+
+LoopEntry2:
+        cmp bx,word ptr [rsi + r8 - 1]
+        jz  LookupLoopIsZero
+
+LookupLoop4:
+        and r8d, edx
+
+        movzx   r8d, word ptr [rdi + r8*2]
+        cmp r8d, ebp
+        jbe LeaveNow
+        sub edx, 00010000h
+        js  LeaveNow
+
+LoopEntry4:
+
+        cmp bx,word ptr [rsi + r8 - 1]
+        jnz LookupLoop1
+        jmp LookupLoopIsZero
+
+
+;;; do {
+;;;     match = s->window + cur_match;
+;;;     if (*(ushf*)(match+best_len-1) != scan_end ||
+;;;         *(ushf*)match != scan_start) continue;
+;;;     [...]
+;;; } while ((cur_match = prev[cur_match & wmask]) > limit
+;;;          && --chain_length != 0);
+;;;
+;;; Here is the inner loop of the function. The function will spend the
+;;; majority of its time in this loop, and majority of that time will
+;;; be spent in the first ten instructions.
+;;;
+;;; Within this loop:
+;;; ebx = scanend
+;;; r8d = curmatch
+;;; edx = chainlenwmask - i.e., ((chainlen << 16) | wmask)
+;;; esi = windowbestlen - i.e., (window + bestlen)
+;;; edi = prev
+;;; ebp = limit
+
+LookupLoop:
+        and r8d, edx
+
+        movzx   r8d, word ptr [rdi + r8*2]
+        cmp r8d, ebp
+        jbe LeaveNow
+        sub edx, 00010000h
+        js  LeaveNow
+
+LoopEntry:
+
+        cmp bx,word ptr [rsi + r8 - 1]
+        jnz LookupLoop1
+LookupLoopIsZero:
+        cmp     r12w, word ptr [r10 + r8]
+        jnz LookupLoop1
+
+
+;;; Store the current value of chainlen.
+        mov [chainlenwmask], edx
+
+;;; Point edi to the string under scrutiny, and esi to the string we
+;;; are hoping to match it up with. In actuality, esi and edi are
+;;; both pointed (MAX_MATCH_8 - scanalign) bytes ahead, and edx is
+;;; initialized to -(MAX_MATCH_8 - scanalign).
+
+        lea rsi,[r8+r10]
+        mov rdx, 0fffffffffffffef8h; -(MAX_MATCH_8)
+        lea rsi, [rsi + r13 + 0108h] ;MAX_MATCH_8]
+        lea rdi, [r9 + r13 + 0108h] ;MAX_MATCH_8]
+
+        prefetcht1 [rsi+rdx]
+        prefetcht1 [rdi+rdx]
+
+
+;;; Test the strings for equality, 8 bytes at a time. At the end,
+;;; adjust rdx so that it is offset to the exact byte that mismatched.
+;;;
+;;; We already know at this point that the first three bytes of the
+;;; strings match each other, and they can be safely passed over before
+;;; starting the compare loop. So what this code does is skip over 0-3
+;;; bytes, as much as necessary in order to dword-align the edi
+;;; pointer. (rsi will still be misaligned three times out of four.)
+;;;
+;;; It should be confessed that this loop usually does not represent
+;;; much of the total running time. Replacing it with a more
+;;; straightforward "rep cmpsb" would not drastically degrade
+;;; performance.
+
+
+LoopCmps:
+        mov rax, [rsi + rdx]
+        xor rax, [rdi + rdx]
+        jnz LeaveLoopCmps
+
+        mov rax, [rsi + rdx + 8]
+        xor rax, [rdi + rdx + 8]
+        jnz LeaveLoopCmps8
+
+
+        mov rax, [rsi + rdx + 8+8]
+        xor rax, [rdi + rdx + 8+8]
+        jnz LeaveLoopCmps16
+
+        add rdx,8+8+8
+
+        jnz short LoopCmps
+        jmp short LenMaximum
+LeaveLoopCmps16: add rdx,8
+LeaveLoopCmps8: add rdx,8
+LeaveLoopCmps:
+
+        test    eax, 0000FFFFh
+        jnz LenLower
+
+        test eax,0ffffffffh
+
+        jnz LenLower32
+
+        add rdx,4
+        shr rax,32
+        or ax,ax
+        jnz LenLower
+
+LenLower32:
+        shr eax,16
+        add rdx,2
+LenLower:   sub al, 1
+        adc rdx, 0
+;;; Calculate the length of the match. If it is longer than MAX_MATCH,
+;;; then automatically accept it as the best possible match and leave.
+
+        lea rax, [rdi + rdx]
+        sub rax, r9
+        cmp eax, MAX_MATCH
+        jge LenMaximum
+
+;;; If the length of the match is not longer than the best match we
+;;; have so far, then forget it and return to the lookup loop.
+;///////////////////////////////////
+
+        cmp eax, r11d
+        jg  LongerMatch
+
+        lea rsi,[r10+r11]
+
+        mov rdi, prev_ad
+        mov edx, [chainlenwmask]
+        jmp LookupLoop
+
+;;;         s->match_start = cur_match;
+;;;         best_len = len;
+;;;         if (len >= nice_match) break;
+;;;         scan_end = *(ushf*)(scan+best_len-1);
+
+LongerMatch:
+        mov r11d, eax
+        mov match_start, r8d
+        cmp eax, [nicematch]
+        jge LeaveNow
+
+        lea rsi,[r10+rax]
+
+        movzx   ebx, word ptr [r9 + rax - 1]
+        mov rdi, prev_ad
+        mov edx, [chainlenwmask]
+        jmp LookupLoop
+
+;;; Accept the current string, with the maximum possible length.
+
+LenMaximum:
+        mov r11d,MAX_MATCH
+        mov match_start, r8d
+
+;;; if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
+;;; return s->lookahead;
+
+LeaveNow:
+IFDEF INFOZIP
+        mov eax,r11d
+ELSE
+        mov eax, Lookahead
+        cmp r11d, eax
+        cmovng eax, r11d
+ENDIF
+
+;;; Restore the stack and return from whence we came.
+
+
+        mov rsi,[save_rsi]
+        mov rdi,[save_rdi]
+        mov rbx,[save_rbx]
+        mov rbp,[save_rbp]
+        mov r12,[save_r12]
+        mov r13,[save_r13]
+;        mov r14,[save_r14]
+;        mov r15,[save_r15]
+
+
+        ret 0
+; please don't remove this string !
+; Your can freely use gvmat64 in any free or commercial app
+; but it is far better don't remove the string in the binary!
+    db     0dh,0ah,"asm686 with masm, optimised assembly code from Brian Raiter, written 1998, converted to amd 64 by Gilles Vollant 2005",0dh,0ah,0
+longest_match   ENDP
+
+match_init PROC
+  ret 0
+match_init ENDP
+
+
+END
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/masmx64/inffas8664.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/masmx64/inffas8664.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,186 @@
+/* inffas8664.c is a hand tuned assembler version of inffast.c - fast decoding
+ * version for AMD64 on Windows using Microsoft C compiler
+ *
+ * Copyright (C) 1995-2003 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ *
+ * Copyright (C) 2003 Chris Anderson <christop@charm.net>
+ * Please use the copyright conditions above.
+ *
+ * 2005 - Adaptation to Microsoft C Compiler for AMD64 by Gilles Vollant
+ *
+ * inffas8664.c call function inffas8664fnc in inffasx64.asm
+ *  inffasx64.asm is automatically convert from AMD64 portion of inffas86.c
+ *
+ * Dec-29-2003 -- I added AMD64 inflate asm support.  This version is also
+ * slightly quicker on x86 systems because, instead of using rep movsb to copy
+ * data, it uses rep movsw, which moves data in 2-byte chunks instead of single
+ * bytes.  I've tested the AMD64 code on a Fedora Core 1 + the x86_64 updates
+ * from http://fedora.linux.duke.edu/fc1_x86_64
+ * which is running on an Athlon 64 3000+ / Gigabyte GA-K8VT800M system with
+ * 1GB ram.  The 64-bit version is about 4% faster than the 32-bit version,
+ * when decompressing mozilla-source-1.3.tar.gz.
+ *
+ * Mar-13-2003 -- Most of this is derived from inffast.S which is derived from
+ * the gcc -S output of zlib-1.2.0/inffast.c.  Zlib-1.2.0 is in beta release at
+ * the moment.  I have successfully compiled and tested this code with gcc2.96,
+ * gcc3.2, icc5.0, msvc6.0.  It is very close to the speed of inffast.S
+ * compiled with gcc -DNO_MMX, but inffast.S is still faster on the P3 with MMX
+ * enabled.  I will attempt to merge the MMX code into this version.  Newer
+ * versions of this and inffast.S can be found at
+ * http://www.eetbeetee.com/zlib/ and http://www.charm.net/~christop/zlib/
+ *
+ */
+
+#include <stdio.h>
+#include "zutil.h"
+#include "inftrees.h"
+#include "inflate.h"
+#include "inffast.h"
+
+/* Mark Adler's comments from inffast.c: */
+
+/*
+   Decode literal, length, and distance codes and write out the resulting
+   literal and match bytes until either not enough input or output is
+   available, an end-of-block is encountered, or a data error is encountered.
+   When large enough input and output buffers are supplied to inflate(), for
+   example, a 16K input buffer and a 64K output buffer, more than 95% of the
+   inflate execution time is spent in this routine.
+
+   Entry assumptions:
+
+        state->mode == LEN
+        strm->avail_in >= 6
+        strm->avail_out >= 258
+        start >= strm->avail_out
+        state->bits < 8
+
+   On return, state->mode is one of:
+
+        LEN -- ran out of enough output space or enough available input
+        TYPE -- reached end of block code, inflate() to interpret next block
+        BAD -- error in block data
+
+   Notes:
+
+    - The maximum input bits used by a length/distance pair is 15 bits for the
+      length code, 5 bits for the length extra, 15 bits for the distance code,
+      and 13 bits for the distance extra.  This totals 48 bits, or six bytes.
+      Therefore if strm->avail_in >= 6, then there is enough input to avoid
+      checking for available input while decoding.
+
+    - The maximum bytes that a single length/distance pair can output is 258
+      bytes, which is the maximum length that can be coded.  inflate_fast()
+      requires strm->avail_out >= 258 for each loop to avoid checking for
+      output space.
+ */
+
+
+
+    typedef struct inffast_ar {
+/* 64   32                               x86  x86_64 */
+/* ar offset                              register */
+/*  0    0 */ void *esp;                /* esp save */
+/*  8    4 */ void *ebp;                /* ebp save */
+/* 16    8 */ unsigned char FAR *in;    /* esi rsi  local strm->next_in */
+/* 24   12 */ unsigned char FAR *last;  /*     r9   while in < last */
+/* 32   16 */ unsigned char FAR *out;   /* edi rdi  local strm->next_out */
+/* 40   20 */ unsigned char FAR *beg;   /*          inflate()'s init next_out */
+/* 48   24 */ unsigned char FAR *end;   /*     r10  while out < end */
+/* 56   28 */ unsigned char FAR *window;/*          size of window, wsize!=0 */
+/* 64   32 */ code const FAR *lcode;    /* ebp rbp  local strm->lencode */
+/* 72   36 */ code const FAR *dcode;    /*     r11  local strm->distcode */
+/* 80   40 */ size_t /*unsigned long */hold;       /* edx rdx  local strm->hold */
+/* 88   44 */ unsigned bits;            /* ebx rbx  local strm->bits */
+/* 92   48 */ unsigned wsize;           /*          window size */
+/* 96   52 */ unsigned write;           /*          window write index */
+/*100   56 */ unsigned lmask;           /*     r12  mask for lcode */
+/*104   60 */ unsigned dmask;           /*     r13  mask for dcode */
+/*108   64 */ unsigned len;             /*     r14  match length */
+/*112   68 */ unsigned dist;            /*     r15  match distance */
+/*116   72 */ unsigned status;          /*          set when state chng*/
+    } type_ar;
+#ifdef ASMINF
+
+void inflate_fast(strm, start)
+z_streamp strm;
+unsigned start;         /* inflate()'s starting value for strm->avail_out */
+{
+    struct inflate_state FAR *state;
+    type_ar ar;
+    void inffas8664fnc(struct inffast_ar * par);
+
+
+
+#if (defined( __GNUC__ ) && defined( __amd64__ ) && ! defined( __i386 )) || (defined(_MSC_VER) && defined(_M_AMD64))
+#define PAD_AVAIL_IN 6
+#define PAD_AVAIL_OUT 258
+#else
+#define PAD_AVAIL_IN 5
+#define PAD_AVAIL_OUT 257
+#endif
+
+    /* copy state to local variables */
+    state = (struct inflate_state FAR *)strm->state;
+
+    ar.in = strm->next_in;
+    ar.last = ar.in + (strm->avail_in - PAD_AVAIL_IN);
+    ar.out = strm->next_out;
+    ar.beg = ar.out - (start - strm->avail_out);
+    ar.end = ar.out + (strm->avail_out - PAD_AVAIL_OUT);
+    ar.wsize = state->wsize;
+    ar.write = state->wnext;
+    ar.window = state->window;
+    ar.hold = state->hold;
+    ar.bits = state->bits;
+    ar.lcode = state->lencode;
+    ar.dcode = state->distcode;
+    ar.lmask = (1U << state->lenbits) - 1;
+    ar.dmask = (1U << state->distbits) - 1;
+
+    /* decode literals and length/distances until end-of-block or not enough
+       input data or output space */
+
+    /* align in on 1/2 hold size boundary */
+    while (((size_t)(void *)ar.in & (sizeof(ar.hold) / 2 - 1)) != 0) {
+        ar.hold += (unsigned long)*ar.in++ << ar.bits;
+        ar.bits += 8;
+    }
+
+    inffas8664fnc(&ar);
+
+    if (ar.status > 1) {
+        if (ar.status == 2)
+            strm->msg = "invalid literal/length code";
+        else if (ar.status == 3)
+            strm->msg = "invalid distance code";
+        else
+            strm->msg = "invalid distance too far back";
+        state->mode = BAD;
+    }
+    else if ( ar.status == 1 ) {
+        state->mode = TYPE;
+    }
+
+    /* return unused bytes (on entry, bits < 8, so in won't go too far back) */
+    ar.len = ar.bits >> 3;
+    ar.in -= ar.len;
+    ar.bits -= ar.len << 3;
+    ar.hold &= (1U << ar.bits) - 1;
+
+    /* update state and return */
+    strm->next_in = ar.in;
+    strm->next_out = ar.out;
+    strm->avail_in = (unsigned)(ar.in < ar.last ?
+                                PAD_AVAIL_IN + (ar.last - ar.in) :
+                                PAD_AVAIL_IN - (ar.in - ar.last));
+    strm->avail_out = (unsigned)(ar.out < ar.end ?
+                                 PAD_AVAIL_OUT + (ar.end - ar.out) :
+                                 PAD_AVAIL_OUT - (ar.out - ar.end));
+    state->hold = (unsigned long)ar.hold;
+    state->bits = ar.bits;
+    return;
+}
+
+#endif
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/masmx64/inffasx64.asm
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/masmx64/inffasx64.asm	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,396 @@
+; inffasx64.asm is a hand tuned assembler version of inffast.c - fast decoding
+; version for AMD64 on Windows using Microsoft C compiler
+;
+; inffasx64.asm is automatically convert from AMD64 portion of inffas86.c
+; inffasx64.asm is called by inffas8664.c, which contain more info.
+
+
+; to compile this file, I use option
+;   ml64.exe /Flinffasx64 /c /Zi inffasx64.asm
+;   with Microsoft Macro Assembler (x64) for AMD64
+;
+
+; This file compile with Microsoft Macro Assembler (x64) for AMD64
+;
+;   ml64.exe is given with Visual Studio 2005/2008/2010 and Windows WDK
+;
+;   (you can get Windows WDK with ml64 for AMD64 from
+;      http://www.microsoft.com/whdc/Devtools/wdk/default.mspx for low price)
+;
+
+
+.code
+inffas8664fnc PROC
+
+; see http://weblogs.asp.net/oldnewthing/archive/2004/01/14/58579.aspx and
+; http://msdn.microsoft.com/library/en-us/kmarch/hh/kmarch/64bitAMD_8e951dd2-ee77-4728-8702-55ce4b5dd24a.xml.asp
+;
+; All registers must be preserved across the call, except for
+;   rax, rcx, rdx, r8, r-9, r10, and r11, which are scratch.
+
+
+	mov [rsp-8],rsi
+	mov [rsp-16],rdi
+	mov [rsp-24],r12
+	mov [rsp-32],r13
+	mov [rsp-40],r14
+	mov [rsp-48],r15
+	mov [rsp-56],rbx
+
+	mov rax,rcx
+
+	mov	[rax+8], rbp       ; /* save regs rbp and rsp */
+	mov	[rax], rsp
+
+	mov	rsp, rax          ; /* make rsp point to &ar */
+
+	mov	rsi, [rsp+16]      ; /* rsi  = in */
+	mov	rdi, [rsp+32]      ; /* rdi  = out */
+	mov	r9, [rsp+24]       ; /* r9   = last */
+	mov	r10, [rsp+48]      ; /* r10  = end */
+	mov	rbp, [rsp+64]      ; /* rbp  = lcode */
+	mov	r11, [rsp+72]      ; /* r11  = dcode */
+	mov	rdx, [rsp+80]      ; /* rdx  = hold */
+	mov	ebx, [rsp+88]      ; /* ebx  = bits */
+	mov	r12d, [rsp+100]    ; /* r12d = lmask */
+	mov	r13d, [rsp+104]    ; /* r13d = dmask */
+                                          ; /* r14d = len */
+                                          ; /* r15d = dist */
+
+
+	cld
+	cmp	r10, rdi
+	je	L_one_time           ; /* if only one decode left */
+	cmp	r9, rsi
+
+    jne L_do_loop
+
+
+L_one_time:
+	mov	r8, r12           ; /* r8 = lmask */
+	cmp	bl, 32
+	ja	L_get_length_code_one_time
+
+	lodsd                         ; /* eax = *(uint *)in++ */
+	mov	cl, bl            ; /* cl = bits, needs it for shifting */
+	add	bl, 32             ; /* bits += 32 */
+	shl	rax, cl
+	or	rdx, rax          ; /* hold |= *((uint *)in)++ << bits */
+	jmp	L_get_length_code_one_time
+
+ALIGN 4
+L_while_test:
+	cmp	r10, rdi
+	jbe	L_break_loop
+	cmp	r9, rsi
+	jbe	L_break_loop
+
+L_do_loop:
+	mov	r8, r12           ; /* r8 = lmask */
+	cmp	bl, 32
+	ja	L_get_length_code    ; /* if (32 < bits) */
+
+	lodsd                         ; /* eax = *(uint *)in++ */
+	mov	cl, bl            ; /* cl = bits, needs it for shifting */
+	add	bl, 32             ; /* bits += 32 */
+	shl	rax, cl
+	or	rdx, rax          ; /* hold |= *((uint *)in)++ << bits */
+
+L_get_length_code:
+	and	r8, rdx            ; /* r8 &= hold */
+	mov	eax, [rbp+r8*4]  ; /* eax = lcode[hold & lmask] */
+
+	mov	cl, ah            ; /* cl = this.bits */
+	sub	bl, ah            ; /* bits -= this.bits */
+	shr	rdx, cl           ; /* hold >>= this.bits */
+
+	test	al, al
+	jnz	L_test_for_length_base ; /* if (op != 0) 45.7% */
+
+	mov	r8, r12            ; /* r8 = lmask */
+	shr	eax, 16            ; /* output this.val char */
+	stosb
+
+L_get_length_code_one_time:
+	and	r8, rdx            ; /* r8 &= hold */
+	mov	eax, [rbp+r8*4] ; /* eax = lcode[hold & lmask] */
+
+L_dolen:
+	mov	cl, ah            ; /* cl = this.bits */
+	sub	bl, ah            ; /* bits -= this.bits */
+	shr	rdx, cl           ; /* hold >>= this.bits */
+
+	test	al, al
+	jnz	L_test_for_length_base ; /* if (op != 0) 45.7% */
+
+	shr	eax, 16            ; /* output this.val char */
+	stosb
+	jmp	L_while_test
+
+ALIGN 4
+L_test_for_length_base:
+	mov	r14d, eax         ; /* len = this */
+	shr	r14d, 16           ; /* len = this.val */
+	mov	cl, al
+
+	test	al, 16
+	jz	L_test_for_second_level_length ; /* if ((op & 16) == 0) 8% */
+	and	cl, 15             ; /* op &= 15 */
+	jz	L_decode_distance    ; /* if (!op) */
+
+L_add_bits_to_len:
+	sub	bl, cl
+	xor	eax, eax
+	inc	eax
+	shl	eax, cl
+	dec	eax
+	and	eax, edx          ; /* eax &= hold */
+	shr	rdx, cl
+	add	r14d, eax         ; /* len += hold & mask[op] */
+
+L_decode_distance:
+	mov	r8, r13           ; /* r8 = dmask */
+	cmp	bl, 32
+	ja	L_get_distance_code  ; /* if (32 < bits) */
+
+	lodsd                         ; /* eax = *(uint *)in++ */
+	mov	cl, bl            ; /* cl = bits, needs it for shifting */
+	add	bl, 32             ; /* bits += 32 */
+	shl	rax, cl
+	or	rdx, rax          ; /* hold |= *((uint *)in)++ << bits */
+
+L_get_distance_code:
+	and	r8, rdx           ; /* r8 &= hold */
+	mov	eax, [r11+r8*4] ; /* eax = dcode[hold & dmask] */
+
+L_dodist:
+	mov	r15d, eax         ; /* dist = this */
+	shr	r15d, 16           ; /* dist = this.val */
+	mov	cl, ah
+	sub	bl, ah            ; /* bits -= this.bits */
+	shr	rdx, cl           ; /* hold >>= this.bits */
+	mov	cl, al            ; /* cl = this.op */
+
+	test	al, 16             ; /* if ((op & 16) == 0) */
+	jz	L_test_for_second_level_dist
+	and	cl, 15             ; /* op &= 15 */
+	jz	L_check_dist_one
+
+L_add_bits_to_dist:
+	sub	bl, cl
+	xor	eax, eax
+	inc	eax
+	shl	eax, cl
+	dec	eax                 ; /* (1 << op) - 1 */
+	and	eax, edx          ; /* eax &= hold */
+	shr	rdx, cl
+	add	r15d, eax         ; /* dist += hold & ((1 << op) - 1) */
+
+L_check_window:
+	mov	r8, rsi           ; /* save in so from can use it's reg */
+	mov	rax, rdi
+	sub	rax, [rsp+40]      ; /* nbytes = out - beg */
+
+	cmp	eax, r15d
+	jb	L_clip_window        ; /* if (dist > nbytes) 4.2% */
+
+	mov	ecx, r14d         ; /* ecx = len */
+	mov	rsi, rdi
+	sub	rsi, r15          ; /* from = out - dist */
+
+	sar	ecx, 1
+	jnc	L_copy_two           ; /* if len % 2 == 0 */
+
+	rep     movsw
+	mov	al, [rsi]
+	mov	[rdi], al
+	inc	rdi
+
+	mov	rsi, r8           ; /* move in back to %rsi, toss from */
+	jmp	L_while_test
+
+L_copy_two:
+	rep     movsw
+	mov	rsi, r8           ; /* move in back to %rsi, toss from */
+	jmp	L_while_test
+
+ALIGN 4
+L_check_dist_one:
+	cmp	r15d, 1            ; /* if dist 1, is a memset */
+	jne	L_check_window
+	cmp	[rsp+40], rdi      ; /* if out == beg, outside window */
+	je	L_check_window
+
+	mov	ecx, r14d         ; /* ecx = len */
+	mov	al, [rdi-1]
+	mov	ah, al
+
+	sar	ecx, 1
+	jnc	L_set_two
+	mov	[rdi], al
+	inc	rdi
+
+L_set_two:
+	rep     stosw
+	jmp	L_while_test
+
+ALIGN 4
+L_test_for_second_level_length:
+	test	al, 64
+	jnz	L_test_for_end_of_block ; /* if ((op & 64) != 0) */
+
+	xor	eax, eax
+	inc	eax
+	shl	eax, cl
+	dec	eax
+	and	eax, edx         ; /* eax &= hold */
+	add	eax, r14d        ; /* eax += len */
+	mov	eax, [rbp+rax*4] ; /* eax = lcode[val+(hold&mask[op])]*/
+	jmp	L_dolen
+
+ALIGN 4
+L_test_for_second_level_dist:
+	test	al, 64
+	jnz	L_invalid_distance_code ; /* if ((op & 64) != 0) */
+
+	xor	eax, eax
+	inc	eax
+	shl	eax, cl
+	dec	eax
+	and	eax, edx         ; /* eax &= hold */
+	add	eax, r15d        ; /* eax += dist */
+	mov	eax, [r11+rax*4] ; /* eax = dcode[val+(hold&mask[op])]*/
+	jmp	L_dodist
+
+ALIGN 4
+L_clip_window:
+	mov	ecx, eax         ; /* ecx = nbytes */
+	mov	eax, [rsp+92]     ; /* eax = wsize, prepare for dist cmp */
+	neg	ecx                ; /* nbytes = -nbytes */
+
+	cmp	eax, r15d
+	jb	L_invalid_distance_too_far ; /* if (dist > wsize) */
+
+	add	ecx, r15d         ; /* nbytes = dist - nbytes */
+	cmp	dword ptr [rsp+96], 0
+	jne	L_wrap_around_window ; /* if (write != 0) */
+
+	mov	rsi, [rsp+56]     ; /* from  = window */
+	sub	eax, ecx         ; /* eax  -= nbytes */
+	add	rsi, rax         ; /* from += wsize - nbytes */
+
+	mov	eax, r14d        ; /* eax = len */
+	cmp	r14d, ecx
+	jbe	L_do_copy           ; /* if (nbytes >= len) */
+
+	sub	eax, ecx         ; /* eax -= nbytes */
+	rep     movsb
+	mov	rsi, rdi
+	sub	rsi, r15         ; /* from = &out[ -dist ] */
+	jmp	L_do_copy
+
+ALIGN 4
+L_wrap_around_window:
+	mov	eax, [rsp+96]     ; /* eax = write */
+	cmp	ecx, eax
+	jbe	L_contiguous_in_window ; /* if (write >= nbytes) */
+
+	mov	esi, [rsp+92]     ; /* from  = wsize */
+	add	rsi, [rsp+56]     ; /* from += window */
+	add	rsi, rax         ; /* from += write */
+	sub	rsi, rcx         ; /* from -= nbytes */
+	sub	ecx, eax         ; /* nbytes -= write */
+
+	mov	eax, r14d        ; /* eax = len */
+	cmp	eax, ecx
+	jbe	L_do_copy           ; /* if (nbytes >= len) */
+
+	sub	eax, ecx         ; /* len -= nbytes */
+	rep     movsb
+	mov	rsi, [rsp+56]     ; /* from = window */
+	mov	ecx, [rsp+96]     ; /* nbytes = write */
+	cmp	eax, ecx
+	jbe	L_do_copy           ; /* if (nbytes >= len) */
+
+	sub	eax, ecx         ; /* len -= nbytes */
+	rep     movsb
+	mov	rsi, rdi
+	sub	rsi, r15         ; /* from = out - dist */
+	jmp	L_do_copy
+
+ALIGN 4
+L_contiguous_in_window:
+	mov	rsi, [rsp+56]     ; /* rsi = window */
+	add	rsi, rax
+	sub	rsi, rcx         ; /* from += write - nbytes */
+
+	mov	eax, r14d        ; /* eax = len */
+	cmp	eax, ecx
+	jbe	L_do_copy           ; /* if (nbytes >= len) */
+
+	sub	eax, ecx         ; /* len -= nbytes */
+	rep     movsb
+	mov	rsi, rdi
+	sub	rsi, r15         ; /* from = out - dist */
+	jmp	L_do_copy           ; /* if (nbytes >= len) */
+
+ALIGN 4
+L_do_copy:
+	mov	ecx, eax         ; /* ecx = len */
+	rep     movsb
+
+	mov	rsi, r8          ; /* move in back to %esi, toss from */
+	jmp	L_while_test
+
+L_test_for_end_of_block:
+	test	al, 32
+	jz	L_invalid_literal_length_code
+	mov	dword ptr [rsp+116], 1
+	jmp	L_break_loop_with_status
+
+L_invalid_literal_length_code:
+	mov	dword ptr [rsp+116], 2
+	jmp	L_break_loop_with_status
+
+L_invalid_distance_code:
+	mov	dword ptr [rsp+116], 3
+	jmp	L_break_loop_with_status
+
+L_invalid_distance_too_far:
+	mov	dword ptr [rsp+116], 4
+	jmp	L_break_loop_with_status
+
+L_break_loop:
+	mov	dword ptr [rsp+116], 0
+
+L_break_loop_with_status:
+; /* put in, out, bits, and hold back into ar and pop esp */
+	mov	[rsp+16], rsi     ; /* in */
+	mov	[rsp+32], rdi     ; /* out */
+	mov	[rsp+88], ebx     ; /* bits */
+	mov	[rsp+80], rdx     ; /* hold */
+
+	mov	rax, [rsp]       ; /* restore rbp and rsp */
+	mov	rbp, [rsp+8]
+	mov	rsp, rax
+
+
+
+	mov rsi,[rsp-8]
+	mov rdi,[rsp-16]
+	mov r12,[rsp-24]
+	mov r13,[rsp-32]
+	mov r14,[rsp-40]
+	mov r15,[rsp-48]
+	mov rbx,[rsp-56]
+
+    ret 0
+;          :
+;          : "m" (ar)
+;          : "memory", "%rax", "%rbx", "%rcx", "%rdx", "%rsi", "%rdi",
+;            "%r8", "%r9", "%r10", "%r11", "%r12", "%r13", "%r14", "%r15"
+;    );
+
+inffas8664fnc 	ENDP
+;_TEXT	ENDS
+END
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/masmx64/readme.txt
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/masmx64/readme.txt	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,31 @@
+Summary
+-------
+This directory contains ASM implementations of the functions
+longest_match() and inflate_fast(), for 64 bits x86 (both AMD64 and Intel EM64t),
+for use with Microsoft Macro Assembler (x64) for AMD64 and Microsoft C++ 64 bits.
+
+gvmat64.asm is written by Gilles Vollant (2005), by using Brian Raiter 686/32 bits
+   assembly optimized version from Jean-loup Gailly original longest_match function
+
+inffasx64.asm and inffas8664.c were written by Chris Anderson, by optimizing
+   original function from Mark Adler
+
+Use instructions
+----------------
+Assemble the .asm files using MASM and put the object files into the zlib source
+directory.  You can also get object files here:
+
+     http://www.winimage.com/zLibDll/zlib124_masm_obj.zip
+
+define ASMV and ASMINF in your project. Include inffas8664.c in your source tree,
+and inffasx64.obj and gvmat64.obj as object to link.
+
+
+Build instructions
+------------------
+run bld_64.bat with Microsoft Macro Assembler (x64) for AMD64 (ml64.exe)
+
+ml64.exe is given with Visual Studio 2005, Windows 2003 server DDK
+
+You can get Windows 2003 server DDK with ml64 and cl for AMD64 from
+  http://www.microsoft.com/whdc/devtools/ddk/default.mspx for low price)
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/masmx86/bld_ml32.bat
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/masmx86/bld_ml32.bat	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,2 @@
+ml /coff /Zi /c /Flmatch686.lst match686.asm
+ml /coff /Zi /c /Flinffas32.lst inffas32.asm
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/masmx86/inffas32.asm
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/masmx86/inffas32.asm	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,1080 @@
+;/* inffas32.asm is a hand tuned assembler version of inffast.c -- fast decoding
+; *
+; * inffas32.asm is derivated from inffas86.c, with translation of assembly code
+; *
+; * Copyright (C) 1995-2003 Mark Adler
+; * For conditions of distribution and use, see copyright notice in zlib.h
+; *
+; * Copyright (C) 2003 Chris Anderson <christop@charm.net>
+; * Please use the copyright conditions above.
+; *
+; * Mar-13-2003 -- Most of this is derived from inffast.S which is derived from
+; * the gcc -S output of zlib-1.2.0/inffast.c.  Zlib-1.2.0 is in beta release at
+; * the moment.  I have successfully compiled and tested this code with gcc2.96,
+; * gcc3.2, icc5.0, msvc6.0.  It is very close to the speed of inffast.S
+; * compiled with gcc -DNO_MMX, but inffast.S is still faster on the P3 with MMX
+; * enabled.  I will attempt to merge the MMX code into this version.  Newer
+; * versions of this and inffast.S can be found at
+; * http://www.eetbeetee.com/zlib/ and http://www.charm.net/~christop/zlib/
+; *
+; * 2005 : modification by Gilles Vollant
+; */
+; For Visual C++ 4.x and higher and ML 6.x and higher
+;   ml.exe is in directory \MASM611C of Win95 DDK
+;   ml.exe is also distributed in http://www.masm32.com/masmdl.htm
+;    and in VC++2003 toolkit at http://msdn.microsoft.com/visualc/vctoolkit2003/
+;
+;
+;   compile with command line option
+;   ml  /coff /Zi /c /Flinffas32.lst inffas32.asm
+
+;   if you define NO_GZIP (see inflate.h), compile with
+;   ml  /coff /Zi /c /Flinffas32.lst /DNO_GUNZIP inffas32.asm
+
+
+; zlib122sup is 0 fort zlib 1.2.2.1 and lower
+; zlib122sup is 8 fort zlib 1.2.2.2 and more (with addition of dmax and head
+;        in inflate_state in inflate.h)
+zlib1222sup      equ    8
+
+
+IFDEF GUNZIP
+  INFLATE_MODE_TYPE    equ 11
+  INFLATE_MODE_BAD     equ 26
+ELSE
+  IFNDEF NO_GUNZIP
+    INFLATE_MODE_TYPE    equ 11
+    INFLATE_MODE_BAD     equ 26
+  ELSE
+    INFLATE_MODE_TYPE    equ 3
+    INFLATE_MODE_BAD     equ 17
+  ENDIF
+ENDIF
+
+
+; 75 "inffast.S"
+;FILE "inffast.S"
+
+;;;GLOBAL _inflate_fast
+
+;;;SECTION .text
+
+
+
+	.586p
+	.mmx
+
+	name	inflate_fast_x86
+	.MODEL	FLAT
+
+_DATA			segment
+inflate_fast_use_mmx:
+	dd	1
+
+
+_TEXT			segment
+
+
+
+ALIGN 4
+	db	'Fast decoding Code from Chris Anderson'
+	db	0
+
+ALIGN 4
+invalid_literal_length_code_msg:
+	db	'invalid literal/length code'
+	db	0
+
+ALIGN 4
+invalid_distance_code_msg:
+	db	'invalid distance code'
+	db	0
+
+ALIGN 4
+invalid_distance_too_far_msg:
+	db	'invalid distance too far back'
+	db	0
+
+
+ALIGN 4
+inflate_fast_mask:
+dd	0
+dd	1
+dd	3
+dd	7
+dd	15
+dd	31
+dd	63
+dd	127
+dd	255
+dd	511
+dd	1023
+dd	2047
+dd	4095
+dd	8191
+dd	16383
+dd	32767
+dd	65535
+dd	131071
+dd	262143
+dd	524287
+dd	1048575
+dd	2097151
+dd	4194303
+dd	8388607
+dd	16777215
+dd	33554431
+dd	67108863
+dd	134217727
+dd	268435455
+dd	536870911
+dd	1073741823
+dd	2147483647
+dd	4294967295
+
+
+mode_state	 equ	0	;/* state->mode	*/
+wsize_state	 equ	(32+zlib1222sup)	;/* state->wsize */
+write_state	 equ	(36+4+zlib1222sup)	;/* state->write */
+window_state	 equ	(40+4+zlib1222sup)	;/* state->window */
+hold_state	 equ	(44+4+zlib1222sup)	;/* state->hold	*/
+bits_state	 equ	(48+4+zlib1222sup)	;/* state->bits	*/
+lencode_state	 equ	(64+4+zlib1222sup)	;/* state->lencode */
+distcode_state	 equ	(68+4+zlib1222sup)	;/* state->distcode */
+lenbits_state	 equ	(72+4+zlib1222sup)	;/* state->lenbits */
+distbits_state	 equ	(76+4+zlib1222sup)	;/* state->distbits */
+
+
+;;SECTION .text
+; 205 "inffast.S"
+;GLOBAL	inflate_fast_use_mmx
+
+;SECTION .data
+
+
+; GLOBAL inflate_fast_use_mmx:object
+;.size inflate_fast_use_mmx, 4
+; 226 "inffast.S"
+;SECTION .text
+
+ALIGN 4
+_inflate_fast proc near
+.FPO (16, 4, 0, 0, 1, 0)
+	push  edi
+	push  esi
+	push  ebp
+	push  ebx
+	pushfd
+	sub  esp,64
+	cld
+
+
+
+
+	mov  esi, [esp+88]
+	mov  edi, [esi+28]
+
+
+
+
+
+
+
+	mov  edx, [esi+4]
+	mov  eax, [esi+0]
+
+	add  edx,eax
+	sub  edx,11
+
+	mov  [esp+44],eax
+	mov  [esp+20],edx
+
+	mov  ebp, [esp+92]
+	mov  ecx, [esi+16]
+	mov  ebx, [esi+12]
+
+	sub  ebp,ecx
+	neg  ebp
+	add  ebp,ebx
+
+	sub  ecx,257
+	add  ecx,ebx
+
+	mov  [esp+60],ebx
+	mov  [esp+40],ebp
+	mov  [esp+16],ecx
+; 285 "inffast.S"
+	mov  eax, [edi+lencode_state]
+	mov  ecx, [edi+distcode_state]
+
+	mov  [esp+8],eax
+	mov  [esp+12],ecx
+
+	mov  eax,1
+	mov  ecx, [edi+lenbits_state]
+	shl  eax,cl
+	dec  eax
+	mov  [esp+0],eax
+
+	mov  eax,1
+	mov  ecx, [edi+distbits_state]
+	shl  eax,cl
+	dec  eax
+	mov  [esp+4],eax
+
+	mov  eax, [edi+wsize_state]
+	mov  ecx, [edi+write_state]
+	mov  edx, [edi+window_state]
+
+	mov  [esp+52],eax
+	mov  [esp+48],ecx
+	mov  [esp+56],edx
+
+	mov  ebp, [edi+hold_state]
+	mov  ebx, [edi+bits_state]
+; 321 "inffast.S"
+	mov  esi, [esp+44]
+	mov  ecx, [esp+20]
+	cmp  ecx,esi
+	ja   L_align_long
+
+	add  ecx,11
+	sub  ecx,esi
+	mov  eax,12
+	sub  eax,ecx
+	lea  edi, [esp+28]
+	rep movsb
+	mov  ecx,eax
+	xor  eax,eax
+	rep stosb
+	lea  esi, [esp+28]
+	mov  [esp+20],esi
+	jmp  L_is_aligned
+
+
+L_align_long:
+	test  esi,3
+	jz   L_is_aligned
+	xor  eax,eax
+	mov  al, [esi]
+	inc  esi
+	mov  ecx,ebx
+	add  ebx,8
+	shl  eax,cl
+	or  ebp,eax
+	jmp L_align_long
+
+L_is_aligned:
+	mov  edi, [esp+60]
+; 366 "inffast.S"
+L_check_mmx:
+	cmp  dword ptr [inflate_fast_use_mmx],2
+	je   L_init_mmx
+	ja   L_do_loop
+
+	push  eax
+	push  ebx
+	push  ecx
+	push  edx
+	pushfd
+	mov  eax, [esp]
+	xor  dword ptr [esp],0200000h
+
+
+
+
+	popfd
+	pushfd
+	pop  edx
+	xor  edx,eax
+	jz   L_dont_use_mmx
+	xor  eax,eax
+	cpuid
+	cmp  ebx,0756e6547h
+	jne  L_dont_use_mmx
+	cmp  ecx,06c65746eh
+	jne  L_dont_use_mmx
+	cmp  edx,049656e69h
+	jne  L_dont_use_mmx
+	mov  eax,1
+	cpuid
+	shr  eax,8
+	and  eax,15
+	cmp  eax,6
+	jne  L_dont_use_mmx
+	test  edx,0800000h
+	jnz  L_use_mmx
+	jmp  L_dont_use_mmx
+L_use_mmx:
+	mov  dword ptr [inflate_fast_use_mmx],2
+	jmp  L_check_mmx_pop
+L_dont_use_mmx:
+	mov  dword ptr [inflate_fast_use_mmx],3
+L_check_mmx_pop:
+	pop  edx
+	pop  ecx
+	pop  ebx
+	pop  eax
+	jmp  L_check_mmx
+; 426 "inffast.S"
+ALIGN 4
+L_do_loop:
+; 437 "inffast.S"
+	cmp  bl,15
+	ja   L_get_length_code
+
+	xor  eax,eax
+	lodsw
+	mov  cl,bl
+	add  bl,16
+	shl  eax,cl
+	or  ebp,eax
+
+L_get_length_code:
+	mov  edx, [esp+0]
+	mov  ecx, [esp+8]
+	and  edx,ebp
+	mov  eax, [ecx+edx*4]
+
+L_dolen:
+
+
+
+
+
+
+	mov  cl,ah
+	sub  bl,ah
+	shr  ebp,cl
+
+
+
+
+
+
+	test  al,al
+	jnz   L_test_for_length_base
+
+	shr  eax,16
+	stosb
+
+L_while_test:
+
+
+	cmp  [esp+16],edi
+	jbe  L_break_loop
+
+	cmp  [esp+20],esi
+	ja   L_do_loop
+	jmp  L_break_loop
+
+L_test_for_length_base:
+; 502 "inffast.S"
+	mov  edx,eax
+	shr  edx,16
+	mov  cl,al
+
+	test  al,16
+	jz   L_test_for_second_level_length
+	and  cl,15
+	jz   L_save_len
+	cmp  bl,cl
+	jae  L_add_bits_to_len
+
+	mov  ch,cl
+	xor  eax,eax
+	lodsw
+	mov  cl,bl
+	add  bl,16
+	shl  eax,cl
+	or  ebp,eax
+	mov  cl,ch
+
+L_add_bits_to_len:
+	mov  eax,1
+	shl  eax,cl
+	dec  eax
+	sub  bl,cl
+	and  eax,ebp
+	shr  ebp,cl
+	add  edx,eax
+
+L_save_len:
+	mov  [esp+24],edx
+
+
+L_decode_distance:
+; 549 "inffast.S"
+	cmp  bl,15
+	ja   L_get_distance_code
+
+	xor  eax,eax
+	lodsw
+	mov  cl,bl
+	add  bl,16
+	shl  eax,cl
+	or  ebp,eax
+
+L_get_distance_code:
+	mov  edx, [esp+4]
+	mov  ecx, [esp+12]
+	and  edx,ebp
+	mov  eax, [ecx+edx*4]
+
+
+L_dodist:
+	mov  edx,eax
+	shr  edx,16
+	mov  cl,ah
+	sub  bl,ah
+	shr  ebp,cl
+; 584 "inffast.S"
+	mov  cl,al
+
+	test  al,16
+	jz  L_test_for_second_level_dist
+	and  cl,15
+	jz  L_check_dist_one
+	cmp  bl,cl
+	jae  L_add_bits_to_dist
+
+	mov  ch,cl
+	xor  eax,eax
+	lodsw
+	mov  cl,bl
+	add  bl,16
+	shl  eax,cl
+	or  ebp,eax
+	mov  cl,ch
+
+L_add_bits_to_dist:
+	mov  eax,1
+	shl  eax,cl
+	dec  eax
+	sub  bl,cl
+	and  eax,ebp
+	shr  ebp,cl
+	add  edx,eax
+	jmp  L_check_window
+
+L_check_window:
+; 625 "inffast.S"
+	mov  [esp+44],esi
+	mov  eax,edi
+	sub  eax, [esp+40]
+
+	cmp  eax,edx
+	jb   L_clip_window
+
+	mov  ecx, [esp+24]
+	mov  esi,edi
+	sub  esi,edx
+
+	sub  ecx,3
+	mov  al, [esi]
+	mov  [edi],al
+	mov  al, [esi+1]
+	mov  dl, [esi+2]
+	add  esi,3
+	mov  [edi+1],al
+	mov  [edi+2],dl
+	add  edi,3
+	rep movsb
+
+	mov  esi, [esp+44]
+	jmp  L_while_test
+
+ALIGN 4
+L_check_dist_one:
+	cmp  edx,1
+	jne  L_check_window
+	cmp  [esp+40],edi
+	je  L_check_window
+
+	dec  edi
+	mov  ecx, [esp+24]
+	mov  al, [edi]
+	sub  ecx,3
+
+	mov  [edi+1],al
+	mov  [edi+2],al
+	mov  [edi+3],al
+	add  edi,4
+	rep stosb
+
+	jmp  L_while_test
+
+ALIGN 4
+L_test_for_second_level_length:
+
+
+
+
+	test  al,64
+	jnz   L_test_for_end_of_block
+
+	mov  eax,1
+	shl  eax,cl
+	dec  eax
+	and  eax,ebp
+	add  eax,edx
+	mov  edx, [esp+8]
+	mov  eax, [edx+eax*4]
+	jmp  L_dolen
+
+ALIGN 4
+L_test_for_second_level_dist:
+
+
+
+
+	test  al,64
+	jnz   L_invalid_distance_code
+
+	mov  eax,1
+	shl  eax,cl
+	dec  eax
+	and  eax,ebp
+	add  eax,edx
+	mov  edx, [esp+12]
+	mov  eax, [edx+eax*4]
+	jmp  L_dodist
+
+ALIGN 4
+L_clip_window:
+; 721 "inffast.S"
+	mov  ecx,eax
+	mov  eax, [esp+52]
+	neg  ecx
+	mov  esi, [esp+56]
+
+	cmp  eax,edx
+	jb   L_invalid_distance_too_far
+
+	add  ecx,edx
+	cmp  dword ptr [esp+48],0
+	jne  L_wrap_around_window
+
+	sub  eax,ecx
+	add  esi,eax
+; 749 "inffast.S"
+	mov  eax, [esp+24]
+	cmp  eax,ecx
+	jbe  L_do_copy1
+
+	sub  eax,ecx
+	rep movsb
+	mov  esi,edi
+	sub  esi,edx
+	jmp  L_do_copy1
+
+	cmp  eax,ecx
+	jbe  L_do_copy1
+
+	sub  eax,ecx
+	rep movsb
+	mov  esi,edi
+	sub  esi,edx
+	jmp  L_do_copy1
+
+L_wrap_around_window:
+; 793 "inffast.S"
+	mov  eax, [esp+48]
+	cmp  ecx,eax
+	jbe  L_contiguous_in_window
+
+	add  esi, [esp+52]
+	add  esi,eax
+	sub  esi,ecx
+	sub  ecx,eax
+
+
+	mov  eax, [esp+24]
+	cmp  eax,ecx
+	jbe  L_do_copy1
+
+	sub  eax,ecx
+	rep movsb
+	mov  esi, [esp+56]
+	mov  ecx, [esp+48]
+	cmp  eax,ecx
+	jbe  L_do_copy1
+
+	sub  eax,ecx
+	rep movsb
+	mov  esi,edi
+	sub  esi,edx
+	jmp  L_do_copy1
+
+L_contiguous_in_window:
+; 836 "inffast.S"
+	add  esi,eax
+	sub  esi,ecx
+
+
+	mov  eax, [esp+24]
+	cmp  eax,ecx
+	jbe  L_do_copy1
+
+	sub  eax,ecx
+	rep movsb
+	mov  esi,edi
+	sub  esi,edx
+
+L_do_copy1:
+; 862 "inffast.S"
+	mov  ecx,eax
+	rep movsb
+
+	mov  esi, [esp+44]
+	jmp  L_while_test
+; 878 "inffast.S"
+ALIGN 4
+L_init_mmx:
+	emms
+
+
+
+
+
+	movd mm0,ebp
+	mov  ebp,ebx
+; 896 "inffast.S"
+	movd mm4,dword ptr [esp+0]
+	movq mm3,mm4
+	movd mm5,dword ptr [esp+4]
+	movq mm2,mm5
+	pxor mm1,mm1
+	mov  ebx, [esp+8]
+	jmp  L_do_loop_mmx
+
+ALIGN 4
+L_do_loop_mmx:
+	psrlq mm0,mm1
+
+	cmp  ebp,32
+	ja  L_get_length_code_mmx
+
+	movd mm6,ebp
+	movd mm7,dword ptr [esi]
+	add  esi,4
+	psllq mm7,mm6
+	add  ebp,32
+	por mm0,mm7
+
+L_get_length_code_mmx:
+	pand mm4,mm0
+	movd eax,mm4
+	movq mm4,mm3
+	mov  eax, [ebx+eax*4]
+
+L_dolen_mmx:
+	movzx  ecx,ah
+	movd mm1,ecx
+	sub  ebp,ecx
+
+	test  al,al
+	jnz L_test_for_length_base_mmx
+
+	shr  eax,16
+	stosb
+
+L_while_test_mmx:
+
+
+	cmp  [esp+16],edi
+	jbe L_break_loop
+
+	cmp  [esp+20],esi
+	ja L_do_loop_mmx
+	jmp L_break_loop
+
+L_test_for_length_base_mmx:
+
+	mov  edx,eax
+	shr  edx,16
+
+	test  al,16
+	jz  L_test_for_second_level_length_mmx
+	and  eax,15
+	jz L_decode_distance_mmx
+
+	psrlq mm0,mm1
+	movd mm1,eax
+	movd ecx,mm0
+	sub  ebp,eax
+	and  ecx, [inflate_fast_mask+eax*4]
+	add  edx,ecx
+
+L_decode_distance_mmx:
+	psrlq mm0,mm1
+
+	cmp  ebp,32
+	ja L_get_dist_code_mmx
+
+	movd mm6,ebp
+	movd mm7,dword ptr [esi]
+	add  esi,4
+	psllq mm7,mm6
+	add  ebp,32
+	por mm0,mm7
+
+L_get_dist_code_mmx:
+	mov  ebx, [esp+12]
+	pand mm5,mm0
+	movd eax,mm5
+	movq mm5,mm2
+	mov  eax, [ebx+eax*4]
+
+L_dodist_mmx:
+
+	movzx  ecx,ah
+	mov  ebx,eax
+	shr  ebx,16
+	sub  ebp,ecx
+	movd mm1,ecx
+
+	test  al,16
+	jz L_test_for_second_level_dist_mmx
+	and  eax,15
+	jz L_check_dist_one_mmx
+
+L_add_bits_to_dist_mmx:
+	psrlq mm0,mm1
+	movd mm1,eax
+	movd ecx,mm0
+	sub  ebp,eax
+	and  ecx, [inflate_fast_mask+eax*4]
+	add  ebx,ecx
+
+L_check_window_mmx:
+	mov  [esp+44],esi
+	mov  eax,edi
+	sub  eax, [esp+40]
+
+	cmp  eax,ebx
+	jb L_clip_window_mmx
+
+	mov  ecx,edx
+	mov  esi,edi
+	sub  esi,ebx
+
+	sub  ecx,3
+	mov  al, [esi]
+	mov  [edi],al
+	mov  al, [esi+1]
+	mov  dl, [esi+2]
+	add  esi,3
+	mov  [edi+1],al
+	mov  [edi+2],dl
+	add  edi,3
+	rep movsb
+
+	mov  esi, [esp+44]
+	mov  ebx, [esp+8]
+	jmp  L_while_test_mmx
+
+ALIGN 4
+L_check_dist_one_mmx:
+	cmp  ebx,1
+	jne  L_check_window_mmx
+	cmp  [esp+40],edi
+	je   L_check_window_mmx
+
+	dec  edi
+	mov  ecx,edx
+	mov  al, [edi]
+	sub  ecx,3
+
+	mov  [edi+1],al
+	mov  [edi+2],al
+	mov  [edi+3],al
+	add  edi,4
+	rep stosb
+
+	mov  ebx, [esp+8]
+	jmp  L_while_test_mmx
+
+ALIGN 4
+L_test_for_second_level_length_mmx:
+	test  al,64
+	jnz L_test_for_end_of_block
+
+	and  eax,15
+	psrlq mm0,mm1
+	movd ecx,mm0
+	and  ecx, [inflate_fast_mask+eax*4]
+	add  ecx,edx
+	mov  eax, [ebx+ecx*4]
+	jmp L_dolen_mmx
+
+ALIGN 4
+L_test_for_second_level_dist_mmx:
+	test  al,64
+	jnz L_invalid_distance_code
+
+	and  eax,15
+	psrlq mm0,mm1
+	movd ecx,mm0
+	and  ecx, [inflate_fast_mask+eax*4]
+	mov  eax, [esp+12]
+	add  ecx,ebx
+	mov  eax, [eax+ecx*4]
+	jmp  L_dodist_mmx
+
+ALIGN 4
+L_clip_window_mmx:
+
+	mov  ecx,eax
+	mov  eax, [esp+52]
+	neg  ecx
+	mov  esi, [esp+56]
+
+	cmp  eax,ebx
+	jb  L_invalid_distance_too_far
+
+	add  ecx,ebx
+	cmp  dword ptr [esp+48],0
+	jne  L_wrap_around_window_mmx
+
+	sub  eax,ecx
+	add  esi,eax
+
+	cmp  edx,ecx
+	jbe  L_do_copy1_mmx
+
+	sub  edx,ecx
+	rep movsb
+	mov  esi,edi
+	sub  esi,ebx
+	jmp  L_do_copy1_mmx
+
+	cmp  edx,ecx
+	jbe  L_do_copy1_mmx
+
+	sub  edx,ecx
+	rep movsb
+	mov  esi,edi
+	sub  esi,ebx
+	jmp  L_do_copy1_mmx
+
+L_wrap_around_window_mmx:
+
+	mov  eax, [esp+48]
+	cmp  ecx,eax
+	jbe  L_contiguous_in_window_mmx
+
+	add  esi, [esp+52]
+	add  esi,eax
+	sub  esi,ecx
+	sub  ecx,eax
+
+
+	cmp  edx,ecx
+	jbe  L_do_copy1_mmx
+
+	sub  edx,ecx
+	rep movsb
+	mov  esi, [esp+56]
+	mov  ecx, [esp+48]
+	cmp  edx,ecx
+	jbe  L_do_copy1_mmx
+
+	sub  edx,ecx
+	rep movsb
+	mov  esi,edi
+	sub  esi,ebx
+	jmp  L_do_copy1_mmx
+
+L_contiguous_in_window_mmx:
+
+	add  esi,eax
+	sub  esi,ecx
+
+
+	cmp  edx,ecx
+	jbe  L_do_copy1_mmx
+
+	sub  edx,ecx
+	rep movsb
+	mov  esi,edi
+	sub  esi,ebx
+
+L_do_copy1_mmx:
+
+
+	mov  ecx,edx
+	rep movsb
+
+	mov  esi, [esp+44]
+	mov  ebx, [esp+8]
+	jmp  L_while_test_mmx
+; 1174 "inffast.S"
+L_invalid_distance_code:
+
+
+
+
+
+	mov  ecx, invalid_distance_code_msg
+	mov  edx,INFLATE_MODE_BAD
+	jmp  L_update_stream_state
+
+L_test_for_end_of_block:
+
+
+
+
+
+	test  al,32
+	jz  L_invalid_literal_length_code
+
+	mov  ecx,0
+	mov  edx,INFLATE_MODE_TYPE
+	jmp  L_update_stream_state
+
+L_invalid_literal_length_code:
+
+
+
+
+
+	mov  ecx, invalid_literal_length_code_msg
+	mov  edx,INFLATE_MODE_BAD
+	jmp  L_update_stream_state
+
+L_invalid_distance_too_far:
+
+
+
+	mov  esi, [esp+44]
+	mov  ecx, invalid_distance_too_far_msg
+	mov  edx,INFLATE_MODE_BAD
+	jmp  L_update_stream_state
+
+L_update_stream_state:
+
+	mov  eax, [esp+88]
+	test  ecx,ecx
+	jz  L_skip_msg
+	mov  [eax+24],ecx
+L_skip_msg:
+	mov  eax, [eax+28]
+	mov  [eax+mode_state],edx
+	jmp  L_break_loop
+
+ALIGN 4
+L_break_loop:
+; 1243 "inffast.S"
+	cmp  dword ptr [inflate_fast_use_mmx],2
+	jne  L_update_next_in
+
+
+
+	mov  ebx,ebp
+
+L_update_next_in:
+; 1266 "inffast.S"
+	mov  eax, [esp+88]
+	mov  ecx,ebx
+	mov  edx, [eax+28]
+	shr  ecx,3
+	sub  esi,ecx
+	shl  ecx,3
+	sub  ebx,ecx
+	mov  [eax+12],edi
+	mov  [edx+bits_state],ebx
+	mov  ecx,ebx
+
+	lea  ebx, [esp+28]
+	cmp  [esp+20],ebx
+	jne  L_buf_not_used
+
+	sub  esi,ebx
+	mov  ebx, [eax+0]
+	mov  [esp+20],ebx
+	add  esi,ebx
+	mov  ebx, [eax+4]
+	sub  ebx,11
+	add  [esp+20],ebx
+
+L_buf_not_used:
+	mov  [eax+0],esi
+
+	mov  ebx,1
+	shl  ebx,cl
+	dec  ebx
+
+
+
+
+
+	cmp  dword ptr [inflate_fast_use_mmx],2
+	jne  L_update_hold
+
+
+
+	psrlq mm0,mm1
+	movd ebp,mm0
+
+	emms
+
+L_update_hold:
+
+
+
+	and  ebp,ebx
+	mov  [edx+hold_state],ebp
+
+
+
+
+	mov  ebx, [esp+20]
+	cmp  ebx,esi
+	jbe  L_last_is_smaller
+
+	sub  ebx,esi
+	add  ebx,11
+	mov  [eax+4],ebx
+	jmp  L_fixup_out
+L_last_is_smaller:
+	sub  esi,ebx
+	neg  esi
+	add  esi,11
+	mov  [eax+4],esi
+
+
+
+
+L_fixup_out:
+
+	mov  ebx, [esp+16]
+	cmp  ebx,edi
+	jbe  L_end_is_smaller
+
+	sub  ebx,edi
+	add  ebx,257
+	mov  [eax+16],ebx
+	jmp  L_done
+L_end_is_smaller:
+	sub  edi,ebx
+	neg  edi
+	add  edi,257
+	mov  [eax+16],edi
+
+
+
+
+
+L_done:
+	add  esp,64
+	popfd
+	pop  ebx
+	pop  ebp
+	pop  esi
+	pop  edi
+	ret
+_inflate_fast endp
+
+_TEXT	ends
+end
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/masmx86/match686.asm
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/masmx86/match686.asm	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,479 @@
+; match686.asm -- Asm portion of the optimized longest_match for 32 bits x86
+; Copyright (C) 1995-1996 Jean-loup Gailly, Brian Raiter and Gilles Vollant.
+; File written by Gilles Vollant, by converting match686.S from Brian Raiter
+; for MASM. This is as assembly version of longest_match
+;  from Jean-loup Gailly in deflate.c
+;
+;         http://www.zlib.net
+;         http://www.winimage.com/zLibDll
+;         http://www.muppetlabs.com/~breadbox/software/assembly.html
+;
+; For Visual C++ 4.x and higher and ML 6.x and higher
+;   ml.exe is distributed in
+;  http://www.microsoft.com/downloads/details.aspx?FamilyID=7a1c9da0-0510-44a2-b042-7ef370530c64
+;
+; this file contain two implementation of longest_match
+;
+;  this longest_match was written by Brian raiter (1998), optimized for Pentium Pro
+;   (and the faster known version of match_init on modern Core 2 Duo and AMD Phenom)
+;
+;  for using an assembly version of longest_match, you need define ASMV in project
+;
+;    compile the asm file running
+;           ml /coff /Zi /c /Flmatch686.lst match686.asm
+;    and do not include match686.obj in your project
+;
+; note: contrib of zLib 1.2.3 and earlier contained both a deprecated version for
+;  Pentium (prior Pentium Pro) and this version for Pentium Pro and modern processor
+;  with autoselect (with cpu detection code)
+;  if you want support the old pentium optimization, you can still use these version
+;
+; this file is not optimized for old pentium, but it compatible with all x86 32 bits
+; processor (starting 80386)
+;
+;
+; see below : zlib1222add must be adjuster if you use a zlib version < 1.2.2.2
+
+;uInt longest_match(s, cur_match)
+;    deflate_state *s;
+;    IPos cur_match;                             /* current match */
+
+    NbStack         equ     76
+    cur_match       equ     dword ptr[esp+NbStack-0]
+    str_s           equ     dword ptr[esp+NbStack-4]
+; 5 dword on top (ret,ebp,esi,edi,ebx)
+    adrret          equ     dword ptr[esp+NbStack-8]
+    pushebp         equ     dword ptr[esp+NbStack-12]
+    pushedi         equ     dword ptr[esp+NbStack-16]
+    pushesi         equ     dword ptr[esp+NbStack-20]
+    pushebx         equ     dword ptr[esp+NbStack-24]
+
+    chain_length    equ     dword ptr [esp+NbStack-28]
+    limit           equ     dword ptr [esp+NbStack-32]
+    best_len        equ     dword ptr [esp+NbStack-36]
+    window          equ     dword ptr [esp+NbStack-40]
+    prev            equ     dword ptr [esp+NbStack-44]
+    scan_start      equ      word ptr [esp+NbStack-48]
+    wmask           equ     dword ptr [esp+NbStack-52]
+    match_start_ptr equ     dword ptr [esp+NbStack-56]
+    nice_match      equ     dword ptr [esp+NbStack-60]
+    scan            equ     dword ptr [esp+NbStack-64]
+
+    windowlen       equ     dword ptr [esp+NbStack-68]
+    match_start     equ     dword ptr [esp+NbStack-72]
+    strend          equ     dword ptr [esp+NbStack-76]
+    NbStackAdd      equ     (NbStack-24)
+
+    .386p
+
+    name    gvmatch
+    .MODEL  FLAT
+
+
+
+;  all the +zlib1222add offsets are due to the addition of fields
+;  in zlib in the deflate_state structure since the asm code was first written
+;  (if you compile with zlib 1.0.4 or older, use "zlib1222add equ (-4)").
+;  (if you compile with zlib between 1.0.5 and 1.2.2.1, use "zlib1222add equ 0").
+;  if you compile with zlib 1.2.2.2 or later , use "zlib1222add equ 8").
+
+    zlib1222add         equ     8
+
+;  Note : these value are good with a 8 bytes boundary pack structure
+    dep_chain_length    equ     74h+zlib1222add
+    dep_window          equ     30h+zlib1222add
+    dep_strstart        equ     64h+zlib1222add
+    dep_prev_length     equ     70h+zlib1222add
+    dep_nice_match      equ     88h+zlib1222add
+    dep_w_size          equ     24h+zlib1222add
+    dep_prev            equ     38h+zlib1222add
+    dep_w_mask          equ     2ch+zlib1222add
+    dep_good_match      equ     84h+zlib1222add
+    dep_match_start     equ     68h+zlib1222add
+    dep_lookahead       equ     6ch+zlib1222add
+
+
+_TEXT                   segment
+
+IFDEF NOUNDERLINE
+            public  longest_match
+            public  match_init
+ELSE
+            public  _longest_match
+            public  _match_init
+ENDIF
+
+    MAX_MATCH           equ     258
+    MIN_MATCH           equ     3
+    MIN_LOOKAHEAD       equ     (MAX_MATCH+MIN_MATCH+1)
+
+
+
+MAX_MATCH       equ     258
+MIN_MATCH       equ     3
+MIN_LOOKAHEAD   equ     (MAX_MATCH + MIN_MATCH + 1)
+MAX_MATCH_8_     equ     ((MAX_MATCH + 7) AND 0FFF0h)
+
+
+;;; stack frame offsets
+
+chainlenwmask   equ  esp + 0    ; high word: current chain len
+                    ; low word: s->wmask
+window      equ  esp + 4    ; local copy of s->window
+windowbestlen   equ  esp + 8    ; s->window + bestlen
+scanstart   equ  esp + 16   ; first two bytes of string
+scanend     equ  esp + 12   ; last two bytes of string
+scanalign   equ  esp + 20   ; dword-misalignment of string
+nicematch   equ  esp + 24   ; a good enough match size
+bestlen     equ  esp + 28   ; size of best match so far
+scan        equ  esp + 32   ; ptr to string wanting match
+
+LocalVarsSize   equ 36
+;   saved ebx   byte esp + 36
+;   saved edi   byte esp + 40
+;   saved esi   byte esp + 44
+;   saved ebp   byte esp + 48
+;   return address  byte esp + 52
+deflatestate    equ  esp + 56   ; the function arguments
+curmatch    equ  esp + 60
+
+;;; Offsets for fields in the deflate_state structure. These numbers
+;;; are calculated from the definition of deflate_state, with the
+;;; assumption that the compiler will dword-align the fields. (Thus,
+;;; changing the definition of deflate_state could easily cause this
+;;; program to crash horribly, without so much as a warning at
+;;; compile time. Sigh.)
+
+dsWSize     equ 36+zlib1222add
+dsWMask     equ 44+zlib1222add
+dsWindow    equ 48+zlib1222add
+dsPrev      equ 56+zlib1222add
+dsMatchLen  equ 88+zlib1222add
+dsPrevMatch equ 92+zlib1222add
+dsStrStart  equ 100+zlib1222add
+dsMatchStart    equ 104+zlib1222add
+dsLookahead equ 108+zlib1222add
+dsPrevLen   equ 112+zlib1222add
+dsMaxChainLen   equ 116+zlib1222add
+dsGoodMatch equ 132+zlib1222add
+dsNiceMatch equ 136+zlib1222add
+
+
+;;; match686.asm -- Pentium-Pro-optimized version of longest_match()
+;;; Written for zlib 1.1.2
+;;; Copyright (C) 1998 Brian Raiter <breadbox@muppetlabs.com>
+;;; You can look at http://www.muppetlabs.com/~breadbox/software/assembly.html
+;;;
+;;
+;;  This software is provided 'as-is', without any express or implied
+;;  warranty.  In no event will the authors be held liable for any damages
+;;  arising from the use of this software.
+;;
+;;  Permission is granted to anyone to use this software for any purpose,
+;;  including commercial applications, and to alter it and redistribute it
+;;  freely, subject to the following restrictions:
+;;
+;;  1. The origin of this software must not be misrepresented; you must not
+;;     claim that you wrote the original software. If you use this software
+;;     in a product, an acknowledgment in the product documentation would be
+;;     appreciated but is not required.
+;;  2. Altered source versions must be plainly marked as such, and must not be
+;;     misrepresented as being the original software
+;;  3. This notice may not be removed or altered from any source distribution.
+;;
+
+;GLOBAL _longest_match, _match_init
+
+
+;SECTION    .text
+
+;;; uInt longest_match(deflate_state *deflatestate, IPos curmatch)
+
+;_longest_match:
+    IFDEF NOUNDERLINE
+    longest_match       proc near
+    ELSE
+    _longest_match      proc near
+    ENDIF
+.FPO (9, 4, 0, 0, 1, 0)
+
+;;; Save registers that the compiler may be using, and adjust esp to
+;;; make room for our stack frame.
+
+        push    ebp
+        push    edi
+        push    esi
+        push    ebx
+        sub esp, LocalVarsSize
+
+;;; Retrieve the function arguments. ecx will hold cur_match
+;;; throughout the entire function. edx will hold the pointer to the
+;;; deflate_state structure during the function's setup (before
+;;; entering the main loop.
+
+        mov edx, [deflatestate]
+        mov ecx, [curmatch]
+
+;;; uInt wmask = s->w_mask;
+;;; unsigned chain_length = s->max_chain_length;
+;;; if (s->prev_length >= s->good_match) {
+;;;     chain_length >>= 2;
+;;; }
+
+        mov eax, [edx + dsPrevLen]
+        mov ebx, [edx + dsGoodMatch]
+        cmp eax, ebx
+        mov eax, [edx + dsWMask]
+        mov ebx, [edx + dsMaxChainLen]
+        jl  LastMatchGood
+        shr ebx, 2
+LastMatchGood:
+
+;;; chainlen is decremented once beforehand so that the function can
+;;; use the sign flag instead of the zero flag for the exit test.
+;;; It is then shifted into the high word, to make room for the wmask
+;;; value, which it will always accompany.
+
+        dec ebx
+        shl ebx, 16
+        or  ebx, eax
+        mov [chainlenwmask], ebx
+
+;;; if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
+
+        mov eax, [edx + dsNiceMatch]
+        mov ebx, [edx + dsLookahead]
+        cmp ebx, eax
+        jl  LookaheadLess
+        mov ebx, eax
+LookaheadLess:  mov [nicematch], ebx
+
+;;; register Bytef *scan = s->window + s->strstart;
+
+        mov esi, [edx + dsWindow]
+        mov [window], esi
+        mov ebp, [edx + dsStrStart]
+        lea edi, [esi + ebp]
+        mov [scan], edi
+
+;;; Determine how many bytes the scan ptr is off from being
+;;; dword-aligned.
+
+        mov eax, edi
+        neg eax
+        and eax, 3
+        mov [scanalign], eax
+
+;;; IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
+;;;     s->strstart - (IPos)MAX_DIST(s) : NIL;
+
+        mov eax, [edx + dsWSize]
+        sub eax, MIN_LOOKAHEAD
+        sub ebp, eax
+        jg  LimitPositive
+        xor ebp, ebp
+LimitPositive:
+
+;;; int best_len = s->prev_length;
+
+        mov eax, [edx + dsPrevLen]
+        mov [bestlen], eax
+
+;;; Store the sum of s->window + best_len in esi locally, and in esi.
+
+        add esi, eax
+        mov [windowbestlen], esi
+
+;;; register ush scan_start = *(ushf*)scan;
+;;; register ush scan_end   = *(ushf*)(scan+best_len-1);
+;;; Posf *prev = s->prev;
+
+        movzx   ebx, word ptr [edi]
+        mov [scanstart], ebx
+        movzx   ebx, word ptr [edi + eax - 1]
+        mov [scanend], ebx
+        mov edi, [edx + dsPrev]
+
+;;; Jump into the main loop.
+
+        mov edx, [chainlenwmask]
+        jmp short LoopEntry
+
+align 4
+
+;;; do {
+;;;     match = s->window + cur_match;
+;;;     if (*(ushf*)(match+best_len-1) != scan_end ||
+;;;         *(ushf*)match != scan_start) continue;
+;;;     [...]
+;;; } while ((cur_match = prev[cur_match & wmask]) > limit
+;;;          && --chain_length != 0);
+;;;
+;;; Here is the inner loop of the function. The function will spend the
+;;; majority of its time in this loop, and majority of that time will
+;;; be spent in the first ten instructions.
+;;;
+;;; Within this loop:
+;;; ebx = scanend
+;;; ecx = curmatch
+;;; edx = chainlenwmask - i.e., ((chainlen << 16) | wmask)
+;;; esi = windowbestlen - i.e., (window + bestlen)
+;;; edi = prev
+;;; ebp = limit
+
+LookupLoop:
+        and ecx, edx
+        movzx   ecx, word ptr [edi + ecx*2]
+        cmp ecx, ebp
+        jbe LeaveNow
+        sub edx, 00010000h
+        js  LeaveNow
+LoopEntry:  movzx   eax, word ptr [esi + ecx - 1]
+        cmp eax, ebx
+        jnz LookupLoop
+        mov eax, [window]
+        movzx   eax, word ptr [eax + ecx]
+        cmp eax, [scanstart]
+        jnz LookupLoop
+
+;;; Store the current value of chainlen.
+
+        mov [chainlenwmask], edx
+
+;;; Point edi to the string under scrutiny, and esi to the string we
+;;; are hoping to match it up with. In actuality, esi and edi are
+;;; both pointed (MAX_MATCH_8 - scanalign) bytes ahead, and edx is
+;;; initialized to -(MAX_MATCH_8 - scanalign).
+
+        mov esi, [window]
+        mov edi, [scan]
+        add esi, ecx
+        mov eax, [scanalign]
+        mov edx, 0fffffef8h; -(MAX_MATCH_8)
+        lea edi, [edi + eax + 0108h] ;MAX_MATCH_8]
+        lea esi, [esi + eax + 0108h] ;MAX_MATCH_8]
+
+;;; Test the strings for equality, 8 bytes at a time. At the end,
+;;; adjust edx so that it is offset to the exact byte that mismatched.
+;;;
+;;; We already know at this point that the first three bytes of the
+;;; strings match each other, and they can be safely passed over before
+;;; starting the compare loop. So what this code does is skip over 0-3
+;;; bytes, as much as necessary in order to dword-align the edi
+;;; pointer. (esi will still be misaligned three times out of four.)
+;;;
+;;; It should be confessed that this loop usually does not represent
+;;; much of the total running time. Replacing it with a more
+;;; straightforward "rep cmpsb" would not drastically degrade
+;;; performance.
+
+LoopCmps:
+        mov eax, [esi + edx]
+        xor eax, [edi + edx]
+        jnz LeaveLoopCmps
+        mov eax, [esi + edx + 4]
+        xor eax, [edi + edx + 4]
+        jnz LeaveLoopCmps4
+        add edx, 8
+        jnz LoopCmps
+        jmp short LenMaximum
+LeaveLoopCmps4: add edx, 4
+LeaveLoopCmps:  test    eax, 0000FFFFh
+        jnz LenLower
+        add edx,  2
+        shr eax, 16
+LenLower:   sub al, 1
+        adc edx, 0
+
+;;; Calculate the length of the match. If it is longer than MAX_MATCH,
+;;; then automatically accept it as the best possible match and leave.
+
+        lea eax, [edi + edx]
+        mov edi, [scan]
+        sub eax, edi
+        cmp eax, MAX_MATCH
+        jge LenMaximum
+
+;;; If the length of the match is not longer than the best match we
+;;; have so far, then forget it and return to the lookup loop.
+
+        mov edx, [deflatestate]
+        mov ebx, [bestlen]
+        cmp eax, ebx
+        jg  LongerMatch
+        mov esi, [windowbestlen]
+        mov edi, [edx + dsPrev]
+        mov ebx, [scanend]
+        mov edx, [chainlenwmask]
+        jmp LookupLoop
+
+;;;         s->match_start = cur_match;
+;;;         best_len = len;
+;;;         if (len >= nice_match) break;
+;;;         scan_end = *(ushf*)(scan+best_len-1);
+
+LongerMatch:    mov ebx, [nicematch]
+        mov [bestlen], eax
+        mov [edx + dsMatchStart], ecx
+        cmp eax, ebx
+        jge LeaveNow
+        mov esi, [window]
+        add esi, eax
+        mov [windowbestlen], esi
+        movzx   ebx, word ptr [edi + eax - 1]
+        mov edi, [edx + dsPrev]
+        mov [scanend], ebx
+        mov edx, [chainlenwmask]
+        jmp LookupLoop
+
+;;; Accept the current string, with the maximum possible length.
+
+LenMaximum: mov edx, [deflatestate]
+        mov dword ptr [bestlen], MAX_MATCH
+        mov [edx + dsMatchStart], ecx
+
+;;; if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
+;;; return s->lookahead;
+
+LeaveNow:
+        mov edx, [deflatestate]
+        mov ebx, [bestlen]
+        mov eax, [edx + dsLookahead]
+        cmp ebx, eax
+        jg  LookaheadRet
+        mov eax, ebx
+LookaheadRet:
+
+;;; Restore the stack and return from whence we came.
+
+        add esp, LocalVarsSize
+        pop ebx
+        pop esi
+        pop edi
+        pop ebp
+
+        ret
+; please don't remove this string !
+; Your can freely use match686 in any free or commercial app if you don't remove the string in the binary!
+    db     0dh,0ah,"asm686 with masm, optimised assembly code from Brian Raiter, written 1998",0dh,0ah
+
+
+    IFDEF NOUNDERLINE
+    longest_match       endp
+    ELSE
+    _longest_match      endp
+    ENDIF
+
+    IFDEF NOUNDERLINE
+    match_init      proc near
+                    ret
+    match_init      endp
+    ELSE
+    _match_init     proc near
+                    ret
+    _match_init     endp
+    ENDIF
+
+
+_TEXT   ends
+end
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/masmx86/readme.txt
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/masmx86/readme.txt	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,27 @@
+
+Summary
+-------
+This directory contains ASM implementations of the functions
+longest_match() and inflate_fast().
+
+
+Use instructions
+----------------
+Assemble using MASM, and copy the object files into the zlib source
+directory, then run the appropriate makefile, as suggested below.  You can
+donwload MASM from here:
+
+    http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=7a1c9da0-0510-44a2-b042-7ef370530c64
+
+You can also get objects files here:
+
+    http://www.winimage.com/zLibDll/zlib124_masm_obj.zip
+
+Build instructions
+------------------
+* With Microsoft C and MASM:
+nmake -f win32/Makefile.msc LOC="-DASMV -DASMINF" OBJA="match686.obj inffas32.obj"
+
+* With Borland C and TASM:
+make -f win32/Makefile.bor LOCAL_ZLIB="-DASMV -DASMINF" OBJA="match686.obj inffas32.obj" OBJPA="+match686c.obj+match686.obj+inffas32.obj"
+
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/minizip/Makefile
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/minizip/Makefile	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,25 @@
+CC=cc
+CFLAGS=-O -I../..
+
+UNZ_OBJS = miniunz.o unzip.o ioapi.o ../../libz.a
+ZIP_OBJS = minizip.o zip.o   ioapi.o ../../libz.a
+
+.c.o:
+	$(CC) -c $(CFLAGS) $*.c
+
+all: miniunz minizip
+
+miniunz:  $(UNZ_OBJS)
+	$(CC) $(CFLAGS) -o $@ $(UNZ_OBJS)
+
+minizip:  $(ZIP_OBJS)
+	$(CC) $(CFLAGS) -o $@ $(ZIP_OBJS)
+
+test:	miniunz minizip
+	./minizip test readme.txt
+	./miniunz -l test.zip
+	mv readme.txt readme.old
+	./miniunz test.zip
+
+clean:
+	/bin/rm -f *.o *~ minizip miniunz
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/minizip/Makefile.am
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/minizip/Makefile.am	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,45 @@
+lib_LTLIBRARIES = libminizip.la
+
+if COND_DEMOS
+bin_PROGRAMS = miniunzip minizip
+endif
+
+zlib_top_srcdir = $(top_srcdir)/../..
+zlib_top_builddir = $(top_builddir)/../..
+
+AM_CPPFLAGS = -I$(zlib_top_srcdir)
+AM_LDFLAGS = -L$(zlib_top_builddir)
+
+if WIN32
+iowin32_src = iowin32.c
+iowin32_h = iowin32.h
+endif
+
+libminizip_la_SOURCES = \
+	ioapi.c \
+	mztools.c \
+	unzip.c \
+	zip.c \
+	${iowin32_src}
+
+libminizip_la_LDFLAGS = $(AM_LDFLAGS) -version-info 1:0:0 -lz
+
+minizip_includedir = $(includedir)/minizip
+minizip_include_HEADERS = \
+	crypt.h \
+	ioapi.h \
+	mztools.h \
+	unzip.h \
+	zip.h \
+	${iowin32_h}
+
+pkgconfigdir = $(libdir)/pkgconfig
+pkgconfig_DATA = minizip.pc
+
+EXTRA_PROGRAMS = miniunzip minizip
+
+miniunzip_SOURCES = miniunz.c
+miniunzip_LDADD = libminizip.la
+
+minizip_SOURCES = minizip.c
+minizip_LDADD = libminizip.la -lz
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/minizip/MiniZip64_Changes.txt
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/minizip/MiniZip64_Changes.txt	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,6 @@
+
+MiniZip 1.1 was derrived from MiniZip at version 1.01f
+
+Change in 1.0 (Okt 2009)
+ - **TODO - Add history**
+
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/minizip/MiniZip64_info.txt
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/minizip/MiniZip64_info.txt	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,74 @@
+MiniZip - Copyright (c) 1998-2010 - by Gilles Vollant - version 1.1 64 bits from Mathias Svensson
+
+Introduction
+---------------------
+MiniZip 1.1 is built from MiniZip 1.0 by Gilles Vollant ( http://www.winimage.com/zLibDll/minizip.html )
+
+When adding ZIP64 support into minizip it would result into risk of breaking compatibility with minizip 1.0.
+All possible work was done for compatibility.
+
+
+Background
+---------------------
+When adding ZIP64 support Mathias Svensson found that Even Rouault have added ZIP64 
+support for unzip.c into minizip for a open source project called gdal ( http://www.gdal.org/ )
+
+That was used as a starting point. And after that ZIP64 support was added to zip.c
+some refactoring and code cleanup was also done.
+
+
+Changed from MiniZip 1.0 to MiniZip 1.1
+---------------------------------------
+* Added ZIP64 support for unzip ( by Even Rouault )
+* Added ZIP64 support for zip ( by Mathias Svensson )
+* Reverted some changed that Even Rouault did.
+* Bunch of patches received from Gulles Vollant that he received for MiniZip from various users.
+* Added unzip patch for BZIP Compression method (patch create by Daniel Borca)
+* Added BZIP Compress method for zip
+* Did some refactoring and code cleanup
+
+
+Credits
+
+ Gilles Vollant    - Original MiniZip author
+ Even Rouault      - ZIP64 unzip Support
+ Daniel Borca      - BZip Compression method support in unzip
+ Mathias Svensson  - ZIP64 zip support
+ Mathias Svensson  - BZip Compression method support in zip
+
+ Resources
+
+ ZipLayout   http://result42.com/projects/ZipFileLayout
+             Command line tool for Windows that shows the layout and information of the headers in a zip archive.
+             Used when debugging and validating the creation of zip files using MiniZip64
+
+
+ ZIP App Note  http://www.pkware.com/documents/casestudies/APPNOTE.TXT
+               Zip File specification
+
+
+Notes.
+ * To be able to use BZip compression method in zip64.c or unzip64.c the BZIP2 lib is needed and HAVE_BZIP2 need to be defined.
+
+License
+----------------------------------------------------------
+   Condition of use and distribution are the same than zlib :
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+----------------------------------------------------------
+
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/minizip/configure.ac
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/minizip/configure.ac	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,32 @@
+#                                               -*- Autoconf -*-
+# Process this file with autoconf to produce a configure script.
+
+AC_INIT([minizip], [1.2.11], [bugzilla.redhat.com])
+AC_CONFIG_SRCDIR([minizip.c])
+AM_INIT_AUTOMAKE([foreign])
+LT_INIT
+
+AC_MSG_CHECKING([whether to build example programs])
+AC_ARG_ENABLE([demos], AC_HELP_STRING([--enable-demos], [build example programs]))
+AM_CONDITIONAL([COND_DEMOS], [test "$enable_demos" = yes])
+if test "$enable_demos" = yes
+then
+	AC_MSG_RESULT([yes])
+else
+	AC_MSG_RESULT([no])
+fi
+
+case "${host}" in
+	*-mingw* | mingw*)
+		WIN32="yes"
+		;;
+	*)
+		;;
+esac
+AM_CONDITIONAL([WIN32], [test "${WIN32}" = "yes"])
+
+
+AC_SUBST([HAVE_UNISTD_H], [0])
+AC_CHECK_HEADER([unistd.h], [HAVE_UNISTD_H=1], [])
+AC_CONFIG_FILES([Makefile minizip.pc])
+AC_OUTPUT
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/minizip/crypt.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/minizip/crypt.h	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,131 @@
+/* crypt.h -- base code for crypt/uncrypt ZIPfile
+
+
+   Version 1.01e, February 12th, 2005
+
+   Copyright (C) 1998-2005 Gilles Vollant
+
+   This code is a modified version of crypting code in Infozip distribution
+
+   The encryption/decryption parts of this source code (as opposed to the
+   non-echoing password parts) were originally written in Europe.  The
+   whole source package can be freely distributed, including from the USA.
+   (Prior to January 2000, re-export from the US was a violation of US law.)
+
+   This encryption code is a direct transcription of the algorithm from
+   Roger Schlafly, described by Phil Katz in the file appnote.txt.  This
+   file (appnote.txt) is distributed with the PKZIP program (even in the
+   version without encryption capabilities).
+
+   If you don't need crypting in your application, just define symbols
+   NOCRYPT and NOUNCRYPT.
+
+   This code support the "Traditional PKWARE Encryption".
+
+   The new AES encryption added on Zip format by Winzip (see the page
+   http://www.winzip.com/aes_info.htm ) and PKWare PKZip 5.x Strong
+   Encryption is not supported.
+*/
+
+#define CRC32(c, b) ((*(pcrc_32_tab+(((int)(c) ^ (b)) & 0xff))) ^ ((c) >> 8))
+
+/***********************************************************************
+ * Return the next byte in the pseudo-random sequence
+ */
+static int decrypt_byte(unsigned long* pkeys, const z_crc_t* pcrc_32_tab)
+{
+    unsigned temp;  /* POTENTIAL BUG:  temp*(temp^1) may overflow in an
+                     * unpredictable manner on 16-bit systems; not a problem
+                     * with any known compiler so far, though */
+
+    temp = ((unsigned)(*(pkeys+2)) & 0xffff) | 2;
+    return (int)(((temp * (temp ^ 1)) >> 8) & 0xff);
+}
+
+/***********************************************************************
+ * Update the encryption keys with the next byte of plain text
+ */
+static int update_keys(unsigned long* pkeys,const z_crc_t* pcrc_32_tab,int c)
+{
+    (*(pkeys+0)) = CRC32((*(pkeys+0)), c);
+    (*(pkeys+1)) += (*(pkeys+0)) & 0xff;
+    (*(pkeys+1)) = (*(pkeys+1)) * 134775813L + 1;
+    {
+      register int keyshift = (int)((*(pkeys+1)) >> 24);
+      (*(pkeys+2)) = CRC32((*(pkeys+2)), keyshift);
+    }
+    return c;
+}
+
+
+/***********************************************************************
+ * Initialize the encryption keys and the random header according to
+ * the given password.
+ */
+static void init_keys(const char* passwd,unsigned long* pkeys,const z_crc_t* pcrc_32_tab)
+{
+    *(pkeys+0) = 305419896L;
+    *(pkeys+1) = 591751049L;
+    *(pkeys+2) = 878082192L;
+    while (*passwd != '\0') {
+        update_keys(pkeys,pcrc_32_tab,(int)*passwd);
+        passwd++;
+    }
+}
+
+#define zdecode(pkeys,pcrc_32_tab,c) \
+    (update_keys(pkeys,pcrc_32_tab,c ^= decrypt_byte(pkeys,pcrc_32_tab)))
+
+#define zencode(pkeys,pcrc_32_tab,c,t) \
+    (t=decrypt_byte(pkeys,pcrc_32_tab), update_keys(pkeys,pcrc_32_tab,c), t^(c))
+
+#ifdef INCLUDECRYPTINGCODE_IFCRYPTALLOWED
+
+#define RAND_HEAD_LEN  12
+   /* "last resort" source for second part of crypt seed pattern */
+#  ifndef ZCR_SEED2
+#    define ZCR_SEED2 3141592654UL     /* use PI as default pattern */
+#  endif
+
+static int crypthead(const char* passwd,      /* password string */
+                     unsigned char* buf,      /* where to write header */
+                     int bufSize,
+                     unsigned long* pkeys,
+                     const z_crc_t* pcrc_32_tab,
+                     unsigned long crcForCrypting)
+{
+    int n;                       /* index in random header */
+    int t;                       /* temporary */
+    int c;                       /* random byte */
+    unsigned char header[RAND_HEAD_LEN-2]; /* random header */
+    static unsigned calls = 0;   /* ensure different random header each time */
+
+    if (bufSize<RAND_HEAD_LEN)
+      return 0;
+
+    /* First generate RAND_HEAD_LEN-2 random bytes. We encrypt the
+     * output of rand() to get less predictability, since rand() is
+     * often poorly implemented.
+     */
+    if (++calls == 1)
+    {
+        srand((unsigned)(time(NULL) ^ ZCR_SEED2));
+    }
+    init_keys(passwd, pkeys, pcrc_32_tab);
+    for (n = 0; n < RAND_HEAD_LEN-2; n++)
+    {
+        c = (rand() >> 7) & 0xff;
+        header[n] = (unsigned char)zencode(pkeys, pcrc_32_tab, c, t);
+    }
+    /* Encrypt random header (last two bytes is high word of crc) */
+    init_keys(passwd, pkeys, pcrc_32_tab);
+    for (n = 0; n < RAND_HEAD_LEN-2; n++)
+    {
+        buf[n] = (unsigned char)zencode(pkeys, pcrc_32_tab, header[n], t);
+    }
+    buf[n++] = (unsigned char)zencode(pkeys, pcrc_32_tab, (int)(crcForCrypting >> 16) & 0xff, t);
+    buf[n++] = (unsigned char)zencode(pkeys, pcrc_32_tab, (int)(crcForCrypting >> 24) & 0xff, t);
+    return n;
+}
+
+#endif
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/minizip/ioapi.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/minizip/ioapi.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,247 @@
+/* ioapi.h -- IO base function header for compress/uncompress .zip
+   part of the MiniZip project - ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Copyright (C) 1998-2010 Gilles Vollant (minizip) ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Modifications for Zip64 support
+         Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )
+
+         For more info read MiniZip_info.txt
+
+*/
+
+#if defined(_WIN32) && (!(defined(_CRT_SECURE_NO_WARNINGS)))
+        #define _CRT_SECURE_NO_WARNINGS
+#endif
+
+#if defined(__APPLE__) || defined(IOAPI_NO_64)
+// In darwin and perhaps other BSD variants off_t is a 64 bit value, hence no need for specific 64 bit functions
+#define FOPEN_FUNC(filename, mode) fopen(filename, mode)
+#define FTELLO_FUNC(stream) ftello(stream)
+#define FSEEKO_FUNC(stream, offset, origin) fseeko(stream, offset, origin)
+#else
+#define FOPEN_FUNC(filename, mode) fopen64(filename, mode)
+#define FTELLO_FUNC(stream) ftello64(stream)
+#define FSEEKO_FUNC(stream, offset, origin) fseeko64(stream, offset, origin)
+#endif
+
+
+#include "ioapi.h"
+
+voidpf call_zopen64 (const zlib_filefunc64_32_def* pfilefunc,const void*filename,int mode)
+{
+    if (pfilefunc->zfile_func64.zopen64_file != NULL)
+        return (*(pfilefunc->zfile_func64.zopen64_file)) (pfilefunc->zfile_func64.opaque,filename,mode);
+    else
+    {
+        return (*(pfilefunc->zopen32_file))(pfilefunc->zfile_func64.opaque,(const char*)filename,mode);
+    }
+}
+
+long call_zseek64 (const zlib_filefunc64_32_def* pfilefunc,voidpf filestream, ZPOS64_T offset, int origin)
+{
+    if (pfilefunc->zfile_func64.zseek64_file != NULL)
+        return (*(pfilefunc->zfile_func64.zseek64_file)) (pfilefunc->zfile_func64.opaque,filestream,offset,origin);
+    else
+    {
+        uLong offsetTruncated = (uLong)offset;
+        if (offsetTruncated != offset)
+            return -1;
+        else
+            return (*(pfilefunc->zseek32_file))(pfilefunc->zfile_func64.opaque,filestream,offsetTruncated,origin);
+    }
+}
+
+ZPOS64_T call_ztell64 (const zlib_filefunc64_32_def* pfilefunc,voidpf filestream)
+{
+    if (pfilefunc->zfile_func64.zseek64_file != NULL)
+        return (*(pfilefunc->zfile_func64.ztell64_file)) (pfilefunc->zfile_func64.opaque,filestream);
+    else
+    {
+        uLong tell_uLong = (*(pfilefunc->ztell32_file))(pfilefunc->zfile_func64.opaque,filestream);
+        if ((tell_uLong) == MAXU32)
+            return (ZPOS64_T)-1;
+        else
+            return tell_uLong;
+    }
+}
+
+void fill_zlib_filefunc64_32_def_from_filefunc32(zlib_filefunc64_32_def* p_filefunc64_32,const zlib_filefunc_def* p_filefunc32)
+{
+    p_filefunc64_32->zfile_func64.zopen64_file = NULL;
+    p_filefunc64_32->zopen32_file = p_filefunc32->zopen_file;
+    p_filefunc64_32->zfile_func64.zerror_file = p_filefunc32->zerror_file;
+    p_filefunc64_32->zfile_func64.zread_file = p_filefunc32->zread_file;
+    p_filefunc64_32->zfile_func64.zwrite_file = p_filefunc32->zwrite_file;
+    p_filefunc64_32->zfile_func64.ztell64_file = NULL;
+    p_filefunc64_32->zfile_func64.zseek64_file = NULL;
+    p_filefunc64_32->zfile_func64.zclose_file = p_filefunc32->zclose_file;
+    p_filefunc64_32->zfile_func64.zerror_file = p_filefunc32->zerror_file;
+    p_filefunc64_32->zfile_func64.opaque = p_filefunc32->opaque;
+    p_filefunc64_32->zseek32_file = p_filefunc32->zseek_file;
+    p_filefunc64_32->ztell32_file = p_filefunc32->ztell_file;
+}
+
+
+
+static voidpf  ZCALLBACK fopen_file_func OF((voidpf opaque, const char* filename, int mode));
+static uLong   ZCALLBACK fread_file_func OF((voidpf opaque, voidpf stream, void* buf, uLong size));
+static uLong   ZCALLBACK fwrite_file_func OF((voidpf opaque, voidpf stream, const void* buf,uLong size));
+static ZPOS64_T ZCALLBACK ftell64_file_func OF((voidpf opaque, voidpf stream));
+static long    ZCALLBACK fseek64_file_func OF((voidpf opaque, voidpf stream, ZPOS64_T offset, int origin));
+static int     ZCALLBACK fclose_file_func OF((voidpf opaque, voidpf stream));
+static int     ZCALLBACK ferror_file_func OF((voidpf opaque, voidpf stream));
+
+static voidpf ZCALLBACK fopen_file_func (voidpf opaque, const char* filename, int mode)
+{
+    FILE* file = NULL;
+    const char* mode_fopen = NULL;
+    if ((mode & ZLIB_FILEFUNC_MODE_READWRITEFILTER)==ZLIB_FILEFUNC_MODE_READ)
+        mode_fopen = "rb";
+    else
+    if (mode & ZLIB_FILEFUNC_MODE_EXISTING)
+        mode_fopen = "r+b";
+    else
+    if (mode & ZLIB_FILEFUNC_MODE_CREATE)
+        mode_fopen = "wb";
+
+    if ((filename!=NULL) && (mode_fopen != NULL))
+        file = fopen(filename, mode_fopen);
+    return file;
+}
+
+static voidpf ZCALLBACK fopen64_file_func (voidpf opaque, const void* filename, int mode)
+{
+    FILE* file = NULL;
+    const char* mode_fopen = NULL;
+    if ((mode & ZLIB_FILEFUNC_MODE_READWRITEFILTER)==ZLIB_FILEFUNC_MODE_READ)
+        mode_fopen = "rb";
+    else
+    if (mode & ZLIB_FILEFUNC_MODE_EXISTING)
+        mode_fopen = "r+b";
+    else
+    if (mode & ZLIB_FILEFUNC_MODE_CREATE)
+        mode_fopen = "wb";
+
+    if ((filename!=NULL) && (mode_fopen != NULL))
+        file = FOPEN_FUNC((const char*)filename, mode_fopen);
+    return file;
+}
+
+
+static uLong ZCALLBACK fread_file_func (voidpf opaque, voidpf stream, void* buf, uLong size)
+{
+    uLong ret;
+    ret = (uLong)fread(buf, 1, (size_t)size, (FILE *)stream);
+    return ret;
+}
+
+static uLong ZCALLBACK fwrite_file_func (voidpf opaque, voidpf stream, const void* buf, uLong size)
+{
+    uLong ret;
+    ret = (uLong)fwrite(buf, 1, (size_t)size, (FILE *)stream);
+    return ret;
+}
+
+static long ZCALLBACK ftell_file_func (voidpf opaque, voidpf stream)
+{
+    long ret;
+    ret = ftell((FILE *)stream);
+    return ret;
+}
+
+
+static ZPOS64_T ZCALLBACK ftell64_file_func (voidpf opaque, voidpf stream)
+{
+    ZPOS64_T ret;
+    ret = FTELLO_FUNC((FILE *)stream);
+    return ret;
+}
+
+static long ZCALLBACK fseek_file_func (voidpf  opaque, voidpf stream, uLong offset, int origin)
+{
+    int fseek_origin=0;
+    long ret;
+    switch (origin)
+    {
+    case ZLIB_FILEFUNC_SEEK_CUR :
+        fseek_origin = SEEK_CUR;
+        break;
+    case ZLIB_FILEFUNC_SEEK_END :
+        fseek_origin = SEEK_END;
+        break;
+    case ZLIB_FILEFUNC_SEEK_SET :
+        fseek_origin = SEEK_SET;
+        break;
+    default: return -1;
+    }
+    ret = 0;
+    if (fseek((FILE *)stream, offset, fseek_origin) != 0)
+        ret = -1;
+    return ret;
+}
+
+static long ZCALLBACK fseek64_file_func (voidpf  opaque, voidpf stream, ZPOS64_T offset, int origin)
+{
+    int fseek_origin=0;
+    long ret;
+    switch (origin)
+    {
+    case ZLIB_FILEFUNC_SEEK_CUR :
+        fseek_origin = SEEK_CUR;
+        break;
+    case ZLIB_FILEFUNC_SEEK_END :
+        fseek_origin = SEEK_END;
+        break;
+    case ZLIB_FILEFUNC_SEEK_SET :
+        fseek_origin = SEEK_SET;
+        break;
+    default: return -1;
+    }
+    ret = 0;
+
+    if(FSEEKO_FUNC((FILE *)stream, offset, fseek_origin) != 0)
+                        ret = -1;
+
+    return ret;
+}
+
+
+static int ZCALLBACK fclose_file_func (voidpf opaque, voidpf stream)
+{
+    int ret;
+    ret = fclose((FILE *)stream);
+    return ret;
+}
+
+static int ZCALLBACK ferror_file_func (voidpf opaque, voidpf stream)
+{
+    int ret;
+    ret = ferror((FILE *)stream);
+    return ret;
+}
+
+void fill_fopen_filefunc (pzlib_filefunc_def)
+  zlib_filefunc_def* pzlib_filefunc_def;
+{
+    pzlib_filefunc_def->zopen_file = fopen_file_func;
+    pzlib_filefunc_def->zread_file = fread_file_func;
+    pzlib_filefunc_def->zwrite_file = fwrite_file_func;
+    pzlib_filefunc_def->ztell_file = ftell_file_func;
+    pzlib_filefunc_def->zseek_file = fseek_file_func;
+    pzlib_filefunc_def->zclose_file = fclose_file_func;
+    pzlib_filefunc_def->zerror_file = ferror_file_func;
+    pzlib_filefunc_def->opaque = NULL;
+}
+
+void fill_fopen64_filefunc (zlib_filefunc64_def*  pzlib_filefunc_def)
+{
+    pzlib_filefunc_def->zopen64_file = fopen64_file_func;
+    pzlib_filefunc_def->zread_file = fread_file_func;
+    pzlib_filefunc_def->zwrite_file = fwrite_file_func;
+    pzlib_filefunc_def->ztell64_file = ftell64_file_func;
+    pzlib_filefunc_def->zseek64_file = fseek64_file_func;
+    pzlib_filefunc_def->zclose_file = fclose_file_func;
+    pzlib_filefunc_def->zerror_file = ferror_file_func;
+    pzlib_filefunc_def->opaque = NULL;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/minizip/ioapi.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/minizip/ioapi.h	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,208 @@
+/* ioapi.h -- IO base function header for compress/uncompress .zip
+   part of the MiniZip project - ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Copyright (C) 1998-2010 Gilles Vollant (minizip) ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Modifications for Zip64 support
+         Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )
+
+         For more info read MiniZip_info.txt
+
+         Changes
+
+    Oct-2009 - Defined ZPOS64_T to fpos_t on windows and u_int64_t on linux. (might need to find a better why for this)
+    Oct-2009 - Change to fseeko64, ftello64 and fopen64 so large files would work on linux.
+               More if/def section may be needed to support other platforms
+    Oct-2009 - Defined fxxxx64 calls to normal fopen/ftell/fseek so they would compile on windows.
+                          (but you should use iowin32.c for windows instead)
+
+*/
+
+#ifndef _ZLIBIOAPI64_H
+#define _ZLIBIOAPI64_H
+
+#if (!defined(_WIN32)) && (!defined(WIN32)) && (!defined(__APPLE__))
+
+  // Linux needs this to support file operation on files larger then 4+GB
+  // But might need better if/def to select just the platforms that needs them.
+
+        #ifndef __USE_FILE_OFFSET64
+                #define __USE_FILE_OFFSET64
+        #endif
+        #ifndef __USE_LARGEFILE64
+                #define __USE_LARGEFILE64
+        #endif
+        #ifndef _LARGEFILE64_SOURCE
+                #define _LARGEFILE64_SOURCE
+        #endif
+        #ifndef _FILE_OFFSET_BIT
+                #define _FILE_OFFSET_BIT 64
+        #endif
+
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "zlib.h"
+
+#if defined(USE_FILE32API)
+#define fopen64 fopen
+#define ftello64 ftell
+#define fseeko64 fseek
+#else
+#ifdef __FreeBSD__
+#define fopen64 fopen
+#define ftello64 ftello
+#define fseeko64 fseeko
+#endif
+#ifdef _MSC_VER
+ #define fopen64 fopen
+ #if (_MSC_VER >= 1400) && (!(defined(NO_MSCVER_FILE64_FUNC)))
+  #define ftello64 _ftelli64
+  #define fseeko64 _fseeki64
+ #else // old MSC
+  #define ftello64 ftell
+  #define fseeko64 fseek
+ #endif
+#endif
+#endif
+
+/*
+#ifndef ZPOS64_T
+  #ifdef _WIN32
+                #define ZPOS64_T fpos_t
+  #else
+    #include <stdint.h>
+    #define ZPOS64_T uint64_t
+  #endif
+#endif
+*/
+
+#ifdef HAVE_MINIZIP64_CONF_H
+#include "mz64conf.h"
+#endif
+
+/* a type choosen by DEFINE */
+#ifdef HAVE_64BIT_INT_CUSTOM
+typedef  64BIT_INT_CUSTOM_TYPE ZPOS64_T;
+#else
+#ifdef HAS_STDINT_H
+#include "stdint.h"
+typedef uint64_t ZPOS64_T;
+#else
+
+/* Maximum unsigned 32-bit value used as placeholder for zip64 */
+#define MAXU32 0xffffffff
+
+#if defined(_MSC_VER) || defined(__BORLANDC__)
+typedef unsigned __int64 ZPOS64_T;
+#else
+typedef unsigned long long int ZPOS64_T;
+#endif
+#endif
+#endif
+
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+#define ZLIB_FILEFUNC_SEEK_CUR (1)
+#define ZLIB_FILEFUNC_SEEK_END (2)
+#define ZLIB_FILEFUNC_SEEK_SET (0)
+
+#define ZLIB_FILEFUNC_MODE_READ      (1)
+#define ZLIB_FILEFUNC_MODE_WRITE     (2)
+#define ZLIB_FILEFUNC_MODE_READWRITEFILTER (3)
+
+#define ZLIB_FILEFUNC_MODE_EXISTING (4)
+#define ZLIB_FILEFUNC_MODE_CREATE   (8)
+
+
+#ifndef ZCALLBACK
+ #if (defined(WIN32) || defined(_WIN32) || defined (WINDOWS) || defined (_WINDOWS)) && defined(CALLBACK) && defined (USEWINDOWS_CALLBACK)
+   #define ZCALLBACK CALLBACK
+ #else
+   #define ZCALLBACK
+ #endif
+#endif
+
+
+
+
+typedef voidpf   (ZCALLBACK *open_file_func)      OF((voidpf opaque, const char* filename, int mode));
+typedef uLong    (ZCALLBACK *read_file_func)      OF((voidpf opaque, voidpf stream, void* buf, uLong size));
+typedef uLong    (ZCALLBACK *write_file_func)     OF((voidpf opaque, voidpf stream, const void* buf, uLong size));
+typedef int      (ZCALLBACK *close_file_func)     OF((voidpf opaque, voidpf stream));
+typedef int      (ZCALLBACK *testerror_file_func) OF((voidpf opaque, voidpf stream));
+
+typedef long     (ZCALLBACK *tell_file_func)      OF((voidpf opaque, voidpf stream));
+typedef long     (ZCALLBACK *seek_file_func)      OF((voidpf opaque, voidpf stream, uLong offset, int origin));
+
+
+/* here is the "old" 32 bits structure structure */
+typedef struct zlib_filefunc_def_s
+{
+    open_file_func      zopen_file;
+    read_file_func      zread_file;
+    write_file_func     zwrite_file;
+    tell_file_func      ztell_file;
+    seek_file_func      zseek_file;
+    close_file_func     zclose_file;
+    testerror_file_func zerror_file;
+    voidpf              opaque;
+} zlib_filefunc_def;
+
+typedef ZPOS64_T (ZCALLBACK *tell64_file_func)    OF((voidpf opaque, voidpf stream));
+typedef long     (ZCALLBACK *seek64_file_func)    OF((voidpf opaque, voidpf stream, ZPOS64_T offset, int origin));
+typedef voidpf   (ZCALLBACK *open64_file_func)    OF((voidpf opaque, const void* filename, int mode));
+
+typedef struct zlib_filefunc64_def_s
+{
+    open64_file_func    zopen64_file;
+    read_file_func      zread_file;
+    write_file_func     zwrite_file;
+    tell64_file_func    ztell64_file;
+    seek64_file_func    zseek64_file;
+    close_file_func     zclose_file;
+    testerror_file_func zerror_file;
+    voidpf              opaque;
+} zlib_filefunc64_def;
+
+void fill_fopen64_filefunc OF((zlib_filefunc64_def* pzlib_filefunc_def));
+void fill_fopen_filefunc OF((zlib_filefunc_def* pzlib_filefunc_def));
+
+/* now internal definition, only for zip.c and unzip.h */
+typedef struct zlib_filefunc64_32_def_s
+{
+    zlib_filefunc64_def zfile_func64;
+    open_file_func      zopen32_file;
+    tell_file_func      ztell32_file;
+    seek_file_func      zseek32_file;
+} zlib_filefunc64_32_def;
+
+
+#define ZREAD64(filefunc,filestream,buf,size)     ((*((filefunc).zfile_func64.zread_file))   ((filefunc).zfile_func64.opaque,filestream,buf,size))
+#define ZWRITE64(filefunc,filestream,buf,size)    ((*((filefunc).zfile_func64.zwrite_file))  ((filefunc).zfile_func64.opaque,filestream,buf,size))
+//#define ZTELL64(filefunc,filestream)            ((*((filefunc).ztell64_file)) ((filefunc).opaque,filestream))
+//#define ZSEEK64(filefunc,filestream,pos,mode)   ((*((filefunc).zseek64_file)) ((filefunc).opaque,filestream,pos,mode))
+#define ZCLOSE64(filefunc,filestream)             ((*((filefunc).zfile_func64.zclose_file))  ((filefunc).zfile_func64.opaque,filestream))
+#define ZERROR64(filefunc,filestream)             ((*((filefunc).zfile_func64.zerror_file))  ((filefunc).zfile_func64.opaque,filestream))
+
+voidpf call_zopen64 OF((const zlib_filefunc64_32_def* pfilefunc,const void*filename,int mode));
+long    call_zseek64 OF((const zlib_filefunc64_32_def* pfilefunc,voidpf filestream, ZPOS64_T offset, int origin));
+ZPOS64_T call_ztell64 OF((const zlib_filefunc64_32_def* pfilefunc,voidpf filestream));
+
+void    fill_zlib_filefunc64_32_def_from_filefunc32(zlib_filefunc64_32_def* p_filefunc64_32,const zlib_filefunc_def* p_filefunc32);
+
+#define ZOPEN64(filefunc,filename,mode)         (call_zopen64((&(filefunc)),(filename),(mode)))
+#define ZTELL64(filefunc,filestream)            (call_ztell64((&(filefunc)),(filestream)))
+#define ZSEEK64(filefunc,filestream,pos,mode)   (call_zseek64((&(filefunc)),(filestream),(pos),(mode)))
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/minizip/iowin32.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/minizip/iowin32.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,462 @@
+/* iowin32.c -- IO base function header for compress/uncompress .zip
+     Version 1.1, February 14h, 2010
+     part of the MiniZip project - ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Copyright (C) 1998-2010 Gilles Vollant (minizip) ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Modifications for Zip64 support
+         Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )
+
+     For more info read MiniZip_info.txt
+
+*/
+
+#include <stdlib.h>
+
+#include "zlib.h"
+#include "ioapi.h"
+#include "iowin32.h"
+
+#ifndef INVALID_HANDLE_VALUE
+#define INVALID_HANDLE_VALUE (0xFFFFFFFF)
+#endif
+
+#ifndef INVALID_SET_FILE_POINTER
+#define INVALID_SET_FILE_POINTER ((DWORD)-1)
+#endif
+
+
+// see Include/shared/winapifamily.h in the Windows Kit
+#if defined(WINAPI_FAMILY_PARTITION) && (!(defined(IOWIN32_USING_WINRT_API)))
+#if WINAPI_FAMILY_ONE_PARTITION(WINAPI_FAMILY, WINAPI_PARTITION_APP)
+#define IOWIN32_USING_WINRT_API 1
+#endif
+#endif
+
+voidpf  ZCALLBACK win32_open_file_func  OF((voidpf opaque, const char* filename, int mode));
+uLong   ZCALLBACK win32_read_file_func  OF((voidpf opaque, voidpf stream, void* buf, uLong size));
+uLong   ZCALLBACK win32_write_file_func OF((voidpf opaque, voidpf stream, const void* buf, uLong size));
+ZPOS64_T ZCALLBACK win32_tell64_file_func  OF((voidpf opaque, voidpf stream));
+long    ZCALLBACK win32_seek64_file_func  OF((voidpf opaque, voidpf stream, ZPOS64_T offset, int origin));
+int     ZCALLBACK win32_close_file_func OF((voidpf opaque, voidpf stream));
+int     ZCALLBACK win32_error_file_func OF((voidpf opaque, voidpf stream));
+
+typedef struct
+{
+    HANDLE hf;
+    int error;
+} WIN32FILE_IOWIN;
+
+
+static void win32_translate_open_mode(int mode,
+                                      DWORD* lpdwDesiredAccess,
+                                      DWORD* lpdwCreationDisposition,
+                                      DWORD* lpdwShareMode,
+                                      DWORD* lpdwFlagsAndAttributes)
+{
+    *lpdwDesiredAccess = *lpdwShareMode = *lpdwFlagsAndAttributes = *lpdwCreationDisposition = 0;
+
+    if ((mode & ZLIB_FILEFUNC_MODE_READWRITEFILTER)==ZLIB_FILEFUNC_MODE_READ)
+    {
+        *lpdwDesiredAccess = GENERIC_READ;
+        *lpdwCreationDisposition = OPEN_EXISTING;
+        *lpdwShareMode = FILE_SHARE_READ;
+    }
+    else if (mode & ZLIB_FILEFUNC_MODE_EXISTING)
+    {
+        *lpdwDesiredAccess = GENERIC_WRITE | GENERIC_READ;
+        *lpdwCreationDisposition = OPEN_EXISTING;
+    }
+    else if (mode & ZLIB_FILEFUNC_MODE_CREATE)
+    {
+        *lpdwDesiredAccess = GENERIC_WRITE | GENERIC_READ;
+        *lpdwCreationDisposition = CREATE_ALWAYS;
+    }
+}
+
+static voidpf win32_build_iowin(HANDLE hFile)
+{
+    voidpf ret=NULL;
+
+    if ((hFile != NULL) && (hFile != INVALID_HANDLE_VALUE))
+    {
+        WIN32FILE_IOWIN w32fiow;
+        w32fiow.hf = hFile;
+        w32fiow.error = 0;
+        ret = malloc(sizeof(WIN32FILE_IOWIN));
+
+        if (ret==NULL)
+            CloseHandle(hFile);
+        else
+            *((WIN32FILE_IOWIN*)ret) = w32fiow;
+    }
+    return ret;
+}
+
+voidpf ZCALLBACK win32_open64_file_func (voidpf opaque,const void* filename,int mode)
+{
+    const char* mode_fopen = NULL;
+    DWORD dwDesiredAccess,dwCreationDisposition,dwShareMode,dwFlagsAndAttributes ;
+    HANDLE hFile = NULL;
+
+    win32_translate_open_mode(mode,&dwDesiredAccess,&dwCreationDisposition,&dwShareMode,&dwFlagsAndAttributes);
+
+#ifdef IOWIN32_USING_WINRT_API
+#ifdef UNICODE
+    if ((filename!=NULL) && (dwDesiredAccess != 0))
+        hFile = CreateFile2((LPCTSTR)filename, dwDesiredAccess, dwShareMode, dwCreationDisposition, NULL);
+#else
+    if ((filename!=NULL) && (dwDesiredAccess != 0))
+    {
+        WCHAR filenameW[FILENAME_MAX + 0x200 + 1];
+        MultiByteToWideChar(CP_ACP,0,(const char*)filename,-1,filenameW,FILENAME_MAX + 0x200);
+        hFile = CreateFile2(filenameW, dwDesiredAccess, dwShareMode, dwCreationDisposition, NULL);
+    }
+#endif
+#else
+    if ((filename!=NULL) && (dwDesiredAccess != 0))
+        hFile = CreateFile((LPCTSTR)filename, dwDesiredAccess, dwShareMode, NULL, dwCreationDisposition, dwFlagsAndAttributes, NULL);
+#endif
+
+    return win32_build_iowin(hFile);
+}
+
+
+voidpf ZCALLBACK win32_open64_file_funcA (voidpf opaque,const void* filename,int mode)
+{
+    const char* mode_fopen = NULL;
+    DWORD dwDesiredAccess,dwCreationDisposition,dwShareMode,dwFlagsAndAttributes ;
+    HANDLE hFile = NULL;
+
+    win32_translate_open_mode(mode,&dwDesiredAccess,&dwCreationDisposition,&dwShareMode,&dwFlagsAndAttributes);
+
+#ifdef IOWIN32_USING_WINRT_API
+    if ((filename!=NULL) && (dwDesiredAccess != 0))
+    {
+        WCHAR filenameW[FILENAME_MAX + 0x200 + 1];
+        MultiByteToWideChar(CP_ACP,0,(const char*)filename,-1,filenameW,FILENAME_MAX + 0x200);
+        hFile = CreateFile2(filenameW, dwDesiredAccess, dwShareMode, dwCreationDisposition, NULL);
+    }
+#else
+    if ((filename!=NULL) && (dwDesiredAccess != 0))
+        hFile = CreateFileA((LPCSTR)filename, dwDesiredAccess, dwShareMode, NULL, dwCreationDisposition, dwFlagsAndAttributes, NULL);
+#endif
+
+    return win32_build_iowin(hFile);
+}
+
+
+voidpf ZCALLBACK win32_open64_file_funcW (voidpf opaque,const void* filename,int mode)
+{
+    const char* mode_fopen = NULL;
+    DWORD dwDesiredAccess,dwCreationDisposition,dwShareMode,dwFlagsAndAttributes ;
+    HANDLE hFile = NULL;
+
+    win32_translate_open_mode(mode,&dwDesiredAccess,&dwCreationDisposition,&dwShareMode,&dwFlagsAndAttributes);
+
+#ifdef IOWIN32_USING_WINRT_API
+    if ((filename!=NULL) && (dwDesiredAccess != 0))
+        hFile = CreateFile2((LPCWSTR)filename, dwDesiredAccess, dwShareMode, dwCreationDisposition,NULL);
+#else
+    if ((filename!=NULL) && (dwDesiredAccess != 0))
+        hFile = CreateFileW((LPCWSTR)filename, dwDesiredAccess, dwShareMode, NULL, dwCreationDisposition, dwFlagsAndAttributes, NULL);
+#endif
+
+    return win32_build_iowin(hFile);
+}
+
+
+voidpf ZCALLBACK win32_open_file_func (voidpf opaque,const char* filename,int mode)
+{
+    const char* mode_fopen = NULL;
+    DWORD dwDesiredAccess,dwCreationDisposition,dwShareMode,dwFlagsAndAttributes ;
+    HANDLE hFile = NULL;
+
+    win32_translate_open_mode(mode,&dwDesiredAccess,&dwCreationDisposition,&dwShareMode,&dwFlagsAndAttributes);
+
+#ifdef IOWIN32_USING_WINRT_API
+#ifdef UNICODE
+    if ((filename!=NULL) && (dwDesiredAccess != 0))
+        hFile = CreateFile2((LPCTSTR)filename, dwDesiredAccess, dwShareMode, dwCreationDisposition, NULL);
+#else
+    if ((filename!=NULL) && (dwDesiredAccess != 0))
+    {
+        WCHAR filenameW[FILENAME_MAX + 0x200 + 1];
+        MultiByteToWideChar(CP_ACP,0,(const char*)filename,-1,filenameW,FILENAME_MAX + 0x200);
+        hFile = CreateFile2(filenameW, dwDesiredAccess, dwShareMode, dwCreationDisposition, NULL);
+    }
+#endif
+#else
+    if ((filename!=NULL) && (dwDesiredAccess != 0))
+        hFile = CreateFile((LPCTSTR)filename, dwDesiredAccess, dwShareMode, NULL, dwCreationDisposition, dwFlagsAndAttributes, NULL);
+#endif
+
+    return win32_build_iowin(hFile);
+}
+
+
+uLong ZCALLBACK win32_read_file_func (voidpf opaque, voidpf stream, void* buf,uLong size)
+{
+    uLong ret=0;
+    HANDLE hFile = NULL;
+    if (stream!=NULL)
+        hFile = ((WIN32FILE_IOWIN*)stream) -> hf;
+
+    if (hFile != NULL)
+    {
+        if (!ReadFile(hFile, buf, size, &ret, NULL))
+        {
+            DWORD dwErr = GetLastError();
+            if (dwErr == ERROR_HANDLE_EOF)
+                dwErr = 0;
+            ((WIN32FILE_IOWIN*)stream) -> error=(int)dwErr;
+        }
+    }
+
+    return ret;
+}
+
+
+uLong ZCALLBACK win32_write_file_func (voidpf opaque,voidpf stream,const void* buf,uLong size)
+{
+    uLong ret=0;
+    HANDLE hFile = NULL;
+    if (stream!=NULL)
+        hFile = ((WIN32FILE_IOWIN*)stream) -> hf;
+
+    if (hFile != NULL)
+    {
+        if (!WriteFile(hFile, buf, size, &ret, NULL))
+        {
+            DWORD dwErr = GetLastError();
+            if (dwErr == ERROR_HANDLE_EOF)
+                dwErr = 0;
+            ((WIN32FILE_IOWIN*)stream) -> error=(int)dwErr;
+        }
+    }
+
+    return ret;
+}
+
+static BOOL MySetFilePointerEx(HANDLE hFile, LARGE_INTEGER pos, LARGE_INTEGER *newPos,  DWORD dwMoveMethod)
+{
+#ifdef IOWIN32_USING_WINRT_API
+    return SetFilePointerEx(hFile, pos, newPos, dwMoveMethod);
+#else
+    LONG lHigh = pos.HighPart;
+    DWORD dwNewPos = SetFilePointer(hFile, pos.LowPart, &lHigh, dwMoveMethod);
+    BOOL fOk = TRUE;
+    if (dwNewPos == 0xFFFFFFFF)
+        if (GetLastError() != NO_ERROR)
+            fOk = FALSE;
+    if ((newPos != NULL) && (fOk))
+    {
+        newPos->LowPart = dwNewPos;
+        newPos->HighPart = lHigh;
+    }
+    return fOk;
+#endif
+}
+
+long ZCALLBACK win32_tell_file_func (voidpf opaque,voidpf stream)
+{
+    long ret=-1;
+    HANDLE hFile = NULL;
+    if (stream!=NULL)
+        hFile = ((WIN32FILE_IOWIN*)stream) -> hf;
+    if (hFile != NULL)
+    {
+        LARGE_INTEGER pos;
+        pos.QuadPart = 0;
+
+        if (!MySetFilePointerEx(hFile, pos, &pos, FILE_CURRENT))
+        {
+            DWORD dwErr = GetLastError();
+            ((WIN32FILE_IOWIN*)stream) -> error=(int)dwErr;
+            ret = -1;
+        }
+        else
+            ret=(long)pos.LowPart;
+    }
+    return ret;
+}
+
+ZPOS64_T ZCALLBACK win32_tell64_file_func (voidpf opaque, voidpf stream)
+{
+    ZPOS64_T ret= (ZPOS64_T)-1;
+    HANDLE hFile = NULL;
+    if (stream!=NULL)
+        hFile = ((WIN32FILE_IOWIN*)stream)->hf;
+
+    if (hFile)
+    {
+        LARGE_INTEGER pos;
+        pos.QuadPart = 0;
+
+        if (!MySetFilePointerEx(hFile, pos, &pos, FILE_CURRENT))
+        {
+            DWORD dwErr = GetLastError();
+            ((WIN32FILE_IOWIN*)stream) -> error=(int)dwErr;
+            ret = (ZPOS64_T)-1;
+        }
+        else
+            ret=pos.QuadPart;
+    }
+    return ret;
+}
+
+
+long ZCALLBACK win32_seek_file_func (voidpf opaque,voidpf stream,uLong offset,int origin)
+{
+    DWORD dwMoveMethod=0xFFFFFFFF;
+    HANDLE hFile = NULL;
+
+    long ret=-1;
+    if (stream!=NULL)
+        hFile = ((WIN32FILE_IOWIN*)stream) -> hf;
+    switch (origin)
+    {
+    case ZLIB_FILEFUNC_SEEK_CUR :
+        dwMoveMethod = FILE_CURRENT;
+        break;
+    case ZLIB_FILEFUNC_SEEK_END :
+        dwMoveMethod = FILE_END;
+        break;
+    case ZLIB_FILEFUNC_SEEK_SET :
+        dwMoveMethod = FILE_BEGIN;
+        break;
+    default: return -1;
+    }
+
+    if (hFile != NULL)
+    {
+        LARGE_INTEGER pos;
+        pos.QuadPart = offset;
+        if (!MySetFilePointerEx(hFile, pos, NULL, dwMoveMethod))
+        {
+            DWORD dwErr = GetLastError();
+            ((WIN32FILE_IOWIN*)stream) -> error=(int)dwErr;
+            ret = -1;
+        }
+        else
+            ret=0;
+    }
+    return ret;
+}
+
+long ZCALLBACK win32_seek64_file_func (voidpf opaque, voidpf stream,ZPOS64_T offset,int origin)
+{
+    DWORD dwMoveMethod=0xFFFFFFFF;
+    HANDLE hFile = NULL;
+    long ret=-1;
+
+    if (stream!=NULL)
+        hFile = ((WIN32FILE_IOWIN*)stream)->hf;
+
+    switch (origin)
+    {
+        case ZLIB_FILEFUNC_SEEK_CUR :
+            dwMoveMethod = FILE_CURRENT;
+            break;
+        case ZLIB_FILEFUNC_SEEK_END :
+            dwMoveMethod = FILE_END;
+            break;
+        case ZLIB_FILEFUNC_SEEK_SET :
+            dwMoveMethod = FILE_BEGIN;
+            break;
+        default: return -1;
+    }
+
+    if (hFile)
+    {
+        LARGE_INTEGER pos;
+        pos.QuadPart = offset;
+        if (!MySetFilePointerEx(hFile, pos, NULL, dwMoveMethod))
+        {
+            DWORD dwErr = GetLastError();
+            ((WIN32FILE_IOWIN*)stream) -> error=(int)dwErr;
+            ret = -1;
+        }
+        else
+            ret=0;
+    }
+    return ret;
+}
+
+int ZCALLBACK win32_close_file_func (voidpf opaque, voidpf stream)
+{
+    int ret=-1;
+
+    if (stream!=NULL)
+    {
+        HANDLE hFile;
+        hFile = ((WIN32FILE_IOWIN*)stream) -> hf;
+        if (hFile != NULL)
+        {
+            CloseHandle(hFile);
+            ret=0;
+        }
+        free(stream);
+    }
+    return ret;
+}
+
+int ZCALLBACK win32_error_file_func (voidpf opaque,voidpf stream)
+{
+    int ret=-1;
+    if (stream!=NULL)
+    {
+        ret = ((WIN32FILE_IOWIN*)stream) -> error;
+    }
+    return ret;
+}
+
+void fill_win32_filefunc (zlib_filefunc_def* pzlib_filefunc_def)
+{
+    pzlib_filefunc_def->zopen_file = win32_open_file_func;
+    pzlib_filefunc_def->zread_file = win32_read_file_func;
+    pzlib_filefunc_def->zwrite_file = win32_write_file_func;
+    pzlib_filefunc_def->ztell_file = win32_tell_file_func;
+    pzlib_filefunc_def->zseek_file = win32_seek_file_func;
+    pzlib_filefunc_def->zclose_file = win32_close_file_func;
+    pzlib_filefunc_def->zerror_file = win32_error_file_func;
+    pzlib_filefunc_def->opaque = NULL;
+}
+
+void fill_win32_filefunc64(zlib_filefunc64_def* pzlib_filefunc_def)
+{
+    pzlib_filefunc_def->zopen64_file = win32_open64_file_func;
+    pzlib_filefunc_def->zread_file = win32_read_file_func;
+    pzlib_filefunc_def->zwrite_file = win32_write_file_func;
+    pzlib_filefunc_def->ztell64_file = win32_tell64_file_func;
+    pzlib_filefunc_def->zseek64_file = win32_seek64_file_func;
+    pzlib_filefunc_def->zclose_file = win32_close_file_func;
+    pzlib_filefunc_def->zerror_file = win32_error_file_func;
+    pzlib_filefunc_def->opaque = NULL;
+}
+
+
+void fill_win32_filefunc64A(zlib_filefunc64_def* pzlib_filefunc_def)
+{
+    pzlib_filefunc_def->zopen64_file = win32_open64_file_funcA;
+    pzlib_filefunc_def->zread_file = win32_read_file_func;
+    pzlib_filefunc_def->zwrite_file = win32_write_file_func;
+    pzlib_filefunc_def->ztell64_file = win32_tell64_file_func;
+    pzlib_filefunc_def->zseek64_file = win32_seek64_file_func;
+    pzlib_filefunc_def->zclose_file = win32_close_file_func;
+    pzlib_filefunc_def->zerror_file = win32_error_file_func;
+    pzlib_filefunc_def->opaque = NULL;
+}
+
+
+void fill_win32_filefunc64W(zlib_filefunc64_def* pzlib_filefunc_def)
+{
+    pzlib_filefunc_def->zopen64_file = win32_open64_file_funcW;
+    pzlib_filefunc_def->zread_file = win32_read_file_func;
+    pzlib_filefunc_def->zwrite_file = win32_write_file_func;
+    pzlib_filefunc_def->ztell64_file = win32_tell64_file_func;
+    pzlib_filefunc_def->zseek64_file = win32_seek64_file_func;
+    pzlib_filefunc_def->zclose_file = win32_close_file_func;
+    pzlib_filefunc_def->zerror_file = win32_error_file_func;
+    pzlib_filefunc_def->opaque = NULL;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/minizip/iowin32.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/minizip/iowin32.h	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,28 @@
+/* iowin32.h -- IO base function header for compress/uncompress .zip
+     Version 1.1, February 14h, 2010
+     part of the MiniZip project - ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Copyright (C) 1998-2010 Gilles Vollant (minizip) ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Modifications for Zip64 support
+         Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )
+
+         For more info read MiniZip_info.txt
+
+*/
+
+#include <windows.h>
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void fill_win32_filefunc OF((zlib_filefunc_def* pzlib_filefunc_def));
+void fill_win32_filefunc64 OF((zlib_filefunc64_def* pzlib_filefunc_def));
+void fill_win32_filefunc64A OF((zlib_filefunc64_def* pzlib_filefunc_def));
+void fill_win32_filefunc64W OF((zlib_filefunc64_def* pzlib_filefunc_def));
+
+#ifdef __cplusplus
+}
+#endif
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/minizip/make_vms.com
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/minizip/make_vms.com	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,25 @@
+$ if f$search("ioapi.h_orig") .eqs. "" then copy ioapi.h ioapi.h_orig
+$ open/write zdef vmsdefs.h
+$ copy sys$input: zdef
+$ deck
+#define unix
+#define fill_zlib_filefunc64_32_def_from_filefunc32 fillzffunc64from
+#define Write_Zip64EndOfCentralDirectoryLocator Write_Zip64EoDLocator
+#define Write_Zip64EndOfCentralDirectoryRecord Write_Zip64EoDRecord
+#define Write_EndOfCentralDirectoryRecord Write_EoDRecord
+$ eod
+$ close zdef
+$ copy vmsdefs.h,ioapi.h_orig ioapi.h
+$ cc/include=[--]/prefix=all ioapi.c
+$ cc/include=[--]/prefix=all miniunz.c
+$ cc/include=[--]/prefix=all unzip.c
+$ cc/include=[--]/prefix=all minizip.c
+$ cc/include=[--]/prefix=all zip.c
+$ link miniunz,unzip,ioapi,[--]libz.olb/lib
+$ link minizip,zip,ioapi,[--]libz.olb/lib
+$ mcr []minizip test minizip_info.txt
+$ mcr []miniunz -l test.zip
+$ rename minizip_info.txt; minizip_info.txt_old
+$ mcr []miniunz test.zip
+$ delete test.zip;*
+$exit
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/minizip/miniunz.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/minizip/miniunz.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,660 @@
+/*
+   miniunz.c
+   Version 1.1, February 14h, 2010
+   sample part of the MiniZip project - ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Copyright (C) 1998-2010 Gilles Vollant (minizip) ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Modifications of Unzip for Zip64
+         Copyright (C) 2007-2008 Even Rouault
+
+         Modifications for Zip64 support on both zip and unzip
+         Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )
+*/
+
+#if (!defined(_WIN32)) && (!defined(WIN32)) && (!defined(__APPLE__))
+        #ifndef __USE_FILE_OFFSET64
+                #define __USE_FILE_OFFSET64
+        #endif
+        #ifndef __USE_LARGEFILE64
+                #define __USE_LARGEFILE64
+        #endif
+        #ifndef _LARGEFILE64_SOURCE
+                #define _LARGEFILE64_SOURCE
+        #endif
+        #ifndef _FILE_OFFSET_BIT
+                #define _FILE_OFFSET_BIT 64
+        #endif
+#endif
+
+#ifdef __APPLE__
+// In darwin and perhaps other BSD variants off_t is a 64 bit value, hence no need for specific 64 bit functions
+#define FOPEN_FUNC(filename, mode) fopen(filename, mode)
+#define FTELLO_FUNC(stream) ftello(stream)
+#define FSEEKO_FUNC(stream, offset, origin) fseeko(stream, offset, origin)
+#else
+#define FOPEN_FUNC(filename, mode) fopen64(filename, mode)
+#define FTELLO_FUNC(stream) ftello64(stream)
+#define FSEEKO_FUNC(stream, offset, origin) fseeko64(stream, offset, origin)
+#endif
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <errno.h>
+#include <fcntl.h>
+
+#ifdef _WIN32
+# include <direct.h>
+# include <io.h>
+#else
+# include <unistd.h>
+# include <utime.h>
+#endif
+
+
+#include "unzip.h"
+
+#define CASESENSITIVITY (0)
+#define WRITEBUFFERSIZE (8192)
+#define MAXFILENAME (256)
+
+#ifdef _WIN32
+#define USEWIN32IOAPI
+#include "iowin32.h"
+#endif
+/*
+  mini unzip, demo of unzip package
+
+  usage :
+  Usage : miniunz [-exvlo] file.zip [file_to_extract] [-d extractdir]
+
+  list the file in the zipfile, and print the content of FILE_ID.ZIP or README.TXT
+    if it exists
+*/
+
+
+/* change_file_date : change the date/time of a file
+    filename : the filename of the file where date/time must be modified
+    dosdate : the new date at the MSDos format (4 bytes)
+    tmu_date : the SAME new date at the tm_unz format */
+void change_file_date(filename,dosdate,tmu_date)
+    const char *filename;
+    uLong dosdate;
+    tm_unz tmu_date;
+{
+#ifdef _WIN32
+  HANDLE hFile;
+  FILETIME ftm,ftLocal,ftCreate,ftLastAcc,ftLastWrite;
+
+  hFile = CreateFileA(filename,GENERIC_READ | GENERIC_WRITE,
+                      0,NULL,OPEN_EXISTING,0,NULL);
+  GetFileTime(hFile,&ftCreate,&ftLastAcc,&ftLastWrite);
+  DosDateTimeToFileTime((WORD)(dosdate>>16),(WORD)dosdate,&ftLocal);
+  LocalFileTimeToFileTime(&ftLocal,&ftm);
+  SetFileTime(hFile,&ftm,&ftLastAcc,&ftm);
+  CloseHandle(hFile);
+#else
+#ifdef unix || __APPLE__
+  struct utimbuf ut;
+  struct tm newdate;
+  newdate.tm_sec = tmu_date.tm_sec;
+  newdate.tm_min=tmu_date.tm_min;
+  newdate.tm_hour=tmu_date.tm_hour;
+  newdate.tm_mday=tmu_date.tm_mday;
+  newdate.tm_mon=tmu_date.tm_mon;
+  if (tmu_date.tm_year > 1900)
+      newdate.tm_year=tmu_date.tm_year - 1900;
+  else
+      newdate.tm_year=tmu_date.tm_year ;
+  newdate.tm_isdst=-1;
+
+  ut.actime=ut.modtime=mktime(&newdate);
+  utime(filename,&ut);
+#endif
+#endif
+}
+
+
+/* mymkdir and change_file_date are not 100 % portable
+   As I don't know well Unix, I wait feedback for the unix portion */
+
+int mymkdir(dirname)
+    const char* dirname;
+{
+    int ret=0;
+#ifdef _WIN32
+    ret = _mkdir(dirname);
+#elif unix
+    ret = mkdir (dirname,0775);
+#elif __APPLE__
+    ret = mkdir (dirname,0775);
+#endif
+    return ret;
+}
+
+int makedir (newdir)
+    char *newdir;
+{
+  char *buffer ;
+  char *p;
+  int  len = (int)strlen(newdir);
+
+  if (len <= 0)
+    return 0;
+
+  buffer = (char*)malloc(len+1);
+        if (buffer==NULL)
+        {
+                printf("Error allocating memory\n");
+                return UNZ_INTERNALERROR;
+        }
+  strcpy(buffer,newdir);
+
+  if (buffer[len-1] == '/') {
+    buffer[len-1] = '\0';
+  }
+  if (mymkdir(buffer) == 0)
+    {
+      free(buffer);
+      return 1;
+    }
+
+  p = buffer+1;
+  while (1)
+    {
+      char hold;
+
+      while(*p && *p != '\\' && *p != '/')
+        p++;
+      hold = *p;
+      *p = 0;
+      if ((mymkdir(buffer) == -1) && (errno == ENOENT))
+        {
+          printf("couldn't create directory %s\n",buffer);
+          free(buffer);
+          return 0;
+        }
+      if (hold == 0)
+        break;
+      *p++ = hold;
+    }
+  free(buffer);
+  return 1;
+}
+
+void do_banner()
+{
+    printf("MiniUnz 1.01b, demo of zLib + Unz package written by Gilles Vollant\n");
+    printf("more info at http://www.winimage.com/zLibDll/unzip.html\n\n");
+}
+
+void do_help()
+{
+    printf("Usage : miniunz [-e] [-x] [-v] [-l] [-o] [-p password] file.zip [file_to_extr.] [-d extractdir]\n\n" \
+           "  -e  Extract without pathname (junk paths)\n" \
+           "  -x  Extract with pathname\n" \
+           "  -v  list files\n" \
+           "  -l  list files\n" \
+           "  -d  directory to extract into\n" \
+           "  -o  overwrite files without prompting\n" \
+           "  -p  extract crypted file using password\n\n");
+}
+
+void Display64BitsSize(ZPOS64_T n, int size_char)
+{
+  /* to avoid compatibility problem , we do here the conversion */
+  char number[21];
+  int offset=19;
+  int pos_string = 19;
+  number[20]=0;
+  for (;;) {
+      number[offset]=(char)((n%10)+'0');
+      if (number[offset] != '0')
+          pos_string=offset;
+      n/=10;
+      if (offset==0)
+          break;
+      offset--;
+  }
+  {
+      int size_display_string = 19-pos_string;
+      while (size_char > size_display_string)
+      {
+          size_char--;
+          printf(" ");
+      }
+  }
+
+  printf("%s",&number[pos_string]);
+}
+
+int do_list(uf)
+    unzFile uf;
+{
+    uLong i;
+    unz_global_info64 gi;
+    int err;
+
+    err = unzGetGlobalInfo64(uf,&gi);
+    if (err!=UNZ_OK)
+        printf("error %d with zipfile in unzGetGlobalInfo \n",err);
+    printf("  Length  Method     Size Ratio   Date    Time   CRC-32     Name\n");
+    printf("  ------  ------     ---- -----   ----    ----   ------     ----\n");
+    for (i=0;i<gi.number_entry;i++)
+    {
+        char filename_inzip[256];
+        unz_file_info64 file_info;
+        uLong ratio=0;
+        const char *string_method;
+        char charCrypt=' ';
+        err = unzGetCurrentFileInfo64(uf,&file_info,filename_inzip,sizeof(filename_inzip),NULL,0,NULL,0);
+        if (err!=UNZ_OK)
+        {
+            printf("error %d with zipfile in unzGetCurrentFileInfo\n",err);
+            break;
+        }
+        if (file_info.uncompressed_size>0)
+            ratio = (uLong)((file_info.compressed_size*100)/file_info.uncompressed_size);
+
+        /* display a '*' if the file is crypted */
+        if ((file_info.flag & 1) != 0)
+            charCrypt='*';
+
+        if (file_info.compression_method==0)
+            string_method="Stored";
+        else
+        if (file_info.compression_method==Z_DEFLATED)
+        {
+            uInt iLevel=(uInt)((file_info.flag & 0x6)/2);
+            if (iLevel==0)
+              string_method="Defl:N";
+            else if (iLevel==1)
+              string_method="Defl:X";
+            else if ((iLevel==2) || (iLevel==3))
+              string_method="Defl:F"; /* 2:fast , 3 : extra fast*/
+        }
+        else
+        if (file_info.compression_method==Z_BZIP2ED)
+        {
+              string_method="BZip2 ";
+        }
+        else
+            string_method="Unkn. ";
+
+        Display64BitsSize(file_info.uncompressed_size,7);
+        printf("  %6s%c",string_method,charCrypt);
+        Display64BitsSize(file_info.compressed_size,7);
+        printf(" %3lu%%  %2.2lu-%2.2lu-%2.2lu  %2.2lu:%2.2lu  %8.8lx   %s\n",
+                ratio,
+                (uLong)file_info.tmu_date.tm_mon + 1,
+                (uLong)file_info.tmu_date.tm_mday,
+                (uLong)file_info.tmu_date.tm_year % 100,
+                (uLong)file_info.tmu_date.tm_hour,(uLong)file_info.tmu_date.tm_min,
+                (uLong)file_info.crc,filename_inzip);
+        if ((i+1)<gi.number_entry)
+        {
+            err = unzGoToNextFile(uf);
+            if (err!=UNZ_OK)
+            {
+                printf("error %d with zipfile in unzGoToNextFile\n",err);
+                break;
+            }
+        }
+    }
+
+    return 0;
+}
+
+
+int do_extract_currentfile(uf,popt_extract_without_path,popt_overwrite,password)
+    unzFile uf;
+    const int* popt_extract_without_path;
+    int* popt_overwrite;
+    const char* password;
+{
+    char filename_inzip[256];
+    char* filename_withoutpath;
+    char* p;
+    int err=UNZ_OK;
+    FILE *fout=NULL;
+    void* buf;
+    uInt size_buf;
+
+    unz_file_info64 file_info;
+    uLong ratio=0;
+    err = unzGetCurrentFileInfo64(uf,&file_info,filename_inzip,sizeof(filename_inzip),NULL,0,NULL,0);
+
+    if (err!=UNZ_OK)
+    {
+        printf("error %d with zipfile in unzGetCurrentFileInfo\n",err);
+        return err;
+    }
+
+    size_buf = WRITEBUFFERSIZE;
+    buf = (void*)malloc(size_buf);
+    if (buf==NULL)
+    {
+        printf("Error allocating memory\n");
+        return UNZ_INTERNALERROR;
+    }
+
+    p = filename_withoutpath = filename_inzip;
+    while ((*p) != '\0')
+    {
+        if (((*p)=='/') || ((*p)=='\\'))
+            filename_withoutpath = p+1;
+        p++;
+    }
+
+    if ((*filename_withoutpath)=='\0')
+    {
+        if ((*popt_extract_without_path)==0)
+        {
+            printf("creating directory: %s\n",filename_inzip);
+            mymkdir(filename_inzip);
+        }
+    }
+    else
+    {
+        const char* write_filename;
+        int skip=0;
+
+        if ((*popt_extract_without_path)==0)
+            write_filename = filename_inzip;
+        else
+            write_filename = filename_withoutpath;
+
+        err = unzOpenCurrentFilePassword(uf,password);
+        if (err!=UNZ_OK)
+        {
+            printf("error %d with zipfile in unzOpenCurrentFilePassword\n",err);
+        }
+
+        if (((*popt_overwrite)==0) && (err==UNZ_OK))
+        {
+            char rep=0;
+            FILE* ftestexist;
+            ftestexist = FOPEN_FUNC(write_filename,"rb");
+            if (ftestexist!=NULL)
+            {
+                fclose(ftestexist);
+                do
+                {
+                    char answer[128];
+                    int ret;
+
+                    printf("The file %s exists. Overwrite ? [y]es, [n]o, [A]ll: ",write_filename);
+                    ret = scanf("%1s",answer);
+                    if (ret != 1)
+                    {
+                       exit(EXIT_FAILURE);
+                    }
+                    rep = answer[0] ;
+                    if ((rep>='a') && (rep<='z'))
+                        rep -= 0x20;
+                }
+                while ((rep!='Y') && (rep!='N') && (rep!='A'));
+            }
+
+            if (rep == 'N')
+                skip = 1;
+
+            if (rep == 'A')
+                *popt_overwrite=1;
+        }
+
+        if ((skip==0) && (err==UNZ_OK))
+        {
+            fout=FOPEN_FUNC(write_filename,"wb");
+            /* some zipfile don't contain directory alone before file */
+            if ((fout==NULL) && ((*popt_extract_without_path)==0) &&
+                                (filename_withoutpath!=(char*)filename_inzip))
+            {
+                char c=*(filename_withoutpath-1);
+                *(filename_withoutpath-1)='\0';
+                makedir(write_filename);
+                *(filename_withoutpath-1)=c;
+                fout=FOPEN_FUNC(write_filename,"wb");
+            }
+
+            if (fout==NULL)
+            {
+                printf("error opening %s\n",write_filename);
+            }
+        }
+
+        if (fout!=NULL)
+        {
+            printf(" extracting: %s\n",write_filename);
+
+            do
+            {
+                err = unzReadCurrentFile(uf,buf,size_buf);
+                if (err<0)
+                {
+                    printf("error %d with zipfile in unzReadCurrentFile\n",err);
+                    break;
+                }
+                if (err>0)
+                    if (fwrite(buf,err,1,fout)!=1)
+                    {
+                        printf("error in writing extracted file\n");
+                        err=UNZ_ERRNO;
+                        break;
+                    }
+            }
+            while (err>0);
+            if (fout)
+                    fclose(fout);
+
+            if (err==0)
+                change_file_date(write_filename,file_info.dosDate,
+                                 file_info.tmu_date);
+        }
+
+        if (err==UNZ_OK)
+        {
+            err = unzCloseCurrentFile (uf);
+            if (err!=UNZ_OK)
+            {
+                printf("error %d with zipfile in unzCloseCurrentFile\n",err);
+            }
+        }
+        else
+            unzCloseCurrentFile(uf); /* don't lose the error */
+    }
+
+    free(buf);
+    return err;
+}
+
+
+int do_extract(uf,opt_extract_without_path,opt_overwrite,password)
+    unzFile uf;
+    int opt_extract_without_path;
+    int opt_overwrite;
+    const char* password;
+{
+    uLong i;
+    unz_global_info64 gi;
+    int err;
+    FILE* fout=NULL;
+
+    err = unzGetGlobalInfo64(uf,&gi);
+    if (err!=UNZ_OK)
+        printf("error %d with zipfile in unzGetGlobalInfo \n",err);
+
+    for (i=0;i<gi.number_entry;i++)
+    {
+        if (do_extract_currentfile(uf,&opt_extract_without_path,
+                                      &opt_overwrite,
+                                      password) != UNZ_OK)
+            break;
+
+        if ((i+1)<gi.number_entry)
+        {
+            err = unzGoToNextFile(uf);
+            if (err!=UNZ_OK)
+            {
+                printf("error %d with zipfile in unzGoToNextFile\n",err);
+                break;
+            }
+        }
+    }
+
+    return 0;
+}
+
+int do_extract_onefile(uf,filename,opt_extract_without_path,opt_overwrite,password)
+    unzFile uf;
+    const char* filename;
+    int opt_extract_without_path;
+    int opt_overwrite;
+    const char* password;
+{
+    int err = UNZ_OK;
+    if (unzLocateFile(uf,filename,CASESENSITIVITY)!=UNZ_OK)
+    {
+        printf("file %s not found in the zipfile\n",filename);
+        return 2;
+    }
+
+    if (do_extract_currentfile(uf,&opt_extract_without_path,
+                                      &opt_overwrite,
+                                      password) == UNZ_OK)
+        return 0;
+    else
+        return 1;
+}
+
+
+int main(argc,argv)
+    int argc;
+    char *argv[];
+{
+    const char *zipfilename=NULL;
+    const char *filename_to_extract=NULL;
+    const char *password=NULL;
+    char filename_try[MAXFILENAME+16] = "";
+    int i;
+    int ret_value=0;
+    int opt_do_list=0;
+    int opt_do_extract=1;
+    int opt_do_extract_withoutpath=0;
+    int opt_overwrite=0;
+    int opt_extractdir=0;
+    const char *dirname=NULL;
+    unzFile uf=NULL;
+
+    do_banner();
+    if (argc==1)
+    {
+        do_help();
+        return 0;
+    }
+    else
+    {
+        for (i=1;i<argc;i++)
+        {
+            if ((*argv[i])=='-')
+            {
+                const char *p=argv[i]+1;
+
+                while ((*p)!='\0')
+                {
+                    char c=*(p++);;
+                    if ((c=='l') || (c=='L'))
+                        opt_do_list = 1;
+                    if ((c=='v') || (c=='V'))
+                        opt_do_list = 1;
+                    if ((c=='x') || (c=='X'))
+                        opt_do_extract = 1;
+                    if ((c=='e') || (c=='E'))
+                        opt_do_extract = opt_do_extract_withoutpath = 1;
+                    if ((c=='o') || (c=='O'))
+                        opt_overwrite=1;
+                    if ((c=='d') || (c=='D'))
+                    {
+                        opt_extractdir=1;
+                        dirname=argv[i+1];
+                    }
+
+                    if (((c=='p') || (c=='P')) && (i+1<argc))
+                    {
+                        password=argv[i+1];
+                        i++;
+                    }
+                }
+            }
+            else
+            {
+                if (zipfilename == NULL)
+                    zipfilename = argv[i];
+                else if ((filename_to_extract==NULL) && (!opt_extractdir))
+                        filename_to_extract = argv[i] ;
+            }
+        }
+    }
+
+    if (zipfilename!=NULL)
+    {
+
+#        ifdef USEWIN32IOAPI
+        zlib_filefunc64_def ffunc;
+#        endif
+
+        strncpy(filename_try, zipfilename,MAXFILENAME-1);
+        /* strncpy doesnt append the trailing NULL, of the string is too long. */
+        filename_try[ MAXFILENAME ] = '\0';
+
+#        ifdef USEWIN32IOAPI
+        fill_win32_filefunc64A(&ffunc);
+        uf = unzOpen2_64(zipfilename,&ffunc);
+#        else
+        uf = unzOpen64(zipfilename);
+#        endif
+        if (uf==NULL)
+        {
+            strcat(filename_try,".zip");
+#            ifdef USEWIN32IOAPI
+            uf = unzOpen2_64(filename_try,&ffunc);
+#            else
+            uf = unzOpen64(filename_try);
+#            endif
+        }
+    }
+
+    if (uf==NULL)
+    {
+        printf("Cannot open %s or %s.zip\n",zipfilename,zipfilename);
+        return 1;
+    }
+    printf("%s opened\n",filename_try);
+
+    if (opt_do_list==1)
+        ret_value = do_list(uf);
+    else if (opt_do_extract==1)
+    {
+#ifdef _WIN32
+        if (opt_extractdir && _chdir(dirname))
+#else
+        if (opt_extractdir && chdir(dirname))
+#endif
+        {
+          printf("Error changing into %s, aborting\n", dirname);
+          exit(-1);
+        }
+
+        if (filename_to_extract == NULL)
+            ret_value = do_extract(uf, opt_do_extract_withoutpath, opt_overwrite, password);
+        else
+            ret_value = do_extract_onefile(uf, filename_to_extract, opt_do_extract_withoutpath, opt_overwrite, password);
+    }
+
+    unzClose(uf);
+
+    return ret_value;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/minizip/minizip.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/minizip/minizip.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,520 @@
+/*
+   minizip.c
+   Version 1.1, February 14h, 2010
+   sample part of the MiniZip project - ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Copyright (C) 1998-2010 Gilles Vollant (minizip) ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Modifications of Unzip for Zip64
+         Copyright (C) 2007-2008 Even Rouault
+
+         Modifications for Zip64 support on both zip and unzip
+         Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )
+*/
+
+
+#if (!defined(_WIN32)) && (!defined(WIN32)) && (!defined(__APPLE__))
+        #ifndef __USE_FILE_OFFSET64
+                #define __USE_FILE_OFFSET64
+        #endif
+        #ifndef __USE_LARGEFILE64
+                #define __USE_LARGEFILE64
+        #endif
+        #ifndef _LARGEFILE64_SOURCE
+                #define _LARGEFILE64_SOURCE
+        #endif
+        #ifndef _FILE_OFFSET_BIT
+                #define _FILE_OFFSET_BIT 64
+        #endif
+#endif
+
+#ifdef __APPLE__
+// In darwin and perhaps other BSD variants off_t is a 64 bit value, hence no need for specific 64 bit functions
+#define FOPEN_FUNC(filename, mode) fopen(filename, mode)
+#define FTELLO_FUNC(stream) ftello(stream)
+#define FSEEKO_FUNC(stream, offset, origin) fseeko(stream, offset, origin)
+#else
+#define FOPEN_FUNC(filename, mode) fopen64(filename, mode)
+#define FTELLO_FUNC(stream) ftello64(stream)
+#define FSEEKO_FUNC(stream, offset, origin) fseeko64(stream, offset, origin)
+#endif
+
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <errno.h>
+#include <fcntl.h>
+
+#ifdef _WIN32
+# include <direct.h>
+# include <io.h>
+#else
+# include <unistd.h>
+# include <utime.h>
+# include <sys/types.h>
+# include <sys/stat.h>
+#endif
+
+#include "zip.h"
+
+#ifdef _WIN32
+        #define USEWIN32IOAPI
+        #include "iowin32.h"
+#endif
+
+
+
+#define WRITEBUFFERSIZE (16384)
+#define MAXFILENAME (256)
+
+#ifdef _WIN32
+uLong filetime(f, tmzip, dt)
+    char *f;                /* name of file to get info on */
+    tm_zip *tmzip;             /* return value: access, modific. and creation times */
+    uLong *dt;             /* dostime */
+{
+  int ret = 0;
+  {
+      FILETIME ftLocal;
+      HANDLE hFind;
+      WIN32_FIND_DATAA ff32;
+
+      hFind = FindFirstFileA(f,&ff32);
+      if (hFind != INVALID_HANDLE_VALUE)
+      {
+        FileTimeToLocalFileTime(&(ff32.ftLastWriteTime),&ftLocal);
+        FileTimeToDosDateTime(&ftLocal,((LPWORD)dt)+1,((LPWORD)dt)+0);
+        FindClose(hFind);
+        ret = 1;
+      }
+  }
+  return ret;
+}
+#else
+#ifdef unix || __APPLE__
+uLong filetime(f, tmzip, dt)
+    char *f;               /* name of file to get info on */
+    tm_zip *tmzip;         /* return value: access, modific. and creation times */
+    uLong *dt;             /* dostime */
+{
+  int ret=0;
+  struct stat s;        /* results of stat() */
+  struct tm* filedate;
+  time_t tm_t=0;
+
+  if (strcmp(f,"-")!=0)
+  {
+    char name[MAXFILENAME+1];
+    int len = strlen(f);
+    if (len > MAXFILENAME)
+      len = MAXFILENAME;
+
+    strncpy(name, f,MAXFILENAME-1);
+    /* strncpy doesnt append the trailing NULL, of the string is too long. */
+    name[ MAXFILENAME ] = '\0';
+
+    if (name[len - 1] == '/')
+      name[len - 1] = '\0';
+    /* not all systems allow stat'ing a file with / appended */
+    if (stat(name,&s)==0)
+    {
+      tm_t = s.st_mtime;
+      ret = 1;
+    }
+  }
+  filedate = localtime(&tm_t);
+
+  tmzip->tm_sec  = filedate->tm_sec;
+  tmzip->tm_min  = filedate->tm_min;
+  tmzip->tm_hour = filedate->tm_hour;
+  tmzip->tm_mday = filedate->tm_mday;
+  tmzip->tm_mon  = filedate->tm_mon ;
+  tmzip->tm_year = filedate->tm_year;
+
+  return ret;
+}
+#else
+uLong filetime(f, tmzip, dt)
+    char *f;                /* name of file to get info on */
+    tm_zip *tmzip;             /* return value: access, modific. and creation times */
+    uLong *dt;             /* dostime */
+{
+    return 0;
+}
+#endif
+#endif
+
+
+
+
+int check_exist_file(filename)
+    const char* filename;
+{
+    FILE* ftestexist;
+    int ret = 1;
+    ftestexist = FOPEN_FUNC(filename,"rb");
+    if (ftestexist==NULL)
+        ret = 0;
+    else
+        fclose(ftestexist);
+    return ret;
+}
+
+void do_banner()
+{
+    printf("MiniZip 1.1, demo of zLib + MiniZip64 package, written by Gilles Vollant\n");
+    printf("more info on MiniZip at http://www.winimage.com/zLibDll/minizip.html\n\n");
+}
+
+void do_help()
+{
+    printf("Usage : minizip [-o] [-a] [-0 to -9] [-p password] [-j] file.zip [files_to_add]\n\n" \
+           "  -o  Overwrite existing file.zip\n" \
+           "  -a  Append to existing file.zip\n" \
+           "  -0  Store only\n" \
+           "  -1  Compress faster\n" \
+           "  -9  Compress better\n\n" \
+           "  -j  exclude path. store only the file name.\n\n");
+}
+
+/* calculate the CRC32 of a file,
+   because to encrypt a file, we need known the CRC32 of the file before */
+int getFileCrc(const char* filenameinzip,void*buf,unsigned long size_buf,unsigned long* result_crc)
+{
+   unsigned long calculate_crc=0;
+   int err=ZIP_OK;
+   FILE * fin = FOPEN_FUNC(filenameinzip,"rb");
+
+   unsigned long size_read = 0;
+   unsigned long total_read = 0;
+   if (fin==NULL)
+   {
+       err = ZIP_ERRNO;
+   }
+
+    if (err == ZIP_OK)
+        do
+        {
+            err = ZIP_OK;
+            size_read = (int)fread(buf,1,size_buf,fin);
+            if (size_read < size_buf)
+                if (feof(fin)==0)
+            {
+                printf("error in reading %s\n",filenameinzip);
+                err = ZIP_ERRNO;
+            }
+
+            if (size_read>0)
+                calculate_crc = crc32(calculate_crc,buf,size_read);
+            total_read += size_read;
+
+        } while ((err == ZIP_OK) && (size_read>0));
+
+    if (fin)
+        fclose(fin);
+
+    *result_crc=calculate_crc;
+    printf("file %s crc %lx\n", filenameinzip, calculate_crc);
+    return err;
+}
+
+int isLargeFile(const char* filename)
+{
+  int largeFile = 0;
+  ZPOS64_T pos = 0;
+  FILE* pFile = FOPEN_FUNC(filename, "rb");
+
+  if(pFile != NULL)
+  {
+    int n = FSEEKO_FUNC(pFile, 0, SEEK_END);
+    pos = FTELLO_FUNC(pFile);
+
+                printf("File : %s is %lld bytes\n", filename, pos);
+
+    if(pos >= 0xffffffff)
+     largeFile = 1;
+
+                fclose(pFile);
+  }
+
+ return largeFile;
+}
+
+int main(argc,argv)
+    int argc;
+    char *argv[];
+{
+    int i;
+    int opt_overwrite=0;
+    int opt_compress_level=Z_DEFAULT_COMPRESSION;
+    int opt_exclude_path=0;
+    int zipfilenamearg = 0;
+    char filename_try[MAXFILENAME+16];
+    int zipok;
+    int err=0;
+    int size_buf=0;
+    void* buf=NULL;
+    const char* password=NULL;
+
+
+    do_banner();
+    if (argc==1)
+    {
+        do_help();
+        return 0;
+    }
+    else
+    {
+        for (i=1;i<argc;i++)
+        {
+            if ((*argv[i])=='-')
+            {
+                const char *p=argv[i]+1;
+
+                while ((*p)!='\0')
+                {
+                    char c=*(p++);;
+                    if ((c=='o') || (c=='O'))
+                        opt_overwrite = 1;
+                    if ((c=='a') || (c=='A'))
+                        opt_overwrite = 2;
+                    if ((c>='0') && (c<='9'))
+                        opt_compress_level = c-'0';
+                    if ((c=='j') || (c=='J'))
+                        opt_exclude_path = 1;
+
+                    if (((c=='p') || (c=='P')) && (i+1<argc))
+                    {
+                        password=argv[i+1];
+                        i++;
+                    }
+                }
+            }
+            else
+            {
+                if (zipfilenamearg == 0)
+                {
+                    zipfilenamearg = i ;
+                }
+            }
+        }
+    }
+
+    size_buf = WRITEBUFFERSIZE;
+    buf = (void*)malloc(size_buf);
+    if (buf==NULL)
+    {
+        printf("Error allocating memory\n");
+        return ZIP_INTERNALERROR;
+    }
+
+    if (zipfilenamearg==0)
+    {
+        zipok=0;
+    }
+    else
+    {
+        int i,len;
+        int dot_found=0;
+
+        zipok = 1 ;
+        strncpy(filename_try, argv[zipfilenamearg],MAXFILENAME-1);
+        /* strncpy doesnt append the trailing NULL, of the string is too long. */
+        filename_try[ MAXFILENAME ] = '\0';
+
+        len=(int)strlen(filename_try);
+        for (i=0;i<len;i++)
+            if (filename_try[i]=='.')
+                dot_found=1;
+
+        if (dot_found==0)
+            strcat(filename_try,".zip");
+
+        if (opt_overwrite==2)
+        {
+            /* if the file don't exist, we not append file */
+            if (check_exist_file(filename_try)==0)
+                opt_overwrite=1;
+        }
+        else
+        if (opt_overwrite==0)
+            if (check_exist_file(filename_try)!=0)
+            {
+                char rep=0;
+                do
+                {
+                    char answer[128];
+                    int ret;
+                    printf("The file %s exists. Overwrite ? [y]es, [n]o, [a]ppend : ",filename_try);
+                    ret = scanf("%1s",answer);
+                    if (ret != 1)
+                    {
+                       exit(EXIT_FAILURE);
+                    }
+                    rep = answer[0] ;
+                    if ((rep>='a') && (rep<='z'))
+                        rep -= 0x20;
+                }
+                while ((rep!='Y') && (rep!='N') && (rep!='A'));
+                if (rep=='N')
+                    zipok = 0;
+                if (rep=='A')
+                    opt_overwrite = 2;
+            }
+    }
+
+    if (zipok==1)
+    {
+        zipFile zf;
+        int errclose;
+#        ifdef USEWIN32IOAPI
+        zlib_filefunc64_def ffunc;
+        fill_win32_filefunc64A(&ffunc);
+        zf = zipOpen2_64(filename_try,(opt_overwrite==2) ? 2 : 0,NULL,&ffunc);
+#        else
+        zf = zipOpen64(filename_try,(opt_overwrite==2) ? 2 : 0);
+#        endif
+
+        if (zf == NULL)
+        {
+            printf("error opening %s\n",filename_try);
+            err= ZIP_ERRNO;
+        }
+        else
+            printf("creating %s\n",filename_try);
+
+        for (i=zipfilenamearg+1;(i<argc) && (err==ZIP_OK);i++)
+        {
+            if (!((((*(argv[i]))=='-') || ((*(argv[i]))=='/')) &&
+                  ((argv[i][1]=='o') || (argv[i][1]=='O') ||
+                   (argv[i][1]=='a') || (argv[i][1]=='A') ||
+                   (argv[i][1]=='p') || (argv[i][1]=='P') ||
+                   ((argv[i][1]>='0') || (argv[i][1]<='9'))) &&
+                  (strlen(argv[i]) == 2)))
+            {
+                FILE * fin;
+                int size_read;
+                const char* filenameinzip = argv[i];
+                const char *savefilenameinzip;
+                zip_fileinfo zi;
+                unsigned long crcFile=0;
+                int zip64 = 0;
+
+                zi.tmz_date.tm_sec = zi.tmz_date.tm_min = zi.tmz_date.tm_hour =
+                zi.tmz_date.tm_mday = zi.tmz_date.tm_mon = zi.tmz_date.tm_year = 0;
+                zi.dosDate = 0;
+                zi.internal_fa = 0;
+                zi.external_fa = 0;
+                filetime(filenameinzip,&zi.tmz_date,&zi.dosDate);
+
+/*
+                err = zipOpenNewFileInZip(zf,filenameinzip,&zi,
+                                 NULL,0,NULL,0,NULL / * comment * /,
+                                 (opt_compress_level != 0) ? Z_DEFLATED : 0,
+                                 opt_compress_level);
+*/
+                if ((password != NULL) && (err==ZIP_OK))
+                    err = getFileCrc(filenameinzip,buf,size_buf,&crcFile);
+
+                zip64 = isLargeFile(filenameinzip);
+
+                                                         /* The path name saved, should not include a leading slash. */
+               /*if it did, windows/xp and dynazip couldn't read the zip file. */
+                 savefilenameinzip = filenameinzip;
+                 while( savefilenameinzip[0] == '\\' || savefilenameinzip[0] == '/' )
+                 {
+                     savefilenameinzip++;
+                 }
+
+                 /*should the zip file contain any path at all?*/
+                 if( opt_exclude_path )
+                 {
+                     const char *tmpptr;
+                     const char *lastslash = 0;
+                     for( tmpptr = savefilenameinzip; *tmpptr; tmpptr++)
+                     {
+                         if( *tmpptr == '\\' || *tmpptr == '/')
+                         {
+                             lastslash = tmpptr;
+                         }
+                     }
+                     if( lastslash != NULL )
+                     {
+                         savefilenameinzip = lastslash+1; // base filename follows last slash.
+                     }
+                 }
+
+                 /**/
+                err = zipOpenNewFileInZip3_64(zf,savefilenameinzip,&zi,
+                                 NULL,0,NULL,0,NULL /* comment*/,
+                                 (opt_compress_level != 0) ? Z_DEFLATED : 0,
+                                 opt_compress_level,0,
+                                 /* -MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY, */
+                                 -MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY,
+                                 password,crcFile, zip64);
+
+                if (err != ZIP_OK)
+                    printf("error in opening %s in zipfile\n",filenameinzip);
+                else
+                {
+                    fin = FOPEN_FUNC(filenameinzip,"rb");
+                    if (fin==NULL)
+                    {
+                        err=ZIP_ERRNO;
+                        printf("error in opening %s for reading\n",filenameinzip);
+                    }
+                }
+
+                if (err == ZIP_OK)
+                    do
+                    {
+                        err = ZIP_OK;
+                        size_read = (int)fread(buf,1,size_buf,fin);
+                        if (size_read < size_buf)
+                            if (feof(fin)==0)
+                        {
+                            printf("error in reading %s\n",filenameinzip);
+                            err = ZIP_ERRNO;
+                        }
+
+                        if (size_read>0)
+                        {
+                            err = zipWriteInFileInZip (zf,buf,size_read);
+                            if (err<0)
+                            {
+                                printf("error in writing %s in the zipfile\n",
+                                                 filenameinzip);
+                            }
+
+                        }
+                    } while ((err == ZIP_OK) && (size_read>0));
+
+                if (fin)
+                    fclose(fin);
+
+                if (err<0)
+                    err=ZIP_ERRNO;
+                else
+                {
+                    err = zipCloseFileInZip(zf);
+                    if (err!=ZIP_OK)
+                        printf("error in closing %s in the zipfile\n",
+                                    filenameinzip);
+                }
+            }
+        }
+        errclose = zipClose(zf,NULL);
+        if (errclose != ZIP_OK)
+            printf("error in closing %s\n",filename_try);
+    }
+    else
+    {
+       do_help();
+    }
+
+    free(buf);
+    return 0;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/minizip/minizip.pc.in
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/minizip/minizip.pc.in	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,12 @@
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+libdir=@libdir@
+includedir=@includedir@/minizip
+
+Name: minizip
+Description: Minizip zip file manipulation library
+Requires:
+Version: @PACKAGE_VERSION@
+Libs: -L${libdir} -lminizip
+Libs.private: -lz
+Cflags: -I${includedir}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/minizip/mztools.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/minizip/mztools.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,291 @@
+/*
+  Additional tools for Minizip
+  Code: Xavier Roche '2004
+  License: Same as ZLIB (www.gzip.org)
+*/
+
+/* Code */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "zlib.h"
+#include "unzip.h"
+
+#define READ_8(adr)  ((unsigned char)*(adr))
+#define READ_16(adr) ( READ_8(adr) | (READ_8(adr+1) << 8) )
+#define READ_32(adr) ( READ_16(adr) | (READ_16((adr)+2) << 16) )
+
+#define WRITE_8(buff, n) do { \
+  *((unsigned char*)(buff)) = (unsigned char) ((n) & 0xff); \
+} while(0)
+#define WRITE_16(buff, n) do { \
+  WRITE_8((unsigned char*)(buff), n); \
+  WRITE_8(((unsigned char*)(buff)) + 1, (n) >> 8); \
+} while(0)
+#define WRITE_32(buff, n) do { \
+  WRITE_16((unsigned char*)(buff), (n) & 0xffff); \
+  WRITE_16((unsigned char*)(buff) + 2, (n) >> 16); \
+} while(0)
+
+extern int ZEXPORT unzRepair(file, fileOut, fileOutTmp, nRecovered, bytesRecovered)
+const char* file;
+const char* fileOut;
+const char* fileOutTmp;
+uLong* nRecovered;
+uLong* bytesRecovered;
+{
+  int err = Z_OK;
+  FILE* fpZip = fopen(file, "rb");
+  FILE* fpOut = fopen(fileOut, "wb");
+  FILE* fpOutCD = fopen(fileOutTmp, "wb");
+  if (fpZip != NULL &&  fpOut != NULL) {
+    int entries = 0;
+    uLong totalBytes = 0;
+    char header[30];
+    char filename[1024];
+    char extra[1024];
+    int offset = 0;
+    int offsetCD = 0;
+    while ( fread(header, 1, 30, fpZip) == 30 ) {
+      int currentOffset = offset;
+
+      /* File entry */
+      if (READ_32(header) == 0x04034b50) {
+        unsigned int version = READ_16(header + 4);
+        unsigned int gpflag = READ_16(header + 6);
+        unsigned int method = READ_16(header + 8);
+        unsigned int filetime = READ_16(header + 10);
+        unsigned int filedate = READ_16(header + 12);
+        unsigned int crc = READ_32(header + 14); /* crc */
+        unsigned int cpsize = READ_32(header + 18); /* compressed size */
+        unsigned int uncpsize = READ_32(header + 22); /* uncompressed sz */
+        unsigned int fnsize = READ_16(header + 26); /* file name length */
+        unsigned int extsize = READ_16(header + 28); /* extra field length */
+        filename[0] = extra[0] = '\0';
+
+        /* Header */
+        if (fwrite(header, 1, 30, fpOut) == 30) {
+          offset += 30;
+        } else {
+          err = Z_ERRNO;
+          break;
+        }
+
+        /* Filename */
+        if (fnsize > 0) {
+          if (fnsize < sizeof(filename)) {
+            if (fread(filename, 1, fnsize, fpZip) == fnsize) {
+                if (fwrite(filename, 1, fnsize, fpOut) == fnsize) {
+                offset += fnsize;
+              } else {
+                err = Z_ERRNO;
+                break;
+              }
+            } else {
+              err = Z_ERRNO;
+              break;
+            }
+          } else {
+            err = Z_ERRNO;
+            break;
+          }
+        } else {
+          err = Z_STREAM_ERROR;
+          break;
+        }
+
+        /* Extra field */
+        if (extsize > 0) {
+          if (extsize < sizeof(extra)) {
+            if (fread(extra, 1, extsize, fpZip) == extsize) {
+              if (fwrite(extra, 1, extsize, fpOut) == extsize) {
+                offset += extsize;
+                } else {
+                err = Z_ERRNO;
+                break;
+              }
+            } else {
+              err = Z_ERRNO;
+              break;
+            }
+          } else {
+            err = Z_ERRNO;
+            break;
+          }
+        }
+
+        /* Data */
+        {
+          int dataSize = cpsize;
+          if (dataSize == 0) {
+            dataSize = uncpsize;
+          }
+          if (dataSize > 0) {
+            char* data = malloc(dataSize);
+            if (data != NULL) {
+              if ((int)fread(data, 1, dataSize, fpZip) == dataSize) {
+                if ((int)fwrite(data, 1, dataSize, fpOut) == dataSize) {
+                  offset += dataSize;
+                  totalBytes += dataSize;
+                } else {
+                  err = Z_ERRNO;
+                }
+              } else {
+                err = Z_ERRNO;
+              }
+              free(data);
+              if (err != Z_OK) {
+                break;
+              }
+            } else {
+              err = Z_MEM_ERROR;
+              break;
+            }
+          }
+        }
+
+        /* Central directory entry */
+        {
+          char header[46];
+          char* comment = "";
+          int comsize = (int) strlen(comment);
+          WRITE_32(header, 0x02014b50);
+          WRITE_16(header + 4, version);
+          WRITE_16(header + 6, version);
+          WRITE_16(header + 8, gpflag);
+          WRITE_16(header + 10, method);
+          WRITE_16(header + 12, filetime);
+          WRITE_16(header + 14, filedate);
+          WRITE_32(header + 16, crc);
+          WRITE_32(header + 20, cpsize);
+          WRITE_32(header + 24, uncpsize);
+          WRITE_16(header + 28, fnsize);
+          WRITE_16(header + 30, extsize);
+          WRITE_16(header + 32, comsize);
+          WRITE_16(header + 34, 0);     /* disk # */
+          WRITE_16(header + 36, 0);     /* int attrb */
+          WRITE_32(header + 38, 0);     /* ext attrb */
+          WRITE_32(header + 42, currentOffset);
+          /* Header */
+          if (fwrite(header, 1, 46, fpOutCD) == 46) {
+            offsetCD += 46;
+
+            /* Filename */
+            if (fnsize > 0) {
+              if (fwrite(filename, 1, fnsize, fpOutCD) == fnsize) {
+                offsetCD += fnsize;
+              } else {
+                err = Z_ERRNO;
+                break;
+              }
+            } else {
+              err = Z_STREAM_ERROR;
+              break;
+            }
+
+            /* Extra field */
+            if (extsize > 0) {
+              if (fwrite(extra, 1, extsize, fpOutCD) == extsize) {
+                offsetCD += extsize;
+              } else {
+                err = Z_ERRNO;
+                break;
+              }
+            }
+
+            /* Comment field */
+            if (comsize > 0) {
+              if ((int)fwrite(comment, 1, comsize, fpOutCD) == comsize) {
+                offsetCD += comsize;
+              } else {
+                err = Z_ERRNO;
+                break;
+              }
+            }
+
+
+          } else {
+            err = Z_ERRNO;
+            break;
+          }
+        }
+
+        /* Success */
+        entries++;
+
+      } else {
+        break;
+      }
+    }
+
+    /* Final central directory  */
+    {
+      int entriesZip = entries;
+      char header[22];
+      char* comment = ""; // "ZIP File recovered by zlib/minizip/mztools";
+      int comsize = (int) strlen(comment);
+      if (entriesZip > 0xffff) {
+        entriesZip = 0xffff;
+      }
+      WRITE_32(header, 0x06054b50);
+      WRITE_16(header + 4, 0);    /* disk # */
+      WRITE_16(header + 6, 0);    /* disk # */
+      WRITE_16(header + 8, entriesZip);   /* hack */
+      WRITE_16(header + 10, entriesZip);  /* hack */
+      WRITE_32(header + 12, offsetCD);    /* size of CD */
+      WRITE_32(header + 16, offset);      /* offset to CD */
+      WRITE_16(header + 20, comsize);     /* comment */
+
+      /* Header */
+      if (fwrite(header, 1, 22, fpOutCD) == 22) {
+
+        /* Comment field */
+        if (comsize > 0) {
+          if ((int)fwrite(comment, 1, comsize, fpOutCD) != comsize) {
+            err = Z_ERRNO;
+          }
+        }
+
+      } else {
+        err = Z_ERRNO;
+      }
+    }
+
+    /* Final merge (file + central directory) */
+    fclose(fpOutCD);
+    if (err == Z_OK) {
+      fpOutCD = fopen(fileOutTmp, "rb");
+      if (fpOutCD != NULL) {
+        int nRead;
+        char buffer[8192];
+        while ( (nRead = (int)fread(buffer, 1, sizeof(buffer), fpOutCD)) > 0) {
+          if ((int)fwrite(buffer, 1, nRead, fpOut) != nRead) {
+            err = Z_ERRNO;
+            break;
+          }
+        }
+        fclose(fpOutCD);
+      }
+    }
+
+    /* Close */
+    fclose(fpZip);
+    fclose(fpOut);
+
+    /* Wipe temporary file */
+    (void)remove(fileOutTmp);
+
+    /* Number of recovered entries */
+    if (err == Z_OK) {
+      if (nRecovered != NULL) {
+        *nRecovered = entries;
+      }
+      if (bytesRecovered != NULL) {
+        *bytesRecovered = totalBytes;
+      }
+    }
+  } else {
+    err = Z_STREAM_ERROR;
+  }
+  return err;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/minizip/mztools.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/minizip/mztools.h	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,37 @@
+/*
+  Additional tools for Minizip
+  Code: Xavier Roche '2004
+  License: Same as ZLIB (www.gzip.org)
+*/
+
+#ifndef _zip_tools_H
+#define _zip_tools_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef _ZLIB_H
+#include "zlib.h"
+#endif
+
+#include "unzip.h"
+
+/* Repair a ZIP file (missing central directory)
+   file: file to recover
+   fileOut: output file after recovery
+   fileOutTmp: temporary file name used for recovery
+*/
+extern int ZEXPORT unzRepair(const char* file,
+                             const char* fileOut,
+                             const char* fileOutTmp,
+                             uLong* nRecovered,
+                             uLong* bytesRecovered);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/minizip/unzip.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/minizip/unzip.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,2125 @@
+/* unzip.c -- IO for uncompress .zip files using zlib
+   Version 1.1, February 14h, 2010
+   part of the MiniZip project - ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Copyright (C) 1998-2010 Gilles Vollant (minizip) ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Modifications of Unzip for Zip64
+         Copyright (C) 2007-2008 Even Rouault
+
+         Modifications for Zip64 support on both zip and unzip
+         Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )
+
+         For more info read MiniZip_info.txt
+
+
+  ------------------------------------------------------------------------------------
+  Decryption code comes from crypt.c by Info-ZIP but has been greatly reduced in terms of
+  compatibility with older software. The following is from the original crypt.c.
+  Code woven in by Terry Thorsen 1/2003.
+
+  Copyright (c) 1990-2000 Info-ZIP.  All rights reserved.
+
+  See the accompanying file LICENSE, version 2000-Apr-09 or later
+  (the contents of which are also included in zip.h) for terms of use.
+  If, for some reason, all these files are missing, the Info-ZIP license
+  also may be found at:  ftp://ftp.info-zip.org/pub/infozip/license.html
+
+        crypt.c (full version) by Info-ZIP.      Last revised:  [see crypt.h]
+
+  The encryption/decryption parts of this source code (as opposed to the
+  non-echoing password parts) were originally written in Europe.  The
+  whole source package can be freely distributed, including from the USA.
+  (Prior to January 2000, re-export from the US was a violation of US law.)
+
+        This encryption code is a direct transcription of the algorithm from
+  Roger Schlafly, described by Phil Katz in the file appnote.txt.  This
+  file (appnote.txt) is distributed with the PKZIP program (even in the
+  version without encryption capabilities).
+
+        ------------------------------------------------------------------------------------
+
+        Changes in unzip.c
+
+        2007-2008 - Even Rouault - Addition of cpl_unzGetCurrentFileZStreamPos
+  2007-2008 - Even Rouault - Decoration of symbol names unz* -> cpl_unz*
+  2007-2008 - Even Rouault - Remove old C style function prototypes
+  2007-2008 - Even Rouault - Add unzip support for ZIP64
+
+        Copyright (C) 2007-2008 Even Rouault
+
+
+        Oct-2009 - Mathias Svensson - Removed cpl_* from symbol names (Even Rouault added them but since this is now moved to a new project (minizip64) I renamed them again).
+  Oct-2009 - Mathias Svensson - Fixed problem if uncompressed size was > 4G and compressed size was <4G
+                                should only read the compressed/uncompressed size from the Zip64 format if
+                                the size from normal header was 0xFFFFFFFF
+  Oct-2009 - Mathias Svensson - Applied some bug fixes from paches recived from Gilles Vollant
+        Oct-2009 - Mathias Svensson - Applied support to unzip files with compression mathod BZIP2 (bzip2 lib is required)
+                                Patch created by Daniel Borca
+
+  Jan-2010 - back to unzip and minizip 1.0 name scheme, with compatibility layer
+
+  Copyright (C) 1998 - 2010 Gilles Vollant, Even Rouault, Mathias Svensson
+
+*/
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifndef NOUNCRYPT
+        #define NOUNCRYPT
+#endif
+
+#include "zlib.h"
+#include "unzip.h"
+
+#ifdef STDC
+#  include <stddef.h>
+#  include <string.h>
+#  include <stdlib.h>
+#endif
+#ifdef NO_ERRNO_H
+    extern int errno;
+#else
+#   include <errno.h>
+#endif
+
+
+#ifndef local
+#  define local static
+#endif
+/* compile with -Dlocal if your debugger can't find static symbols */
+
+
+#ifndef CASESENSITIVITYDEFAULT_NO
+#  if !defined(unix) && !defined(CASESENSITIVITYDEFAULT_YES)
+#    define CASESENSITIVITYDEFAULT_NO
+#  endif
+#endif
+
+
+#ifndef UNZ_BUFSIZE
+#define UNZ_BUFSIZE (16384)
+#endif
+
+#ifndef UNZ_MAXFILENAMEINZIP
+#define UNZ_MAXFILENAMEINZIP (256)
+#endif
+
+#ifndef ALLOC
+# define ALLOC(size) (malloc(size))
+#endif
+#ifndef TRYFREE
+# define TRYFREE(p) {if (p) free(p);}
+#endif
+
+#define SIZECENTRALDIRITEM (0x2e)
+#define SIZEZIPLOCALHEADER (0x1e)
+
+
+const char unz_copyright[] =
+   " unzip 1.01 Copyright 1998-2004 Gilles Vollant - http://www.winimage.com/zLibDll";
+
+/* unz_file_info_interntal contain internal info about a file in zipfile*/
+typedef struct unz_file_info64_internal_s
+{
+    ZPOS64_T offset_curfile;/* relative offset of local header 8 bytes */
+} unz_file_info64_internal;
+
+
+/* file_in_zip_read_info_s contain internal information about a file in zipfile,
+    when reading and decompress it */
+typedef struct
+{
+    char  *read_buffer;         /* internal buffer for compressed data */
+    z_stream stream;            /* zLib stream structure for inflate */
+
+#ifdef HAVE_BZIP2
+    bz_stream bstream;          /* bzLib stream structure for bziped */
+#endif
+
+    ZPOS64_T pos_in_zipfile;       /* position in byte on the zipfile, for fseek*/
+    uLong stream_initialised;   /* flag set if stream structure is initialised*/
+
+    ZPOS64_T offset_local_extrafield;/* offset of the local extra field */
+    uInt  size_local_extrafield;/* size of the local extra field */
+    ZPOS64_T pos_local_extrafield;   /* position in the local extra field in read*/
+    ZPOS64_T total_out_64;
+
+    uLong crc32;                /* crc32 of all data uncompressed */
+    uLong crc32_wait;           /* crc32 we must obtain after decompress all */
+    ZPOS64_T rest_read_compressed; /* number of byte to be decompressed */
+    ZPOS64_T rest_read_uncompressed;/*number of byte to be obtained after decomp*/
+    zlib_filefunc64_32_def z_filefunc;
+    voidpf filestream;        /* io structore of the zipfile */
+    uLong compression_method;   /* compression method (0==store) */
+    ZPOS64_T byte_before_the_zipfile;/* byte before the zipfile, (>0 for sfx)*/
+    int   raw;
+} file_in_zip64_read_info_s;
+
+
+/* unz64_s contain internal information about the zipfile
+*/
+typedef struct
+{
+    zlib_filefunc64_32_def z_filefunc;
+    int is64bitOpenFunction;
+    voidpf filestream;        /* io structore of the zipfile */
+    unz_global_info64 gi;       /* public global information */
+    ZPOS64_T byte_before_the_zipfile;/* byte before the zipfile, (>0 for sfx)*/
+    ZPOS64_T num_file;             /* number of the current file in the zipfile*/
+    ZPOS64_T pos_in_central_dir;   /* pos of the current file in the central dir*/
+    ZPOS64_T current_file_ok;      /* flag about the usability of the current file*/
+    ZPOS64_T central_pos;          /* position of the beginning of the central dir*/
+
+    ZPOS64_T size_central_dir;     /* size of the central directory  */
+    ZPOS64_T offset_central_dir;   /* offset of start of central directory with
+                                   respect to the starting disk number */
+
+    unz_file_info64 cur_file_info; /* public info about the current file in zip*/
+    unz_file_info64_internal cur_file_info_internal; /* private info about it*/
+    file_in_zip64_read_info_s* pfile_in_zip_read; /* structure about the current
+                                        file if we are decompressing it */
+    int encrypted;
+
+    int isZip64;
+
+#    ifndef NOUNCRYPT
+    unsigned long keys[3];     /* keys defining the pseudo-random sequence */
+    const z_crc_t* pcrc_32_tab;
+#    endif
+} unz64_s;
+
+
+#ifndef NOUNCRYPT
+#include "crypt.h"
+#endif
+
+/* ===========================================================================
+     Read a byte from a gz_stream; update next_in and avail_in. Return EOF
+   for end of file.
+   IN assertion: the stream s has been successfully opened for reading.
+*/
+
+
+local int unz64local_getByte OF((
+    const zlib_filefunc64_32_def* pzlib_filefunc_def,
+    voidpf filestream,
+    int *pi));
+
+local int unz64local_getByte(const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream, int *pi)
+{
+    unsigned char c;
+    int err = (int)ZREAD64(*pzlib_filefunc_def,filestream,&c,1);
+    if (err==1)
+    {
+        *pi = (int)c;
+        return UNZ_OK;
+    }
+    else
+    {
+        if (ZERROR64(*pzlib_filefunc_def,filestream))
+            return UNZ_ERRNO;
+        else
+            return UNZ_EOF;
+    }
+}
+
+
+/* ===========================================================================
+   Reads a long in LSB order from the given gz_stream. Sets
+*/
+local int unz64local_getShort OF((
+    const zlib_filefunc64_32_def* pzlib_filefunc_def,
+    voidpf filestream,
+    uLong *pX));
+
+local int unz64local_getShort (const zlib_filefunc64_32_def* pzlib_filefunc_def,
+                             voidpf filestream,
+                             uLong *pX)
+{
+    uLong x ;
+    int i = 0;
+    int err;
+
+    err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x = (uLong)i;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x |= ((uLong)i)<<8;
+
+    if (err==UNZ_OK)
+        *pX = x;
+    else
+        *pX = 0;
+    return err;
+}
+
+local int unz64local_getLong OF((
+    const zlib_filefunc64_32_def* pzlib_filefunc_def,
+    voidpf filestream,
+    uLong *pX));
+
+local int unz64local_getLong (const zlib_filefunc64_32_def* pzlib_filefunc_def,
+                            voidpf filestream,
+                            uLong *pX)
+{
+    uLong x ;
+    int i = 0;
+    int err;
+
+    err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x = (uLong)i;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x |= ((uLong)i)<<8;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x |= ((uLong)i)<<16;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x += ((uLong)i)<<24;
+
+    if (err==UNZ_OK)
+        *pX = x;
+    else
+        *pX = 0;
+    return err;
+}
+
+local int unz64local_getLong64 OF((
+    const zlib_filefunc64_32_def* pzlib_filefunc_def,
+    voidpf filestream,
+    ZPOS64_T *pX));
+
+
+local int unz64local_getLong64 (const zlib_filefunc64_32_def* pzlib_filefunc_def,
+                            voidpf filestream,
+                            ZPOS64_T *pX)
+{
+    ZPOS64_T x ;
+    int i = 0;
+    int err;
+
+    err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x = (ZPOS64_T)i;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x |= ((ZPOS64_T)i)<<8;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x |= ((ZPOS64_T)i)<<16;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x |= ((ZPOS64_T)i)<<24;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x |= ((ZPOS64_T)i)<<32;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x |= ((ZPOS64_T)i)<<40;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x |= ((ZPOS64_T)i)<<48;
+
+    if (err==UNZ_OK)
+        err = unz64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x |= ((ZPOS64_T)i)<<56;
+
+    if (err==UNZ_OK)
+        *pX = x;
+    else
+        *pX = 0;
+    return err;
+}
+
+/* My own strcmpi / strcasecmp */
+local int strcmpcasenosensitive_internal (const char* fileName1, const char* fileName2)
+{
+    for (;;)
+    {
+        char c1=*(fileName1++);
+        char c2=*(fileName2++);
+        if ((c1>='a') && (c1<='z'))
+            c1 -= 0x20;
+        if ((c2>='a') && (c2<='z'))
+            c2 -= 0x20;
+        if (c1=='\0')
+            return ((c2=='\0') ? 0 : -1);
+        if (c2=='\0')
+            return 1;
+        if (c1<c2)
+            return -1;
+        if (c1>c2)
+            return 1;
+    }
+}
+
+
+#ifdef  CASESENSITIVITYDEFAULT_NO
+#define CASESENSITIVITYDEFAULTVALUE 2
+#else
+#define CASESENSITIVITYDEFAULTVALUE 1
+#endif
+
+#ifndef STRCMPCASENOSENTIVEFUNCTION
+#define STRCMPCASENOSENTIVEFUNCTION strcmpcasenosensitive_internal
+#endif
+
+/*
+   Compare two filename (fileName1,fileName2).
+   If iCaseSenisivity = 1, comparision is case sensitivity (like strcmp)
+   If iCaseSenisivity = 2, comparision is not case sensitivity (like strcmpi
+                                                                or strcasecmp)
+   If iCaseSenisivity = 0, case sensitivity is defaut of your operating system
+        (like 1 on Unix, 2 on Windows)
+
+*/
+extern int ZEXPORT unzStringFileNameCompare (const char*  fileName1,
+                                                 const char*  fileName2,
+                                                 int iCaseSensitivity)
+
+{
+    if (iCaseSensitivity==0)
+        iCaseSensitivity=CASESENSITIVITYDEFAULTVALUE;
+
+    if (iCaseSensitivity==1)
+        return strcmp(fileName1,fileName2);
+
+    return STRCMPCASENOSENTIVEFUNCTION(fileName1,fileName2);
+}
+
+#ifndef BUFREADCOMMENT
+#define BUFREADCOMMENT (0x400)
+#endif
+
+/*
+  Locate the Central directory of a zipfile (at the end, just before
+    the global comment)
+*/
+local ZPOS64_T unz64local_SearchCentralDir OF((const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream));
+local ZPOS64_T unz64local_SearchCentralDir(const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream)
+{
+    unsigned char* buf;
+    ZPOS64_T uSizeFile;
+    ZPOS64_T uBackRead;
+    ZPOS64_T uMaxBack=0xffff; /* maximum size of global comment */
+    ZPOS64_T uPosFound=0;
+
+    if (ZSEEK64(*pzlib_filefunc_def,filestream,0,ZLIB_FILEFUNC_SEEK_END) != 0)
+        return 0;
+
+
+    uSizeFile = ZTELL64(*pzlib_filefunc_def,filestream);
+
+    if (uMaxBack>uSizeFile)
+        uMaxBack = uSizeFile;
+
+    buf = (unsigned char*)ALLOC(BUFREADCOMMENT+4);
+    if (buf==NULL)
+        return 0;
+
+    uBackRead = 4;
+    while (uBackRead<uMaxBack)
+    {
+        uLong uReadSize;
+        ZPOS64_T uReadPos ;
+        int i;
+        if (uBackRead+BUFREADCOMMENT>uMaxBack)
+            uBackRead = uMaxBack;
+        else
+            uBackRead+=BUFREADCOMMENT;
+        uReadPos = uSizeFile-uBackRead ;
+
+        uReadSize = ((BUFREADCOMMENT+4) < (uSizeFile-uReadPos)) ?
+                     (BUFREADCOMMENT+4) : (uLong)(uSizeFile-uReadPos);
+        if (ZSEEK64(*pzlib_filefunc_def,filestream,uReadPos,ZLIB_FILEFUNC_SEEK_SET)!=0)
+            break;
+
+        if (ZREAD64(*pzlib_filefunc_def,filestream,buf,uReadSize)!=uReadSize)
+            break;
+
+        for (i=(int)uReadSize-3; (i--)>0;)
+            if (((*(buf+i))==0x50) && ((*(buf+i+1))==0x4b) &&
+                ((*(buf+i+2))==0x05) && ((*(buf+i+3))==0x06))
+            {
+                uPosFound = uReadPos+i;
+                break;
+            }
+
+        if (uPosFound!=0)
+            break;
+    }
+    TRYFREE(buf);
+    return uPosFound;
+}
+
+
+/*
+  Locate the Central directory 64 of a zipfile (at the end, just before
+    the global comment)
+*/
+local ZPOS64_T unz64local_SearchCentralDir64 OF((
+    const zlib_filefunc64_32_def* pzlib_filefunc_def,
+    voidpf filestream));
+
+local ZPOS64_T unz64local_SearchCentralDir64(const zlib_filefunc64_32_def* pzlib_filefunc_def,
+                                      voidpf filestream)
+{
+    unsigned char* buf;
+    ZPOS64_T uSizeFile;
+    ZPOS64_T uBackRead;
+    ZPOS64_T uMaxBack=0xffff; /* maximum size of global comment */
+    ZPOS64_T uPosFound=0;
+    uLong uL;
+                ZPOS64_T relativeOffset;
+
+    if (ZSEEK64(*pzlib_filefunc_def,filestream,0,ZLIB_FILEFUNC_SEEK_END) != 0)
+        return 0;
+
+
+    uSizeFile = ZTELL64(*pzlib_filefunc_def,filestream);
+
+    if (uMaxBack>uSizeFile)
+        uMaxBack = uSizeFile;
+
+    buf = (unsigned char*)ALLOC(BUFREADCOMMENT+4);
+    if (buf==NULL)
+        return 0;
+
+    uBackRead = 4;
+    while (uBackRead<uMaxBack)
+    {
+        uLong uReadSize;
+        ZPOS64_T uReadPos;
+        int i;
+        if (uBackRead+BUFREADCOMMENT>uMaxBack)
+            uBackRead = uMaxBack;
+        else
+            uBackRead+=BUFREADCOMMENT;
+        uReadPos = uSizeFile-uBackRead ;
+
+        uReadSize = ((BUFREADCOMMENT+4) < (uSizeFile-uReadPos)) ?
+                     (BUFREADCOMMENT+4) : (uLong)(uSizeFile-uReadPos);
+        if (ZSEEK64(*pzlib_filefunc_def,filestream,uReadPos,ZLIB_FILEFUNC_SEEK_SET)!=0)
+            break;
+
+        if (ZREAD64(*pzlib_filefunc_def,filestream,buf,uReadSize)!=uReadSize)
+            break;
+
+        for (i=(int)uReadSize-3; (i--)>0;)
+            if (((*(buf+i))==0x50) && ((*(buf+i+1))==0x4b) &&
+                ((*(buf+i+2))==0x06) && ((*(buf+i+3))==0x07))
+            {
+                uPosFound = uReadPos+i;
+                break;
+            }
+
+        if (uPosFound!=0)
+            break;
+    }
+    TRYFREE(buf);
+    if (uPosFound == 0)
+        return 0;
+
+    /* Zip64 end of central directory locator */
+    if (ZSEEK64(*pzlib_filefunc_def,filestream, uPosFound,ZLIB_FILEFUNC_SEEK_SET)!=0)
+        return 0;
+
+    /* the signature, already checked */
+    if (unz64local_getLong(pzlib_filefunc_def,filestream,&uL)!=UNZ_OK)
+        return 0;
+
+    /* number of the disk with the start of the zip64 end of  central directory */
+    if (unz64local_getLong(pzlib_filefunc_def,filestream,&uL)!=UNZ_OK)
+        return 0;
+    if (uL != 0)
+        return 0;
+
+    /* relative offset of the zip64 end of central directory record */
+    if (unz64local_getLong64(pzlib_filefunc_def,filestream,&relativeOffset)!=UNZ_OK)
+        return 0;
+
+    /* total number of disks */
+    if (unz64local_getLong(pzlib_filefunc_def,filestream,&uL)!=UNZ_OK)
+        return 0;
+    if (uL != 1)
+        return 0;
+
+    /* Goto end of central directory record */
+    if (ZSEEK64(*pzlib_filefunc_def,filestream, relativeOffset,ZLIB_FILEFUNC_SEEK_SET)!=0)
+        return 0;
+
+     /* the signature */
+    if (unz64local_getLong(pzlib_filefunc_def,filestream,&uL)!=UNZ_OK)
+        return 0;
+
+    if (uL != 0x06064b50)
+        return 0;
+
+    return relativeOffset;
+}
+
+/*
+  Open a Zip file. path contain the full pathname (by example,
+     on a Windows NT computer "c:\\test\\zlib114.zip" or on an Unix computer
+     "zlib/zlib114.zip".
+     If the zipfile cannot be opened (file doesn't exist or in not valid), the
+       return value is NULL.
+     Else, the return value is a unzFile Handle, usable with other function
+       of this unzip package.
+*/
+local unzFile unzOpenInternal (const void *path,
+                               zlib_filefunc64_32_def* pzlib_filefunc64_32_def,
+                               int is64bitOpenFunction)
+{
+    unz64_s us;
+    unz64_s *s;
+    ZPOS64_T central_pos;
+    uLong   uL;
+
+    uLong number_disk;          /* number of the current dist, used for
+                                   spaning ZIP, unsupported, always 0*/
+    uLong number_disk_with_CD;  /* number the the disk with central dir, used
+                                   for spaning ZIP, unsupported, always 0*/
+    ZPOS64_T number_entry_CD;      /* total number of entries in
+                                   the central dir
+                                   (same than number_entry on nospan) */
+
+    int err=UNZ_OK;
+
+    if (unz_copyright[0]!=' ')
+        return NULL;
+
+    us.z_filefunc.zseek32_file = NULL;
+    us.z_filefunc.ztell32_file = NULL;
+    if (pzlib_filefunc64_32_def==NULL)
+        fill_fopen64_filefunc(&us.z_filefunc.zfile_func64);
+    else
+        us.z_filefunc = *pzlib_filefunc64_32_def;
+    us.is64bitOpenFunction = is64bitOpenFunction;
+
+
+
+    us.filestream = ZOPEN64(us.z_filefunc,
+                                                 path,
+                                                 ZLIB_FILEFUNC_MODE_READ |
+                                                 ZLIB_FILEFUNC_MODE_EXISTING);
+    if (us.filestream==NULL)
+        return NULL;
+
+    central_pos = unz64local_SearchCentralDir64(&us.z_filefunc,us.filestream);
+    if (central_pos)
+    {
+        uLong uS;
+        ZPOS64_T uL64;
+
+        us.isZip64 = 1;
+
+        if (ZSEEK64(us.z_filefunc, us.filestream,
+                                      central_pos,ZLIB_FILEFUNC_SEEK_SET)!=0)
+        err=UNZ_ERRNO;
+
+        /* the signature, already checked */
+        if (unz64local_getLong(&us.z_filefunc, us.filestream,&uL)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* size of zip64 end of central directory record */
+        if (unz64local_getLong64(&us.z_filefunc, us.filestream,&uL64)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* version made by */
+        if (unz64local_getShort(&us.z_filefunc, us.filestream,&uS)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* version needed to extract */
+        if (unz64local_getShort(&us.z_filefunc, us.filestream,&uS)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* number of this disk */
+        if (unz64local_getLong(&us.z_filefunc, us.filestream,&number_disk)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* number of the disk with the start of the central directory */
+        if (unz64local_getLong(&us.z_filefunc, us.filestream,&number_disk_with_CD)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* total number of entries in the central directory on this disk */
+        if (unz64local_getLong64(&us.z_filefunc, us.filestream,&us.gi.number_entry)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* total number of entries in the central directory */
+        if (unz64local_getLong64(&us.z_filefunc, us.filestream,&number_entry_CD)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        if ((number_entry_CD!=us.gi.number_entry) ||
+            (number_disk_with_CD!=0) ||
+            (number_disk!=0))
+            err=UNZ_BADZIPFILE;
+
+        /* size of the central directory */
+        if (unz64local_getLong64(&us.z_filefunc, us.filestream,&us.size_central_dir)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* offset of start of central directory with respect to the
+          starting disk number */
+        if (unz64local_getLong64(&us.z_filefunc, us.filestream,&us.offset_central_dir)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        us.gi.size_comment = 0;
+    }
+    else
+    {
+        central_pos = unz64local_SearchCentralDir(&us.z_filefunc,us.filestream);
+        if (central_pos==0)
+            err=UNZ_ERRNO;
+
+        us.isZip64 = 0;
+
+        if (ZSEEK64(us.z_filefunc, us.filestream,
+                                        central_pos,ZLIB_FILEFUNC_SEEK_SET)!=0)
+            err=UNZ_ERRNO;
+
+        /* the signature, already checked */
+        if (unz64local_getLong(&us.z_filefunc, us.filestream,&uL)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* number of this disk */
+        if (unz64local_getShort(&us.z_filefunc, us.filestream,&number_disk)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* number of the disk with the start of the central directory */
+        if (unz64local_getShort(&us.z_filefunc, us.filestream,&number_disk_with_CD)!=UNZ_OK)
+            err=UNZ_ERRNO;
+
+        /* total number of entries in the central dir on this disk */
+        if (unz64local_getShort(&us.z_filefunc, us.filestream,&uL)!=UNZ_OK)
+            err=UNZ_ERRNO;
+        us.gi.number_entry = uL;
+
+        /* total number of entries in the central dir */
+        if (unz64local_getShort(&us.z_filefunc, us.filestream,&uL)!=UNZ_OK)
+            err=UNZ_ERRNO;
+        number_entry_CD = uL;
+
+        if ((number_entry_CD!=us.gi.number_entry) ||
+            (number_disk_with_CD!=0) ||
+            (number_disk!=0))
+            err=UNZ_BADZIPFILE;
+
+        /* size of the central directory */
+        if (unz64local_getLong(&us.z_filefunc, us.filestream,&uL)!=UNZ_OK)
+            err=UNZ_ERRNO;
+        us.size_central_dir = uL;
+
+        /* offset of start of central directory with respect to the
+            starting disk number */
+        if (unz64local_getLong(&us.z_filefunc, us.filestream,&uL)!=UNZ_OK)
+            err=UNZ_ERRNO;
+        us.offset_central_dir = uL;
+
+        /* zipfile comment length */
+        if (unz64local_getShort(&us.z_filefunc, us.filestream,&us.gi.size_comment)!=UNZ_OK)
+            err=UNZ_ERRNO;
+    }
+
+    if ((central_pos<us.offset_central_dir+us.size_central_dir) &&
+        (err==UNZ_OK))
+        err=UNZ_BADZIPFILE;
+
+    if (err!=UNZ_OK)
+    {
+        ZCLOSE64(us.z_filefunc, us.filestream);
+        return NULL;
+    }
+
+    us.byte_before_the_zipfile = central_pos -
+                            (us.offset_central_dir+us.size_central_dir);
+    us.central_pos = central_pos;
+    us.pfile_in_zip_read = NULL;
+    us.encrypted = 0;
+
+
+    s=(unz64_s*)ALLOC(sizeof(unz64_s));
+    if( s != NULL)
+    {
+        *s=us;
+        unzGoToFirstFile((unzFile)s);
+    }
+    return (unzFile)s;
+}
+
+
+extern unzFile ZEXPORT unzOpen2 (const char *path,
+                                        zlib_filefunc_def* pzlib_filefunc32_def)
+{
+    if (pzlib_filefunc32_def != NULL)
+    {
+        zlib_filefunc64_32_def zlib_filefunc64_32_def_fill;
+        fill_zlib_filefunc64_32_def_from_filefunc32(&zlib_filefunc64_32_def_fill,pzlib_filefunc32_def);
+        return unzOpenInternal(path, &zlib_filefunc64_32_def_fill, 0);
+    }
+    else
+        return unzOpenInternal(path, NULL, 0);
+}
+
+extern unzFile ZEXPORT unzOpen2_64 (const void *path,
+                                     zlib_filefunc64_def* pzlib_filefunc_def)
+{
+    if (pzlib_filefunc_def != NULL)
+    {
+        zlib_filefunc64_32_def zlib_filefunc64_32_def_fill;
+        zlib_filefunc64_32_def_fill.zfile_func64 = *pzlib_filefunc_def;
+        zlib_filefunc64_32_def_fill.ztell32_file = NULL;
+        zlib_filefunc64_32_def_fill.zseek32_file = NULL;
+        return unzOpenInternal(path, &zlib_filefunc64_32_def_fill, 1);
+    }
+    else
+        return unzOpenInternal(path, NULL, 1);
+}
+
+extern unzFile ZEXPORT unzOpen (const char *path)
+{
+    return unzOpenInternal(path, NULL, 0);
+}
+
+extern unzFile ZEXPORT unzOpen64 (const void *path)
+{
+    return unzOpenInternal(path, NULL, 1);
+}
+
+/*
+  Close a ZipFile opened with unzOpen.
+  If there is files inside the .Zip opened with unzOpenCurrentFile (see later),
+    these files MUST be closed with unzCloseCurrentFile before call unzClose.
+  return UNZ_OK if there is no problem. */
+extern int ZEXPORT unzClose (unzFile file)
+{
+    unz64_s* s;
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+
+    if (s->pfile_in_zip_read!=NULL)
+        unzCloseCurrentFile(file);
+
+    ZCLOSE64(s->z_filefunc, s->filestream);
+    TRYFREE(s);
+    return UNZ_OK;
+}
+
+
+/*
+  Write info about the ZipFile in the *pglobal_info structure.
+  No preparation of the structure is needed
+  return UNZ_OK if there is no problem. */
+extern int ZEXPORT unzGetGlobalInfo64 (unzFile file, unz_global_info64* pglobal_info)
+{
+    unz64_s* s;
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    *pglobal_info=s->gi;
+    return UNZ_OK;
+}
+
+extern int ZEXPORT unzGetGlobalInfo (unzFile file, unz_global_info* pglobal_info32)
+{
+    unz64_s* s;
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    /* to do : check if number_entry is not truncated */
+    pglobal_info32->number_entry = (uLong)s->gi.number_entry;
+    pglobal_info32->size_comment = s->gi.size_comment;
+    return UNZ_OK;
+}
+/*
+   Translate date/time from Dos format to tm_unz (readable more easilty)
+*/
+local void unz64local_DosDateToTmuDate (ZPOS64_T ulDosDate, tm_unz* ptm)
+{
+    ZPOS64_T uDate;
+    uDate = (ZPOS64_T)(ulDosDate>>16);
+    ptm->tm_mday = (uInt)(uDate&0x1f) ;
+    ptm->tm_mon =  (uInt)((((uDate)&0x1E0)/0x20)-1) ;
+    ptm->tm_year = (uInt)(((uDate&0x0FE00)/0x0200)+1980) ;
+
+    ptm->tm_hour = (uInt) ((ulDosDate &0xF800)/0x800);
+    ptm->tm_min =  (uInt) ((ulDosDate&0x7E0)/0x20) ;
+    ptm->tm_sec =  (uInt) (2*(ulDosDate&0x1f)) ;
+}
+
+/*
+  Get Info about the current file in the zipfile, with internal only info
+*/
+local int unz64local_GetCurrentFileInfoInternal OF((unzFile file,
+                                                  unz_file_info64 *pfile_info,
+                                                  unz_file_info64_internal
+                                                  *pfile_info_internal,
+                                                  char *szFileName,
+                                                  uLong fileNameBufferSize,
+                                                  void *extraField,
+                                                  uLong extraFieldBufferSize,
+                                                  char *szComment,
+                                                  uLong commentBufferSize));
+
+local int unz64local_GetCurrentFileInfoInternal (unzFile file,
+                                                  unz_file_info64 *pfile_info,
+                                                  unz_file_info64_internal
+                                                  *pfile_info_internal,
+                                                  char *szFileName,
+                                                  uLong fileNameBufferSize,
+                                                  void *extraField,
+                                                  uLong extraFieldBufferSize,
+                                                  char *szComment,
+                                                  uLong commentBufferSize)
+{
+    unz64_s* s;
+    unz_file_info64 file_info;
+    unz_file_info64_internal file_info_internal;
+    int err=UNZ_OK;
+    uLong uMagic;
+    long lSeek=0;
+    uLong uL;
+
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    if (ZSEEK64(s->z_filefunc, s->filestream,
+              s->pos_in_central_dir+s->byte_before_the_zipfile,
+              ZLIB_FILEFUNC_SEEK_SET)!=0)
+        err=UNZ_ERRNO;
+
+
+    /* we check the magic */
+    if (err==UNZ_OK)
+    {
+        if (unz64local_getLong(&s->z_filefunc, s->filestream,&uMagic) != UNZ_OK)
+            err=UNZ_ERRNO;
+        else if (uMagic!=0x02014b50)
+            err=UNZ_BADZIPFILE;
+    }
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&file_info.version) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&file_info.version_needed) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&file_info.flag) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&file_info.compression_method) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getLong(&s->z_filefunc, s->filestream,&file_info.dosDate) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    unz64local_DosDateToTmuDate(file_info.dosDate,&file_info.tmu_date);
+
+    if (unz64local_getLong(&s->z_filefunc, s->filestream,&file_info.crc) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getLong(&s->z_filefunc, s->filestream,&uL) != UNZ_OK)
+        err=UNZ_ERRNO;
+    file_info.compressed_size = uL;
+
+    if (unz64local_getLong(&s->z_filefunc, s->filestream,&uL) != UNZ_OK)
+        err=UNZ_ERRNO;
+    file_info.uncompressed_size = uL;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&file_info.size_filename) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&file_info.size_file_extra) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&file_info.size_file_comment) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&file_info.disk_num_start) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&file_info.internal_fa) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getLong(&s->z_filefunc, s->filestream,&file_info.external_fa) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+                // relative offset of local header
+    if (unz64local_getLong(&s->z_filefunc, s->filestream,&uL) != UNZ_OK)
+        err=UNZ_ERRNO;
+    file_info_internal.offset_curfile = uL;
+
+    lSeek+=file_info.size_filename;
+    if ((err==UNZ_OK) && (szFileName!=NULL))
+    {
+        uLong uSizeRead ;
+        if (file_info.size_filename<fileNameBufferSize)
+        {
+            *(szFileName+file_info.size_filename)='\0';
+            uSizeRead = file_info.size_filename;
+        }
+        else
+            uSizeRead = fileNameBufferSize;
+
+        if ((file_info.size_filename>0) && (fileNameBufferSize>0))
+            if (ZREAD64(s->z_filefunc, s->filestream,szFileName,uSizeRead)!=uSizeRead)
+                err=UNZ_ERRNO;
+        lSeek -= uSizeRead;
+    }
+
+    // Read extrafield
+    if ((err==UNZ_OK) && (extraField!=NULL))
+    {
+        ZPOS64_T uSizeRead ;
+        if (file_info.size_file_extra<extraFieldBufferSize)
+            uSizeRead = file_info.size_file_extra;
+        else
+            uSizeRead = extraFieldBufferSize;
+
+        if (lSeek!=0)
+        {
+            if (ZSEEK64(s->z_filefunc, s->filestream,lSeek,ZLIB_FILEFUNC_SEEK_CUR)==0)
+                lSeek=0;
+            else
+                err=UNZ_ERRNO;
+        }
+
+        if ((file_info.size_file_extra>0) && (extraFieldBufferSize>0))
+            if (ZREAD64(s->z_filefunc, s->filestream,extraField,(uLong)uSizeRead)!=uSizeRead)
+                err=UNZ_ERRNO;
+
+        lSeek += file_info.size_file_extra - (uLong)uSizeRead;
+    }
+    else
+        lSeek += file_info.size_file_extra;
+
+
+    if ((err==UNZ_OK) && (file_info.size_file_extra != 0))
+    {
+                                uLong acc = 0;
+
+        // since lSeek now points to after the extra field we need to move back
+        lSeek -= file_info.size_file_extra;
+
+        if (lSeek!=0)
+        {
+            if (ZSEEK64(s->z_filefunc, s->filestream,lSeek,ZLIB_FILEFUNC_SEEK_CUR)==0)
+                lSeek=0;
+            else
+                err=UNZ_ERRNO;
+        }
+
+        while(acc < file_info.size_file_extra)
+        {
+            uLong headerId;
+                                                uLong dataSize;
+
+            if (unz64local_getShort(&s->z_filefunc, s->filestream,&headerId) != UNZ_OK)
+                err=UNZ_ERRNO;
+
+            if (unz64local_getShort(&s->z_filefunc, s->filestream,&dataSize) != UNZ_OK)
+                err=UNZ_ERRNO;
+
+            /* ZIP64 extra fields */
+            if (headerId == 0x0001)
+            {
+                                                        uLong uL;
+
+                                                                if(file_info.uncompressed_size == MAXU32)
+                                                                {
+                                                                        if (unz64local_getLong64(&s->z_filefunc, s->filestream,&file_info.uncompressed_size) != UNZ_OK)
+                                                                                        err=UNZ_ERRNO;
+                                                                }
+
+                                                                if(file_info.compressed_size == MAXU32)
+                                                                {
+                                                                        if (unz64local_getLong64(&s->z_filefunc, s->filestream,&file_info.compressed_size) != UNZ_OK)
+                                                                                  err=UNZ_ERRNO;
+                                                                }
+
+                                                                if(file_info_internal.offset_curfile == MAXU32)
+                                                                {
+                                                                        /* Relative Header offset */
+                                                                        if (unz64local_getLong64(&s->z_filefunc, s->filestream,&file_info_internal.offset_curfile) != UNZ_OK)
+                                                                                err=UNZ_ERRNO;
+                                                                }
+
+                                                                if(file_info.disk_num_start == MAXU32)
+                                                                {
+                                                                        /* Disk Start Number */
+                                                                        if (unz64local_getLong(&s->z_filefunc, s->filestream,&uL) != UNZ_OK)
+                                                                                err=UNZ_ERRNO;
+                                                                }
+
+            }
+            else
+            {
+                if (ZSEEK64(s->z_filefunc, s->filestream,dataSize,ZLIB_FILEFUNC_SEEK_CUR)!=0)
+                    err=UNZ_ERRNO;
+            }
+
+            acc += 2 + 2 + dataSize;
+        }
+    }
+
+    if ((err==UNZ_OK) && (szComment!=NULL))
+    {
+        uLong uSizeRead ;
+        if (file_info.size_file_comment<commentBufferSize)
+        {
+            *(szComment+file_info.size_file_comment)='\0';
+            uSizeRead = file_info.size_file_comment;
+        }
+        else
+            uSizeRead = commentBufferSize;
+
+        if (lSeek!=0)
+        {
+            if (ZSEEK64(s->z_filefunc, s->filestream,lSeek,ZLIB_FILEFUNC_SEEK_CUR)==0)
+                lSeek=0;
+            else
+                err=UNZ_ERRNO;
+        }
+
+        if ((file_info.size_file_comment>0) && (commentBufferSize>0))
+            if (ZREAD64(s->z_filefunc, s->filestream,szComment,uSizeRead)!=uSizeRead)
+                err=UNZ_ERRNO;
+        lSeek+=file_info.size_file_comment - uSizeRead;
+    }
+    else
+        lSeek+=file_info.size_file_comment;
+
+
+    if ((err==UNZ_OK) && (pfile_info!=NULL))
+        *pfile_info=file_info;
+
+    if ((err==UNZ_OK) && (pfile_info_internal!=NULL))
+        *pfile_info_internal=file_info_internal;
+
+    return err;
+}
+
+
+
+/*
+  Write info about the ZipFile in the *pglobal_info structure.
+  No preparation of the structure is needed
+  return UNZ_OK if there is no problem.
+*/
+extern int ZEXPORT unzGetCurrentFileInfo64 (unzFile file,
+                                          unz_file_info64 * pfile_info,
+                                          char * szFileName, uLong fileNameBufferSize,
+                                          void *extraField, uLong extraFieldBufferSize,
+                                          char* szComment,  uLong commentBufferSize)
+{
+    return unz64local_GetCurrentFileInfoInternal(file,pfile_info,NULL,
+                                                szFileName,fileNameBufferSize,
+                                                extraField,extraFieldBufferSize,
+                                                szComment,commentBufferSize);
+}
+
+extern int ZEXPORT unzGetCurrentFileInfo (unzFile file,
+                                          unz_file_info * pfile_info,
+                                          char * szFileName, uLong fileNameBufferSize,
+                                          void *extraField, uLong extraFieldBufferSize,
+                                          char* szComment,  uLong commentBufferSize)
+{
+    int err;
+    unz_file_info64 file_info64;
+    err = unz64local_GetCurrentFileInfoInternal(file,&file_info64,NULL,
+                                                szFileName,fileNameBufferSize,
+                                                extraField,extraFieldBufferSize,
+                                                szComment,commentBufferSize);
+    if ((err==UNZ_OK) && (pfile_info != NULL))
+    {
+        pfile_info->version = file_info64.version;
+        pfile_info->version_needed = file_info64.version_needed;
+        pfile_info->flag = file_info64.flag;
+        pfile_info->compression_method = file_info64.compression_method;
+        pfile_info->dosDate = file_info64.dosDate;
+        pfile_info->crc = file_info64.crc;
+
+        pfile_info->size_filename = file_info64.size_filename;
+        pfile_info->size_file_extra = file_info64.size_file_extra;
+        pfile_info->size_file_comment = file_info64.size_file_comment;
+
+        pfile_info->disk_num_start = file_info64.disk_num_start;
+        pfile_info->internal_fa = file_info64.internal_fa;
+        pfile_info->external_fa = file_info64.external_fa;
+
+        pfile_info->tmu_date = file_info64.tmu_date,
+
+
+        pfile_info->compressed_size = (uLong)file_info64.compressed_size;
+        pfile_info->uncompressed_size = (uLong)file_info64.uncompressed_size;
+
+    }
+    return err;
+}
+/*
+  Set the current file of the zipfile to the first file.
+  return UNZ_OK if there is no problem
+*/
+extern int ZEXPORT unzGoToFirstFile (unzFile file)
+{
+    int err=UNZ_OK;
+    unz64_s* s;
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    s->pos_in_central_dir=s->offset_central_dir;
+    s->num_file=0;
+    err=unz64local_GetCurrentFileInfoInternal(file,&s->cur_file_info,
+                                             &s->cur_file_info_internal,
+                                             NULL,0,NULL,0,NULL,0);
+    s->current_file_ok = (err == UNZ_OK);
+    return err;
+}
+
+/*
+  Set the current file of the zipfile to the next file.
+  return UNZ_OK if there is no problem
+  return UNZ_END_OF_LIST_OF_FILE if the actual file was the latest.
+*/
+extern int ZEXPORT unzGoToNextFile (unzFile  file)
+{
+    unz64_s* s;
+    int err;
+
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    if (!s->current_file_ok)
+        return UNZ_END_OF_LIST_OF_FILE;
+    if (s->gi.number_entry != 0xffff)    /* 2^16 files overflow hack */
+      if (s->num_file+1==s->gi.number_entry)
+        return UNZ_END_OF_LIST_OF_FILE;
+
+    s->pos_in_central_dir += SIZECENTRALDIRITEM + s->cur_file_info.size_filename +
+            s->cur_file_info.size_file_extra + s->cur_file_info.size_file_comment ;
+    s->num_file++;
+    err = unz64local_GetCurrentFileInfoInternal(file,&s->cur_file_info,
+                                               &s->cur_file_info_internal,
+                                               NULL,0,NULL,0,NULL,0);
+    s->current_file_ok = (err == UNZ_OK);
+    return err;
+}
+
+
+/*
+  Try locate the file szFileName in the zipfile.
+  For the iCaseSensitivity signification, see unzStringFileNameCompare
+
+  return value :
+  UNZ_OK if the file is found. It becomes the current file.
+  UNZ_END_OF_LIST_OF_FILE if the file is not found
+*/
+extern int ZEXPORT unzLocateFile (unzFile file, const char *szFileName, int iCaseSensitivity)
+{
+    unz64_s* s;
+    int err;
+
+    /* We remember the 'current' position in the file so that we can jump
+     * back there if we fail.
+     */
+    unz_file_info64 cur_file_infoSaved;
+    unz_file_info64_internal cur_file_info_internalSaved;
+    ZPOS64_T num_fileSaved;
+    ZPOS64_T pos_in_central_dirSaved;
+
+
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+
+    if (strlen(szFileName)>=UNZ_MAXFILENAMEINZIP)
+        return UNZ_PARAMERROR;
+
+    s=(unz64_s*)file;
+    if (!s->current_file_ok)
+        return UNZ_END_OF_LIST_OF_FILE;
+
+    /* Save the current state */
+    num_fileSaved = s->num_file;
+    pos_in_central_dirSaved = s->pos_in_central_dir;
+    cur_file_infoSaved = s->cur_file_info;
+    cur_file_info_internalSaved = s->cur_file_info_internal;
+
+    err = unzGoToFirstFile(file);
+
+    while (err == UNZ_OK)
+    {
+        char szCurrentFileName[UNZ_MAXFILENAMEINZIP+1];
+        err = unzGetCurrentFileInfo64(file,NULL,
+                                    szCurrentFileName,sizeof(szCurrentFileName)-1,
+                                    NULL,0,NULL,0);
+        if (err == UNZ_OK)
+        {
+            if (unzStringFileNameCompare(szCurrentFileName,
+                                            szFileName,iCaseSensitivity)==0)
+                return UNZ_OK;
+            err = unzGoToNextFile(file);
+        }
+    }
+
+    /* We failed, so restore the state of the 'current file' to where we
+     * were.
+     */
+    s->num_file = num_fileSaved ;
+    s->pos_in_central_dir = pos_in_central_dirSaved ;
+    s->cur_file_info = cur_file_infoSaved;
+    s->cur_file_info_internal = cur_file_info_internalSaved;
+    return err;
+}
+
+
+/*
+///////////////////////////////////////////
+// Contributed by Ryan Haksi (mailto://cryogen@infoserve.net)
+// I need random access
+//
+// Further optimization could be realized by adding an ability
+// to cache the directory in memory. The goal being a single
+// comprehensive file read to put the file I need in a memory.
+*/
+
+/*
+typedef struct unz_file_pos_s
+{
+    ZPOS64_T pos_in_zip_directory;   // offset in file
+    ZPOS64_T num_of_file;            // # of file
+} unz_file_pos;
+*/
+
+extern int ZEXPORT unzGetFilePos64(unzFile file, unz64_file_pos*  file_pos)
+{
+    unz64_s* s;
+
+    if (file==NULL || file_pos==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    if (!s->current_file_ok)
+        return UNZ_END_OF_LIST_OF_FILE;
+
+    file_pos->pos_in_zip_directory  = s->pos_in_central_dir;
+    file_pos->num_of_file           = s->num_file;
+
+    return UNZ_OK;
+}
+
+extern int ZEXPORT unzGetFilePos(
+    unzFile file,
+    unz_file_pos* file_pos)
+{
+    unz64_file_pos file_pos64;
+    int err = unzGetFilePos64(file,&file_pos64);
+    if (err==UNZ_OK)
+    {
+        file_pos->pos_in_zip_directory = (uLong)file_pos64.pos_in_zip_directory;
+        file_pos->num_of_file = (uLong)file_pos64.num_of_file;
+    }
+    return err;
+}
+
+extern int ZEXPORT unzGoToFilePos64(unzFile file, const unz64_file_pos* file_pos)
+{
+    unz64_s* s;
+    int err;
+
+    if (file==NULL || file_pos==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+
+    /* jump to the right spot */
+    s->pos_in_central_dir = file_pos->pos_in_zip_directory;
+    s->num_file           = file_pos->num_of_file;
+
+    /* set the current file */
+    err = unz64local_GetCurrentFileInfoInternal(file,&s->cur_file_info,
+                                               &s->cur_file_info_internal,
+                                               NULL,0,NULL,0,NULL,0);
+    /* return results */
+    s->current_file_ok = (err == UNZ_OK);
+    return err;
+}
+
+extern int ZEXPORT unzGoToFilePos(
+    unzFile file,
+    unz_file_pos* file_pos)
+{
+    unz64_file_pos file_pos64;
+    if (file_pos == NULL)
+        return UNZ_PARAMERROR;
+
+    file_pos64.pos_in_zip_directory = file_pos->pos_in_zip_directory;
+    file_pos64.num_of_file = file_pos->num_of_file;
+    return unzGoToFilePos64(file,&file_pos64);
+}
+
+/*
+// Unzip Helper Functions - should be here?
+///////////////////////////////////////////
+*/
+
+/*
+  Read the local header of the current zipfile
+  Check the coherency of the local header and info in the end of central
+        directory about this file
+  store in *piSizeVar the size of extra info in local header
+        (filename and size of extra field data)
+*/
+local int unz64local_CheckCurrentFileCoherencyHeader (unz64_s* s, uInt* piSizeVar,
+                                                    ZPOS64_T * poffset_local_extrafield,
+                                                    uInt  * psize_local_extrafield)
+{
+    uLong uMagic,uData,uFlags;
+    uLong size_filename;
+    uLong size_extra_field;
+    int err=UNZ_OK;
+
+    *piSizeVar = 0;
+    *poffset_local_extrafield = 0;
+    *psize_local_extrafield = 0;
+
+    if (ZSEEK64(s->z_filefunc, s->filestream,s->cur_file_info_internal.offset_curfile +
+                                s->byte_before_the_zipfile,ZLIB_FILEFUNC_SEEK_SET)!=0)
+        return UNZ_ERRNO;
+
+
+    if (err==UNZ_OK)
+    {
+        if (unz64local_getLong(&s->z_filefunc, s->filestream,&uMagic) != UNZ_OK)
+            err=UNZ_ERRNO;
+        else if (uMagic!=0x04034b50)
+            err=UNZ_BADZIPFILE;
+    }
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&uData) != UNZ_OK)
+        err=UNZ_ERRNO;
+/*
+    else if ((err==UNZ_OK) && (uData!=s->cur_file_info.wVersion))
+        err=UNZ_BADZIPFILE;
+*/
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&uFlags) != UNZ_OK)
+        err=UNZ_ERRNO;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&uData) != UNZ_OK)
+        err=UNZ_ERRNO;
+    else if ((err==UNZ_OK) && (uData!=s->cur_file_info.compression_method))
+        err=UNZ_BADZIPFILE;
+
+    if ((err==UNZ_OK) && (s->cur_file_info.compression_method!=0) &&
+/* #ifdef HAVE_BZIP2 */
+                         (s->cur_file_info.compression_method!=Z_BZIP2ED) &&
+/* #endif */
+                         (s->cur_file_info.compression_method!=Z_DEFLATED))
+        err=UNZ_BADZIPFILE;
+
+    if (unz64local_getLong(&s->z_filefunc, s->filestream,&uData) != UNZ_OK) /* date/time */
+        err=UNZ_ERRNO;
+
+    if (unz64local_getLong(&s->z_filefunc, s->filestream,&uData) != UNZ_OK) /* crc */
+        err=UNZ_ERRNO;
+    else if ((err==UNZ_OK) && (uData!=s->cur_file_info.crc) && ((uFlags & 8)==0))
+        err=UNZ_BADZIPFILE;
+
+    if (unz64local_getLong(&s->z_filefunc, s->filestream,&uData) != UNZ_OK) /* size compr */
+        err=UNZ_ERRNO;
+    else if (uData != 0xFFFFFFFF && (err==UNZ_OK) && (uData!=s->cur_file_info.compressed_size) && ((uFlags & 8)==0))
+        err=UNZ_BADZIPFILE;
+
+    if (unz64local_getLong(&s->z_filefunc, s->filestream,&uData) != UNZ_OK) /* size uncompr */
+        err=UNZ_ERRNO;
+    else if (uData != 0xFFFFFFFF && (err==UNZ_OK) && (uData!=s->cur_file_info.uncompressed_size) && ((uFlags & 8)==0))
+        err=UNZ_BADZIPFILE;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&size_filename) != UNZ_OK)
+        err=UNZ_ERRNO;
+    else if ((err==UNZ_OK) && (size_filename!=s->cur_file_info.size_filename))
+        err=UNZ_BADZIPFILE;
+
+    *piSizeVar += (uInt)size_filename;
+
+    if (unz64local_getShort(&s->z_filefunc, s->filestream,&size_extra_field) != UNZ_OK)
+        err=UNZ_ERRNO;
+    *poffset_local_extrafield= s->cur_file_info_internal.offset_curfile +
+                                    SIZEZIPLOCALHEADER + size_filename;
+    *psize_local_extrafield = (uInt)size_extra_field;
+
+    *piSizeVar += (uInt)size_extra_field;
+
+    return err;
+}
+
+/*
+  Open for reading data the current file in the zipfile.
+  If there is no error and the file is opened, the return value is UNZ_OK.
+*/
+extern int ZEXPORT unzOpenCurrentFile3 (unzFile file, int* method,
+                                            int* level, int raw, const char* password)
+{
+    int err=UNZ_OK;
+    uInt iSizeVar;
+    unz64_s* s;
+    file_in_zip64_read_info_s* pfile_in_zip_read_info;
+    ZPOS64_T offset_local_extrafield;  /* offset of the local extra field */
+    uInt  size_local_extrafield;    /* size of the local extra field */
+#    ifndef NOUNCRYPT
+    char source[12];
+#    else
+    if (password != NULL)
+        return UNZ_PARAMERROR;
+#    endif
+
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    if (!s->current_file_ok)
+        return UNZ_PARAMERROR;
+
+    if (s->pfile_in_zip_read != NULL)
+        unzCloseCurrentFile(file);
+
+    if (unz64local_CheckCurrentFileCoherencyHeader(s,&iSizeVar, &offset_local_extrafield,&size_local_extrafield)!=UNZ_OK)
+        return UNZ_BADZIPFILE;
+
+    pfile_in_zip_read_info = (file_in_zip64_read_info_s*)ALLOC(sizeof(file_in_zip64_read_info_s));
+    if (pfile_in_zip_read_info==NULL)
+        return UNZ_INTERNALERROR;
+
+    pfile_in_zip_read_info->read_buffer=(char*)ALLOC(UNZ_BUFSIZE);
+    pfile_in_zip_read_info->offset_local_extrafield = offset_local_extrafield;
+    pfile_in_zip_read_info->size_local_extrafield = size_local_extrafield;
+    pfile_in_zip_read_info->pos_local_extrafield=0;
+    pfile_in_zip_read_info->raw=raw;
+
+    if (pfile_in_zip_read_info->read_buffer==NULL)
+    {
+        TRYFREE(pfile_in_zip_read_info);
+        return UNZ_INTERNALERROR;
+    }
+
+    pfile_in_zip_read_info->stream_initialised=0;
+
+    if (method!=NULL)
+        *method = (int)s->cur_file_info.compression_method;
+
+    if (level!=NULL)
+    {
+        *level = 6;
+        switch (s->cur_file_info.flag & 0x06)
+        {
+          case 6 : *level = 1; break;
+          case 4 : *level = 2; break;
+          case 2 : *level = 9; break;
+        }
+    }
+
+    if ((s->cur_file_info.compression_method!=0) &&
+/* #ifdef HAVE_BZIP2 */
+        (s->cur_file_info.compression_method!=Z_BZIP2ED) &&
+/* #endif */
+        (s->cur_file_info.compression_method!=Z_DEFLATED))
+
+        err=UNZ_BADZIPFILE;
+
+    pfile_in_zip_read_info->crc32_wait=s->cur_file_info.crc;
+    pfile_in_zip_read_info->crc32=0;
+    pfile_in_zip_read_info->total_out_64=0;
+    pfile_in_zip_read_info->compression_method = s->cur_file_info.compression_method;
+    pfile_in_zip_read_info->filestream=s->filestream;
+    pfile_in_zip_read_info->z_filefunc=s->z_filefunc;
+    pfile_in_zip_read_info->byte_before_the_zipfile=s->byte_before_the_zipfile;
+
+    pfile_in_zip_read_info->stream.total_out = 0;
+
+    if ((s->cur_file_info.compression_method==Z_BZIP2ED) && (!raw))
+    {
+#ifdef HAVE_BZIP2
+      pfile_in_zip_read_info->bstream.bzalloc = (void *(*) (void *, int, int))0;
+      pfile_in_zip_read_info->bstream.bzfree = (free_func)0;
+      pfile_in_zip_read_info->bstream.opaque = (voidpf)0;
+      pfile_in_zip_read_info->bstream.state = (voidpf)0;
+
+      pfile_in_zip_read_info->stream.zalloc = (alloc_func)0;
+      pfile_in_zip_read_info->stream.zfree = (free_func)0;
+      pfile_in_zip_read_info->stream.opaque = (voidpf)0;
+      pfile_in_zip_read_info->stream.next_in = (voidpf)0;
+      pfile_in_zip_read_info->stream.avail_in = 0;
+
+      err=BZ2_bzDecompressInit(&pfile_in_zip_read_info->bstream, 0, 0);
+      if (err == Z_OK)
+        pfile_in_zip_read_info->stream_initialised=Z_BZIP2ED;
+      else
+      {
+        TRYFREE(pfile_in_zip_read_info);
+        return err;
+      }
+#else
+      pfile_in_zip_read_info->raw=1;
+#endif
+    }
+    else if ((s->cur_file_info.compression_method==Z_DEFLATED) && (!raw))
+    {
+      pfile_in_zip_read_info->stream.zalloc = (alloc_func)0;
+      pfile_in_zip_read_info->stream.zfree = (free_func)0;
+      pfile_in_zip_read_info->stream.opaque = (voidpf)0;
+      pfile_in_zip_read_info->stream.next_in = 0;
+      pfile_in_zip_read_info->stream.avail_in = 0;
+
+      err=inflateInit2(&pfile_in_zip_read_info->stream, -MAX_WBITS);
+      if (err == Z_OK)
+        pfile_in_zip_read_info->stream_initialised=Z_DEFLATED;
+      else
+      {
+        TRYFREE(pfile_in_zip_read_info);
+        return err;
+      }
+        /* windowBits is passed < 0 to tell that there is no zlib header.
+         * Note that in this case inflate *requires* an extra "dummy" byte
+         * after the compressed stream in order to complete decompression and
+         * return Z_STREAM_END.
+         * In unzip, i don't wait absolutely Z_STREAM_END because I known the
+         * size of both compressed and uncompressed data
+         */
+    }
+    pfile_in_zip_read_info->rest_read_compressed =
+            s->cur_file_info.compressed_size ;
+    pfile_in_zip_read_info->rest_read_uncompressed =
+            s->cur_file_info.uncompressed_size ;
+
+
+    pfile_in_zip_read_info->pos_in_zipfile =
+            s->cur_file_info_internal.offset_curfile + SIZEZIPLOCALHEADER +
+              iSizeVar;
+
+    pfile_in_zip_read_info->stream.avail_in = (uInt)0;
+
+    s->pfile_in_zip_read = pfile_in_zip_read_info;
+                s->encrypted = 0;
+
+#    ifndef NOUNCRYPT
+    if (password != NULL)
+    {
+        int i;
+        s->pcrc_32_tab = get_crc_table();
+        init_keys(password,s->keys,s->pcrc_32_tab);
+        if (ZSEEK64(s->z_filefunc, s->filestream,
+                  s->pfile_in_zip_read->pos_in_zipfile +
+                     s->pfile_in_zip_read->byte_before_the_zipfile,
+                  SEEK_SET)!=0)
+            return UNZ_INTERNALERROR;
+        if(ZREAD64(s->z_filefunc, s->filestream,source, 12)<12)
+            return UNZ_INTERNALERROR;
+
+        for (i = 0; i<12; i++)
+            zdecode(s->keys,s->pcrc_32_tab,source[i]);
+
+        s->pfile_in_zip_read->pos_in_zipfile+=12;
+        s->encrypted=1;
+    }
+#    endif
+
+
+    return UNZ_OK;
+}
+
+extern int ZEXPORT unzOpenCurrentFile (unzFile file)
+{
+    return unzOpenCurrentFile3(file, NULL, NULL, 0, NULL);
+}
+
+extern int ZEXPORT unzOpenCurrentFilePassword (unzFile file, const char*  password)
+{
+    return unzOpenCurrentFile3(file, NULL, NULL, 0, password);
+}
+
+extern int ZEXPORT unzOpenCurrentFile2 (unzFile file, int* method, int* level, int raw)
+{
+    return unzOpenCurrentFile3(file, method, level, raw, NULL);
+}
+
+/** Addition for GDAL : START */
+
+extern ZPOS64_T ZEXPORT unzGetCurrentFileZStreamPos64( unzFile file)
+{
+    unz64_s* s;
+    file_in_zip64_read_info_s* pfile_in_zip_read_info;
+    s=(unz64_s*)file;
+    if (file==NULL)
+        return 0; //UNZ_PARAMERROR;
+    pfile_in_zip_read_info=s->pfile_in_zip_read;
+    if (pfile_in_zip_read_info==NULL)
+        return 0; //UNZ_PARAMERROR;
+    return pfile_in_zip_read_info->pos_in_zipfile +
+                         pfile_in_zip_read_info->byte_before_the_zipfile;
+}
+
+/** Addition for GDAL : END */
+
+/*
+  Read bytes from the current file.
+  buf contain buffer where data must be copied
+  len the size of buf.
+
+  return the number of byte copied if somes bytes are copied
+  return 0 if the end of file was reached
+  return <0 with error code if there is an error
+    (UNZ_ERRNO for IO error, or zLib error for uncompress error)
+*/
+extern int ZEXPORT unzReadCurrentFile  (unzFile file, voidp buf, unsigned len)
+{
+    int err=UNZ_OK;
+    uInt iRead = 0;
+    unz64_s* s;
+    file_in_zip64_read_info_s* pfile_in_zip_read_info;
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    pfile_in_zip_read_info=s->pfile_in_zip_read;
+
+    if (pfile_in_zip_read_info==NULL)
+        return UNZ_PARAMERROR;
+
+
+    if (pfile_in_zip_read_info->read_buffer == NULL)
+        return UNZ_END_OF_LIST_OF_FILE;
+    if (len==0)
+        return 0;
+
+    pfile_in_zip_read_info->stream.next_out = (Bytef*)buf;
+
+    pfile_in_zip_read_info->stream.avail_out = (uInt)len;
+
+    if ((len>pfile_in_zip_read_info->rest_read_uncompressed) &&
+        (!(pfile_in_zip_read_info->raw)))
+        pfile_in_zip_read_info->stream.avail_out =
+            (uInt)pfile_in_zip_read_info->rest_read_uncompressed;
+
+    if ((len>pfile_in_zip_read_info->rest_read_compressed+
+           pfile_in_zip_read_info->stream.avail_in) &&
+         (pfile_in_zip_read_info->raw))
+        pfile_in_zip_read_info->stream.avail_out =
+            (uInt)pfile_in_zip_read_info->rest_read_compressed+
+            pfile_in_zip_read_info->stream.avail_in;
+
+    while (pfile_in_zip_read_info->stream.avail_out>0)
+    {
+        if ((pfile_in_zip_read_info->stream.avail_in==0) &&
+            (pfile_in_zip_read_info->rest_read_compressed>0))
+        {
+            uInt uReadThis = UNZ_BUFSIZE;
+            if (pfile_in_zip_read_info->rest_read_compressed<uReadThis)
+                uReadThis = (uInt)pfile_in_zip_read_info->rest_read_compressed;
+            if (uReadThis == 0)
+                return UNZ_EOF;
+            if (ZSEEK64(pfile_in_zip_read_info->z_filefunc,
+                      pfile_in_zip_read_info->filestream,
+                      pfile_in_zip_read_info->pos_in_zipfile +
+                         pfile_in_zip_read_info->byte_before_the_zipfile,
+                         ZLIB_FILEFUNC_SEEK_SET)!=0)
+                return UNZ_ERRNO;
+            if (ZREAD64(pfile_in_zip_read_info->z_filefunc,
+                      pfile_in_zip_read_info->filestream,
+                      pfile_in_zip_read_info->read_buffer,
+                      uReadThis)!=uReadThis)
+                return UNZ_ERRNO;
+
+
+#            ifndef NOUNCRYPT
+            if(s->encrypted)
+            {
+                uInt i;
+                for(i=0;i<uReadThis;i++)
+                  pfile_in_zip_read_info->read_buffer[i] =
+                      zdecode(s->keys,s->pcrc_32_tab,
+                              pfile_in_zip_read_info->read_buffer[i]);
+            }
+#            endif
+
+
+            pfile_in_zip_read_info->pos_in_zipfile += uReadThis;
+
+            pfile_in_zip_read_info->rest_read_compressed-=uReadThis;
+
+            pfile_in_zip_read_info->stream.next_in =
+                (Bytef*)pfile_in_zip_read_info->read_buffer;
+            pfile_in_zip_read_info->stream.avail_in = (uInt)uReadThis;
+        }
+
+        if ((pfile_in_zip_read_info->compression_method==0) || (pfile_in_zip_read_info->raw))
+        {
+            uInt uDoCopy,i ;
+
+            if ((pfile_in_zip_read_info->stream.avail_in == 0) &&
+                (pfile_in_zip_read_info->rest_read_compressed == 0))
+                return (iRead==0) ? UNZ_EOF : iRead;
+
+            if (pfile_in_zip_read_info->stream.avail_out <
+                            pfile_in_zip_read_info->stream.avail_in)
+                uDoCopy = pfile_in_zip_read_info->stream.avail_out ;
+            else
+                uDoCopy = pfile_in_zip_read_info->stream.avail_in ;
+
+            for (i=0;i<uDoCopy;i++)
+                *(pfile_in_zip_read_info->stream.next_out+i) =
+                        *(pfile_in_zip_read_info->stream.next_in+i);
+
+            pfile_in_zip_read_info->total_out_64 = pfile_in_zip_read_info->total_out_64 + uDoCopy;
+
+            pfile_in_zip_read_info->crc32 = crc32(pfile_in_zip_read_info->crc32,
+                                pfile_in_zip_read_info->stream.next_out,
+                                uDoCopy);
+            pfile_in_zip_read_info->rest_read_uncompressed-=uDoCopy;
+            pfile_in_zip_read_info->stream.avail_in -= uDoCopy;
+            pfile_in_zip_read_info->stream.avail_out -= uDoCopy;
+            pfile_in_zip_read_info->stream.next_out += uDoCopy;
+            pfile_in_zip_read_info->stream.next_in += uDoCopy;
+            pfile_in_zip_read_info->stream.total_out += uDoCopy;
+            iRead += uDoCopy;
+        }
+        else if (pfile_in_zip_read_info->compression_method==Z_BZIP2ED)
+        {
+#ifdef HAVE_BZIP2
+            uLong uTotalOutBefore,uTotalOutAfter;
+            const Bytef *bufBefore;
+            uLong uOutThis;
+
+            pfile_in_zip_read_info->bstream.next_in        = (char*)pfile_in_zip_read_info->stream.next_in;
+            pfile_in_zip_read_info->bstream.avail_in       = pfile_in_zip_read_info->stream.avail_in;
+            pfile_in_zip_read_info->bstream.total_in_lo32  = pfile_in_zip_read_info->stream.total_in;
+            pfile_in_zip_read_info->bstream.total_in_hi32  = 0;
+            pfile_in_zip_read_info->bstream.next_out       = (char*)pfile_in_zip_read_info->stream.next_out;
+            pfile_in_zip_read_info->bstream.avail_out      = pfile_in_zip_read_info->stream.avail_out;
+            pfile_in_zip_read_info->bstream.total_out_lo32 = pfile_in_zip_read_info->stream.total_out;
+            pfile_in_zip_read_info->bstream.total_out_hi32 = 0;
+
+            uTotalOutBefore = pfile_in_zip_read_info->bstream.total_out_lo32;
+            bufBefore = (const Bytef *)pfile_in_zip_read_info->bstream.next_out;
+
+            err=BZ2_bzDecompress(&pfile_in_zip_read_info->bstream);
+
+            uTotalOutAfter = pfile_in_zip_read_info->bstream.total_out_lo32;
+            uOutThis = uTotalOutAfter-uTotalOutBefore;
+
+            pfile_in_zip_read_info->total_out_64 = pfile_in_zip_read_info->total_out_64 + uOutThis;
+
+            pfile_in_zip_read_info->crc32 = crc32(pfile_in_zip_read_info->crc32,bufBefore, (uInt)(uOutThis));
+            pfile_in_zip_read_info->rest_read_uncompressed -= uOutThis;
+            iRead += (uInt)(uTotalOutAfter - uTotalOutBefore);
+
+            pfile_in_zip_read_info->stream.next_in   = (Bytef*)pfile_in_zip_read_info->bstream.next_in;
+            pfile_in_zip_read_info->stream.avail_in  = pfile_in_zip_read_info->bstream.avail_in;
+            pfile_in_zip_read_info->stream.total_in  = pfile_in_zip_read_info->bstream.total_in_lo32;
+            pfile_in_zip_read_info->stream.next_out  = (Bytef*)pfile_in_zip_read_info->bstream.next_out;
+            pfile_in_zip_read_info->stream.avail_out = pfile_in_zip_read_info->bstream.avail_out;
+            pfile_in_zip_read_info->stream.total_out = pfile_in_zip_read_info->bstream.total_out_lo32;
+
+            if (err==BZ_STREAM_END)
+              return (iRead==0) ? UNZ_EOF : iRead;
+            if (err!=BZ_OK)
+              break;
+#endif
+        } // end Z_BZIP2ED
+        else
+        {
+            ZPOS64_T uTotalOutBefore,uTotalOutAfter;
+            const Bytef *bufBefore;
+            ZPOS64_T uOutThis;
+            int flush=Z_SYNC_FLUSH;
+
+            uTotalOutBefore = pfile_in_zip_read_info->stream.total_out;
+            bufBefore = pfile_in_zip_read_info->stream.next_out;
+
+            /*
+            if ((pfile_in_zip_read_info->rest_read_uncompressed ==
+                     pfile_in_zip_read_info->stream.avail_out) &&
+                (pfile_in_zip_read_info->rest_read_compressed == 0))
+                flush = Z_FINISH;
+            */
+            err=inflate(&pfile_in_zip_read_info->stream,flush);
+
+            if ((err>=0) && (pfile_in_zip_read_info->stream.msg!=NULL))
+              err = Z_DATA_ERROR;
+
+            uTotalOutAfter = pfile_in_zip_read_info->stream.total_out;
+            uOutThis = uTotalOutAfter-uTotalOutBefore;
+
+            pfile_in_zip_read_info->total_out_64 = pfile_in_zip_read_info->total_out_64 + uOutThis;
+
+            pfile_in_zip_read_info->crc32 =
+                crc32(pfile_in_zip_read_info->crc32,bufBefore,
+                        (uInt)(uOutThis));
+
+            pfile_in_zip_read_info->rest_read_uncompressed -=
+                uOutThis;
+
+            iRead += (uInt)(uTotalOutAfter - uTotalOutBefore);
+
+            if (err==Z_STREAM_END)
+                return (iRead==0) ? UNZ_EOF : iRead;
+            if (err!=Z_OK)
+                break;
+        }
+    }
+
+    if (err==Z_OK)
+        return iRead;
+    return err;
+}
+
+
+/*
+  Give the current position in uncompressed data
+*/
+extern z_off_t ZEXPORT unztell (unzFile file)
+{
+    unz64_s* s;
+    file_in_zip64_read_info_s* pfile_in_zip_read_info;
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    pfile_in_zip_read_info=s->pfile_in_zip_read;
+
+    if (pfile_in_zip_read_info==NULL)
+        return UNZ_PARAMERROR;
+
+    return (z_off_t)pfile_in_zip_read_info->stream.total_out;
+}
+
+extern ZPOS64_T ZEXPORT unztell64 (unzFile file)
+{
+
+    unz64_s* s;
+    file_in_zip64_read_info_s* pfile_in_zip_read_info;
+    if (file==NULL)
+        return (ZPOS64_T)-1;
+    s=(unz64_s*)file;
+    pfile_in_zip_read_info=s->pfile_in_zip_read;
+
+    if (pfile_in_zip_read_info==NULL)
+        return (ZPOS64_T)-1;
+
+    return pfile_in_zip_read_info->total_out_64;
+}
+
+
+/*
+  return 1 if the end of file was reached, 0 elsewhere
+*/
+extern int ZEXPORT unzeof (unzFile file)
+{
+    unz64_s* s;
+    file_in_zip64_read_info_s* pfile_in_zip_read_info;
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    pfile_in_zip_read_info=s->pfile_in_zip_read;
+
+    if (pfile_in_zip_read_info==NULL)
+        return UNZ_PARAMERROR;
+
+    if (pfile_in_zip_read_info->rest_read_uncompressed == 0)
+        return 1;
+    else
+        return 0;
+}
+
+
+
+/*
+Read extra field from the current file (opened by unzOpenCurrentFile)
+This is the local-header version of the extra field (sometimes, there is
+more info in the local-header version than in the central-header)
+
+  if buf==NULL, it return the size of the local extra field that can be read
+
+  if buf!=NULL, len is the size of the buffer, the extra header is copied in
+    buf.
+  the return value is the number of bytes copied in buf, or (if <0)
+    the error code
+*/
+extern int ZEXPORT unzGetLocalExtrafield (unzFile file, voidp buf, unsigned len)
+{
+    unz64_s* s;
+    file_in_zip64_read_info_s* pfile_in_zip_read_info;
+    uInt read_now;
+    ZPOS64_T size_to_read;
+
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    pfile_in_zip_read_info=s->pfile_in_zip_read;
+
+    if (pfile_in_zip_read_info==NULL)
+        return UNZ_PARAMERROR;
+
+    size_to_read = (pfile_in_zip_read_info->size_local_extrafield -
+                pfile_in_zip_read_info->pos_local_extrafield);
+
+    if (buf==NULL)
+        return (int)size_to_read;
+
+    if (len>size_to_read)
+        read_now = (uInt)size_to_read;
+    else
+        read_now = (uInt)len ;
+
+    if (read_now==0)
+        return 0;
+
+    if (ZSEEK64(pfile_in_zip_read_info->z_filefunc,
+              pfile_in_zip_read_info->filestream,
+              pfile_in_zip_read_info->offset_local_extrafield +
+              pfile_in_zip_read_info->pos_local_extrafield,
+              ZLIB_FILEFUNC_SEEK_SET)!=0)
+        return UNZ_ERRNO;
+
+    if (ZREAD64(pfile_in_zip_read_info->z_filefunc,
+              pfile_in_zip_read_info->filestream,
+              buf,read_now)!=read_now)
+        return UNZ_ERRNO;
+
+    return (int)read_now;
+}
+
+/*
+  Close the file in zip opened with unzOpenCurrentFile
+  Return UNZ_CRCERROR if all the file was read but the CRC is not good
+*/
+extern int ZEXPORT unzCloseCurrentFile (unzFile file)
+{
+    int err=UNZ_OK;
+
+    unz64_s* s;
+    file_in_zip64_read_info_s* pfile_in_zip_read_info;
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    pfile_in_zip_read_info=s->pfile_in_zip_read;
+
+    if (pfile_in_zip_read_info==NULL)
+        return UNZ_PARAMERROR;
+
+
+    if ((pfile_in_zip_read_info->rest_read_uncompressed == 0) &&
+        (!pfile_in_zip_read_info->raw))
+    {
+        if (pfile_in_zip_read_info->crc32 != pfile_in_zip_read_info->crc32_wait)
+            err=UNZ_CRCERROR;
+    }
+
+
+    TRYFREE(pfile_in_zip_read_info->read_buffer);
+    pfile_in_zip_read_info->read_buffer = NULL;
+    if (pfile_in_zip_read_info->stream_initialised == Z_DEFLATED)
+        inflateEnd(&pfile_in_zip_read_info->stream);
+#ifdef HAVE_BZIP2
+    else if (pfile_in_zip_read_info->stream_initialised == Z_BZIP2ED)
+        BZ2_bzDecompressEnd(&pfile_in_zip_read_info->bstream);
+#endif
+
+
+    pfile_in_zip_read_info->stream_initialised = 0;
+    TRYFREE(pfile_in_zip_read_info);
+
+    s->pfile_in_zip_read=NULL;
+
+    return err;
+}
+
+
+/*
+  Get the global comment string of the ZipFile, in the szComment buffer.
+  uSizeBuf is the size of the szComment buffer.
+  return the number of byte copied or an error code <0
+*/
+extern int ZEXPORT unzGetGlobalComment (unzFile file, char * szComment, uLong uSizeBuf)
+{
+    unz64_s* s;
+    uLong uReadThis ;
+    if (file==NULL)
+        return (int)UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+
+    uReadThis = uSizeBuf;
+    if (uReadThis>s->gi.size_comment)
+        uReadThis = s->gi.size_comment;
+
+    if (ZSEEK64(s->z_filefunc,s->filestream,s->central_pos+22,ZLIB_FILEFUNC_SEEK_SET)!=0)
+        return UNZ_ERRNO;
+
+    if (uReadThis>0)
+    {
+      *szComment='\0';
+      if (ZREAD64(s->z_filefunc,s->filestream,szComment,uReadThis)!=uReadThis)
+        return UNZ_ERRNO;
+    }
+
+    if ((szComment != NULL) && (uSizeBuf > s->gi.size_comment))
+        *(szComment+s->gi.size_comment)='\0';
+    return (int)uReadThis;
+}
+
+/* Additions by RX '2004 */
+extern ZPOS64_T ZEXPORT unzGetOffset64(unzFile file)
+{
+    unz64_s* s;
+
+    if (file==NULL)
+          return 0; //UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+    if (!s->current_file_ok)
+      return 0;
+    if (s->gi.number_entry != 0 && s->gi.number_entry != 0xffff)
+      if (s->num_file==s->gi.number_entry)
+         return 0;
+    return s->pos_in_central_dir;
+}
+
+extern uLong ZEXPORT unzGetOffset (unzFile file)
+{
+    ZPOS64_T offset64;
+
+    if (file==NULL)
+          return 0; //UNZ_PARAMERROR;
+    offset64 = unzGetOffset64(file);
+    return (uLong)offset64;
+}
+
+extern int ZEXPORT unzSetOffset64(unzFile file, ZPOS64_T pos)
+{
+    unz64_s* s;
+    int err;
+
+    if (file==NULL)
+        return UNZ_PARAMERROR;
+    s=(unz64_s*)file;
+
+    s->pos_in_central_dir = pos;
+    s->num_file = s->gi.number_entry;      /* hack */
+    err = unz64local_GetCurrentFileInfoInternal(file,&s->cur_file_info,
+                                              &s->cur_file_info_internal,
+                                              NULL,0,NULL,0,NULL,0);
+    s->current_file_ok = (err == UNZ_OK);
+    return err;
+}
+
+extern int ZEXPORT unzSetOffset (unzFile file, uLong pos)
+{
+    return unzSetOffset64(file,pos);
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/minizip/unzip.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/minizip/unzip.h	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,437 @@
+/* unzip.h -- IO for uncompress .zip files using zlib
+   Version 1.1, February 14h, 2010
+   part of the MiniZip project - ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Copyright (C) 1998-2010 Gilles Vollant (minizip) ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Modifications of Unzip for Zip64
+         Copyright (C) 2007-2008 Even Rouault
+
+         Modifications for Zip64 support on both zip and unzip
+         Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )
+
+         For more info read MiniZip_info.txt
+
+         ---------------------------------------------------------------------------------
+
+        Condition of use and distribution are the same than zlib :
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  ---------------------------------------------------------------------------------
+
+        Changes
+
+        See header of unzip64.c
+
+*/
+
+#ifndef _unz64_H
+#define _unz64_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef _ZLIB_H
+#include "zlib.h"
+#endif
+
+#ifndef  _ZLIBIOAPI_H
+#include "ioapi.h"
+#endif
+
+#ifdef HAVE_BZIP2
+#include "bzlib.h"
+#endif
+
+#define Z_BZIP2ED 12
+
+#if defined(STRICTUNZIP) || defined(STRICTZIPUNZIP)
+/* like the STRICT of WIN32, we define a pointer that cannot be converted
+    from (void*) without cast */
+typedef struct TagunzFile__ { int unused; } unzFile__;
+typedef unzFile__ *unzFile;
+#else
+typedef voidp unzFile;
+#endif
+
+
+#define UNZ_OK                          (0)
+#define UNZ_END_OF_LIST_OF_FILE         (-100)
+#define UNZ_ERRNO                       (Z_ERRNO)
+#define UNZ_EOF                         (0)
+#define UNZ_PARAMERROR                  (-102)
+#define UNZ_BADZIPFILE                  (-103)
+#define UNZ_INTERNALERROR               (-104)
+#define UNZ_CRCERROR                    (-105)
+
+/* tm_unz contain date/time info */
+typedef struct tm_unz_s
+{
+    uInt tm_sec;            /* seconds after the minute - [0,59] */
+    uInt tm_min;            /* minutes after the hour - [0,59] */
+    uInt tm_hour;           /* hours since midnight - [0,23] */
+    uInt tm_mday;           /* day of the month - [1,31] */
+    uInt tm_mon;            /* months since January - [0,11] */
+    uInt tm_year;           /* years - [1980..2044] */
+} tm_unz;
+
+/* unz_global_info structure contain global data about the ZIPfile
+   These data comes from the end of central dir */
+typedef struct unz_global_info64_s
+{
+    ZPOS64_T number_entry;         /* total number of entries in
+                                     the central dir on this disk */
+    uLong size_comment;         /* size of the global comment of the zipfile */
+} unz_global_info64;
+
+typedef struct unz_global_info_s
+{
+    uLong number_entry;         /* total number of entries in
+                                     the central dir on this disk */
+    uLong size_comment;         /* size of the global comment of the zipfile */
+} unz_global_info;
+
+/* unz_file_info contain information about a file in the zipfile */
+typedef struct unz_file_info64_s
+{
+    uLong version;              /* version made by                 2 bytes */
+    uLong version_needed;       /* version needed to extract       2 bytes */
+    uLong flag;                 /* general purpose bit flag        2 bytes */
+    uLong compression_method;   /* compression method              2 bytes */
+    uLong dosDate;              /* last mod file date in Dos fmt   4 bytes */
+    uLong crc;                  /* crc-32                          4 bytes */
+    ZPOS64_T compressed_size;   /* compressed size                 8 bytes */
+    ZPOS64_T uncompressed_size; /* uncompressed size               8 bytes */
+    uLong size_filename;        /* filename length                 2 bytes */
+    uLong size_file_extra;      /* extra field length              2 bytes */
+    uLong size_file_comment;    /* file comment length             2 bytes */
+
+    uLong disk_num_start;       /* disk number start               2 bytes */
+    uLong internal_fa;          /* internal file attributes        2 bytes */
+    uLong external_fa;          /* external file attributes        4 bytes */
+
+    tm_unz tmu_date;
+} unz_file_info64;
+
+typedef struct unz_file_info_s
+{
+    uLong version;              /* version made by                 2 bytes */
+    uLong version_needed;       /* version needed to extract       2 bytes */
+    uLong flag;                 /* general purpose bit flag        2 bytes */
+    uLong compression_method;   /* compression method              2 bytes */
+    uLong dosDate;              /* last mod file date in Dos fmt   4 bytes */
+    uLong crc;                  /* crc-32                          4 bytes */
+    uLong compressed_size;      /* compressed size                 4 bytes */
+    uLong uncompressed_size;    /* uncompressed size               4 bytes */
+    uLong size_filename;        /* filename length                 2 bytes */
+    uLong size_file_extra;      /* extra field length              2 bytes */
+    uLong size_file_comment;    /* file comment length             2 bytes */
+
+    uLong disk_num_start;       /* disk number start               2 bytes */
+    uLong internal_fa;          /* internal file attributes        2 bytes */
+    uLong external_fa;          /* external file attributes        4 bytes */
+
+    tm_unz tmu_date;
+} unz_file_info;
+
+extern int ZEXPORT unzStringFileNameCompare OF ((const char* fileName1,
+                                                 const char* fileName2,
+                                                 int iCaseSensitivity));
+/*
+   Compare two filename (fileName1,fileName2).
+   If iCaseSenisivity = 1, comparision is case sensitivity (like strcmp)
+   If iCaseSenisivity = 2, comparision is not case sensitivity (like strcmpi
+                                or strcasecmp)
+   If iCaseSenisivity = 0, case sensitivity is defaut of your operating system
+    (like 1 on Unix, 2 on Windows)
+*/
+
+
+extern unzFile ZEXPORT unzOpen OF((const char *path));
+extern unzFile ZEXPORT unzOpen64 OF((const void *path));
+/*
+  Open a Zip file. path contain the full pathname (by example,
+     on a Windows XP computer "c:\\zlib\\zlib113.zip" or on an Unix computer
+     "zlib/zlib113.zip".
+     If the zipfile cannot be opened (file don't exist or in not valid), the
+       return value is NULL.
+     Else, the return value is a unzFile Handle, usable with other function
+       of this unzip package.
+     the "64" function take a const void* pointer, because the path is just the
+       value passed to the open64_file_func callback.
+     Under Windows, if UNICODE is defined, using fill_fopen64_filefunc, the path
+       is a pointer to a wide unicode string (LPCTSTR is LPCWSTR), so const char*
+       does not describe the reality
+*/
+
+
+extern unzFile ZEXPORT unzOpen2 OF((const char *path,
+                                    zlib_filefunc_def* pzlib_filefunc_def));
+/*
+   Open a Zip file, like unzOpen, but provide a set of file low level API
+      for read/write the zip file (see ioapi.h)
+*/
+
+extern unzFile ZEXPORT unzOpen2_64 OF((const void *path,
+                                    zlib_filefunc64_def* pzlib_filefunc_def));
+/*
+   Open a Zip file, like unz64Open, but provide a set of file low level API
+      for read/write the zip file (see ioapi.h)
+*/
+
+extern int ZEXPORT unzClose OF((unzFile file));
+/*
+  Close a ZipFile opened with unzOpen.
+  If there is files inside the .Zip opened with unzOpenCurrentFile (see later),
+    these files MUST be closed with unzCloseCurrentFile before call unzClose.
+  return UNZ_OK if there is no problem. */
+
+extern int ZEXPORT unzGetGlobalInfo OF((unzFile file,
+                                        unz_global_info *pglobal_info));
+
+extern int ZEXPORT unzGetGlobalInfo64 OF((unzFile file,
+                                        unz_global_info64 *pglobal_info));
+/*
+  Write info about the ZipFile in the *pglobal_info structure.
+  No preparation of the structure is needed
+  return UNZ_OK if there is no problem. */
+
+
+extern int ZEXPORT unzGetGlobalComment OF((unzFile file,
+                                           char *szComment,
+                                           uLong uSizeBuf));
+/*
+  Get the global comment string of the ZipFile, in the szComment buffer.
+  uSizeBuf is the size of the szComment buffer.
+  return the number of byte copied or an error code <0
+*/
+
+
+/***************************************************************************/
+/* Unzip package allow you browse the directory of the zipfile */
+
+extern int ZEXPORT unzGoToFirstFile OF((unzFile file));
+/*
+  Set the current file of the zipfile to the first file.
+  return UNZ_OK if there is no problem
+*/
+
+extern int ZEXPORT unzGoToNextFile OF((unzFile file));
+/*
+  Set the current file of the zipfile to the next file.
+  return UNZ_OK if there is no problem
+  return UNZ_END_OF_LIST_OF_FILE if the actual file was the latest.
+*/
+
+extern int ZEXPORT unzLocateFile OF((unzFile file,
+                     const char *szFileName,
+                     int iCaseSensitivity));
+/*
+  Try locate the file szFileName in the zipfile.
+  For the iCaseSensitivity signification, see unzStringFileNameCompare
+
+  return value :
+  UNZ_OK if the file is found. It becomes the current file.
+  UNZ_END_OF_LIST_OF_FILE if the file is not found
+*/
+
+
+/* ****************************************** */
+/* Ryan supplied functions */
+/* unz_file_info contain information about a file in the zipfile */
+typedef struct unz_file_pos_s
+{
+    uLong pos_in_zip_directory;   /* offset in zip file directory */
+    uLong num_of_file;            /* # of file */
+} unz_file_pos;
+
+extern int ZEXPORT unzGetFilePos(
+    unzFile file,
+    unz_file_pos* file_pos);
+
+extern int ZEXPORT unzGoToFilePos(
+    unzFile file,
+    unz_file_pos* file_pos);
+
+typedef struct unz64_file_pos_s
+{
+    ZPOS64_T pos_in_zip_directory;   /* offset in zip file directory */
+    ZPOS64_T num_of_file;            /* # of file */
+} unz64_file_pos;
+
+extern int ZEXPORT unzGetFilePos64(
+    unzFile file,
+    unz64_file_pos* file_pos);
+
+extern int ZEXPORT unzGoToFilePos64(
+    unzFile file,
+    const unz64_file_pos* file_pos);
+
+/* ****************************************** */
+
+extern int ZEXPORT unzGetCurrentFileInfo64 OF((unzFile file,
+                         unz_file_info64 *pfile_info,
+                         char *szFileName,
+                         uLong fileNameBufferSize,
+                         void *extraField,
+                         uLong extraFieldBufferSize,
+                         char *szComment,
+                         uLong commentBufferSize));
+
+extern int ZEXPORT unzGetCurrentFileInfo OF((unzFile file,
+                         unz_file_info *pfile_info,
+                         char *szFileName,
+                         uLong fileNameBufferSize,
+                         void *extraField,
+                         uLong extraFieldBufferSize,
+                         char *szComment,
+                         uLong commentBufferSize));
+/*
+  Get Info about the current file
+  if pfile_info!=NULL, the *pfile_info structure will contain somes info about
+        the current file
+  if szFileName!=NULL, the filemane string will be copied in szFileName
+            (fileNameBufferSize is the size of the buffer)
+  if extraField!=NULL, the extra field information will be copied in extraField
+            (extraFieldBufferSize is the size of the buffer).
+            This is the Central-header version of the extra field
+  if szComment!=NULL, the comment string of the file will be copied in szComment
+            (commentBufferSize is the size of the buffer)
+*/
+
+
+/** Addition for GDAL : START */
+
+extern ZPOS64_T ZEXPORT unzGetCurrentFileZStreamPos64 OF((unzFile file));
+
+/** Addition for GDAL : END */
+
+
+/***************************************************************************/
+/* for reading the content of the current zipfile, you can open it, read data
+   from it, and close it (you can close it before reading all the file)
+   */
+
+extern int ZEXPORT unzOpenCurrentFile OF((unzFile file));
+/*
+  Open for reading data the current file in the zipfile.
+  If there is no error, the return value is UNZ_OK.
+*/
+
+extern int ZEXPORT unzOpenCurrentFilePassword OF((unzFile file,
+                                                  const char* password));
+/*
+  Open for reading data the current file in the zipfile.
+  password is a crypting password
+  If there is no error, the return value is UNZ_OK.
+*/
+
+extern int ZEXPORT unzOpenCurrentFile2 OF((unzFile file,
+                                           int* method,
+                                           int* level,
+                                           int raw));
+/*
+  Same than unzOpenCurrentFile, but open for read raw the file (not uncompress)
+    if raw==1
+  *method will receive method of compression, *level will receive level of
+     compression
+  note : you can set level parameter as NULL (if you did not want known level,
+         but you CANNOT set method parameter as NULL
+*/
+
+extern int ZEXPORT unzOpenCurrentFile3 OF((unzFile file,
+                                           int* method,
+                                           int* level,
+                                           int raw,
+                                           const char* password));
+/*
+  Same than unzOpenCurrentFile, but open for read raw the file (not uncompress)
+    if raw==1
+  *method will receive method of compression, *level will receive level of
+     compression
+  note : you can set level parameter as NULL (if you did not want known level,
+         but you CANNOT set method parameter as NULL
+*/
+
+
+extern int ZEXPORT unzCloseCurrentFile OF((unzFile file));
+/*
+  Close the file in zip opened with unzOpenCurrentFile
+  Return UNZ_CRCERROR if all the file was read but the CRC is not good
+*/
+
+extern int ZEXPORT unzReadCurrentFile OF((unzFile file,
+                      voidp buf,
+                      unsigned len));
+/*
+  Read bytes from the current file (opened by unzOpenCurrentFile)
+  buf contain buffer where data must be copied
+  len the size of buf.
+
+  return the number of byte copied if somes bytes are copied
+  return 0 if the end of file was reached
+  return <0 with error code if there is an error
+    (UNZ_ERRNO for IO error, or zLib error for uncompress error)
+*/
+
+extern z_off_t ZEXPORT unztell OF((unzFile file));
+
+extern ZPOS64_T ZEXPORT unztell64 OF((unzFile file));
+/*
+  Give the current position in uncompressed data
+*/
+
+extern int ZEXPORT unzeof OF((unzFile file));
+/*
+  return 1 if the end of file was reached, 0 elsewhere
+*/
+
+extern int ZEXPORT unzGetLocalExtrafield OF((unzFile file,
+                                             voidp buf,
+                                             unsigned len));
+/*
+  Read extra field from the current file (opened by unzOpenCurrentFile)
+  This is the local-header version of the extra field (sometimes, there is
+    more info in the local-header version than in the central-header)
+
+  if buf==NULL, it return the size of the local extra field
+
+  if buf!=NULL, len is the size of the buffer, the extra header is copied in
+    buf.
+  the return value is the number of bytes copied in buf, or (if <0)
+    the error code
+*/
+
+/***************************************************************************/
+
+/* Get the current file offset */
+extern ZPOS64_T ZEXPORT unzGetOffset64 (unzFile file);
+extern uLong ZEXPORT unzGetOffset (unzFile file);
+
+/* Set the current file offset */
+extern int ZEXPORT unzSetOffset64 (unzFile file, ZPOS64_T pos);
+extern int ZEXPORT unzSetOffset (unzFile file, uLong pos);
+
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _unz64_H */
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/minizip/zip.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/minizip/zip.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,2007 @@
+/* zip.c -- IO on .zip files using zlib
+   Version 1.1, February 14h, 2010
+   part of the MiniZip project - ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Copyright (C) 1998-2010 Gilles Vollant (minizip) ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Modifications for Zip64 support
+         Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )
+
+         For more info read MiniZip_info.txt
+
+         Changes
+   Oct-2009 - Mathias Svensson - Remove old C style function prototypes
+   Oct-2009 - Mathias Svensson - Added Zip64 Support when creating new file archives
+   Oct-2009 - Mathias Svensson - Did some code cleanup and refactoring to get better overview of some functions.
+   Oct-2009 - Mathias Svensson - Added zipRemoveExtraInfoBlock to strip extra field data from its ZIP64 data
+                                 It is used when recreting zip archive with RAW when deleting items from a zip.
+                                 ZIP64 data is automatically added to items that needs it, and existing ZIP64 data need to be removed.
+   Oct-2009 - Mathias Svensson - Added support for BZIP2 as compression mode (bzip2 lib is required)
+   Jan-2010 - back to unzip and minizip 1.0 name scheme, with compatibility layer
+
+*/
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include "zlib.h"
+#include "zip.h"
+
+#ifdef STDC
+#  include <stddef.h>
+#  include <string.h>
+#  include <stdlib.h>
+#endif
+#ifdef NO_ERRNO_H
+    extern int errno;
+#else
+#   include <errno.h>
+#endif
+
+
+#ifndef local
+#  define local static
+#endif
+/* compile with -Dlocal if your debugger can't find static symbols */
+
+#ifndef VERSIONMADEBY
+# define VERSIONMADEBY   (0x0) /* platform depedent */
+#endif
+
+#ifndef Z_BUFSIZE
+#define Z_BUFSIZE (64*1024) //(16384)
+#endif
+
+#ifndef Z_MAXFILENAMEINZIP
+#define Z_MAXFILENAMEINZIP (256)
+#endif
+
+#ifndef ALLOC
+# define ALLOC(size) (malloc(size))
+#endif
+#ifndef TRYFREE
+# define TRYFREE(p) {if (p) free(p);}
+#endif
+
+/*
+#define SIZECENTRALDIRITEM (0x2e)
+#define SIZEZIPLOCALHEADER (0x1e)
+*/
+
+/* I've found an old Unix (a SunOS 4.1.3_U1) without all SEEK_* defined.... */
+
+
+// NOT sure that this work on ALL platform
+#define MAKEULONG64(a, b) ((ZPOS64_T)(((unsigned long)(a)) | ((ZPOS64_T)((unsigned long)(b))) << 32))
+
+#ifndef SEEK_CUR
+#define SEEK_CUR    1
+#endif
+
+#ifndef SEEK_END
+#define SEEK_END    2
+#endif
+
+#ifndef SEEK_SET
+#define SEEK_SET    0
+#endif
+
+#ifndef DEF_MEM_LEVEL
+#if MAX_MEM_LEVEL >= 8
+#  define DEF_MEM_LEVEL 8
+#else
+#  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
+#endif
+#endif
+const char zip_copyright[] =" zip 1.01 Copyright 1998-2004 Gilles Vollant - http://www.winimage.com/zLibDll";
+
+
+#define SIZEDATA_INDATABLOCK (4096-(4*4))
+
+#define LOCALHEADERMAGIC    (0x04034b50)
+#define CENTRALHEADERMAGIC  (0x02014b50)
+#define ENDHEADERMAGIC      (0x06054b50)
+#define ZIP64ENDHEADERMAGIC      (0x6064b50)
+#define ZIP64ENDLOCHEADERMAGIC   (0x7064b50)
+
+#define FLAG_LOCALHEADER_OFFSET (0x06)
+#define CRC_LOCALHEADER_OFFSET  (0x0e)
+
+#define SIZECENTRALHEADER (0x2e) /* 46 */
+
+typedef struct linkedlist_datablock_internal_s
+{
+  struct linkedlist_datablock_internal_s* next_datablock;
+  uLong  avail_in_this_block;
+  uLong  filled_in_this_block;
+  uLong  unused; /* for future use and alignment */
+  unsigned char data[SIZEDATA_INDATABLOCK];
+} linkedlist_datablock_internal;
+
+typedef struct linkedlist_data_s
+{
+    linkedlist_datablock_internal* first_block;
+    linkedlist_datablock_internal* last_block;
+} linkedlist_data;
+
+
+typedef struct
+{
+    z_stream stream;            /* zLib stream structure for inflate */
+#ifdef HAVE_BZIP2
+    bz_stream bstream;          /* bzLib stream structure for bziped */
+#endif
+
+    int  stream_initialised;    /* 1 is stream is initialised */
+    uInt pos_in_buffered_data;  /* last written byte in buffered_data */
+
+    ZPOS64_T pos_local_header;     /* offset of the local header of the file
+                                     currenty writing */
+    char* central_header;       /* central header data for the current file */
+    uLong size_centralExtra;
+    uLong size_centralheader;   /* size of the central header for cur file */
+    uLong size_centralExtraFree; /* Extra bytes allocated to the centralheader but that are not used */
+    uLong flag;                 /* flag of the file currently writing */
+
+    int  method;                /* compression method of file currenty wr.*/
+    int  raw;                   /* 1 for directly writing raw data */
+    Byte buffered_data[Z_BUFSIZE];/* buffer contain compressed data to be writ*/
+    uLong dosDate;
+    uLong crc32;
+    int  encrypt;
+    int  zip64;               /* Add ZIP64 extened information in the extra field */
+    ZPOS64_T pos_zip64extrainfo;
+    ZPOS64_T totalCompressedData;
+    ZPOS64_T totalUncompressedData;
+#ifndef NOCRYPT
+    unsigned long keys[3];     /* keys defining the pseudo-random sequence */
+    const z_crc_t* pcrc_32_tab;
+    int crypt_header_size;
+#endif
+} curfile64_info;
+
+typedef struct
+{
+    zlib_filefunc64_32_def z_filefunc;
+    voidpf filestream;        /* io structore of the zipfile */
+    linkedlist_data central_dir;/* datablock with central dir in construction*/
+    int  in_opened_file_inzip;  /* 1 if a file in the zip is currently writ.*/
+    curfile64_info ci;            /* info on the file curretly writing */
+
+    ZPOS64_T begin_pos;            /* position of the beginning of the zipfile */
+    ZPOS64_T add_position_when_writing_offset;
+    ZPOS64_T number_entry;
+
+#ifndef NO_ADDFILEINEXISTINGZIP
+    char *globalcomment;
+#endif
+
+} zip64_internal;
+
+
+#ifndef NOCRYPT
+#define INCLUDECRYPTINGCODE_IFCRYPTALLOWED
+#include "crypt.h"
+#endif
+
+local linkedlist_datablock_internal* allocate_new_datablock()
+{
+    linkedlist_datablock_internal* ldi;
+    ldi = (linkedlist_datablock_internal*)
+                 ALLOC(sizeof(linkedlist_datablock_internal));
+    if (ldi!=NULL)
+    {
+        ldi->next_datablock = NULL ;
+        ldi->filled_in_this_block = 0 ;
+        ldi->avail_in_this_block = SIZEDATA_INDATABLOCK ;
+    }
+    return ldi;
+}
+
+local void free_datablock(linkedlist_datablock_internal* ldi)
+{
+    while (ldi!=NULL)
+    {
+        linkedlist_datablock_internal* ldinext = ldi->next_datablock;
+        TRYFREE(ldi);
+        ldi = ldinext;
+    }
+}
+
+local void init_linkedlist(linkedlist_data* ll)
+{
+    ll->first_block = ll->last_block = NULL;
+}
+
+local void free_linkedlist(linkedlist_data* ll)
+{
+    free_datablock(ll->first_block);
+    ll->first_block = ll->last_block = NULL;
+}
+
+
+local int add_data_in_datablock(linkedlist_data* ll, const void* buf, uLong len)
+{
+    linkedlist_datablock_internal* ldi;
+    const unsigned char* from_copy;
+
+    if (ll==NULL)
+        return ZIP_INTERNALERROR;
+
+    if (ll->last_block == NULL)
+    {
+        ll->first_block = ll->last_block = allocate_new_datablock();
+        if (ll->first_block == NULL)
+            return ZIP_INTERNALERROR;
+    }
+
+    ldi = ll->last_block;
+    from_copy = (unsigned char*)buf;
+
+    while (len>0)
+    {
+        uInt copy_this;
+        uInt i;
+        unsigned char* to_copy;
+
+        if (ldi->avail_in_this_block==0)
+        {
+            ldi->next_datablock = allocate_new_datablock();
+            if (ldi->next_datablock == NULL)
+                return ZIP_INTERNALERROR;
+            ldi = ldi->next_datablock ;
+            ll->last_block = ldi;
+        }
+
+        if (ldi->avail_in_this_block < len)
+            copy_this = (uInt)ldi->avail_in_this_block;
+        else
+            copy_this = (uInt)len;
+
+        to_copy = &(ldi->data[ldi->filled_in_this_block]);
+
+        for (i=0;i<copy_this;i++)
+            *(to_copy+i)=*(from_copy+i);
+
+        ldi->filled_in_this_block += copy_this;
+        ldi->avail_in_this_block -= copy_this;
+        from_copy += copy_this ;
+        len -= copy_this;
+    }
+    return ZIP_OK;
+}
+
+
+
+/****************************************************************************/
+
+#ifndef NO_ADDFILEINEXISTINGZIP
+/* ===========================================================================
+   Inputs a long in LSB order to the given file
+   nbByte == 1, 2 ,4 or 8 (byte, short or long, ZPOS64_T)
+*/
+
+local int zip64local_putValue OF((const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream, ZPOS64_T x, int nbByte));
+local int zip64local_putValue (const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream, ZPOS64_T x, int nbByte)
+{
+    unsigned char buf[8];
+    int n;
+    for (n = 0; n < nbByte; n++)
+    {
+        buf[n] = (unsigned char)(x & 0xff);
+        x >>= 8;
+    }
+    if (x != 0)
+      {     /* data overflow - hack for ZIP64 (X Roche) */
+      for (n = 0; n < nbByte; n++)
+        {
+          buf[n] = 0xff;
+        }
+      }
+
+    if (ZWRITE64(*pzlib_filefunc_def,filestream,buf,nbByte)!=(uLong)nbByte)
+        return ZIP_ERRNO;
+    else
+        return ZIP_OK;
+}
+
+local void zip64local_putValue_inmemory OF((void* dest, ZPOS64_T x, int nbByte));
+local void zip64local_putValue_inmemory (void* dest, ZPOS64_T x, int nbByte)
+{
+    unsigned char* buf=(unsigned char*)dest;
+    int n;
+    for (n = 0; n < nbByte; n++) {
+        buf[n] = (unsigned char)(x & 0xff);
+        x >>= 8;
+    }
+
+    if (x != 0)
+    {     /* data overflow - hack for ZIP64 */
+       for (n = 0; n < nbByte; n++)
+       {
+          buf[n] = 0xff;
+       }
+    }
+}
+
+/****************************************************************************/
+
+
+local uLong zip64local_TmzDateToDosDate(const tm_zip* ptm)
+{
+    uLong year = (uLong)ptm->tm_year;
+    if (year>=1980)
+        year-=1980;
+    else if (year>=80)
+        year-=80;
+    return
+      (uLong) (((ptm->tm_mday) + (32 * (ptm->tm_mon+1)) + (512 * year)) << 16) |
+        ((ptm->tm_sec/2) + (32* ptm->tm_min) + (2048 * (uLong)ptm->tm_hour));
+}
+
+
+/****************************************************************************/
+
+local int zip64local_getByte OF((const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream, int *pi));
+
+local int zip64local_getByte(const zlib_filefunc64_32_def* pzlib_filefunc_def,voidpf filestream,int* pi)
+{
+    unsigned char c;
+    int err = (int)ZREAD64(*pzlib_filefunc_def,filestream,&c,1);
+    if (err==1)
+    {
+        *pi = (int)c;
+        return ZIP_OK;
+    }
+    else
+    {
+        if (ZERROR64(*pzlib_filefunc_def,filestream))
+            return ZIP_ERRNO;
+        else
+            return ZIP_EOF;
+    }
+}
+
+
+/* ===========================================================================
+   Reads a long in LSB order from the given gz_stream. Sets
+*/
+local int zip64local_getShort OF((const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream, uLong *pX));
+
+local int zip64local_getShort (const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream, uLong* pX)
+{
+    uLong x ;
+    int i = 0;
+    int err;
+
+    err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x = (uLong)i;
+
+    if (err==ZIP_OK)
+        err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x += ((uLong)i)<<8;
+
+    if (err==ZIP_OK)
+        *pX = x;
+    else
+        *pX = 0;
+    return err;
+}
+
+local int zip64local_getLong OF((const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream, uLong *pX));
+
+local int zip64local_getLong (const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream, uLong* pX)
+{
+    uLong x ;
+    int i = 0;
+    int err;
+
+    err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x = (uLong)i;
+
+    if (err==ZIP_OK)
+        err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x += ((uLong)i)<<8;
+
+    if (err==ZIP_OK)
+        err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x += ((uLong)i)<<16;
+
+    if (err==ZIP_OK)
+        err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+    x += ((uLong)i)<<24;
+
+    if (err==ZIP_OK)
+        *pX = x;
+    else
+        *pX = 0;
+    return err;
+}
+
+local int zip64local_getLong64 OF((const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream, ZPOS64_T *pX));
+
+
+local int zip64local_getLong64 (const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream, ZPOS64_T *pX)
+{
+  ZPOS64_T x;
+  int i = 0;
+  int err;
+
+  err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+  x = (ZPOS64_T)i;
+
+  if (err==ZIP_OK)
+    err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+  x += ((ZPOS64_T)i)<<8;
+
+  if (err==ZIP_OK)
+    err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+  x += ((ZPOS64_T)i)<<16;
+
+  if (err==ZIP_OK)
+    err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+  x += ((ZPOS64_T)i)<<24;
+
+  if (err==ZIP_OK)
+    err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+  x += ((ZPOS64_T)i)<<32;
+
+  if (err==ZIP_OK)
+    err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+  x += ((ZPOS64_T)i)<<40;
+
+  if (err==ZIP_OK)
+    err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+  x += ((ZPOS64_T)i)<<48;
+
+  if (err==ZIP_OK)
+    err = zip64local_getByte(pzlib_filefunc_def,filestream,&i);
+  x += ((ZPOS64_T)i)<<56;
+
+  if (err==ZIP_OK)
+    *pX = x;
+  else
+    *pX = 0;
+
+  return err;
+}
+
+#ifndef BUFREADCOMMENT
+#define BUFREADCOMMENT (0x400)
+#endif
+/*
+  Locate the Central directory of a zipfile (at the end, just before
+    the global comment)
+*/
+local ZPOS64_T zip64local_SearchCentralDir OF((const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream));
+
+local ZPOS64_T zip64local_SearchCentralDir(const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream)
+{
+  unsigned char* buf;
+  ZPOS64_T uSizeFile;
+  ZPOS64_T uBackRead;
+  ZPOS64_T uMaxBack=0xffff; /* maximum size of global comment */
+  ZPOS64_T uPosFound=0;
+
+  if (ZSEEK64(*pzlib_filefunc_def,filestream,0,ZLIB_FILEFUNC_SEEK_END) != 0)
+    return 0;
+
+
+  uSizeFile = ZTELL64(*pzlib_filefunc_def,filestream);
+
+  if (uMaxBack>uSizeFile)
+    uMaxBack = uSizeFile;
+
+  buf = (unsigned char*)ALLOC(BUFREADCOMMENT+4);
+  if (buf==NULL)
+    return 0;
+
+  uBackRead = 4;
+  while (uBackRead<uMaxBack)
+  {
+    uLong uReadSize;
+    ZPOS64_T uReadPos ;
+    int i;
+    if (uBackRead+BUFREADCOMMENT>uMaxBack)
+      uBackRead = uMaxBack;
+    else
+      uBackRead+=BUFREADCOMMENT;
+    uReadPos = uSizeFile-uBackRead ;
+
+    uReadSize = ((BUFREADCOMMENT+4) < (uSizeFile-uReadPos)) ?
+      (BUFREADCOMMENT+4) : (uLong)(uSizeFile-uReadPos);
+    if (ZSEEK64(*pzlib_filefunc_def,filestream,uReadPos,ZLIB_FILEFUNC_SEEK_SET)!=0)
+      break;
+
+    if (ZREAD64(*pzlib_filefunc_def,filestream,buf,uReadSize)!=uReadSize)
+      break;
+
+    for (i=(int)uReadSize-3; (i--)>0;)
+      if (((*(buf+i))==0x50) && ((*(buf+i+1))==0x4b) &&
+        ((*(buf+i+2))==0x05) && ((*(buf+i+3))==0x06))
+      {
+        uPosFound = uReadPos+i;
+        break;
+      }
+
+      if (uPosFound!=0)
+        break;
+  }
+  TRYFREE(buf);
+  return uPosFound;
+}
+
+/*
+Locate the End of Zip64 Central directory locator and from there find the CD of a zipfile (at the end, just before
+the global comment)
+*/
+local ZPOS64_T zip64local_SearchCentralDir64 OF((const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream));
+
+local ZPOS64_T zip64local_SearchCentralDir64(const zlib_filefunc64_32_def* pzlib_filefunc_def, voidpf filestream)
+{
+  unsigned char* buf;
+  ZPOS64_T uSizeFile;
+  ZPOS64_T uBackRead;
+  ZPOS64_T uMaxBack=0xffff; /* maximum size of global comment */
+  ZPOS64_T uPosFound=0;
+  uLong uL;
+  ZPOS64_T relativeOffset;
+
+  if (ZSEEK64(*pzlib_filefunc_def,filestream,0,ZLIB_FILEFUNC_SEEK_END) != 0)
+    return 0;
+
+  uSizeFile = ZTELL64(*pzlib_filefunc_def,filestream);
+
+  if (uMaxBack>uSizeFile)
+    uMaxBack = uSizeFile;
+
+  buf = (unsigned char*)ALLOC(BUFREADCOMMENT+4);
+  if (buf==NULL)
+    return 0;
+
+  uBackRead = 4;
+  while (uBackRead<uMaxBack)
+  {
+    uLong uReadSize;
+    ZPOS64_T uReadPos;
+    int i;
+    if (uBackRead+BUFREADCOMMENT>uMaxBack)
+      uBackRead = uMaxBack;
+    else
+      uBackRead+=BUFREADCOMMENT;
+    uReadPos = uSizeFile-uBackRead ;
+
+    uReadSize = ((BUFREADCOMMENT+4) < (uSizeFile-uReadPos)) ?
+      (BUFREADCOMMENT+4) : (uLong)(uSizeFile-uReadPos);
+    if (ZSEEK64(*pzlib_filefunc_def,filestream,uReadPos,ZLIB_FILEFUNC_SEEK_SET)!=0)
+      break;
+
+    if (ZREAD64(*pzlib_filefunc_def,filestream,buf,uReadSize)!=uReadSize)
+      break;
+
+    for (i=(int)uReadSize-3; (i--)>0;)
+    {
+      // Signature "0x07064b50" Zip64 end of central directory locater
+      if (((*(buf+i))==0x50) && ((*(buf+i+1))==0x4b) && ((*(buf+i+2))==0x06) && ((*(buf+i+3))==0x07))
+      {
+        uPosFound = uReadPos+i;
+        break;
+      }
+    }
+
+      if (uPosFound!=0)
+        break;
+  }
+
+  TRYFREE(buf);
+  if (uPosFound == 0)
+    return 0;
+
+  /* Zip64 end of central directory locator */
+  if (ZSEEK64(*pzlib_filefunc_def,filestream, uPosFound,ZLIB_FILEFUNC_SEEK_SET)!=0)
+    return 0;
+
+  /* the signature, already checked */
+  if (zip64local_getLong(pzlib_filefunc_def,filestream,&uL)!=ZIP_OK)
+    return 0;
+
+  /* number of the disk with the start of the zip64 end of  central directory */
+  if (zip64local_getLong(pzlib_filefunc_def,filestream,&uL)!=ZIP_OK)
+    return 0;
+  if (uL != 0)
+    return 0;
+
+  /* relative offset of the zip64 end of central directory record */
+  if (zip64local_getLong64(pzlib_filefunc_def,filestream,&relativeOffset)!=ZIP_OK)
+    return 0;
+
+  /* total number of disks */
+  if (zip64local_getLong(pzlib_filefunc_def,filestream,&uL)!=ZIP_OK)
+    return 0;
+  if (uL != 1)
+    return 0;
+
+  /* Goto Zip64 end of central directory record */
+  if (ZSEEK64(*pzlib_filefunc_def,filestream, relativeOffset,ZLIB_FILEFUNC_SEEK_SET)!=0)
+    return 0;
+
+  /* the signature */
+  if (zip64local_getLong(pzlib_filefunc_def,filestream,&uL)!=ZIP_OK)
+    return 0;
+
+  if (uL != 0x06064b50) // signature of 'Zip64 end of central directory'
+    return 0;
+
+  return relativeOffset;
+}
+
+int LoadCentralDirectoryRecord(zip64_internal* pziinit)
+{
+  int err=ZIP_OK;
+  ZPOS64_T byte_before_the_zipfile;/* byte before the zipfile, (>0 for sfx)*/
+
+  ZPOS64_T size_central_dir;     /* size of the central directory  */
+  ZPOS64_T offset_central_dir;   /* offset of start of central directory */
+  ZPOS64_T central_pos;
+  uLong uL;
+
+  uLong number_disk;          /* number of the current dist, used for
+                              spaning ZIP, unsupported, always 0*/
+  uLong number_disk_with_CD;  /* number the the disk with central dir, used
+                              for spaning ZIP, unsupported, always 0*/
+  ZPOS64_T number_entry;
+  ZPOS64_T number_entry_CD;      /* total number of entries in
+                                the central dir
+                                (same than number_entry on nospan) */
+  uLong VersionMadeBy;
+  uLong VersionNeeded;
+  uLong size_comment;
+
+  int hasZIP64Record = 0;
+
+  // check first if we find a ZIP64 record
+  central_pos = zip64local_SearchCentralDir64(&pziinit->z_filefunc,pziinit->filestream);
+  if(central_pos > 0)
+  {
+    hasZIP64Record = 1;
+  }
+  else if(central_pos == 0)
+  {
+    central_pos = zip64local_SearchCentralDir(&pziinit->z_filefunc,pziinit->filestream);
+  }
+
+/* disable to allow appending to empty ZIP archive
+        if (central_pos==0)
+            err=ZIP_ERRNO;
+*/
+
+  if(hasZIP64Record)
+  {
+    ZPOS64_T sizeEndOfCentralDirectory;
+    if (ZSEEK64(pziinit->z_filefunc, pziinit->filestream, central_pos, ZLIB_FILEFUNC_SEEK_SET) != 0)
+      err=ZIP_ERRNO;
+
+    /* the signature, already checked */
+    if (zip64local_getLong(&pziinit->z_filefunc, pziinit->filestream,&uL)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* size of zip64 end of central directory record */
+    if (zip64local_getLong64(&pziinit->z_filefunc, pziinit->filestream, &sizeEndOfCentralDirectory)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* version made by */
+    if (zip64local_getShort(&pziinit->z_filefunc, pziinit->filestream, &VersionMadeBy)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* version needed to extract */
+    if (zip64local_getShort(&pziinit->z_filefunc, pziinit->filestream, &VersionNeeded)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* number of this disk */
+    if (zip64local_getLong(&pziinit->z_filefunc, pziinit->filestream,&number_disk)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* number of the disk with the start of the central directory */
+    if (zip64local_getLong(&pziinit->z_filefunc, pziinit->filestream,&number_disk_with_CD)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* total number of entries in the central directory on this disk */
+    if (zip64local_getLong64(&pziinit->z_filefunc, pziinit->filestream, &number_entry)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* total number of entries in the central directory */
+    if (zip64local_getLong64(&pziinit->z_filefunc, pziinit->filestream,&number_entry_CD)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    if ((number_entry_CD!=number_entry) || (number_disk_with_CD!=0) || (number_disk!=0))
+      err=ZIP_BADZIPFILE;
+
+    /* size of the central directory */
+    if (zip64local_getLong64(&pziinit->z_filefunc, pziinit->filestream,&size_central_dir)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* offset of start of central directory with respect to the
+    starting disk number */
+    if (zip64local_getLong64(&pziinit->z_filefunc, pziinit->filestream,&offset_central_dir)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    // TODO..
+    // read the comment from the standard central header.
+    size_comment = 0;
+  }
+  else
+  {
+    // Read End of central Directory info
+    if (ZSEEK64(pziinit->z_filefunc, pziinit->filestream, central_pos,ZLIB_FILEFUNC_SEEK_SET)!=0)
+      err=ZIP_ERRNO;
+
+    /* the signature, already checked */
+    if (zip64local_getLong(&pziinit->z_filefunc, pziinit->filestream,&uL)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* number of this disk */
+    if (zip64local_getShort(&pziinit->z_filefunc, pziinit->filestream,&number_disk)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* number of the disk with the start of the central directory */
+    if (zip64local_getShort(&pziinit->z_filefunc, pziinit->filestream,&number_disk_with_CD)!=ZIP_OK)
+      err=ZIP_ERRNO;
+
+    /* total number of entries in the central dir on this disk */
+    number_entry = 0;
+    if (zip64local_getShort(&pziinit->z_filefunc, pziinit->filestream, &uL)!=ZIP_OK)
+      err=ZIP_ERRNO;
+    else
+      number_entry = uL;
+
+    /* total number of entries in the central dir */
+    number_entry_CD = 0;
+    if (zip64local_getShort(&pziinit->z_filefunc, pziinit->filestream, &uL)!=ZIP_OK)
+      err=ZIP_ERRNO;
+    else
+      number_entry_CD = uL;
+
+    if ((number_entry_CD!=number_entry) || (number_disk_with_CD!=0) || (number_disk!=0))
+      err=ZIP_BADZIPFILE;
+
+    /* size of the central directory */
+    size_central_dir = 0;
+    if (zip64local_getLong(&pziinit->z_filefunc, pziinit->filestream, &uL)!=ZIP_OK)
+      err=ZIP_ERRNO;
+    else
+      size_central_dir = uL;
+
+    /* offset of start of central directory with respect to the starting disk number */
+    offset_central_dir = 0;
+    if (zip64local_getLong(&pziinit->z_filefunc, pziinit->filestream, &uL)!=ZIP_OK)
+      err=ZIP_ERRNO;
+    else
+      offset_central_dir = uL;
+
+
+    /* zipfile global comment length */
+    if (zip64local_getShort(&pziinit->z_filefunc, pziinit->filestream, &size_comment)!=ZIP_OK)
+      err=ZIP_ERRNO;
+  }
+
+  if ((central_pos<offset_central_dir+size_central_dir) &&
+    (err==ZIP_OK))
+    err=ZIP_BADZIPFILE;
+
+  if (err!=ZIP_OK)
+  {
+    ZCLOSE64(pziinit->z_filefunc, pziinit->filestream);
+    return ZIP_ERRNO;
+  }
+
+  if (size_comment>0)
+  {
+    pziinit->globalcomment = (char*)ALLOC(size_comment+1);
+    if (pziinit->globalcomment)
+    {
+      size_comment = ZREAD64(pziinit->z_filefunc, pziinit->filestream, pziinit->globalcomment,size_comment);
+      pziinit->globalcomment[size_comment]=0;
+    }
+  }
+
+  byte_before_the_zipfile = central_pos - (offset_central_dir+size_central_dir);
+  pziinit->add_position_when_writing_offset = byte_before_the_zipfile;
+
+  {
+    ZPOS64_T size_central_dir_to_read = size_central_dir;
+    size_t buf_size = SIZEDATA_INDATABLOCK;
+    void* buf_read = (void*)ALLOC(buf_size);
+    if (ZSEEK64(pziinit->z_filefunc, pziinit->filestream, offset_central_dir + byte_before_the_zipfile, ZLIB_FILEFUNC_SEEK_SET) != 0)
+      err=ZIP_ERRNO;
+
+    while ((size_central_dir_to_read>0) && (err==ZIP_OK))
+    {
+      ZPOS64_T read_this = SIZEDATA_INDATABLOCK;
+      if (read_this > size_central_dir_to_read)
+        read_this = size_central_dir_to_read;
+
+      if (ZREAD64(pziinit->z_filefunc, pziinit->filestream,buf_read,(uLong)read_this) != read_this)
+        err=ZIP_ERRNO;
+
+      if (err==ZIP_OK)
+        err = add_data_in_datablock(&pziinit->central_dir,buf_read, (uLong)read_this);
+
+      size_central_dir_to_read-=read_this;
+    }
+    TRYFREE(buf_read);
+  }
+  pziinit->begin_pos = byte_before_the_zipfile;
+  pziinit->number_entry = number_entry_CD;
+
+  if (ZSEEK64(pziinit->z_filefunc, pziinit->filestream, offset_central_dir+byte_before_the_zipfile,ZLIB_FILEFUNC_SEEK_SET) != 0)
+    err=ZIP_ERRNO;
+
+  return err;
+}
+
+
+#endif /* !NO_ADDFILEINEXISTINGZIP*/
+
+
+/************************************************************/
+extern zipFile ZEXPORT zipOpen3 (const void *pathname, int append, zipcharpc* globalcomment, zlib_filefunc64_32_def* pzlib_filefunc64_32_def)
+{
+    zip64_internal ziinit;
+    zip64_internal* zi;
+    int err=ZIP_OK;
+
+    ziinit.z_filefunc.zseek32_file = NULL;
+    ziinit.z_filefunc.ztell32_file = NULL;
+    if (pzlib_filefunc64_32_def==NULL)
+        fill_fopen64_filefunc(&ziinit.z_filefunc.zfile_func64);
+    else
+        ziinit.z_filefunc = *pzlib_filefunc64_32_def;
+
+    ziinit.filestream = ZOPEN64(ziinit.z_filefunc,
+                  pathname,
+                  (append == APPEND_STATUS_CREATE) ?
+                  (ZLIB_FILEFUNC_MODE_READ | ZLIB_FILEFUNC_MODE_WRITE | ZLIB_FILEFUNC_MODE_CREATE) :
+                    (ZLIB_FILEFUNC_MODE_READ | ZLIB_FILEFUNC_MODE_WRITE | ZLIB_FILEFUNC_MODE_EXISTING));
+
+    if (ziinit.filestream == NULL)
+        return NULL;
+
+    if (append == APPEND_STATUS_CREATEAFTER)
+        ZSEEK64(ziinit.z_filefunc,ziinit.filestream,0,SEEK_END);
+
+    ziinit.begin_pos = ZTELL64(ziinit.z_filefunc,ziinit.filestream);
+    ziinit.in_opened_file_inzip = 0;
+    ziinit.ci.stream_initialised = 0;
+    ziinit.number_entry = 0;
+    ziinit.add_position_when_writing_offset = 0;
+    init_linkedlist(&(ziinit.central_dir));
+
+
+
+    zi = (zip64_internal*)ALLOC(sizeof(zip64_internal));
+    if (zi==NULL)
+    {
+        ZCLOSE64(ziinit.z_filefunc,ziinit.filestream);
+        return NULL;
+    }
+
+    /* now we add file in a zipfile */
+#    ifndef NO_ADDFILEINEXISTINGZIP
+    ziinit.globalcomment = NULL;
+    if (append == APPEND_STATUS_ADDINZIP)
+    {
+      // Read and Cache Central Directory Records
+      err = LoadCentralDirectoryRecord(&ziinit);
+    }
+
+    if (globalcomment)
+    {
+      *globalcomment = ziinit.globalcomment;
+    }
+#    endif /* !NO_ADDFILEINEXISTINGZIP*/
+
+    if (err != ZIP_OK)
+    {
+#    ifndef NO_ADDFILEINEXISTINGZIP
+        TRYFREE(ziinit.globalcomment);
+#    endif /* !NO_ADDFILEINEXISTINGZIP*/
+        TRYFREE(zi);
+        return NULL;
+    }
+    else
+    {
+        *zi = ziinit;
+        return (zipFile)zi;
+    }
+}
+
+extern zipFile ZEXPORT zipOpen2 (const char *pathname, int append, zipcharpc* globalcomment, zlib_filefunc_def* pzlib_filefunc32_def)
+{
+    if (pzlib_filefunc32_def != NULL)
+    {
+        zlib_filefunc64_32_def zlib_filefunc64_32_def_fill;
+        fill_zlib_filefunc64_32_def_from_filefunc32(&zlib_filefunc64_32_def_fill,pzlib_filefunc32_def);
+        return zipOpen3(pathname, append, globalcomment, &zlib_filefunc64_32_def_fill);
+    }
+    else
+        return zipOpen3(pathname, append, globalcomment, NULL);
+}
+
+extern zipFile ZEXPORT zipOpen2_64 (const void *pathname, int append, zipcharpc* globalcomment, zlib_filefunc64_def* pzlib_filefunc_def)
+{
+    if (pzlib_filefunc_def != NULL)
+    {
+        zlib_filefunc64_32_def zlib_filefunc64_32_def_fill;
+        zlib_filefunc64_32_def_fill.zfile_func64 = *pzlib_filefunc_def;
+        zlib_filefunc64_32_def_fill.ztell32_file = NULL;
+        zlib_filefunc64_32_def_fill.zseek32_file = NULL;
+        return zipOpen3(pathname, append, globalcomment, &zlib_filefunc64_32_def_fill);
+    }
+    else
+        return zipOpen3(pathname, append, globalcomment, NULL);
+}
+
+
+
+extern zipFile ZEXPORT zipOpen (const char* pathname, int append)
+{
+    return zipOpen3((const void*)pathname,append,NULL,NULL);
+}
+
+extern zipFile ZEXPORT zipOpen64 (const void* pathname, int append)
+{
+    return zipOpen3(pathname,append,NULL,NULL);
+}
+
+int Write_LocalFileHeader(zip64_internal* zi, const char* filename, uInt size_extrafield_local, const void* extrafield_local)
+{
+  /* write the local header */
+  int err;
+  uInt size_filename = (uInt)strlen(filename);
+  uInt size_extrafield = size_extrafield_local;
+
+  err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)LOCALHEADERMAGIC, 4);
+
+  if (err==ZIP_OK)
+  {
+    if(zi->ci.zip64)
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)45,2);/* version needed to extract */
+    else
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)20,2);/* version needed to extract */
+  }
+
+  if (err==ZIP_OK)
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)zi->ci.flag,2);
+
+  if (err==ZIP_OK)
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)zi->ci.method,2);
+
+  if (err==ZIP_OK)
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)zi->ci.dosDate,4);
+
+  // CRC / Compressed size / Uncompressed size will be filled in later and rewritten later
+  if (err==ZIP_OK)
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0,4); /* crc 32, unknown */
+  if (err==ZIP_OK)
+  {
+    if(zi->ci.zip64)
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0xFFFFFFFF,4); /* compressed size, unknown */
+    else
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0,4); /* compressed size, unknown */
+  }
+  if (err==ZIP_OK)
+  {
+    if(zi->ci.zip64)
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0xFFFFFFFF,4); /* uncompressed size, unknown */
+    else
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0,4); /* uncompressed size, unknown */
+  }
+
+  if (err==ZIP_OK)
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)size_filename,2);
+
+  if(zi->ci.zip64)
+  {
+    size_extrafield += 20;
+  }
+
+  if (err==ZIP_OK)
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)size_extrafield,2);
+
+  if ((err==ZIP_OK) && (size_filename > 0))
+  {
+    if (ZWRITE64(zi->z_filefunc,zi->filestream,filename,size_filename)!=size_filename)
+      err = ZIP_ERRNO;
+  }
+
+  if ((err==ZIP_OK) && (size_extrafield_local > 0))
+  {
+    if (ZWRITE64(zi->z_filefunc, zi->filestream, extrafield_local, size_extrafield_local) != size_extrafield_local)
+      err = ZIP_ERRNO;
+  }
+
+
+  if ((err==ZIP_OK) && (zi->ci.zip64))
+  {
+      // write the Zip64 extended info
+      short HeaderID = 1;
+      short DataSize = 16;
+      ZPOS64_T CompressedSize = 0;
+      ZPOS64_T UncompressedSize = 0;
+
+      // Remember position of Zip64 extended info for the local file header. (needed when we update size after done with file)
+      zi->ci.pos_zip64extrainfo = ZTELL64(zi->z_filefunc,zi->filestream);
+
+      err = zip64local_putValue(&zi->z_filefunc, zi->filestream, (short)HeaderID,2);
+      err = zip64local_putValue(&zi->z_filefunc, zi->filestream, (short)DataSize,2);
+
+      err = zip64local_putValue(&zi->z_filefunc, zi->filestream, (ZPOS64_T)UncompressedSize,8);
+      err = zip64local_putValue(&zi->z_filefunc, zi->filestream, (ZPOS64_T)CompressedSize,8);
+  }
+
+  return err;
+}
+
+/*
+ NOTE.
+ When writing RAW the ZIP64 extended information in extrafield_local and extrafield_global needs to be stripped
+ before calling this function it can be done with zipRemoveExtraInfoBlock
+
+ It is not done here because then we need to realloc a new buffer since parameters are 'const' and I want to minimize
+ unnecessary allocations.
+ */
+extern int ZEXPORT zipOpenNewFileInZip4_64 (zipFile file, const char* filename, const zip_fileinfo* zipfi,
+                                         const void* extrafield_local, uInt size_extrafield_local,
+                                         const void* extrafield_global, uInt size_extrafield_global,
+                                         const char* comment, int method, int level, int raw,
+                                         int windowBits,int memLevel, int strategy,
+                                         const char* password, uLong crcForCrypting,
+                                         uLong versionMadeBy, uLong flagBase, int zip64)
+{
+    zip64_internal* zi;
+    uInt size_filename;
+    uInt size_comment;
+    uInt i;
+    int err = ZIP_OK;
+
+#    ifdef NOCRYPT
+    (crcForCrypting);
+    if (password != NULL)
+        return ZIP_PARAMERROR;
+#    endif
+
+    if (file == NULL)
+        return ZIP_PARAMERROR;
+
+#ifdef HAVE_BZIP2
+    if ((method!=0) && (method!=Z_DEFLATED) && (method!=Z_BZIP2ED))
+      return ZIP_PARAMERROR;
+#else
+    if ((method!=0) && (method!=Z_DEFLATED))
+      return ZIP_PARAMERROR;
+#endif
+
+    zi = (zip64_internal*)file;
+
+    if (zi->in_opened_file_inzip == 1)
+    {
+        err = zipCloseFileInZip (file);
+        if (err != ZIP_OK)
+            return err;
+    }
+
+    if (filename==NULL)
+        filename="-";
+
+    if (comment==NULL)
+        size_comment = 0;
+    else
+        size_comment = (uInt)strlen(comment);
+
+    size_filename = (uInt)strlen(filename);
+
+    if (zipfi == NULL)
+        zi->ci.dosDate = 0;
+    else
+    {
+        if (zipfi->dosDate != 0)
+            zi->ci.dosDate = zipfi->dosDate;
+        else
+          zi->ci.dosDate = zip64local_TmzDateToDosDate(&zipfi->tmz_date);
+    }
+
+    zi->ci.flag = flagBase;
+    if ((level==8) || (level==9))
+      zi->ci.flag |= 2;
+    if (level==2)
+      zi->ci.flag |= 4;
+    if (level==1)
+      zi->ci.flag |= 6;
+    if (password != NULL)
+      zi->ci.flag |= 1;
+
+    zi->ci.crc32 = 0;
+    zi->ci.method = method;
+    zi->ci.encrypt = 0;
+    zi->ci.stream_initialised = 0;
+    zi->ci.pos_in_buffered_data = 0;
+    zi->ci.raw = raw;
+    zi->ci.pos_local_header = ZTELL64(zi->z_filefunc,zi->filestream);
+
+    zi->ci.size_centralheader = SIZECENTRALHEADER + size_filename + size_extrafield_global + size_comment;
+    zi->ci.size_centralExtraFree = 32; // Extra space we have reserved in case we need to add ZIP64 extra info data
+
+    zi->ci.central_header = (char*)ALLOC((uInt)zi->ci.size_centralheader + zi->ci.size_centralExtraFree);
+
+    zi->ci.size_centralExtra = size_extrafield_global;
+    zip64local_putValue_inmemory(zi->ci.central_header,(uLong)CENTRALHEADERMAGIC,4);
+    /* version info */
+    zip64local_putValue_inmemory(zi->ci.central_header+4,(uLong)versionMadeBy,2);
+    zip64local_putValue_inmemory(zi->ci.central_header+6,(uLong)20,2);
+    zip64local_putValue_inmemory(zi->ci.central_header+8,(uLong)zi->ci.flag,2);
+    zip64local_putValue_inmemory(zi->ci.central_header+10,(uLong)zi->ci.method,2);
+    zip64local_putValue_inmemory(zi->ci.central_header+12,(uLong)zi->ci.dosDate,4);
+    zip64local_putValue_inmemory(zi->ci.central_header+16,(uLong)0,4); /*crc*/
+    zip64local_putValue_inmemory(zi->ci.central_header+20,(uLong)0,4); /*compr size*/
+    zip64local_putValue_inmemory(zi->ci.central_header+24,(uLong)0,4); /*uncompr size*/
+    zip64local_putValue_inmemory(zi->ci.central_header+28,(uLong)size_filename,2);
+    zip64local_putValue_inmemory(zi->ci.central_header+30,(uLong)size_extrafield_global,2);
+    zip64local_putValue_inmemory(zi->ci.central_header+32,(uLong)size_comment,2);
+    zip64local_putValue_inmemory(zi->ci.central_header+34,(uLong)0,2); /*disk nm start*/
+
+    if (zipfi==NULL)
+        zip64local_putValue_inmemory(zi->ci.central_header+36,(uLong)0,2);
+    else
+        zip64local_putValue_inmemory(zi->ci.central_header+36,(uLong)zipfi->internal_fa,2);
+
+    if (zipfi==NULL)
+        zip64local_putValue_inmemory(zi->ci.central_header+38,(uLong)0,4);
+    else
+        zip64local_putValue_inmemory(zi->ci.central_header+38,(uLong)zipfi->external_fa,4);
+
+    if(zi->ci.pos_local_header >= 0xffffffff)
+      zip64local_putValue_inmemory(zi->ci.central_header+42,(uLong)0xffffffff,4);
+    else
+      zip64local_putValue_inmemory(zi->ci.central_header+42,(uLong)zi->ci.pos_local_header - zi->add_position_when_writing_offset,4);
+
+    for (i=0;i<size_filename;i++)
+        *(zi->ci.central_header+SIZECENTRALHEADER+i) = *(filename+i);
+
+    for (i=0;i<size_extrafield_global;i++)
+        *(zi->ci.central_header+SIZECENTRALHEADER+size_filename+i) =
+              *(((const char*)extrafield_global)+i);
+
+    for (i=0;i<size_comment;i++)
+        *(zi->ci.central_header+SIZECENTRALHEADER+size_filename+
+              size_extrafield_global+i) = *(comment+i);
+    if (zi->ci.central_header == NULL)
+        return ZIP_INTERNALERROR;
+
+    zi->ci.zip64 = zip64;
+    zi->ci.totalCompressedData = 0;
+    zi->ci.totalUncompressedData = 0;
+    zi->ci.pos_zip64extrainfo = 0;
+
+    err = Write_LocalFileHeader(zi, filename, size_extrafield_local, extrafield_local);
+
+#ifdef HAVE_BZIP2
+    zi->ci.bstream.avail_in = (uInt)0;
+    zi->ci.bstream.avail_out = (uInt)Z_BUFSIZE;
+    zi->ci.bstream.next_out = (char*)zi->ci.buffered_data;
+    zi->ci.bstream.total_in_hi32 = 0;
+    zi->ci.bstream.total_in_lo32 = 0;
+    zi->ci.bstream.total_out_hi32 = 0;
+    zi->ci.bstream.total_out_lo32 = 0;
+#endif
+
+    zi->ci.stream.avail_in = (uInt)0;
+    zi->ci.stream.avail_out = (uInt)Z_BUFSIZE;
+    zi->ci.stream.next_out = zi->ci.buffered_data;
+    zi->ci.stream.total_in = 0;
+    zi->ci.stream.total_out = 0;
+    zi->ci.stream.data_type = Z_BINARY;
+
+#ifdef HAVE_BZIP2
+    if ((err==ZIP_OK) && (zi->ci.method == Z_DEFLATED || zi->ci.method == Z_BZIP2ED) && (!zi->ci.raw))
+#else
+    if ((err==ZIP_OK) && (zi->ci.method == Z_DEFLATED) && (!zi->ci.raw))
+#endif
+    {
+        if(zi->ci.method == Z_DEFLATED)
+        {
+          zi->ci.stream.zalloc = (alloc_func)0;
+          zi->ci.stream.zfree = (free_func)0;
+          zi->ci.stream.opaque = (voidpf)0;
+
+          if (windowBits>0)
+              windowBits = -windowBits;
+
+          err = deflateInit2(&zi->ci.stream, level, Z_DEFLATED, windowBits, memLevel, strategy);
+
+          if (err==Z_OK)
+              zi->ci.stream_initialised = Z_DEFLATED;
+        }
+        else if(zi->ci.method == Z_BZIP2ED)
+        {
+#ifdef HAVE_BZIP2
+            // Init BZip stuff here
+          zi->ci.bstream.bzalloc = 0;
+          zi->ci.bstream.bzfree = 0;
+          zi->ci.bstream.opaque = (voidpf)0;
+
+          err = BZ2_bzCompressInit(&zi->ci.bstream, level, 0,35);
+          if(err == BZ_OK)
+            zi->ci.stream_initialised = Z_BZIP2ED;
+#endif
+        }
+
+    }
+
+#    ifndef NOCRYPT
+    zi->ci.crypt_header_size = 0;
+    if ((err==Z_OK) && (password != NULL))
+    {
+        unsigned char bufHead[RAND_HEAD_LEN];
+        unsigned int sizeHead;
+        zi->ci.encrypt = 1;
+        zi->ci.pcrc_32_tab = get_crc_table();
+        /*init_keys(password,zi->ci.keys,zi->ci.pcrc_32_tab);*/
+
+        sizeHead=crypthead(password,bufHead,RAND_HEAD_LEN,zi->ci.keys,zi->ci.pcrc_32_tab,crcForCrypting);
+        zi->ci.crypt_header_size = sizeHead;
+
+        if (ZWRITE64(zi->z_filefunc,zi->filestream,bufHead,sizeHead) != sizeHead)
+                err = ZIP_ERRNO;
+    }
+#    endif
+
+    if (err==Z_OK)
+        zi->in_opened_file_inzip = 1;
+    return err;
+}
+
+extern int ZEXPORT zipOpenNewFileInZip4 (zipFile file, const char* filename, const zip_fileinfo* zipfi,
+                                         const void* extrafield_local, uInt size_extrafield_local,
+                                         const void* extrafield_global, uInt size_extrafield_global,
+                                         const char* comment, int method, int level, int raw,
+                                         int windowBits,int memLevel, int strategy,
+                                         const char* password, uLong crcForCrypting,
+                                         uLong versionMadeBy, uLong flagBase)
+{
+    return zipOpenNewFileInZip4_64 (file, filename, zipfi,
+                                 extrafield_local, size_extrafield_local,
+                                 extrafield_global, size_extrafield_global,
+                                 comment, method, level, raw,
+                                 windowBits, memLevel, strategy,
+                                 password, crcForCrypting, versionMadeBy, flagBase, 0);
+}
+
+extern int ZEXPORT zipOpenNewFileInZip3 (zipFile file, const char* filename, const zip_fileinfo* zipfi,
+                                         const void* extrafield_local, uInt size_extrafield_local,
+                                         const void* extrafield_global, uInt size_extrafield_global,
+                                         const char* comment, int method, int level, int raw,
+                                         int windowBits,int memLevel, int strategy,
+                                         const char* password, uLong crcForCrypting)
+{
+    return zipOpenNewFileInZip4_64 (file, filename, zipfi,
+                                 extrafield_local, size_extrafield_local,
+                                 extrafield_global, size_extrafield_global,
+                                 comment, method, level, raw,
+                                 windowBits, memLevel, strategy,
+                                 password, crcForCrypting, VERSIONMADEBY, 0, 0);
+}
+
+extern int ZEXPORT zipOpenNewFileInZip3_64(zipFile file, const char* filename, const zip_fileinfo* zipfi,
+                                         const void* extrafield_local, uInt size_extrafield_local,
+                                         const void* extrafield_global, uInt size_extrafield_global,
+                                         const char* comment, int method, int level, int raw,
+                                         int windowBits,int memLevel, int strategy,
+                                         const char* password, uLong crcForCrypting, int zip64)
+{
+    return zipOpenNewFileInZip4_64 (file, filename, zipfi,
+                                 extrafield_local, size_extrafield_local,
+                                 extrafield_global, size_extrafield_global,
+                                 comment, method, level, raw,
+                                 windowBits, memLevel, strategy,
+                                 password, crcForCrypting, VERSIONMADEBY, 0, zip64);
+}
+
+extern int ZEXPORT zipOpenNewFileInZip2(zipFile file, const char* filename, const zip_fileinfo* zipfi,
+                                        const void* extrafield_local, uInt size_extrafield_local,
+                                        const void* extrafield_global, uInt size_extrafield_global,
+                                        const char* comment, int method, int level, int raw)
+{
+    return zipOpenNewFileInZip4_64 (file, filename, zipfi,
+                                 extrafield_local, size_extrafield_local,
+                                 extrafield_global, size_extrafield_global,
+                                 comment, method, level, raw,
+                                 -MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY,
+                                 NULL, 0, VERSIONMADEBY, 0, 0);
+}
+
+extern int ZEXPORT zipOpenNewFileInZip2_64(zipFile file, const char* filename, const zip_fileinfo* zipfi,
+                                        const void* extrafield_local, uInt size_extrafield_local,
+                                        const void* extrafield_global, uInt size_extrafield_global,
+                                        const char* comment, int method, int level, int raw, int zip64)
+{
+    return zipOpenNewFileInZip4_64 (file, filename, zipfi,
+                                 extrafield_local, size_extrafield_local,
+                                 extrafield_global, size_extrafield_global,
+                                 comment, method, level, raw,
+                                 -MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY,
+                                 NULL, 0, VERSIONMADEBY, 0, zip64);
+}
+
+extern int ZEXPORT zipOpenNewFileInZip64 (zipFile file, const char* filename, const zip_fileinfo* zipfi,
+                                        const void* extrafield_local, uInt size_extrafield_local,
+                                        const void*extrafield_global, uInt size_extrafield_global,
+                                        const char* comment, int method, int level, int zip64)
+{
+    return zipOpenNewFileInZip4_64 (file, filename, zipfi,
+                                 extrafield_local, size_extrafield_local,
+                                 extrafield_global, size_extrafield_global,
+                                 comment, method, level, 0,
+                                 -MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY,
+                                 NULL, 0, VERSIONMADEBY, 0, zip64);
+}
+
+extern int ZEXPORT zipOpenNewFileInZip (zipFile file, const char* filename, const zip_fileinfo* zipfi,
+                                        const void* extrafield_local, uInt size_extrafield_local,
+                                        const void*extrafield_global, uInt size_extrafield_global,
+                                        const char* comment, int method, int level)
+{
+    return zipOpenNewFileInZip4_64 (file, filename, zipfi,
+                                 extrafield_local, size_extrafield_local,
+                                 extrafield_global, size_extrafield_global,
+                                 comment, method, level, 0,
+                                 -MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY,
+                                 NULL, 0, VERSIONMADEBY, 0, 0);
+}
+
+local int zip64FlushWriteBuffer(zip64_internal* zi)
+{
+    int err=ZIP_OK;
+
+    if (zi->ci.encrypt != 0)
+    {
+#ifndef NOCRYPT
+        uInt i;
+        int t;
+        for (i=0;i<zi->ci.pos_in_buffered_data;i++)
+            zi->ci.buffered_data[i] = zencode(zi->ci.keys, zi->ci.pcrc_32_tab, zi->ci.buffered_data[i],t);
+#endif
+    }
+
+    if (ZWRITE64(zi->z_filefunc,zi->filestream,zi->ci.buffered_data,zi->ci.pos_in_buffered_data) != zi->ci.pos_in_buffered_data)
+      err = ZIP_ERRNO;
+
+    zi->ci.totalCompressedData += zi->ci.pos_in_buffered_data;
+
+#ifdef HAVE_BZIP2
+    if(zi->ci.method == Z_BZIP2ED)
+    {
+      zi->ci.totalUncompressedData += zi->ci.bstream.total_in_lo32;
+      zi->ci.bstream.total_in_lo32 = 0;
+      zi->ci.bstream.total_in_hi32 = 0;
+    }
+    else
+#endif
+    {
+      zi->ci.totalUncompressedData += zi->ci.stream.total_in;
+      zi->ci.stream.total_in = 0;
+    }
+
+
+    zi->ci.pos_in_buffered_data = 0;
+
+    return err;
+}
+
+extern int ZEXPORT zipWriteInFileInZip (zipFile file,const void* buf,unsigned int len)
+{
+    zip64_internal* zi;
+    int err=ZIP_OK;
+
+    if (file == NULL)
+        return ZIP_PARAMERROR;
+    zi = (zip64_internal*)file;
+
+    if (zi->in_opened_file_inzip == 0)
+        return ZIP_PARAMERROR;
+
+    zi->ci.crc32 = crc32(zi->ci.crc32,buf,(uInt)len);
+
+#ifdef HAVE_BZIP2
+    if(zi->ci.method == Z_BZIP2ED && (!zi->ci.raw))
+    {
+      zi->ci.bstream.next_in = (void*)buf;
+      zi->ci.bstream.avail_in = len;
+      err = BZ_RUN_OK;
+
+      while ((err==BZ_RUN_OK) && (zi->ci.bstream.avail_in>0))
+      {
+        if (zi->ci.bstream.avail_out == 0)
+        {
+          if (zip64FlushWriteBuffer(zi) == ZIP_ERRNO)
+            err = ZIP_ERRNO;
+          zi->ci.bstream.avail_out = (uInt)Z_BUFSIZE;
+          zi->ci.bstream.next_out = (char*)zi->ci.buffered_data;
+        }
+
+
+        if(err != BZ_RUN_OK)
+          break;
+
+        if ((zi->ci.method == Z_BZIP2ED) && (!zi->ci.raw))
+        {
+          uLong uTotalOutBefore_lo = zi->ci.bstream.total_out_lo32;
+//          uLong uTotalOutBefore_hi = zi->ci.bstream.total_out_hi32;
+          err=BZ2_bzCompress(&zi->ci.bstream,  BZ_RUN);
+
+          zi->ci.pos_in_buffered_data += (uInt)(zi->ci.bstream.total_out_lo32 - uTotalOutBefore_lo) ;
+        }
+      }
+
+      if(err == BZ_RUN_OK)
+        err = ZIP_OK;
+    }
+    else
+#endif
+    {
+      zi->ci.stream.next_in = (Bytef*)buf;
+      zi->ci.stream.avail_in = len;
+
+      while ((err==ZIP_OK) && (zi->ci.stream.avail_in>0))
+      {
+          if (zi->ci.stream.avail_out == 0)
+          {
+              if (zip64FlushWriteBuffer(zi) == ZIP_ERRNO)
+                  err = ZIP_ERRNO;
+              zi->ci.stream.avail_out = (uInt)Z_BUFSIZE;
+              zi->ci.stream.next_out = zi->ci.buffered_data;
+          }
+
+
+          if(err != ZIP_OK)
+              break;
+
+          if ((zi->ci.method == Z_DEFLATED) && (!zi->ci.raw))
+          {
+              uLong uTotalOutBefore = zi->ci.stream.total_out;
+              err=deflate(&zi->ci.stream,  Z_NO_FLUSH);
+              if(uTotalOutBefore > zi->ci.stream.total_out)
+              {
+                int bBreak = 0;
+                bBreak++;
+              }
+
+              zi->ci.pos_in_buffered_data += (uInt)(zi->ci.stream.total_out - uTotalOutBefore) ;
+          }
+          else
+          {
+              uInt copy_this,i;
+              if (zi->ci.stream.avail_in < zi->ci.stream.avail_out)
+                  copy_this = zi->ci.stream.avail_in;
+              else
+                  copy_this = zi->ci.stream.avail_out;
+
+              for (i = 0; i < copy_this; i++)
+                  *(((char*)zi->ci.stream.next_out)+i) =
+                      *(((const char*)zi->ci.stream.next_in)+i);
+              {
+                  zi->ci.stream.avail_in -= copy_this;
+                  zi->ci.stream.avail_out-= copy_this;
+                  zi->ci.stream.next_in+= copy_this;
+                  zi->ci.stream.next_out+= copy_this;
+                  zi->ci.stream.total_in+= copy_this;
+                  zi->ci.stream.total_out+= copy_this;
+                  zi->ci.pos_in_buffered_data += copy_this;
+              }
+          }
+      }// while(...)
+    }
+
+    return err;
+}
+
+extern int ZEXPORT zipCloseFileInZipRaw (zipFile file, uLong uncompressed_size, uLong crc32)
+{
+    return zipCloseFileInZipRaw64 (file, uncompressed_size, crc32);
+}
+
+extern int ZEXPORT zipCloseFileInZipRaw64 (zipFile file, ZPOS64_T uncompressed_size, uLong crc32)
+{
+    zip64_internal* zi;
+    ZPOS64_T compressed_size;
+    uLong invalidValue = 0xffffffff;
+    short datasize = 0;
+    int err=ZIP_OK;
+
+    if (file == NULL)
+        return ZIP_PARAMERROR;
+    zi = (zip64_internal*)file;
+
+    if (zi->in_opened_file_inzip == 0)
+        return ZIP_PARAMERROR;
+    zi->ci.stream.avail_in = 0;
+
+    if ((zi->ci.method == Z_DEFLATED) && (!zi->ci.raw))
+                {
+                        while (err==ZIP_OK)
+                        {
+                                uLong uTotalOutBefore;
+                                if (zi->ci.stream.avail_out == 0)
+                                {
+                                        if (zip64FlushWriteBuffer(zi) == ZIP_ERRNO)
+                                                err = ZIP_ERRNO;
+                                        zi->ci.stream.avail_out = (uInt)Z_BUFSIZE;
+                                        zi->ci.stream.next_out = zi->ci.buffered_data;
+                                }
+                                uTotalOutBefore = zi->ci.stream.total_out;
+                                err=deflate(&zi->ci.stream,  Z_FINISH);
+                                zi->ci.pos_in_buffered_data += (uInt)(zi->ci.stream.total_out - uTotalOutBefore) ;
+                        }
+                }
+    else if ((zi->ci.method == Z_BZIP2ED) && (!zi->ci.raw))
+    {
+#ifdef HAVE_BZIP2
+      err = BZ_FINISH_OK;
+      while (err==BZ_FINISH_OK)
+      {
+        uLong uTotalOutBefore;
+        if (zi->ci.bstream.avail_out == 0)
+        {
+          if (zip64FlushWriteBuffer(zi) == ZIP_ERRNO)
+            err = ZIP_ERRNO;
+          zi->ci.bstream.avail_out = (uInt)Z_BUFSIZE;
+          zi->ci.bstream.next_out = (char*)zi->ci.buffered_data;
+        }
+        uTotalOutBefore = zi->ci.bstream.total_out_lo32;
+        err=BZ2_bzCompress(&zi->ci.bstream,  BZ_FINISH);
+        if(err == BZ_STREAM_END)
+          err = Z_STREAM_END;
+
+        zi->ci.pos_in_buffered_data += (uInt)(zi->ci.bstream.total_out_lo32 - uTotalOutBefore);
+      }
+
+      if(err == BZ_FINISH_OK)
+        err = ZIP_OK;
+#endif
+    }
+
+    if (err==Z_STREAM_END)
+        err=ZIP_OK; /* this is normal */
+
+    if ((zi->ci.pos_in_buffered_data>0) && (err==ZIP_OK))
+                {
+        if (zip64FlushWriteBuffer(zi)==ZIP_ERRNO)
+            err = ZIP_ERRNO;
+                }
+
+    if ((zi->ci.method == Z_DEFLATED) && (!zi->ci.raw))
+    {
+        int tmp_err = deflateEnd(&zi->ci.stream);
+        if (err == ZIP_OK)
+            err = tmp_err;
+        zi->ci.stream_initialised = 0;
+    }
+#ifdef HAVE_BZIP2
+    else if((zi->ci.method == Z_BZIP2ED) && (!zi->ci.raw))
+    {
+      int tmperr = BZ2_bzCompressEnd(&zi->ci.bstream);
+                        if (err==ZIP_OK)
+                                err = tmperr;
+                        zi->ci.stream_initialised = 0;
+    }
+#endif
+
+    if (!zi->ci.raw)
+    {
+        crc32 = (uLong)zi->ci.crc32;
+        uncompressed_size = zi->ci.totalUncompressedData;
+    }
+    compressed_size = zi->ci.totalCompressedData;
+
+#    ifndef NOCRYPT
+    compressed_size += zi->ci.crypt_header_size;
+#    endif
+
+    // update Current Item crc and sizes,
+    if(compressed_size >= 0xffffffff || uncompressed_size >= 0xffffffff || zi->ci.pos_local_header >= 0xffffffff)
+    {
+      /*version Made by*/
+      zip64local_putValue_inmemory(zi->ci.central_header+4,(uLong)45,2);
+      /*version needed*/
+      zip64local_putValue_inmemory(zi->ci.central_header+6,(uLong)45,2);
+
+    }
+
+    zip64local_putValue_inmemory(zi->ci.central_header+16,crc32,4); /*crc*/
+
+
+    if(compressed_size >= 0xffffffff)
+      zip64local_putValue_inmemory(zi->ci.central_header+20, invalidValue,4); /*compr size*/
+    else
+      zip64local_putValue_inmemory(zi->ci.central_header+20, compressed_size,4); /*compr size*/
+
+    /// set internal file attributes field
+    if (zi->ci.stream.data_type == Z_ASCII)
+        zip64local_putValue_inmemory(zi->ci.central_header+36,(uLong)Z_ASCII,2);
+
+    if(uncompressed_size >= 0xffffffff)
+      zip64local_putValue_inmemory(zi->ci.central_header+24, invalidValue,4); /*uncompr size*/
+    else
+      zip64local_putValue_inmemory(zi->ci.central_header+24, uncompressed_size,4); /*uncompr size*/
+
+    // Add ZIP64 extra info field for uncompressed size
+    if(uncompressed_size >= 0xffffffff)
+      datasize += 8;
+
+    // Add ZIP64 extra info field for compressed size
+    if(compressed_size >= 0xffffffff)
+      datasize += 8;
+
+    // Add ZIP64 extra info field for relative offset to local file header of current file
+    if(zi->ci.pos_local_header >= 0xffffffff)
+      datasize += 8;
+
+    if(datasize > 0)
+    {
+      char* p = NULL;
+
+      if((uLong)(datasize + 4) > zi->ci.size_centralExtraFree)
+      {
+        // we can not write more data to the buffer that we have room for.
+        return ZIP_BADZIPFILE;
+      }
+
+      p = zi->ci.central_header + zi->ci.size_centralheader;
+
+      // Add Extra Information Header for 'ZIP64 information'
+      zip64local_putValue_inmemory(p, 0x0001, 2); // HeaderID
+      p += 2;
+      zip64local_putValue_inmemory(p, datasize, 2); // DataSize
+      p += 2;
+
+      if(uncompressed_size >= 0xffffffff)
+      {
+        zip64local_putValue_inmemory(p, uncompressed_size, 8);
+        p += 8;
+      }
+
+      if(compressed_size >= 0xffffffff)
+      {
+        zip64local_putValue_inmemory(p, compressed_size, 8);
+        p += 8;
+      }
+
+      if(zi->ci.pos_local_header >= 0xffffffff)
+      {
+        zip64local_putValue_inmemory(p, zi->ci.pos_local_header, 8);
+        p += 8;
+      }
+
+      // Update how much extra free space we got in the memory buffer
+      // and increase the centralheader size so the new ZIP64 fields are included
+      // ( 4 below is the size of HeaderID and DataSize field )
+      zi->ci.size_centralExtraFree -= datasize + 4;
+      zi->ci.size_centralheader += datasize + 4;
+
+      // Update the extra info size field
+      zi->ci.size_centralExtra += datasize + 4;
+      zip64local_putValue_inmemory(zi->ci.central_header+30,(uLong)zi->ci.size_centralExtra,2);
+    }
+
+    if (err==ZIP_OK)
+        err = add_data_in_datablock(&zi->central_dir, zi->ci.central_header, (uLong)zi->ci.size_centralheader);
+
+    free(zi->ci.central_header);
+
+    if (err==ZIP_OK)
+    {
+        // Update the LocalFileHeader with the new values.
+
+        ZPOS64_T cur_pos_inzip = ZTELL64(zi->z_filefunc,zi->filestream);
+
+        if (ZSEEK64(zi->z_filefunc,zi->filestream, zi->ci.pos_local_header + 14,ZLIB_FILEFUNC_SEEK_SET)!=0)
+            err = ZIP_ERRNO;
+
+        if (err==ZIP_OK)
+            err = zip64local_putValue(&zi->z_filefunc,zi->filestream,crc32,4); /* crc 32, unknown */
+
+        if(uncompressed_size >= 0xffffffff || compressed_size >= 0xffffffff )
+        {
+          if(zi->ci.pos_zip64extrainfo > 0)
+          {
+            // Update the size in the ZIP64 extended field.
+            if (ZSEEK64(zi->z_filefunc,zi->filestream, zi->ci.pos_zip64extrainfo + 4,ZLIB_FILEFUNC_SEEK_SET)!=0)
+              err = ZIP_ERRNO;
+
+            if (err==ZIP_OK) /* compressed size, unknown */
+              err = zip64local_putValue(&zi->z_filefunc, zi->filestream, uncompressed_size, 8);
+
+            if (err==ZIP_OK) /* uncompressed size, unknown */
+              err = zip64local_putValue(&zi->z_filefunc, zi->filestream, compressed_size, 8);
+          }
+          else
+              err = ZIP_BADZIPFILE; // Caller passed zip64 = 0, so no room for zip64 info -> fatal
+        }
+        else
+        {
+          if (err==ZIP_OK) /* compressed size, unknown */
+              err = zip64local_putValue(&zi->z_filefunc,zi->filestream,compressed_size,4);
+
+          if (err==ZIP_OK) /* uncompressed size, unknown */
+              err = zip64local_putValue(&zi->z_filefunc,zi->filestream,uncompressed_size,4);
+        }
+
+        if (ZSEEK64(zi->z_filefunc,zi->filestream, cur_pos_inzip,ZLIB_FILEFUNC_SEEK_SET)!=0)
+            err = ZIP_ERRNO;
+    }
+
+    zi->number_entry ++;
+    zi->in_opened_file_inzip = 0;
+
+    return err;
+}
+
+extern int ZEXPORT zipCloseFileInZip (zipFile file)
+{
+    return zipCloseFileInZipRaw (file,0,0);
+}
+
+int Write_Zip64EndOfCentralDirectoryLocator(zip64_internal* zi, ZPOS64_T zip64eocd_pos_inzip)
+{
+  int err = ZIP_OK;
+  ZPOS64_T pos = zip64eocd_pos_inzip - zi->add_position_when_writing_offset;
+
+  err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)ZIP64ENDLOCHEADERMAGIC,4);
+
+  /*num disks*/
+    if (err==ZIP_OK) /* number of the disk with the start of the central directory */
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0,4);
+
+  /*relative offset*/
+    if (err==ZIP_OK) /* Relative offset to the Zip64EndOfCentralDirectory */
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream, pos,8);
+
+  /*total disks*/ /* Do not support spawning of disk so always say 1 here*/
+    if (err==ZIP_OK) /* number of the disk with the start of the central directory */
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)1,4);
+
+    return err;
+}
+
+int Write_Zip64EndOfCentralDirectoryRecord(zip64_internal* zi, uLong size_centraldir, ZPOS64_T centraldir_pos_inzip)
+{
+  int err = ZIP_OK;
+
+  uLong Zip64DataSize = 44;
+
+  err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)ZIP64ENDHEADERMAGIC,4);
+
+  if (err==ZIP_OK) /* size of this 'zip64 end of central directory' */
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(ZPOS64_T)Zip64DataSize,8); // why ZPOS64_T of this ?
+
+  if (err==ZIP_OK) /* version made by */
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)45,2);
+
+  if (err==ZIP_OK) /* version needed */
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)45,2);
+
+  if (err==ZIP_OK) /* number of this disk */
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0,4);
+
+  if (err==ZIP_OK) /* number of the disk with the start of the central directory */
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0,4);
+
+  if (err==ZIP_OK) /* total number of entries in the central dir on this disk */
+    err = zip64local_putValue(&zi->z_filefunc, zi->filestream, zi->number_entry, 8);
+
+  if (err==ZIP_OK) /* total number of entries in the central dir */
+    err = zip64local_putValue(&zi->z_filefunc, zi->filestream, zi->number_entry, 8);
+
+  if (err==ZIP_OK) /* size of the central directory */
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(ZPOS64_T)size_centraldir,8);
+
+  if (err==ZIP_OK) /* offset of start of central directory with respect to the starting disk number */
+  {
+    ZPOS64_T pos = centraldir_pos_inzip - zi->add_position_when_writing_offset;
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream, (ZPOS64_T)pos,8);
+  }
+  return err;
+}
+int Write_EndOfCentralDirectoryRecord(zip64_internal* zi, uLong size_centraldir, ZPOS64_T centraldir_pos_inzip)
+{
+  int err = ZIP_OK;
+
+  /*signature*/
+  err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)ENDHEADERMAGIC,4);
+
+  if (err==ZIP_OK) /* number of this disk */
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0,2);
+
+  if (err==ZIP_OK) /* number of the disk with the start of the central directory */
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0,2);
+
+  if (err==ZIP_OK) /* total number of entries in the central dir on this disk */
+  {
+    {
+      if(zi->number_entry >= 0xFFFF)
+        err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0xffff,2); // use value in ZIP64 record
+      else
+        err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)zi->number_entry,2);
+    }
+  }
+
+  if (err==ZIP_OK) /* total number of entries in the central dir */
+  {
+    if(zi->number_entry >= 0xFFFF)
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)0xffff,2); // use value in ZIP64 record
+    else
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)zi->number_entry,2);
+  }
+
+  if (err==ZIP_OK) /* size of the central directory */
+    err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)size_centraldir,4);
+
+  if (err==ZIP_OK) /* offset of start of central directory with respect to the starting disk number */
+  {
+    ZPOS64_T pos = centraldir_pos_inzip - zi->add_position_when_writing_offset;
+    if(pos >= 0xffffffff)
+    {
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream, (uLong)0xffffffff,4);
+    }
+    else
+      err = zip64local_putValue(&zi->z_filefunc,zi->filestream, (uLong)(centraldir_pos_inzip - zi->add_position_when_writing_offset),4);
+  }
+
+   return err;
+}
+
+int Write_GlobalComment(zip64_internal* zi, const char* global_comment)
+{
+  int err = ZIP_OK;
+  uInt size_global_comment = 0;
+
+  if(global_comment != NULL)
+    size_global_comment = (uInt)strlen(global_comment);
+
+  err = zip64local_putValue(&zi->z_filefunc,zi->filestream,(uLong)size_global_comment,2);
+
+  if (err == ZIP_OK && size_global_comment > 0)
+  {
+    if (ZWRITE64(zi->z_filefunc,zi->filestream, global_comment, size_global_comment) != size_global_comment)
+      err = ZIP_ERRNO;
+  }
+  return err;
+}
+
+extern int ZEXPORT zipClose (zipFile file, const char* global_comment)
+{
+    zip64_internal* zi;
+    int err = 0;
+    uLong size_centraldir = 0;
+    ZPOS64_T centraldir_pos_inzip;
+    ZPOS64_T pos;
+
+    if (file == NULL)
+        return ZIP_PARAMERROR;
+
+    zi = (zip64_internal*)file;
+
+    if (zi->in_opened_file_inzip == 1)
+    {
+        err = zipCloseFileInZip (file);
+    }
+
+#ifndef NO_ADDFILEINEXISTINGZIP
+    if (global_comment==NULL)
+        global_comment = zi->globalcomment;
+#endif
+
+    centraldir_pos_inzip = ZTELL64(zi->z_filefunc,zi->filestream);
+
+    if (err==ZIP_OK)
+    {
+        linkedlist_datablock_internal* ldi = zi->central_dir.first_block;
+        while (ldi!=NULL)
+        {
+            if ((err==ZIP_OK) && (ldi->filled_in_this_block>0))
+            {
+                if (ZWRITE64(zi->z_filefunc,zi->filestream, ldi->data, ldi->filled_in_this_block) != ldi->filled_in_this_block)
+                    err = ZIP_ERRNO;
+            }
+
+            size_centraldir += ldi->filled_in_this_block;
+            ldi = ldi->next_datablock;
+        }
+    }
+    free_linkedlist(&(zi->central_dir));
+
+    pos = centraldir_pos_inzip - zi->add_position_when_writing_offset;
+    if(pos >= 0xffffffff || zi->number_entry > 0xFFFF)
+    {
+      ZPOS64_T Zip64EOCDpos = ZTELL64(zi->z_filefunc,zi->filestream);
+      Write_Zip64EndOfCentralDirectoryRecord(zi, size_centraldir, centraldir_pos_inzip);
+
+      Write_Zip64EndOfCentralDirectoryLocator(zi, Zip64EOCDpos);
+    }
+
+    if (err==ZIP_OK)
+      err = Write_EndOfCentralDirectoryRecord(zi, size_centraldir, centraldir_pos_inzip);
+
+    if(err == ZIP_OK)
+      err = Write_GlobalComment(zi, global_comment);
+
+    if (ZCLOSE64(zi->z_filefunc,zi->filestream) != 0)
+        if (err == ZIP_OK)
+            err = ZIP_ERRNO;
+
+#ifndef NO_ADDFILEINEXISTINGZIP
+    TRYFREE(zi->globalcomment);
+#endif
+    TRYFREE(zi);
+
+    return err;
+}
+
+extern int ZEXPORT zipRemoveExtraInfoBlock (char* pData, int* dataLen, short sHeader)
+{
+  char* p = pData;
+  int size = 0;
+  char* pNewHeader;
+  char* pTmp;
+  short header;
+  short dataSize;
+
+  int retVal = ZIP_OK;
+
+  if(pData == NULL || *dataLen < 4)
+    return ZIP_PARAMERROR;
+
+  pNewHeader = (char*)ALLOC(*dataLen);
+  pTmp = pNewHeader;
+
+  while(p < (pData + *dataLen))
+  {
+    header = *(short*)p;
+    dataSize = *(((short*)p)+1);
+
+    if( header == sHeader ) // Header found.
+    {
+      p += dataSize + 4; // skip it. do not copy to temp buffer
+    }
+    else
+    {
+      // Extra Info block should not be removed, So copy it to the temp buffer.
+      memcpy(pTmp, p, dataSize + 4);
+      p += dataSize + 4;
+      size += dataSize + 4;
+    }
+
+  }
+
+  if(size < *dataLen)
+  {
+    // clean old extra info block.
+    memset(pData,0, *dataLen);
+
+    // copy the new extra info block over the old
+    if(size > 0)
+      memcpy(pData, pNewHeader, size);
+
+    // set the new extra info size
+    *dataLen = size;
+
+    retVal = ZIP_OK;
+  }
+  else
+    retVal = ZIP_ERRNO;
+
+  TRYFREE(pNewHeader);
+
+  return retVal;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/minizip/zip.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/minizip/zip.h	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,362 @@
+/* zip.h -- IO on .zip files using zlib
+   Version 1.1, February 14h, 2010
+   part of the MiniZip project - ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Copyright (C) 1998-2010 Gilles Vollant (minizip) ( http://www.winimage.com/zLibDll/minizip.html )
+
+         Modifications for Zip64 support
+         Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )
+
+         For more info read MiniZip_info.txt
+
+         ---------------------------------------------------------------------------
+
+   Condition of use and distribution are the same than zlib :
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+        ---------------------------------------------------------------------------
+
+        Changes
+
+        See header of zip.h
+
+*/
+
+#ifndef _zip12_H
+#define _zip12_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+//#define HAVE_BZIP2
+
+#ifndef _ZLIB_H
+#include "zlib.h"
+#endif
+
+#ifndef _ZLIBIOAPI_H
+#include "ioapi.h"
+#endif
+
+#ifdef HAVE_BZIP2
+#include "bzlib.h"
+#endif
+
+#define Z_BZIP2ED 12
+
+#if defined(STRICTZIP) || defined(STRICTZIPUNZIP)
+/* like the STRICT of WIN32, we define a pointer that cannot be converted
+    from (void*) without cast */
+typedef struct TagzipFile__ { int unused; } zipFile__;
+typedef zipFile__ *zipFile;
+#else
+typedef voidp zipFile;
+#endif
+
+#define ZIP_OK                          (0)
+#define ZIP_EOF                         (0)
+#define ZIP_ERRNO                       (Z_ERRNO)
+#define ZIP_PARAMERROR                  (-102)
+#define ZIP_BADZIPFILE                  (-103)
+#define ZIP_INTERNALERROR               (-104)
+
+#ifndef DEF_MEM_LEVEL
+#  if MAX_MEM_LEVEL >= 8
+#    define DEF_MEM_LEVEL 8
+#  else
+#    define DEF_MEM_LEVEL  MAX_MEM_LEVEL
+#  endif
+#endif
+/* default memLevel */
+
+/* tm_zip contain date/time info */
+typedef struct tm_zip_s
+{
+    uInt tm_sec;            /* seconds after the minute - [0,59] */
+    uInt tm_min;            /* minutes after the hour - [0,59] */
+    uInt tm_hour;           /* hours since midnight - [0,23] */
+    uInt tm_mday;           /* day of the month - [1,31] */
+    uInt tm_mon;            /* months since January - [0,11] */
+    uInt tm_year;           /* years - [1980..2044] */
+} tm_zip;
+
+typedef struct
+{
+    tm_zip      tmz_date;       /* date in understandable format           */
+    uLong       dosDate;       /* if dos_date == 0, tmu_date is used      */
+/*    uLong       flag;        */   /* general purpose bit flag        2 bytes */
+
+    uLong       internal_fa;    /* internal file attributes        2 bytes */
+    uLong       external_fa;    /* external file attributes        4 bytes */
+} zip_fileinfo;
+
+typedef const char* zipcharpc;
+
+
+#define APPEND_STATUS_CREATE        (0)
+#define APPEND_STATUS_CREATEAFTER   (1)
+#define APPEND_STATUS_ADDINZIP      (2)
+
+extern zipFile ZEXPORT zipOpen OF((const char *pathname, int append));
+extern zipFile ZEXPORT zipOpen64 OF((const void *pathname, int append));
+/*
+  Create a zipfile.
+     pathname contain on Windows XP a filename like "c:\\zlib\\zlib113.zip" or on
+       an Unix computer "zlib/zlib113.zip".
+     if the file pathname exist and append==APPEND_STATUS_CREATEAFTER, the zip
+       will be created at the end of the file.
+         (useful if the file contain a self extractor code)
+     if the file pathname exist and append==APPEND_STATUS_ADDINZIP, we will
+       add files in existing zip (be sure you don't add file that doesn't exist)
+     If the zipfile cannot be opened, the return value is NULL.
+     Else, the return value is a zipFile Handle, usable with other function
+       of this zip package.
+*/
+
+/* Note : there is no delete function into a zipfile.
+   If you want delete file into a zipfile, you must open a zipfile, and create another
+   Of couse, you can use RAW reading and writing to copy the file you did not want delte
+*/
+
+extern zipFile ZEXPORT zipOpen2 OF((const char *pathname,
+                                   int append,
+                                   zipcharpc* globalcomment,
+                                   zlib_filefunc_def* pzlib_filefunc_def));
+
+extern zipFile ZEXPORT zipOpen2_64 OF((const void *pathname,
+                                   int append,
+                                   zipcharpc* globalcomment,
+                                   zlib_filefunc64_def* pzlib_filefunc_def));
+
+extern int ZEXPORT zipOpenNewFileInZip OF((zipFile file,
+                       const char* filename,
+                       const zip_fileinfo* zipfi,
+                       const void* extrafield_local,
+                       uInt size_extrafield_local,
+                       const void* extrafield_global,
+                       uInt size_extrafield_global,
+                       const char* comment,
+                       int method,
+                       int level));
+
+extern int ZEXPORT zipOpenNewFileInZip64 OF((zipFile file,
+                       const char* filename,
+                       const zip_fileinfo* zipfi,
+                       const void* extrafield_local,
+                       uInt size_extrafield_local,
+                       const void* extrafield_global,
+                       uInt size_extrafield_global,
+                       const char* comment,
+                       int method,
+                       int level,
+                       int zip64));
+
+/*
+  Open a file in the ZIP for writing.
+  filename : the filename in zip (if NULL, '-' without quote will be used
+  *zipfi contain supplemental information
+  if extrafield_local!=NULL and size_extrafield_local>0, extrafield_local
+    contains the extrafield data the the local header
+  if extrafield_global!=NULL and size_extrafield_global>0, extrafield_global
+    contains the extrafield data the the local header
+  if comment != NULL, comment contain the comment string
+  method contain the compression method (0 for store, Z_DEFLATED for deflate)
+  level contain the level of compression (can be Z_DEFAULT_COMPRESSION)
+  zip64 is set to 1 if a zip64 extended information block should be added to the local file header.
+                    this MUST be '1' if the uncompressed size is >= 0xffffffff.
+
+*/
+
+
+extern int ZEXPORT zipOpenNewFileInZip2 OF((zipFile file,
+                                            const char* filename,
+                                            const zip_fileinfo* zipfi,
+                                            const void* extrafield_local,
+                                            uInt size_extrafield_local,
+                                            const void* extrafield_global,
+                                            uInt size_extrafield_global,
+                                            const char* comment,
+                                            int method,
+                                            int level,
+                                            int raw));
+
+
+extern int ZEXPORT zipOpenNewFileInZip2_64 OF((zipFile file,
+                                            const char* filename,
+                                            const zip_fileinfo* zipfi,
+                                            const void* extrafield_local,
+                                            uInt size_extrafield_local,
+                                            const void* extrafield_global,
+                                            uInt size_extrafield_global,
+                                            const char* comment,
+                                            int method,
+                                            int level,
+                                            int raw,
+                                            int zip64));
+/*
+  Same than zipOpenNewFileInZip, except if raw=1, we write raw file
+ */
+
+extern int ZEXPORT zipOpenNewFileInZip3 OF((zipFile file,
+                                            const char* filename,
+                                            const zip_fileinfo* zipfi,
+                                            const void* extrafield_local,
+                                            uInt size_extrafield_local,
+                                            const void* extrafield_global,
+                                            uInt size_extrafield_global,
+                                            const char* comment,
+                                            int method,
+                                            int level,
+                                            int raw,
+                                            int windowBits,
+                                            int memLevel,
+                                            int strategy,
+                                            const char* password,
+                                            uLong crcForCrypting));
+
+extern int ZEXPORT zipOpenNewFileInZip3_64 OF((zipFile file,
+                                            const char* filename,
+                                            const zip_fileinfo* zipfi,
+                                            const void* extrafield_local,
+                                            uInt size_extrafield_local,
+                                            const void* extrafield_global,
+                                            uInt size_extrafield_global,
+                                            const char* comment,
+                                            int method,
+                                            int level,
+                                            int raw,
+                                            int windowBits,
+                                            int memLevel,
+                                            int strategy,
+                                            const char* password,
+                                            uLong crcForCrypting,
+                                            int zip64
+                                            ));
+
+/*
+  Same than zipOpenNewFileInZip2, except
+    windowBits,memLevel,,strategy : see parameter strategy in deflateInit2
+    password : crypting password (NULL for no crypting)
+    crcForCrypting : crc of file to compress (needed for crypting)
+ */
+
+extern int ZEXPORT zipOpenNewFileInZip4 OF((zipFile file,
+                                            const char* filename,
+                                            const zip_fileinfo* zipfi,
+                                            const void* extrafield_local,
+                                            uInt size_extrafield_local,
+                                            const void* extrafield_global,
+                                            uInt size_extrafield_global,
+                                            const char* comment,
+                                            int method,
+                                            int level,
+                                            int raw,
+                                            int windowBits,
+                                            int memLevel,
+                                            int strategy,
+                                            const char* password,
+                                            uLong crcForCrypting,
+                                            uLong versionMadeBy,
+                                            uLong flagBase
+                                            ));
+
+
+extern int ZEXPORT zipOpenNewFileInZip4_64 OF((zipFile file,
+                                            const char* filename,
+                                            const zip_fileinfo* zipfi,
+                                            const void* extrafield_local,
+                                            uInt size_extrafield_local,
+                                            const void* extrafield_global,
+                                            uInt size_extrafield_global,
+                                            const char* comment,
+                                            int method,
+                                            int level,
+                                            int raw,
+                                            int windowBits,
+                                            int memLevel,
+                                            int strategy,
+                                            const char* password,
+                                            uLong crcForCrypting,
+                                            uLong versionMadeBy,
+                                            uLong flagBase,
+                                            int zip64
+                                            ));
+/*
+  Same than zipOpenNewFileInZip4, except
+    versionMadeBy : value for Version made by field
+    flag : value for flag field (compression level info will be added)
+ */
+
+
+extern int ZEXPORT zipWriteInFileInZip OF((zipFile file,
+                       const void* buf,
+                       unsigned len));
+/*
+  Write data in the zipfile
+*/
+
+extern int ZEXPORT zipCloseFileInZip OF((zipFile file));
+/*
+  Close the current file in the zipfile
+*/
+
+extern int ZEXPORT zipCloseFileInZipRaw OF((zipFile file,
+                                            uLong uncompressed_size,
+                                            uLong crc32));
+
+extern int ZEXPORT zipCloseFileInZipRaw64 OF((zipFile file,
+                                            ZPOS64_T uncompressed_size,
+                                            uLong crc32));
+
+/*
+  Close the current file in the zipfile, for file opened with
+    parameter raw=1 in zipOpenNewFileInZip2
+  uncompressed_size and crc32 are value for the uncompressed size
+*/
+
+extern int ZEXPORT zipClose OF((zipFile file,
+                const char* global_comment));
+/*
+  Close the zipfile
+*/
+
+
+extern int ZEXPORT zipRemoveExtraInfoBlock OF((char* pData, int* dataLen, short sHeader));
+/*
+  zipRemoveExtraInfoBlock -  Added by Mathias Svensson
+
+  Remove extra information block from a extra information data for the local file header or central directory header
+
+  It is needed to remove ZIP64 extra information blocks when before data is written if using RAW mode.
+
+  0x0001 is the signature header for the ZIP64 extra information blocks
+
+  usage.
+                        Remove ZIP64 Extra information from a central director extra field data
+              zipRemoveExtraInfoBlock(pCenDirExtraFieldData, &nCenDirExtraFieldDataLen, 0x0001);
+
+                        Remove ZIP64 Extra information from a Local File Header extra field data
+        zipRemoveExtraInfoBlock(pLocalHeaderExtraFieldData, &nLocalHeaderExtraFieldDataLen, 0x0001);
+*/
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _zip64_H */
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/pascal/example.pas
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/pascal/example.pas	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,599 @@
+(* example.c -- usage example of the zlib compression library
+ * Copyright (C) 1995-2003 Jean-loup Gailly.
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ *
+ * Pascal translation
+ * Copyright (C) 1998 by Jacques Nomssi Nzali.
+ * For conditions of distribution and use, see copyright notice in readme.txt
+ *
+ * Adaptation to the zlibpas interface
+ * Copyright (C) 2003 by Cosmin Truta.
+ * For conditions of distribution and use, see copyright notice in readme.txt
+ *)
+
+program example;
+
+{$DEFINE TEST_COMPRESS}
+{DO NOT $DEFINE TEST_GZIO}
+{$DEFINE TEST_DEFLATE}
+{$DEFINE TEST_INFLATE}
+{$DEFINE TEST_FLUSH}
+{$DEFINE TEST_SYNC}
+{$DEFINE TEST_DICT}
+
+uses SysUtils, zlibpas;
+
+const TESTFILE = 'foo.gz';
+
+(* "hello world" would be more standard, but the repeated "hello"
+ * stresses the compression code better, sorry...
+ *)
+const hello: PChar = 'hello, hello!';
+
+const dictionary: PChar = 'hello';
+
+var dictId: LongInt; (* Adler32 value of the dictionary *)
+
+procedure CHECK_ERR(err: Integer; msg: String);
+begin
+  if err <> Z_OK then
+  begin
+    WriteLn(msg, ' error: ', err);
+    Halt(1);
+  end;
+end;
+
+procedure EXIT_ERR(const msg: String);
+begin
+  WriteLn('Error: ', msg);
+  Halt(1);
+end;
+
+(* ===========================================================================
+ * Test compress and uncompress
+ *)
+{$IFDEF TEST_COMPRESS}
+procedure test_compress(compr: Pointer; comprLen: LongInt;
+                        uncompr: Pointer; uncomprLen: LongInt);
+var err: Integer;
+    len: LongInt;
+begin
+  len := StrLen(hello)+1;
+
+  err := compress(compr, comprLen, hello, len);
+  CHECK_ERR(err, 'compress');
+
+  StrCopy(PChar(uncompr), 'garbage');
+
+  err := uncompress(uncompr, uncomprLen, compr, comprLen);
+  CHECK_ERR(err, 'uncompress');
+
+  if StrComp(PChar(uncompr), hello) <> 0 then
+    EXIT_ERR('bad uncompress')
+  else
+    WriteLn('uncompress(): ', PChar(uncompr));
+end;
+{$ENDIF}
+
+(* ===========================================================================
+ * Test read/write of .gz files
+ *)
+{$IFDEF TEST_GZIO}
+procedure test_gzio(const fname: PChar; (* compressed file name *)
+                    uncompr: Pointer;
+                    uncomprLen: LongInt);
+var err: Integer;
+    len: Integer;
+    zfile: gzFile;
+    pos: LongInt;
+begin
+  len := StrLen(hello)+1;
+
+  zfile := gzopen(fname, 'wb');
+  if zfile = NIL then
+  begin
+    WriteLn('gzopen error');
+    Halt(1);
+  end;
+  gzputc(zfile, 'h');
+  if gzputs(zfile, 'ello') <> 4 then
+  begin
+    WriteLn('gzputs err: ', gzerror(zfile, err));
+    Halt(1);
+  end;
+  {$IFDEF GZ_FORMAT_STRING}
+  if gzprintf(zfile, ', %s!', 'hello') <> 8 then
+  begin
+    WriteLn('gzprintf err: ', gzerror(zfile, err));
+    Halt(1);
+  end;
+  {$ELSE}
+  if gzputs(zfile, ', hello!') <> 8 then
+  begin
+    WriteLn('gzputs err: ', gzerror(zfile, err));
+    Halt(1);
+  end;
+  {$ENDIF}
+  gzseek(zfile, 1, SEEK_CUR); (* add one zero byte *)
+  gzclose(zfile);
+
+  zfile := gzopen(fname, 'rb');
+  if zfile = NIL then
+  begin
+    WriteLn('gzopen error');
+    Halt(1);
+  end;
+
+  StrCopy(PChar(uncompr), 'garbage');
+
+  if gzread(zfile, uncompr, uncomprLen) <> len then
+  begin
+    WriteLn('gzread err: ', gzerror(zfile, err));
+    Halt(1);
+  end;
+  if StrComp(PChar(uncompr), hello) <> 0 then
+  begin
+    WriteLn('bad gzread: ', PChar(uncompr));
+    Halt(1);
+  end
+  else
+    WriteLn('gzread(): ', PChar(uncompr));
+
+  pos := gzseek(zfile, -8, SEEK_CUR);
+  if (pos <> 6) or (gztell(zfile) <> pos) then
+  begin
+    WriteLn('gzseek error, pos=', pos, ', gztell=', gztell(zfile));
+    Halt(1);
+  end;
+
+  if gzgetc(zfile) <> ' ' then
+  begin
+    WriteLn('gzgetc error');
+    Halt(1);
+  end;
+
+  if gzungetc(' ', zfile) <> ' ' then
+  begin
+    WriteLn('gzungetc error');
+    Halt(1);
+  end;
+
+  gzgets(zfile, PChar(uncompr), uncomprLen);
+  uncomprLen := StrLen(PChar(uncompr));
+  if uncomprLen <> 7 then (* " hello!" *)
+  begin
+    WriteLn('gzgets err after gzseek: ', gzerror(zfile, err));
+    Halt(1);
+  end;
+  if StrComp(PChar(uncompr), hello + 6) <> 0 then
+  begin
+    WriteLn('bad gzgets after gzseek');
+    Halt(1);
+  end
+  else
+    WriteLn('gzgets() after gzseek: ', PChar(uncompr));
+
+  gzclose(zfile);
+end;
+{$ENDIF}
+
+(* ===========================================================================
+ * Test deflate with small buffers
+ *)
+{$IFDEF TEST_DEFLATE}
+procedure test_deflate(compr: Pointer; comprLen: LongInt);
+var c_stream: z_stream; (* compression stream *)
+    err: Integer;
+    len: LongInt;
+begin
+  len := StrLen(hello)+1;
+
+  c_stream.zalloc := NIL;
+  c_stream.zfree := NIL;
+  c_stream.opaque := NIL;
+
+  err := deflateInit(c_stream, Z_DEFAULT_COMPRESSION);
+  CHECK_ERR(err, 'deflateInit');
+
+  c_stream.next_in := hello;
+  c_stream.next_out := compr;
+
+  while (c_stream.total_in <> len) and
+        (c_stream.total_out < comprLen) do
+  begin
+    c_stream.avail_out := 1; { force small buffers }
+    c_stream.avail_in := 1;
+    err := deflate(c_stream, Z_NO_FLUSH);
+    CHECK_ERR(err, 'deflate');
+  end;
+
+  (* Finish the stream, still forcing small buffers: *)
+  while TRUE do
+  begin
+    c_stream.avail_out := 1;
+    err := deflate(c_stream, Z_FINISH);
+    if err = Z_STREAM_END then
+      break;
+    CHECK_ERR(err, 'deflate');
+  end;
+
+  err := deflateEnd(c_stream);
+  CHECK_ERR(err, 'deflateEnd');
+end;
+{$ENDIF}
+
+(* ===========================================================================
+ * Test inflate with small buffers
+ *)
+{$IFDEF TEST_INFLATE}
+procedure test_inflate(compr: Pointer; comprLen : LongInt;
+                       uncompr: Pointer; uncomprLen : LongInt);
+var err: Integer;
+    d_stream: z_stream; (* decompression stream *)
+begin
+  StrCopy(PChar(uncompr), 'garbage');
+
+  d_stream.zalloc := NIL;
+  d_stream.zfree := NIL;
+  d_stream.opaque := NIL;
+
+  d_stream.next_in := compr;
+  d_stream.avail_in := 0;
+  d_stream.next_out := uncompr;
+
+  err := inflateInit(d_stream);
+  CHECK_ERR(err, 'inflateInit');
+
+  while (d_stream.total_out < uncomprLen) and
+        (d_stream.total_in < comprLen) do
+  begin
+    d_stream.avail_out := 1; (* force small buffers *)
+    d_stream.avail_in := 1;
+    err := inflate(d_stream, Z_NO_FLUSH);
+    if err = Z_STREAM_END then
+      break;
+    CHECK_ERR(err, 'inflate');
+  end;
+
+  err := inflateEnd(d_stream);
+  CHECK_ERR(err, 'inflateEnd');
+
+  if StrComp(PChar(uncompr), hello) <> 0 then
+    EXIT_ERR('bad inflate')
+  else
+    WriteLn('inflate(): ', PChar(uncompr));
+end;
+{$ENDIF}
+
+(* ===========================================================================
+ * Test deflate with large buffers and dynamic change of compression level
+ *)
+{$IFDEF TEST_DEFLATE}
+procedure test_large_deflate(compr: Pointer; comprLen: LongInt;
+                             uncompr: Pointer; uncomprLen: LongInt);
+var c_stream: z_stream; (* compression stream *)
+    err: Integer;
+begin
+  c_stream.zalloc := NIL;
+  c_stream.zfree := NIL;
+  c_stream.opaque := NIL;
+
+  err := deflateInit(c_stream, Z_BEST_SPEED);
+  CHECK_ERR(err, 'deflateInit');
+
+  c_stream.next_out := compr;
+  c_stream.avail_out := Integer(comprLen);
+
+  (* At this point, uncompr is still mostly zeroes, so it should compress
+   * very well:
+   *)
+  c_stream.next_in := uncompr;
+  c_stream.avail_in := Integer(uncomprLen);
+  err := deflate(c_stream, Z_NO_FLUSH);
+  CHECK_ERR(err, 'deflate');
+  if c_stream.avail_in <> 0 then
+    EXIT_ERR('deflate not greedy');
+
+  (* Feed in already compressed data and switch to no compression: *)
+  deflateParams(c_stream, Z_NO_COMPRESSION, Z_DEFAULT_STRATEGY);
+  c_stream.next_in := compr;
+  c_stream.avail_in := Integer(comprLen div 2);
+  err := deflate(c_stream, Z_NO_FLUSH);
+  CHECK_ERR(err, 'deflate');
+
+  (* Switch back to compressing mode: *)
+  deflateParams(c_stream, Z_BEST_COMPRESSION, Z_FILTERED);
+  c_stream.next_in := uncompr;
+  c_stream.avail_in := Integer(uncomprLen);
+  err := deflate(c_stream, Z_NO_FLUSH);
+  CHECK_ERR(err, 'deflate');
+
+  err := deflate(c_stream, Z_FINISH);
+  if err <> Z_STREAM_END then
+    EXIT_ERR('deflate should report Z_STREAM_END');
+
+  err := deflateEnd(c_stream);
+  CHECK_ERR(err, 'deflateEnd');
+end;
+{$ENDIF}
+
+(* ===========================================================================
+ * Test inflate with large buffers
+ *)
+{$IFDEF TEST_INFLATE}
+procedure test_large_inflate(compr: Pointer; comprLen: LongInt;
+                             uncompr: Pointer; uncomprLen: LongInt);
+var err: Integer;
+    d_stream: z_stream; (* decompression stream *)
+begin
+  StrCopy(PChar(uncompr), 'garbage');
+
+  d_stream.zalloc := NIL;
+  d_stream.zfree := NIL;
+  d_stream.opaque := NIL;
+
+  d_stream.next_in := compr;
+  d_stream.avail_in := Integer(comprLen);
+
+  err := inflateInit(d_stream);
+  CHECK_ERR(err, 'inflateInit');
+
+  while TRUE do
+  begin
+    d_stream.next_out := uncompr;            (* discard the output *)
+    d_stream.avail_out := Integer(uncomprLen);
+    err := inflate(d_stream, Z_NO_FLUSH);
+    if err = Z_STREAM_END then
+      break;
+    CHECK_ERR(err, 'large inflate');
+  end;
+
+  err := inflateEnd(d_stream);
+  CHECK_ERR(err, 'inflateEnd');
+
+  if d_stream.total_out <> 2 * uncomprLen + comprLen div 2 then
+  begin
+    WriteLn('bad large inflate: ', d_stream.total_out);
+    Halt(1);
+  end
+  else
+    WriteLn('large_inflate(): OK');
+end;
+{$ENDIF}
+
+(* ===========================================================================
+ * Test deflate with full flush
+ *)
+{$IFDEF TEST_FLUSH}
+procedure test_flush(compr: Pointer; var comprLen : LongInt);
+var c_stream: z_stream; (* compression stream *)
+    err: Integer;
+    len: Integer;
+begin
+  len := StrLen(hello)+1;
+
+  c_stream.zalloc := NIL;
+  c_stream.zfree := NIL;
+  c_stream.opaque := NIL;
+
+  err := deflateInit(c_stream, Z_DEFAULT_COMPRESSION);
+  CHECK_ERR(err, 'deflateInit');
+
+  c_stream.next_in := hello;
+  c_stream.next_out := compr;
+  c_stream.avail_in := 3;
+  c_stream.avail_out := Integer(comprLen);
+  err := deflate(c_stream, Z_FULL_FLUSH);
+  CHECK_ERR(err, 'deflate');
+
+  Inc(PByteArray(compr)^[3]); (* force an error in first compressed block *)
+  c_stream.avail_in := len - 3;
+
+  err := deflate(c_stream, Z_FINISH);
+  if err <> Z_STREAM_END then
+    CHECK_ERR(err, 'deflate');
+
+  err := deflateEnd(c_stream);
+  CHECK_ERR(err, 'deflateEnd');
+
+  comprLen := c_stream.total_out;
+end;
+{$ENDIF}
+
+(* ===========================================================================
+ * Test inflateSync()
+ *)
+{$IFDEF TEST_SYNC}
+procedure test_sync(compr: Pointer; comprLen: LongInt;
+                    uncompr: Pointer; uncomprLen : LongInt);
+var err: Integer;
+    d_stream: z_stream; (* decompression stream *)
+begin
+  StrCopy(PChar(uncompr), 'garbage');
+
+  d_stream.zalloc := NIL;
+  d_stream.zfree := NIL;
+  d_stream.opaque := NIL;
+
+  d_stream.next_in := compr;
+  d_stream.avail_in := 2; (* just read the zlib header *)
+
+  err := inflateInit(d_stream);
+  CHECK_ERR(err, 'inflateInit');
+
+  d_stream.next_out := uncompr;
+  d_stream.avail_out := Integer(uncomprLen);
+
+  inflate(d_stream, Z_NO_FLUSH);
+  CHECK_ERR(err, 'inflate');
+
+  d_stream.avail_in := Integer(comprLen-2);   (* read all compressed data *)
+  err := inflateSync(d_stream);               (* but skip the damaged part *)
+  CHECK_ERR(err, 'inflateSync');
+
+  err := inflate(d_stream, Z_FINISH);
+  if err <> Z_DATA_ERROR then
+    EXIT_ERR('inflate should report DATA_ERROR');
+    (* Because of incorrect adler32 *)
+
+  err := inflateEnd(d_stream);
+  CHECK_ERR(err, 'inflateEnd');
+
+  WriteLn('after inflateSync(): hel', PChar(uncompr));
+end;
+{$ENDIF}
+
+(* ===========================================================================
+ * Test deflate with preset dictionary
+ *)
+{$IFDEF TEST_DICT}
+procedure test_dict_deflate(compr: Pointer; comprLen: LongInt);
+var c_stream: z_stream; (* compression stream *)
+    err: Integer;
+begin
+  c_stream.zalloc := NIL;
+  c_stream.zfree := NIL;
+  c_stream.opaque := NIL;
+
+  err := deflateInit(c_stream, Z_BEST_COMPRESSION);
+  CHECK_ERR(err, 'deflateInit');
+
+  err := deflateSetDictionary(c_stream, dictionary, StrLen(dictionary));
+  CHECK_ERR(err, 'deflateSetDictionary');
+
+  dictId := c_stream.adler;
+  c_stream.next_out := compr;
+  c_stream.avail_out := Integer(comprLen);
+
+  c_stream.next_in := hello;
+  c_stream.avail_in := StrLen(hello)+1;
+
+  err := deflate(c_stream, Z_FINISH);
+  if err <> Z_STREAM_END then
+    EXIT_ERR('deflate should report Z_STREAM_END');
+
+  err := deflateEnd(c_stream);
+  CHECK_ERR(err, 'deflateEnd');
+end;
+{$ENDIF}
+
+(* ===========================================================================
+ * Test inflate with a preset dictionary
+ *)
+{$IFDEF TEST_DICT}
+procedure test_dict_inflate(compr: Pointer; comprLen: LongInt;
+                            uncompr: Pointer; uncomprLen: LongInt);
+var err: Integer;
+    d_stream: z_stream; (* decompression stream *)
+begin
+  StrCopy(PChar(uncompr), 'garbage');
+
+  d_stream.zalloc := NIL;
+  d_stream.zfree := NIL;
+  d_stream.opaque := NIL;
+
+  d_stream.next_in := compr;
+  d_stream.avail_in := Integer(comprLen);
+
+  err := inflateInit(d_stream);
+  CHECK_ERR(err, 'inflateInit');
+
+  d_stream.next_out := uncompr;
+  d_stream.avail_out := Integer(uncomprLen);
+
+  while TRUE do
+  begin
+    err := inflate(d_stream, Z_NO_FLUSH);
+    if err = Z_STREAM_END then
+      break;
+    if err = Z_NEED_DICT then
+    begin
+      if d_stream.adler <> dictId then
+        EXIT_ERR('unexpected dictionary');
+      err := inflateSetDictionary(d_stream, dictionary, StrLen(dictionary));
+    end;
+    CHECK_ERR(err, 'inflate with dict');
+  end;
+
+  err := inflateEnd(d_stream);
+  CHECK_ERR(err, 'inflateEnd');
+
+  if StrComp(PChar(uncompr), hello) <> 0 then
+    EXIT_ERR('bad inflate with dict')
+  else
+    WriteLn('inflate with dictionary: ', PChar(uncompr));
+end;
+{$ENDIF}
+
+var compr, uncompr: Pointer;
+    comprLen, uncomprLen: LongInt;
+
+begin
+  if zlibVersion^ <> ZLIB_VERSION[1] then
+    EXIT_ERR('Incompatible zlib version');
+
+  WriteLn('zlib version: ', zlibVersion);
+  WriteLn('zlib compile flags: ', Format('0x%x', [zlibCompileFlags]));
+
+  comprLen := 10000 * SizeOf(Integer); (* don't overflow on MSDOS *)
+  uncomprLen := comprLen;
+  GetMem(compr, comprLen);
+  GetMem(uncompr, uncomprLen);
+  if (compr = NIL) or (uncompr = NIL) then
+    EXIT_ERR('Out of memory');
+  (* compr and uncompr are cleared to avoid reading uninitialized
+   * data and to ensure that uncompr compresses well.
+   *)
+  FillChar(compr^, comprLen, 0);
+  FillChar(uncompr^, uncomprLen, 0);
+
+  {$IFDEF TEST_COMPRESS}
+  WriteLn('** Testing compress');
+  test_compress(compr, comprLen, uncompr, uncomprLen);
+  {$ENDIF}
+
+  {$IFDEF TEST_GZIO}
+  WriteLn('** Testing gzio');
+  if ParamCount >= 1 then
+    test_gzio(ParamStr(1), uncompr, uncomprLen)
+  else
+    test_gzio(TESTFILE, uncompr, uncomprLen);
+  {$ENDIF}
+
+  {$IFDEF TEST_DEFLATE}
+  WriteLn('** Testing deflate with small buffers');
+  test_deflate(compr, comprLen);
+  {$ENDIF}
+  {$IFDEF TEST_INFLATE}
+  WriteLn('** Testing inflate with small buffers');
+  test_inflate(compr, comprLen, uncompr, uncomprLen);
+  {$ENDIF}
+
+  {$IFDEF TEST_DEFLATE}
+  WriteLn('** Testing deflate with large buffers');
+  test_large_deflate(compr, comprLen, uncompr, uncomprLen);
+  {$ENDIF}
+  {$IFDEF TEST_INFLATE}
+  WriteLn('** Testing inflate with large buffers');
+  test_large_inflate(compr, comprLen, uncompr, uncomprLen);
+  {$ENDIF}
+
+  {$IFDEF TEST_FLUSH}
+  WriteLn('** Testing deflate with full flush');
+  test_flush(compr, comprLen);
+  {$ENDIF}
+  {$IFDEF TEST_SYNC}
+  WriteLn('** Testing inflateSync');
+  test_sync(compr, comprLen, uncompr, uncomprLen);
+  {$ENDIF}
+  comprLen := uncomprLen;
+
+  {$IFDEF TEST_DICT}
+  WriteLn('** Testing deflate and inflate with preset dictionary');
+  test_dict_deflate(compr, comprLen);
+  test_dict_inflate(compr, comprLen, uncompr, uncomprLen);
+  {$ENDIF}
+
+  FreeMem(compr, comprLen);
+  FreeMem(uncompr, uncomprLen);
+end.
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/pascal/readme.txt
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/pascal/readme.txt	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,76 @@
+
+This directory contains a Pascal (Delphi, Kylix) interface to the
+zlib data compression library.
+
+
+Directory listing
+=================
+
+zlibd32.mak     makefile for Borland C++
+example.pas     usage example of zlib
+zlibpas.pas     the Pascal interface to zlib
+readme.txt      this file
+
+
+Compatibility notes
+===================
+
+- Although the name "zlib" would have been more normal for the
+  zlibpas unit, this name is already taken by Borland's ZLib unit.
+  This is somehow unfortunate, because that unit is not a genuine
+  interface to the full-fledged zlib functionality, but a suite of
+  class wrappers around zlib streams.  Other essential features,
+  such as checksums, are missing.
+  It would have been more appropriate for that unit to have a name
+  like "ZStreams", or something similar.
+
+- The C and zlib-supplied types int, uInt, long, uLong, etc. are
+  translated directly into Pascal types of similar sizes (Integer,
+  LongInt, etc.), to avoid namespace pollution.  In particular,
+  there is no conversion of unsigned int into a Pascal unsigned
+  integer.  The Word type is non-portable and has the same size
+  (16 bits) both in a 16-bit and in a 32-bit environment, unlike
+  Integer.  Even if there is a 32-bit Cardinal type, there is no
+  real need for unsigned int in zlib under a 32-bit environment.
+
+- Except for the callbacks, the zlib function interfaces are
+  assuming the calling convention normally used in Pascal
+  (__pascal for DOS and Windows16, __fastcall for Windows32).
+  Since the cdecl keyword is used, the old Turbo Pascal does
+  not work with this interface.
+
+- The gz* function interfaces are not translated, to avoid
+  interfacing problems with the C runtime library.  Besides,
+    gzprintf(gzFile file, const char *format, ...)
+  cannot be translated into Pascal.
+
+
+Legal issues
+============
+
+The zlibpas interface is:
+  Copyright (C) 1995-2003 Jean-loup Gailly and Mark Adler.
+  Copyright (C) 1998 by Bob Dellaca.
+  Copyright (C) 2003 by Cosmin Truta.
+
+The example program is:
+  Copyright (C) 1995-2003 by Jean-loup Gailly.
+  Copyright (C) 1998,1999,2000 by Jacques Nomssi Nzali.
+  Copyright (C) 2003 by Cosmin Truta.
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the author be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/pascal/zlibd32.mak
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/pascal/zlibd32.mak	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,99 @@
+# Makefile for zlib
+# For use with Delphi and C++ Builder under Win32
+# Updated for zlib 1.2.x by Cosmin Truta
+
+# ------------ Borland C++ ------------
+
+# This project uses the Delphi (fastcall/register) calling convention:
+LOC = -DZEXPORT=__fastcall -DZEXPORTVA=__cdecl
+
+CC = bcc32
+LD = bcc32
+AR = tlib
+# do not use "-pr" in CFLAGS
+CFLAGS = -a -d -k- -O2 $(LOC)
+LDFLAGS =
+
+
+# variables
+ZLIB_LIB = zlib.lib
+
+OBJ1 = adler32.obj compress.obj crc32.obj deflate.obj gzclose.obj gzlib.obj gzread.obj
+OBJ2 = gzwrite.obj infback.obj inffast.obj inflate.obj inftrees.obj trees.obj uncompr.obj zutil.obj
+OBJP1 = +adler32.obj+compress.obj+crc32.obj+deflate.obj+gzclose.obj+gzlib.obj+gzread.obj
+OBJP2 = +gzwrite.obj+infback.obj+inffast.obj+inflate.obj+inftrees.obj+trees.obj+uncompr.obj+zutil.obj
+
+
+# targets
+all: $(ZLIB_LIB) example.exe minigzip.exe
+
+.c.obj:
+	$(CC) -c $(CFLAGS) $*.c
+
+adler32.obj: adler32.c zlib.h zconf.h
+
+compress.obj: compress.c zlib.h zconf.h
+
+crc32.obj: crc32.c zlib.h zconf.h crc32.h
+
+deflate.obj: deflate.c deflate.h zutil.h zlib.h zconf.h
+
+gzclose.obj: gzclose.c zlib.h zconf.h gzguts.h
+
+gzlib.obj: gzlib.c zlib.h zconf.h gzguts.h
+
+gzread.obj: gzread.c zlib.h zconf.h gzguts.h
+
+gzwrite.obj: gzwrite.c zlib.h zconf.h gzguts.h
+
+infback.obj: infback.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h inffixed.h
+
+inffast.obj: inffast.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h
+
+inflate.obj: inflate.c zutil.h zlib.h zconf.h inftrees.h inflate.h \
+ inffast.h inffixed.h
+
+inftrees.obj: inftrees.c zutil.h zlib.h zconf.h inftrees.h
+
+trees.obj: trees.c zutil.h zlib.h zconf.h deflate.h trees.h
+
+uncompr.obj: uncompr.c zlib.h zconf.h
+
+zutil.obj: zutil.c zutil.h zlib.h zconf.h
+
+example.obj: test/example.c zlib.h zconf.h
+
+minigzip.obj: test/minigzip.c zlib.h zconf.h
+
+
+# For the sake of the old Borland make,
+# the command line is cut to fit in the MS-DOS 128 byte limit:
+$(ZLIB_LIB): $(OBJ1) $(OBJ2)
+	-del $(ZLIB_LIB)
+	$(AR) $(ZLIB_LIB) $(OBJP1)
+	$(AR) $(ZLIB_LIB) $(OBJP2)
+
+
+# testing
+test: example.exe minigzip.exe
+	example
+	echo hello world | minigzip | minigzip -d
+
+example.exe: example.obj $(ZLIB_LIB)
+	$(LD) $(LDFLAGS) example.obj $(ZLIB_LIB)
+
+minigzip.exe: minigzip.obj $(ZLIB_LIB)
+	$(LD) $(LDFLAGS) minigzip.obj $(ZLIB_LIB)
+
+
+# cleanup
+clean:
+	-del *.obj
+	-del *.exe
+	-del *.lib
+	-del *.tds
+	-del zlib.bak
+	-del foo.gz
+
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/pascal/zlibpas.pas
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/pascal/zlibpas.pas	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,276 @@
+(* zlibpas -- Pascal interface to the zlib data compression library
+ *
+ * Copyright (C) 2003 Cosmin Truta.
+ * Derived from original sources by Bob Dellaca.
+ * For conditions of distribution and use, see copyright notice in readme.txt
+ *)
+
+unit zlibpas;
+
+interface
+
+const
+  ZLIB_VERSION = '1.2.11';
+  ZLIB_VERNUM  = $12a0;
+
+type
+  alloc_func = function(opaque: Pointer; items, size: Integer): Pointer;
+                 cdecl;
+  free_func  = procedure(opaque, address: Pointer);
+                 cdecl;
+
+  in_func    = function(opaque: Pointer; var buf: PByte): Integer;
+                 cdecl;
+  out_func   = function(opaque: Pointer; buf: PByte; size: Integer): Integer;
+                 cdecl;
+
+  z_streamp = ^z_stream;
+  z_stream = packed record
+    next_in: PChar;       (* next input byte *)
+    avail_in: Integer;    (* number of bytes available at next_in *)
+    total_in: LongInt;    (* total nb of input bytes read so far *)
+
+    next_out: PChar;      (* next output byte should be put there *)
+    avail_out: Integer;   (* remaining free space at next_out *)
+    total_out: LongInt;   (* total nb of bytes output so far *)
+
+    msg: PChar;           (* last error message, NULL if no error *)
+    state: Pointer;       (* not visible by applications *)
+
+    zalloc: alloc_func;   (* used to allocate the internal state *)
+    zfree: free_func;     (* used to free the internal state *)
+    opaque: Pointer;      (* private data object passed to zalloc and zfree *)
+
+    data_type: Integer;   (* best guess about the data type: ascii or binary *)
+    adler: LongInt;       (* adler32 value of the uncompressed data *)
+    reserved: LongInt;    (* reserved for future use *)
+  end;
+
+  gz_headerp = ^gz_header;
+  gz_header = packed record
+    text: Integer;        (* true if compressed data believed to be text *)
+    time: LongInt;        (* modification time *)
+    xflags: Integer;      (* extra flags (not used when writing a gzip file) *)
+    os: Integer;          (* operating system *)
+    extra: PChar;         (* pointer to extra field or Z_NULL if none *)
+    extra_len: Integer;   (* extra field length (valid if extra != Z_NULL) *)
+    extra_max: Integer;   (* space at extra (only when reading header) *)
+    name: PChar;          (* pointer to zero-terminated file name or Z_NULL *)
+    name_max: Integer;    (* space at name (only when reading header) *)
+    comment: PChar;       (* pointer to zero-terminated comment or Z_NULL *)
+    comm_max: Integer;    (* space at comment (only when reading header) *)
+    hcrc: Integer;        (* true if there was or will be a header crc *)
+    done: Integer;        (* true when done reading gzip header *)
+  end;
+
+(* constants *)
+const
+  Z_NO_FLUSH      = 0;
+  Z_PARTIAL_FLUSH = 1;
+  Z_SYNC_FLUSH    = 2;
+  Z_FULL_FLUSH    = 3;
+  Z_FINISH        = 4;
+  Z_BLOCK         = 5;
+  Z_TREES         = 6;
+
+  Z_OK            =  0;
+  Z_STREAM_END    =  1;
+  Z_NEED_DICT     =  2;
+  Z_ERRNO         = -1;
+  Z_STREAM_ERROR  = -2;
+  Z_DATA_ERROR    = -3;
+  Z_MEM_ERROR     = -4;
+  Z_BUF_ERROR     = -5;
+  Z_VERSION_ERROR = -6;
+
+  Z_NO_COMPRESSION       =  0;
+  Z_BEST_SPEED           =  1;
+  Z_BEST_COMPRESSION     =  9;
+  Z_DEFAULT_COMPRESSION  = -1;
+
+  Z_FILTERED            = 1;
+  Z_HUFFMAN_ONLY        = 2;
+  Z_RLE                 = 3;
+  Z_FIXED               = 4;
+  Z_DEFAULT_STRATEGY    = 0;
+
+  Z_BINARY   = 0;
+  Z_TEXT     = 1;
+  Z_ASCII    = 1;
+  Z_UNKNOWN  = 2;
+
+  Z_DEFLATED = 8;
+
+(* basic functions *)
+function zlibVersion: PChar;
+function deflateInit(var strm: z_stream; level: Integer): Integer;
+function deflate(var strm: z_stream; flush: Integer): Integer;
+function deflateEnd(var strm: z_stream): Integer;
+function inflateInit(var strm: z_stream): Integer;
+function inflate(var strm: z_stream; flush: Integer): Integer;
+function inflateEnd(var strm: z_stream): Integer;
+
+(* advanced functions *)
+function deflateInit2(var strm: z_stream; level, method, windowBits,
+                      memLevel, strategy: Integer): Integer;
+function deflateSetDictionary(var strm: z_stream; const dictionary: PChar;
+                              dictLength: Integer): Integer;
+function deflateCopy(var dest, source: z_stream): Integer;
+function deflateReset(var strm: z_stream): Integer;
+function deflateParams(var strm: z_stream; level, strategy: Integer): Integer;
+function deflateTune(var strm: z_stream; good_length, max_lazy, nice_length, max_chain: Integer): Integer;
+function deflateBound(var strm: z_stream; sourceLen: LongInt): LongInt;
+function deflatePending(var strm: z_stream; var pending: Integer; var bits: Integer): Integer;
+function deflatePrime(var strm: z_stream; bits, value: Integer): Integer;
+function deflateSetHeader(var strm: z_stream; head: gz_header): Integer;
+function inflateInit2(var strm: z_stream; windowBits: Integer): Integer;
+function inflateSetDictionary(var strm: z_stream; const dictionary: PChar;
+                              dictLength: Integer): Integer;
+function inflateSync(var strm: z_stream): Integer;
+function inflateCopy(var dest, source: z_stream): Integer;
+function inflateReset(var strm: z_stream): Integer;
+function inflateReset2(var strm: z_stream; windowBits: Integer): Integer;
+function inflatePrime(var strm: z_stream; bits, value: Integer): Integer;
+function inflateMark(var strm: z_stream): LongInt;
+function inflateGetHeader(var strm: z_stream; var head: gz_header): Integer;
+function inflateBackInit(var strm: z_stream;
+                         windowBits: Integer; window: PChar): Integer;
+function inflateBack(var strm: z_stream; in_fn: in_func; in_desc: Pointer;
+                     out_fn: out_func; out_desc: Pointer): Integer;
+function inflateBackEnd(var strm: z_stream): Integer;
+function zlibCompileFlags: LongInt;
+
+(* utility functions *)
+function compress(dest: PChar; var destLen: LongInt;
+                  const source: PChar; sourceLen: LongInt): Integer;
+function compress2(dest: PChar; var destLen: LongInt;
+                  const source: PChar; sourceLen: LongInt;
+                  level: Integer): Integer;
+function compressBound(sourceLen: LongInt): LongInt;
+function uncompress(dest: PChar; var destLen: LongInt;
+                    const source: PChar; sourceLen: LongInt): Integer;
+
+(* checksum functions *)
+function adler32(adler: LongInt; const buf: PChar; len: Integer): LongInt;
+function adler32_combine(adler1, adler2, len2: LongInt): LongInt;
+function crc32(crc: LongInt; const buf: PChar; len: Integer): LongInt;
+function crc32_combine(crc1, crc2, len2: LongInt): LongInt;
+
+(* various hacks, don't look :) *)
+function deflateInit_(var strm: z_stream; level: Integer;
+                      const version: PChar; stream_size: Integer): Integer;
+function inflateInit_(var strm: z_stream; const version: PChar;
+                      stream_size: Integer): Integer;
+function deflateInit2_(var strm: z_stream;
+                       level, method, windowBits, memLevel, strategy: Integer;
+                       const version: PChar; stream_size: Integer): Integer;
+function inflateInit2_(var strm: z_stream; windowBits: Integer;
+                       const version: PChar; stream_size: Integer): Integer;
+function inflateBackInit_(var strm: z_stream;
+                          windowBits: Integer; window: PChar;
+                          const version: PChar; stream_size: Integer): Integer;
+
+
+implementation
+
+{$L adler32.obj}
+{$L compress.obj}
+{$L crc32.obj}
+{$L deflate.obj}
+{$L infback.obj}
+{$L inffast.obj}
+{$L inflate.obj}
+{$L inftrees.obj}
+{$L trees.obj}
+{$L uncompr.obj}
+{$L zutil.obj}
+
+function adler32; external;
+function adler32_combine; external;
+function compress; external;
+function compress2; external;
+function compressBound; external;
+function crc32; external;
+function crc32_combine; external;
+function deflate; external;
+function deflateBound; external;
+function deflateCopy; external;
+function deflateEnd; external;
+function deflateInit_; external;
+function deflateInit2_; external;
+function deflateParams; external;
+function deflatePending; external;
+function deflatePrime; external;
+function deflateReset; external;
+function deflateSetDictionary; external;
+function deflateSetHeader; external;
+function deflateTune; external;
+function inflate; external;
+function inflateBack; external;
+function inflateBackEnd; external;
+function inflateBackInit_; external;
+function inflateCopy; external;
+function inflateEnd; external;
+function inflateGetHeader; external;
+function inflateInit_; external;
+function inflateInit2_; external;
+function inflateMark; external;
+function inflatePrime; external;
+function inflateReset; external;
+function inflateReset2; external;
+function inflateSetDictionary; external;
+function inflateSync; external;
+function uncompress; external;
+function zlibCompileFlags; external;
+function zlibVersion; external;
+
+function deflateInit(var strm: z_stream; level: Integer): Integer;
+begin
+  Result := deflateInit_(strm, level, ZLIB_VERSION, sizeof(z_stream));
+end;
+
+function deflateInit2(var strm: z_stream; level, method, windowBits, memLevel,
+                      strategy: Integer): Integer;
+begin
+  Result := deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
+                          ZLIB_VERSION, sizeof(z_stream));
+end;
+
+function inflateInit(var strm: z_stream): Integer;
+begin
+  Result := inflateInit_(strm, ZLIB_VERSION, sizeof(z_stream));
+end;
+
+function inflateInit2(var strm: z_stream; windowBits: Integer): Integer;
+begin
+  Result := inflateInit2_(strm, windowBits, ZLIB_VERSION, sizeof(z_stream));
+end;
+
+function inflateBackInit(var strm: z_stream;
+                         windowBits: Integer; window: PChar): Integer;
+begin
+  Result := inflateBackInit_(strm, windowBits, window,
+                             ZLIB_VERSION, sizeof(z_stream));
+end;
+
+function _malloc(Size: Integer): Pointer; cdecl;
+begin
+  GetMem(Result, Size);
+end;
+
+procedure _free(Block: Pointer); cdecl;
+begin
+  FreeMem(Block);
+end;
+
+procedure _memset(P: Pointer; B: Byte; count: Integer); cdecl;
+begin
+  FillChar(P^, count, B);
+end;
+
+procedure _memcpy(dest, source: Pointer; count: Integer); cdecl;
+begin
+  Move(source^, dest^, count);
+end;
+
+end.
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/puff/Makefile
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/puff/Makefile	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,42 @@
+CFLAGS=-O
+
+puff: puff.o pufftest.o
+
+puff.o: puff.h
+
+pufftest.o: puff.h
+
+test: puff
+	puff zeros.raw
+
+puft: puff.c puff.h pufftest.o
+	cc -fprofile-arcs -ftest-coverage -o puft puff.c pufftest.o
+
+# puff full coverage test (should say 100%)
+cov: puft
+	@rm -f *.gcov *.gcda
+	@puft -w zeros.raw 2>&1 | cat > /dev/null
+	@echo '04' | xxd -r -p | puft 2> /dev/null || test $$? -eq 2
+	@echo '00' | xxd -r -p | puft 2> /dev/null || test $$? -eq 2
+	@echo '00 00 00 00 00' | xxd -r -p | puft 2> /dev/null || test $$? -eq 254
+	@echo '00 01 00 fe ff' | xxd -r -p | puft 2> /dev/null || test $$? -eq 2
+	@echo '01 01 00 fe ff 0a' | xxd -r -p | puft -f 2>&1 | cat > /dev/null
+	@echo '02 7e ff ff' | xxd -r -p | puft 2> /dev/null || test $$? -eq 246
+	@echo '02' | xxd -r -p | puft 2> /dev/null || test $$? -eq 2
+	@echo '04 80 49 92 24 49 92 24 0f b4 ff ff c3 04' | xxd -r -p | puft 2> /dev/null || test $$? -eq 2
+	@echo '04 80 49 92 24 49 92 24 71 ff ff 93 11 00' | xxd -r -p | puft 2> /dev/null || test $$? -eq 249
+	@echo '04 c0 81 08 00 00 00 00 20 7f eb 0b 00 00' | xxd -r -p | puft 2> /dev/null || test $$? -eq 246
+	@echo '0b 00 00' | xxd -r -p | puft -f 2>&1 | cat > /dev/null
+	@echo '1a 07' | xxd -r -p | puft 2> /dev/null || test $$? -eq 246
+	@echo '0c c0 81 00 00 00 00 00 90 ff 6b 04' | xxd -r -p | puft 2> /dev/null || test $$? -eq 245
+	@puft -f zeros.raw 2>&1 | cat > /dev/null
+	@echo 'fc 00 00' | xxd -r -p | puft 2> /dev/null || test $$? -eq 253
+	@echo '04 00 fe ff' | xxd -r -p | puft 2> /dev/null || test $$? -eq 252
+	@echo '04 00 24 49' | xxd -r -p | puft 2> /dev/null || test $$? -eq 251
+	@echo '04 80 49 92 24 49 92 24 0f b4 ff ff c3 84' | xxd -r -p | puft 2> /dev/null || test $$? -eq 248
+	@echo '04 00 24 e9 ff ff' | xxd -r -p | puft 2> /dev/null || test $$? -eq 250
+	@echo '04 00 24 e9 ff 6d' | xxd -r -p | puft 2> /dev/null || test $$? -eq 247
+	@gcov -n puff.c
+
+clean:
+	rm -f puff puft *.o *.gc*
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/puff/README
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/puff/README	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,63 @@
+Puff -- A Simple Inflate
+3 Mar 2003
+Mark Adler
+madler@alumni.caltech.edu
+
+What this is --
+
+puff.c provides the routine puff() to decompress the deflate data format.  It
+does so more slowly than zlib, but the code is about one-fifth the size of the
+inflate code in zlib, and written to be very easy to read.
+
+Why I wrote this --
+
+puff.c was written to document the deflate format unambiguously, by virtue of
+being working C code.  It is meant to supplement RFC 1951, which formally
+describes the deflate format.  I have received many questions on details of the
+deflate format, and I hope that reading this code will answer those questions.
+puff.c is heavily commented with details of the deflate format, especially
+those little nooks and cranies of the format that might not be obvious from a
+specification.
+
+puff.c may also be useful in applications where code size or memory usage is a
+very limited resource, and speed is not as important.
+
+How to use it --
+
+Well, most likely you should just be reading puff.c and using zlib for actual
+applications, but if you must ...
+
+Include puff.h in your code, which provides this prototype:
+
+int puff(unsigned char *dest,           /* pointer to destination pointer */
+         unsigned long *destlen,        /* amount of output space */
+         unsigned char *source,         /* pointer to source data pointer */
+         unsigned long *sourcelen);     /* amount of input available */
+
+Then you can call puff() to decompress a deflate stream that is in memory in
+its entirety at source, to a sufficiently sized block of memory for the
+decompressed data at dest.  puff() is the only external symbol in puff.c  The
+only C library functions that puff.c needs are setjmp() and longjmp(), which
+are used to simplify error checking in the code to improve readabilty.  puff.c
+does no memory allocation, and uses less than 2K bytes off of the stack.
+
+If destlen is not enough space for the uncompressed data, then inflate will
+return an error without writing more than destlen bytes.  Note that this means
+that in order to decompress the deflate data successfully, you need to know
+the size of the uncompressed data ahead of time.
+
+If needed, puff() can determine the size of the uncompressed data with no
+output space.  This is done by passing dest equal to (unsigned char *)0.  Then
+the initial value of *destlen is ignored and *destlen is set to the length of
+the uncompressed data.  So if the size of the uncompressed data is not known,
+then two passes of puff() can be used--first to determine the size, and second
+to do the actual inflation after allocating the appropriate memory.  Not
+pretty, but it works.  (This is one of the reasons you should be using zlib.)
+
+The deflate format is self-terminating.  If the deflate stream does not end
+in *sourcelen bytes, puff() will return an error without reading at or past
+endsource.
+
+On return, *sourcelen is updated to the amount of input data consumed, and
+*destlen is updated to the size of the uncompressed data.  See the comments
+in puff.c for the possible return codes for puff().
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/puff/puff.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/puff/puff.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,840 @@
+/*
+ * puff.c
+ * Copyright (C) 2002-2013 Mark Adler
+ * For conditions of distribution and use, see copyright notice in puff.h
+ * version 2.3, 21 Jan 2013
+ *
+ * puff.c is a simple inflate written to be an unambiguous way to specify the
+ * deflate format.  It is not written for speed but rather simplicity.  As a
+ * side benefit, this code might actually be useful when small code is more
+ * important than speed, such as bootstrap applications.  For typical deflate
+ * data, zlib's inflate() is about four times as fast as puff().  zlib's
+ * inflate compiles to around 20K on my machine, whereas puff.c compiles to
+ * around 4K on my machine (a PowerPC using GNU cc).  If the faster decode()
+ * function here is used, then puff() is only twice as slow as zlib's
+ * inflate().
+ *
+ * All dynamically allocated memory comes from the stack.  The stack required
+ * is less than 2K bytes.  This code is compatible with 16-bit int's and
+ * assumes that long's are at least 32 bits.  puff.c uses the short data type,
+ * assumed to be 16 bits, for arrays in order to conserve memory.  The code
+ * works whether integers are stored big endian or little endian.
+ *
+ * In the comments below are "Format notes" that describe the inflate process
+ * and document some of the less obvious aspects of the format.  This source
+ * code is meant to supplement RFC 1951, which formally describes the deflate
+ * format:
+ *
+ *    http://www.zlib.org/rfc-deflate.html
+ */
+
+/*
+ * Change history:
+ *
+ * 1.0  10 Feb 2002     - First version
+ * 1.1  17 Feb 2002     - Clarifications of some comments and notes
+ *                      - Update puff() dest and source pointers on negative
+ *                        errors to facilitate debugging deflators
+ *                      - Remove longest from struct huffman -- not needed
+ *                      - Simplify offs[] index in construct()
+ *                      - Add input size and checking, using longjmp() to
+ *                        maintain easy readability
+ *                      - Use short data type for large arrays
+ *                      - Use pointers instead of long to specify source and
+ *                        destination sizes to avoid arbitrary 4 GB limits
+ * 1.2  17 Mar 2002     - Add faster version of decode(), doubles speed (!),
+ *                        but leave simple version for readabilty
+ *                      - Make sure invalid distances detected if pointers
+ *                        are 16 bits
+ *                      - Fix fixed codes table error
+ *                      - Provide a scanning mode for determining size of
+ *                        uncompressed data
+ * 1.3  20 Mar 2002     - Go back to lengths for puff() parameters [Gailly]
+ *                      - Add a puff.h file for the interface
+ *                      - Add braces in puff() for else do [Gailly]
+ *                      - Use indexes instead of pointers for readability
+ * 1.4  31 Mar 2002     - Simplify construct() code set check
+ *                      - Fix some comments
+ *                      - Add FIXLCODES #define
+ * 1.5   6 Apr 2002     - Minor comment fixes
+ * 1.6   7 Aug 2002     - Minor format changes
+ * 1.7   3 Mar 2003     - Added test code for distribution
+ *                      - Added zlib-like license
+ * 1.8   9 Jan 2004     - Added some comments on no distance codes case
+ * 1.9  21 Feb 2008     - Fix bug on 16-bit integer architectures [Pohland]
+ *                      - Catch missing end-of-block symbol error
+ * 2.0  25 Jul 2008     - Add #define to permit distance too far back
+ *                      - Add option in TEST code for puff to write the data
+ *                      - Add option in TEST code to skip input bytes
+ *                      - Allow TEST code to read from piped stdin
+ * 2.1   4 Apr 2010     - Avoid variable initialization for happier compilers
+ *                      - Avoid unsigned comparisons for even happier compilers
+ * 2.2  25 Apr 2010     - Fix bug in variable initializations [Oberhumer]
+ *                      - Add const where appropriate [Oberhumer]
+ *                      - Split if's and ?'s for coverage testing
+ *                      - Break out test code to separate file
+ *                      - Move NIL to puff.h
+ *                      - Allow incomplete code only if single code length is 1
+ *                      - Add full code coverage test to Makefile
+ * 2.3  21 Jan 2013     - Check for invalid code length codes in dynamic blocks
+ */
+
+#include <setjmp.h>             /* for setjmp(), longjmp(), and jmp_buf */
+#include "puff.h"               /* prototype for puff() */
+
+#define local static            /* for local function definitions */
+
+/*
+ * Maximums for allocations and loops.  It is not useful to change these --
+ * they are fixed by the deflate format.
+ */
+#define MAXBITS 15              /* maximum bits in a code */
+#define MAXLCODES 286           /* maximum number of literal/length codes */
+#define MAXDCODES 30            /* maximum number of distance codes */
+#define MAXCODES (MAXLCODES+MAXDCODES)  /* maximum codes lengths to read */
+#define FIXLCODES 288           /* number of fixed literal/length codes */
+
+/* input and output state */
+struct state {
+    /* output state */
+    unsigned char *out;         /* output buffer */
+    unsigned long outlen;       /* available space at out */
+    unsigned long outcnt;       /* bytes written to out so far */
+
+    /* input state */
+    const unsigned char *in;    /* input buffer */
+    unsigned long inlen;        /* available input at in */
+    unsigned long incnt;        /* bytes read so far */
+    int bitbuf;                 /* bit buffer */
+    int bitcnt;                 /* number of bits in bit buffer */
+
+    /* input limit error return state for bits() and decode() */
+    jmp_buf env;
+};
+
+/*
+ * Return need bits from the input stream.  This always leaves less than
+ * eight bits in the buffer.  bits() works properly for need == 0.
+ *
+ * Format notes:
+ *
+ * - Bits are stored in bytes from the least significant bit to the most
+ *   significant bit.  Therefore bits are dropped from the bottom of the bit
+ *   buffer, using shift right, and new bytes are appended to the top of the
+ *   bit buffer, using shift left.
+ */
+local int bits(struct state *s, int need)
+{
+    long val;           /* bit accumulator (can use up to 20 bits) */
+
+    /* load at least need bits into val */
+    val = s->bitbuf;
+    while (s->bitcnt < need) {
+        if (s->incnt == s->inlen)
+            longjmp(s->env, 1);         /* out of input */
+        val |= (long)(s->in[s->incnt++]) << s->bitcnt;  /* load eight bits */
+        s->bitcnt += 8;
+    }
+
+    /* drop need bits and update buffer, always zero to seven bits left */
+    s->bitbuf = (int)(val >> need);
+    s->bitcnt -= need;
+
+    /* return need bits, zeroing the bits above that */
+    return (int)(val & ((1L << need) - 1));
+}
+
+/*
+ * Process a stored block.
+ *
+ * Format notes:
+ *
+ * - After the two-bit stored block type (00), the stored block length and
+ *   stored bytes are byte-aligned for fast copying.  Therefore any leftover
+ *   bits in the byte that has the last bit of the type, as many as seven, are
+ *   discarded.  The value of the discarded bits are not defined and should not
+ *   be checked against any expectation.
+ *
+ * - The second inverted copy of the stored block length does not have to be
+ *   checked, but it's probably a good idea to do so anyway.
+ *
+ * - A stored block can have zero length.  This is sometimes used to byte-align
+ *   subsets of the compressed data for random access or partial recovery.
+ */
+local int stored(struct state *s)
+{
+    unsigned len;       /* length of stored block */
+
+    /* discard leftover bits from current byte (assumes s->bitcnt < 8) */
+    s->bitbuf = 0;
+    s->bitcnt = 0;
+
+    /* get length and check against its one's complement */
+    if (s->incnt + 4 > s->inlen)
+        return 2;                               /* not enough input */
+    len = s->in[s->incnt++];
+    len |= s->in[s->incnt++] << 8;
+    if (s->in[s->incnt++] != (~len & 0xff) ||
+        s->in[s->incnt++] != ((~len >> 8) & 0xff))
+        return -2;                              /* didn't match complement! */
+
+    /* copy len bytes from in to out */
+    if (s->incnt + len > s->inlen)
+        return 2;                               /* not enough input */
+    if (s->out != NIL) {
+        if (s->outcnt + len > s->outlen)
+            return 1;                           /* not enough output space */
+        while (len--)
+            s->out[s->outcnt++] = s->in[s->incnt++];
+    }
+    else {                                      /* just scanning */
+        s->outcnt += len;
+        s->incnt += len;
+    }
+
+    /* done with a valid stored block */
+    return 0;
+}
+
+/*
+ * Huffman code decoding tables.  count[1..MAXBITS] is the number of symbols of
+ * each length, which for a canonical code are stepped through in order.
+ * symbol[] are the symbol values in canonical order, where the number of
+ * entries is the sum of the counts in count[].  The decoding process can be
+ * seen in the function decode() below.
+ */
+struct huffman {
+    short *count;       /* number of symbols of each length */
+    short *symbol;      /* canonically ordered symbols */
+};
+
+/*
+ * Decode a code from the stream s using huffman table h.  Return the symbol or
+ * a negative value if there is an error.  If all of the lengths are zero, i.e.
+ * an empty code, or if the code is incomplete and an invalid code is received,
+ * then -10 is returned after reading MAXBITS bits.
+ *
+ * Format notes:
+ *
+ * - The codes as stored in the compressed data are bit-reversed relative to
+ *   a simple integer ordering of codes of the same lengths.  Hence below the
+ *   bits are pulled from the compressed data one at a time and used to
+ *   build the code value reversed from what is in the stream in order to
+ *   permit simple integer comparisons for decoding.  A table-based decoding
+ *   scheme (as used in zlib) does not need to do this reversal.
+ *
+ * - The first code for the shortest length is all zeros.  Subsequent codes of
+ *   the same length are simply integer increments of the previous code.  When
+ *   moving up a length, a zero bit is appended to the code.  For a complete
+ *   code, the last code of the longest length will be all ones.
+ *
+ * - Incomplete codes are handled by this decoder, since they are permitted
+ *   in the deflate format.  See the format notes for fixed() and dynamic().
+ */
+#ifdef SLOW
+local int decode(struct state *s, const struct huffman *h)
+{
+    int len;            /* current number of bits in code */
+    int code;           /* len bits being decoded */
+    int first;          /* first code of length len */
+    int count;          /* number of codes of length len */
+    int index;          /* index of first code of length len in symbol table */
+
+    code = first = index = 0;
+    for (len = 1; len <= MAXBITS; len++) {
+        code |= bits(s, 1);             /* get next bit */
+        count = h->count[len];
+        if (code - count < first)       /* if length len, return symbol */
+            return h->symbol[index + (code - first)];
+        index += count;                 /* else update for next length */
+        first += count;
+        first <<= 1;
+        code <<= 1;
+    }
+    return -10;                         /* ran out of codes */
+}
+
+/*
+ * A faster version of decode() for real applications of this code.   It's not
+ * as readable, but it makes puff() twice as fast.  And it only makes the code
+ * a few percent larger.
+ */
+#else /* !SLOW */
+local int decode(struct state *s, const struct huffman *h)
+{
+    int len;            /* current number of bits in code */
+    int code;           /* len bits being decoded */
+    int first;          /* first code of length len */
+    int count;          /* number of codes of length len */
+    int index;          /* index of first code of length len in symbol table */
+    int bitbuf;         /* bits from stream */
+    int left;           /* bits left in next or left to process */
+    short *next;        /* next number of codes */
+
+    bitbuf = s->bitbuf;
+    left = s->bitcnt;
+    code = first = index = 0;
+    len = 1;
+    next = h->count + 1;
+    while (1) {
+        while (left--) {
+            code |= bitbuf & 1;
+            bitbuf >>= 1;
+            count = *next++;
+            if (code - count < first) { /* if length len, return symbol */
+                s->bitbuf = bitbuf;
+                s->bitcnt = (s->bitcnt - len) & 7;
+                return h->symbol[index + (code - first)];
+            }
+            index += count;             /* else update for next length */
+            first += count;
+            first <<= 1;
+            code <<= 1;
+            len++;
+        }
+        left = (MAXBITS+1) - len;
+        if (left == 0)
+            break;
+        if (s->incnt == s->inlen)
+            longjmp(s->env, 1);         /* out of input */
+        bitbuf = s->in[s->incnt++];
+        if (left > 8)
+            left = 8;
+    }
+    return -10;                         /* ran out of codes */
+}
+#endif /* SLOW */
+
+/*
+ * Given the list of code lengths length[0..n-1] representing a canonical
+ * Huffman code for n symbols, construct the tables required to decode those
+ * codes.  Those tables are the number of codes of each length, and the symbols
+ * sorted by length, retaining their original order within each length.  The
+ * return value is zero for a complete code set, negative for an over-
+ * subscribed code set, and positive for an incomplete code set.  The tables
+ * can be used if the return value is zero or positive, but they cannot be used
+ * if the return value is negative.  If the return value is zero, it is not
+ * possible for decode() using that table to return an error--any stream of
+ * enough bits will resolve to a symbol.  If the return value is positive, then
+ * it is possible for decode() using that table to return an error for received
+ * codes past the end of the incomplete lengths.
+ *
+ * Not used by decode(), but used for error checking, h->count[0] is the number
+ * of the n symbols not in the code.  So n - h->count[0] is the number of
+ * codes.  This is useful for checking for incomplete codes that have more than
+ * one symbol, which is an error in a dynamic block.
+ *
+ * Assumption: for all i in 0..n-1, 0 <= length[i] <= MAXBITS
+ * This is assured by the construction of the length arrays in dynamic() and
+ * fixed() and is not verified by construct().
+ *
+ * Format notes:
+ *
+ * - Permitted and expected examples of incomplete codes are one of the fixed
+ *   codes and any code with a single symbol which in deflate is coded as one
+ *   bit instead of zero bits.  See the format notes for fixed() and dynamic().
+ *
+ * - Within a given code length, the symbols are kept in ascending order for
+ *   the code bits definition.
+ */
+local int construct(struct huffman *h, const short *length, int n)
+{
+    int symbol;         /* current symbol when stepping through length[] */
+    int len;            /* current length when stepping through h->count[] */
+    int left;           /* number of possible codes left of current length */
+    short offs[MAXBITS+1];      /* offsets in symbol table for each length */
+
+    /* count number of codes of each length */
+    for (len = 0; len <= MAXBITS; len++)
+        h->count[len] = 0;
+    for (symbol = 0; symbol < n; symbol++)
+        (h->count[length[symbol]])++;   /* assumes lengths are within bounds */
+    if (h->count[0] == n)               /* no codes! */
+        return 0;                       /* complete, but decode() will fail */
+
+    /* check for an over-subscribed or incomplete set of lengths */
+    left = 1;                           /* one possible code of zero length */
+    for (len = 1; len <= MAXBITS; len++) {
+        left <<= 1;                     /* one more bit, double codes left */
+        left -= h->count[len];          /* deduct count from possible codes */
+        if (left < 0)
+            return left;                /* over-subscribed--return negative */
+    }                                   /* left > 0 means incomplete */
+
+    /* generate offsets into symbol table for each length for sorting */
+    offs[1] = 0;
+    for (len = 1; len < MAXBITS; len++)
+        offs[len + 1] = offs[len] + h->count[len];
+
+    /*
+     * put symbols in table sorted by length, by symbol order within each
+     * length
+     */
+    for (symbol = 0; symbol < n; symbol++)
+        if (length[symbol] != 0)
+            h->symbol[offs[length[symbol]]++] = symbol;
+
+    /* return zero for complete set, positive for incomplete set */
+    return left;
+}
+
+/*
+ * Decode literal/length and distance codes until an end-of-block code.
+ *
+ * Format notes:
+ *
+ * - Compressed data that is after the block type if fixed or after the code
+ *   description if dynamic is a combination of literals and length/distance
+ *   pairs terminated by and end-of-block code.  Literals are simply Huffman
+ *   coded bytes.  A length/distance pair is a coded length followed by a
+ *   coded distance to represent a string that occurs earlier in the
+ *   uncompressed data that occurs again at the current location.
+ *
+ * - Literals, lengths, and the end-of-block code are combined into a single
+ *   code of up to 286 symbols.  They are 256 literals (0..255), 29 length
+ *   symbols (257..285), and the end-of-block symbol (256).
+ *
+ * - There are 256 possible lengths (3..258), and so 29 symbols are not enough
+ *   to represent all of those.  Lengths 3..10 and 258 are in fact represented
+ *   by just a length symbol.  Lengths 11..257 are represented as a symbol and
+ *   some number of extra bits that are added as an integer to the base length
+ *   of the length symbol.  The number of extra bits is determined by the base
+ *   length symbol.  These are in the static arrays below, lens[] for the base
+ *   lengths and lext[] for the corresponding number of extra bits.
+ *
+ * - The reason that 258 gets its own symbol is that the longest length is used
+ *   often in highly redundant files.  Note that 258 can also be coded as the
+ *   base value 227 plus the maximum extra value of 31.  While a good deflate
+ *   should never do this, it is not an error, and should be decoded properly.
+ *
+ * - If a length is decoded, including its extra bits if any, then it is
+ *   followed a distance code.  There are up to 30 distance symbols.  Again
+ *   there are many more possible distances (1..32768), so extra bits are added
+ *   to a base value represented by the symbol.  The distances 1..4 get their
+ *   own symbol, but the rest require extra bits.  The base distances and
+ *   corresponding number of extra bits are below in the static arrays dist[]
+ *   and dext[].
+ *
+ * - Literal bytes are simply written to the output.  A length/distance pair is
+ *   an instruction to copy previously uncompressed bytes to the output.  The
+ *   copy is from distance bytes back in the output stream, copying for length
+ *   bytes.
+ *
+ * - Distances pointing before the beginning of the output data are not
+ *   permitted.
+ *
+ * - Overlapped copies, where the length is greater than the distance, are
+ *   allowed and common.  For example, a distance of one and a length of 258
+ *   simply copies the last byte 258 times.  A distance of four and a length of
+ *   twelve copies the last four bytes three times.  A simple forward copy
+ *   ignoring whether the length is greater than the distance or not implements
+ *   this correctly.  You should not use memcpy() since its behavior is not
+ *   defined for overlapped arrays.  You should not use memmove() or bcopy()
+ *   since though their behavior -is- defined for overlapping arrays, it is
+ *   defined to do the wrong thing in this case.
+ */
+local int codes(struct state *s,
+                const struct huffman *lencode,
+                const struct huffman *distcode)
+{
+    int symbol;         /* decoded symbol */
+    int len;            /* length for copy */
+    unsigned dist;      /* distance for copy */
+    static const short lens[29] = { /* Size base for length codes 257..285 */
+        3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
+        35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258};
+    static const short lext[29] = { /* Extra bits for length codes 257..285 */
+        0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
+        3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0};
+    static const short dists[30] = { /* Offset base for distance codes 0..29 */
+        1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
+        257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
+        8193, 12289, 16385, 24577};
+    static const short dext[30] = { /* Extra bits for distance codes 0..29 */
+        0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
+        7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
+        12, 12, 13, 13};
+
+    /* decode literals and length/distance pairs */
+    do {
+        symbol = decode(s, lencode);
+        if (symbol < 0)
+            return symbol;              /* invalid symbol */
+        if (symbol < 256) {             /* literal: symbol is the byte */
+            /* write out the literal */
+            if (s->out != NIL) {
+                if (s->outcnt == s->outlen)
+                    return 1;
+                s->out[s->outcnt] = symbol;
+            }
+            s->outcnt++;
+        }
+        else if (symbol > 256) {        /* length */
+            /* get and compute length */
+            symbol -= 257;
+            if (symbol >= 29)
+                return -10;             /* invalid fixed code */
+            len = lens[symbol] + bits(s, lext[symbol]);
+
+            /* get and check distance */
+            symbol = decode(s, distcode);
+            if (symbol < 0)
+                return symbol;          /* invalid symbol */
+            dist = dists[symbol] + bits(s, dext[symbol]);
+#ifndef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
+            if (dist > s->outcnt)
+                return -11;     /* distance too far back */
+#endif
+
+            /* copy length bytes from distance bytes back */
+            if (s->out != NIL) {
+                if (s->outcnt + len > s->outlen)
+                    return 1;
+                while (len--) {
+                    s->out[s->outcnt] =
+#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
+                        dist > s->outcnt ?
+                            0 :
+#endif
+                            s->out[s->outcnt - dist];
+                    s->outcnt++;
+                }
+            }
+            else
+                s->outcnt += len;
+        }
+    } while (symbol != 256);            /* end of block symbol */
+
+    /* done with a valid fixed or dynamic block */
+    return 0;
+}
+
+/*
+ * Process a fixed codes block.
+ *
+ * Format notes:
+ *
+ * - This block type can be useful for compressing small amounts of data for
+ *   which the size of the code descriptions in a dynamic block exceeds the
+ *   benefit of custom codes for that block.  For fixed codes, no bits are
+ *   spent on code descriptions.  Instead the code lengths for literal/length
+ *   codes and distance codes are fixed.  The specific lengths for each symbol
+ *   can be seen in the "for" loops below.
+ *
+ * - The literal/length code is complete, but has two symbols that are invalid
+ *   and should result in an error if received.  This cannot be implemented
+ *   simply as an incomplete code since those two symbols are in the "middle"
+ *   of the code.  They are eight bits long and the longest literal/length\
+ *   code is nine bits.  Therefore the code must be constructed with those
+ *   symbols, and the invalid symbols must be detected after decoding.
+ *
+ * - The fixed distance codes also have two invalid symbols that should result
+ *   in an error if received.  Since all of the distance codes are the same
+ *   length, this can be implemented as an incomplete code.  Then the invalid
+ *   codes are detected while decoding.
+ */
+local int fixed(struct state *s)
+{
+    static int virgin = 1;
+    static short lencnt[MAXBITS+1], lensym[FIXLCODES];
+    static short distcnt[MAXBITS+1], distsym[MAXDCODES];
+    static struct huffman lencode, distcode;
+
+    /* build fixed huffman tables if first call (may not be thread safe) */
+    if (virgin) {
+        int symbol;
+        short lengths[FIXLCODES];
+
+        /* construct lencode and distcode */
+        lencode.count = lencnt;
+        lencode.symbol = lensym;
+        distcode.count = distcnt;
+        distcode.symbol = distsym;
+
+        /* literal/length table */
+        for (symbol = 0; symbol < 144; symbol++)
+            lengths[symbol] = 8;
+        for (; symbol < 256; symbol++)
+            lengths[symbol] = 9;
+        for (; symbol < 280; symbol++)
+            lengths[symbol] = 7;
+        for (; symbol < FIXLCODES; symbol++)
+            lengths[symbol] = 8;
+        construct(&lencode, lengths, FIXLCODES);
+
+        /* distance table */
+        for (symbol = 0; symbol < MAXDCODES; symbol++)
+            lengths[symbol] = 5;
+        construct(&distcode, lengths, MAXDCODES);
+
+        /* do this just once */
+        virgin = 0;
+    }
+
+    /* decode data until end-of-block code */
+    return codes(s, &lencode, &distcode);
+}
+
+/*
+ * Process a dynamic codes block.
+ *
+ * Format notes:
+ *
+ * - A dynamic block starts with a description of the literal/length and
+ *   distance codes for that block.  New dynamic blocks allow the compressor to
+ *   rapidly adapt to changing data with new codes optimized for that data.
+ *
+ * - The codes used by the deflate format are "canonical", which means that
+ *   the actual bits of the codes are generated in an unambiguous way simply
+ *   from the number of bits in each code.  Therefore the code descriptions
+ *   are simply a list of code lengths for each symbol.
+ *
+ * - The code lengths are stored in order for the symbols, so lengths are
+ *   provided for each of the literal/length symbols, and for each of the
+ *   distance symbols.
+ *
+ * - If a symbol is not used in the block, this is represented by a zero as
+ *   as the code length.  This does not mean a zero-length code, but rather
+ *   that no code should be created for this symbol.  There is no way in the
+ *   deflate format to represent a zero-length code.
+ *
+ * - The maximum number of bits in a code is 15, so the possible lengths for
+ *   any code are 1..15.
+ *
+ * - The fact that a length of zero is not permitted for a code has an
+ *   interesting consequence.  Normally if only one symbol is used for a given
+ *   code, then in fact that code could be represented with zero bits.  However
+ *   in deflate, that code has to be at least one bit.  So for example, if
+ *   only a single distance base symbol appears in a block, then it will be
+ *   represented by a single code of length one, in particular one 0 bit.  This
+ *   is an incomplete code, since if a 1 bit is received, it has no meaning,
+ *   and should result in an error.  So incomplete distance codes of one symbol
+ *   should be permitted, and the receipt of invalid codes should be handled.
+ *
+ * - It is also possible to have a single literal/length code, but that code
+ *   must be the end-of-block code, since every dynamic block has one.  This
+ *   is not the most efficient way to create an empty block (an empty fixed
+ *   block is fewer bits), but it is allowed by the format.  So incomplete
+ *   literal/length codes of one symbol should also be permitted.
+ *
+ * - If there are only literal codes and no lengths, then there are no distance
+ *   codes.  This is represented by one distance code with zero bits.
+ *
+ * - The list of up to 286 length/literal lengths and up to 30 distance lengths
+ *   are themselves compressed using Huffman codes and run-length encoding.  In
+ *   the list of code lengths, a 0 symbol means no code, a 1..15 symbol means
+ *   that length, and the symbols 16, 17, and 18 are run-length instructions.
+ *   Each of 16, 17, and 18 are follwed by extra bits to define the length of
+ *   the run.  16 copies the last length 3 to 6 times.  17 represents 3 to 10
+ *   zero lengths, and 18 represents 11 to 138 zero lengths.  Unused symbols
+ *   are common, hence the special coding for zero lengths.
+ *
+ * - The symbols for 0..18 are Huffman coded, and so that code must be
+ *   described first.  This is simply a sequence of up to 19 three-bit values
+ *   representing no code (0) or the code length for that symbol (1..7).
+ *
+ * - A dynamic block starts with three fixed-size counts from which is computed
+ *   the number of literal/length code lengths, the number of distance code
+ *   lengths, and the number of code length code lengths (ok, you come up with
+ *   a better name!) in the code descriptions.  For the literal/length and
+ *   distance codes, lengths after those provided are considered zero, i.e. no
+ *   code.  The code length code lengths are received in a permuted order (see
+ *   the order[] array below) to make a short code length code length list more
+ *   likely.  As it turns out, very short and very long codes are less likely
+ *   to be seen in a dynamic code description, hence what may appear initially
+ *   to be a peculiar ordering.
+ *
+ * - Given the number of literal/length code lengths (nlen) and distance code
+ *   lengths (ndist), then they are treated as one long list of nlen + ndist
+ *   code lengths.  Therefore run-length coding can and often does cross the
+ *   boundary between the two sets of lengths.
+ *
+ * - So to summarize, the code description at the start of a dynamic block is
+ *   three counts for the number of code lengths for the literal/length codes,
+ *   the distance codes, and the code length codes.  This is followed by the
+ *   code length code lengths, three bits each.  This is used to construct the
+ *   code length code which is used to read the remainder of the lengths.  Then
+ *   the literal/length code lengths and distance lengths are read as a single
+ *   set of lengths using the code length codes.  Codes are constructed from
+ *   the resulting two sets of lengths, and then finally you can start
+ *   decoding actual compressed data in the block.
+ *
+ * - For reference, a "typical" size for the code description in a dynamic
+ *   block is around 80 bytes.
+ */
+local int dynamic(struct state *s)
+{
+    int nlen, ndist, ncode;             /* number of lengths in descriptor */
+    int index;                          /* index of lengths[] */
+    int err;                            /* construct() return value */
+    short lengths[MAXCODES];            /* descriptor code lengths */
+    short lencnt[MAXBITS+1], lensym[MAXLCODES];         /* lencode memory */
+    short distcnt[MAXBITS+1], distsym[MAXDCODES];       /* distcode memory */
+    struct huffman lencode, distcode;   /* length and distance codes */
+    static const short order[19] =      /* permutation of code length codes */
+        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+
+    /* construct lencode and distcode */
+    lencode.count = lencnt;
+    lencode.symbol = lensym;
+    distcode.count = distcnt;
+    distcode.symbol = distsym;
+
+    /* get number of lengths in each table, check lengths */
+    nlen = bits(s, 5) + 257;
+    ndist = bits(s, 5) + 1;
+    ncode = bits(s, 4) + 4;
+    if (nlen > MAXLCODES || ndist > MAXDCODES)
+        return -3;                      /* bad counts */
+
+    /* read code length code lengths (really), missing lengths are zero */
+    for (index = 0; index < ncode; index++)
+        lengths[order[index]] = bits(s, 3);
+    for (; index < 19; index++)
+        lengths[order[index]] = 0;
+
+    /* build huffman table for code lengths codes (use lencode temporarily) */
+    err = construct(&lencode, lengths, 19);
+    if (err != 0)               /* require complete code set here */
+        return -4;
+
+    /* read length/literal and distance code length tables */
+    index = 0;
+    while (index < nlen + ndist) {
+        int symbol;             /* decoded value */
+        int len;                /* last length to repeat */
+
+        symbol = decode(s, &lencode);
+        if (symbol < 0)
+            return symbol;          /* invalid symbol */
+        if (symbol < 16)                /* length in 0..15 */
+            lengths[index++] = symbol;
+        else {                          /* repeat instruction */
+            len = 0;                    /* assume repeating zeros */
+            if (symbol == 16) {         /* repeat last length 3..6 times */
+                if (index == 0)
+                    return -5;          /* no last length! */
+                len = lengths[index - 1];       /* last length */
+                symbol = 3 + bits(s, 2);
+            }
+            else if (symbol == 17)      /* repeat zero 3..10 times */
+                symbol = 3 + bits(s, 3);
+            else                        /* == 18, repeat zero 11..138 times */
+                symbol = 11 + bits(s, 7);
+            if (index + symbol > nlen + ndist)
+                return -6;              /* too many lengths! */
+            while (symbol--)            /* repeat last or zero symbol times */
+                lengths[index++] = len;
+        }
+    }
+
+    /* check for end-of-block code -- there better be one! */
+    if (lengths[256] == 0)
+        return -9;
+
+    /* build huffman table for literal/length codes */
+    err = construct(&lencode, lengths, nlen);
+    if (err && (err < 0 || nlen != lencode.count[0] + lencode.count[1]))
+        return -7;      /* incomplete code ok only for single length 1 code */
+
+    /* build huffman table for distance codes */
+    err = construct(&distcode, lengths + nlen, ndist);
+    if (err && (err < 0 || ndist != distcode.count[0] + distcode.count[1]))
+        return -8;      /* incomplete code ok only for single length 1 code */
+
+    /* decode data until end-of-block code */
+    return codes(s, &lencode, &distcode);
+}
+
+/*
+ * Inflate source to dest.  On return, destlen and sourcelen are updated to the
+ * size of the uncompressed data and the size of the deflate data respectively.
+ * On success, the return value of puff() is zero.  If there is an error in the
+ * source data, i.e. it is not in the deflate format, then a negative value is
+ * returned.  If there is not enough input available or there is not enough
+ * output space, then a positive error is returned.  In that case, destlen and
+ * sourcelen are not updated to facilitate retrying from the beginning with the
+ * provision of more input data or more output space.  In the case of invalid
+ * inflate data (a negative error), the dest and source pointers are updated to
+ * facilitate the debugging of deflators.
+ *
+ * puff() also has a mode to determine the size of the uncompressed output with
+ * no output written.  For this dest must be (unsigned char *)0.  In this case,
+ * the input value of *destlen is ignored, and on return *destlen is set to the
+ * size of the uncompressed output.
+ *
+ * The return codes are:
+ *
+ *   2:  available inflate data did not terminate
+ *   1:  output space exhausted before completing inflate
+ *   0:  successful inflate
+ *  -1:  invalid block type (type == 3)
+ *  -2:  stored block length did not match one's complement
+ *  -3:  dynamic block code description: too many length or distance codes
+ *  -4:  dynamic block code description: code lengths codes incomplete
+ *  -5:  dynamic block code description: repeat lengths with no first length
+ *  -6:  dynamic block code description: repeat more than specified lengths
+ *  -7:  dynamic block code description: invalid literal/length code lengths
+ *  -8:  dynamic block code description: invalid distance code lengths
+ *  -9:  dynamic block code description: missing end-of-block code
+ * -10:  invalid literal/length or distance code in fixed or dynamic block
+ * -11:  distance is too far back in fixed or dynamic block
+ *
+ * Format notes:
+ *
+ * - Three bits are read for each block to determine the kind of block and
+ *   whether or not it is the last block.  Then the block is decoded and the
+ *   process repeated if it was not the last block.
+ *
+ * - The leftover bits in the last byte of the deflate data after the last
+ *   block (if it was a fixed or dynamic block) are undefined and have no
+ *   expected values to check.
+ */
+int puff(unsigned char *dest,           /* pointer to destination pointer */
+         unsigned long *destlen,        /* amount of output space */
+         const unsigned char *source,   /* pointer to source data pointer */
+         unsigned long *sourcelen)      /* amount of input available */
+{
+    struct state s;             /* input/output state */
+    int last, type;             /* block information */
+    int err;                    /* return value */
+
+    /* initialize output state */
+    s.out = dest;
+    s.outlen = *destlen;                /* ignored if dest is NIL */
+    s.outcnt = 0;
+
+    /* initialize input state */
+    s.in = source;
+    s.inlen = *sourcelen;
+    s.incnt = 0;
+    s.bitbuf = 0;
+    s.bitcnt = 0;
+
+    /* return if bits() or decode() tries to read past available input */
+    if (setjmp(s.env) != 0)             /* if came back here via longjmp() */
+        err = 2;                        /* then skip do-loop, return error */
+    else {
+        /* process blocks until last block or error */
+        do {
+            last = bits(&s, 1);         /* one if last block */
+            type = bits(&s, 2);         /* block type 0..3 */
+            err = type == 0 ?
+                    stored(&s) :
+                    (type == 1 ?
+                        fixed(&s) :
+                        (type == 2 ?
+                            dynamic(&s) :
+                            -1));       /* type == 3, invalid */
+            if (err != 0)
+                break;                  /* return with error */
+        } while (!last);
+    }
+
+    /* update the lengths and return */
+    if (err <= 0) {
+        *destlen = s.outcnt;
+        *sourcelen = s.incnt;
+    }
+    return err;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/puff/puff.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/puff/puff.h	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,35 @@
+/* puff.h
+  Copyright (C) 2002-2013 Mark Adler, all rights reserved
+  version 2.3, 21 Jan 2013
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the author be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  Mark Adler    madler@alumni.caltech.edu
+ */
+
+
+/*
+ * See puff.c for purpose and usage.
+ */
+#ifndef NIL
+#  define NIL ((unsigned char *)0)      /* for no output option */
+#endif
+
+int puff(unsigned char *dest,           /* pointer to destination pointer */
+         unsigned long *destlen,        /* amount of output space */
+         const unsigned char *source,   /* pointer to source data pointer */
+         unsigned long *sourcelen);     /* amount of input available */
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/puff/pufftest.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/puff/pufftest.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,165 @@
+/*
+ * pufftest.c
+ * Copyright (C) 2002-2013 Mark Adler
+ * For conditions of distribution and use, see copyright notice in puff.h
+ * version 2.3, 21 Jan 2013
+ */
+
+/* Example of how to use puff().
+
+   Usage: puff [-w] [-f] [-nnn] file
+          ... | puff [-w] [-f] [-nnn]
+
+   where file is the input file with deflate data, nnn is the number of bytes
+   of input to skip before inflating (e.g. to skip a zlib or gzip header), and
+   -w is used to write the decompressed data to stdout.  -f is for coverage
+   testing, and causes pufftest to fail with not enough output space (-f does
+   a write like -w, so -w is not required). */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "puff.h"
+
+#if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(__CYGWIN__)
+#  include <fcntl.h>
+#  include <io.h>
+#  define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY)
+#else
+#  define SET_BINARY_MODE(file)
+#endif
+
+#define local static
+
+/* Return size times approximately the cube root of 2, keeping the result as 1,
+   3, or 5 times a power of 2 -- the result is always > size, until the result
+   is the maximum value of an unsigned long, where it remains.  This is useful
+   to keep reallocations less than ~33% over the actual data. */
+local size_t bythirds(size_t size)
+{
+    int n;
+    size_t m;
+
+    m = size;
+    for (n = 0; m; n++)
+        m >>= 1;
+    if (n < 3)
+        return size + 1;
+    n -= 3;
+    m = size >> n;
+    m += m == 6 ? 2 : 1;
+    m <<= n;
+    return m > size ? m : (size_t)(-1);
+}
+
+/* Read the input file *name, or stdin if name is NULL, into allocated memory.
+   Reallocate to larger buffers until the entire file is read in.  Return a
+   pointer to the allocated data, or NULL if there was a memory allocation
+   failure.  *len is the number of bytes of data read from the input file (even
+   if load() returns NULL).  If the input file was empty or could not be opened
+   or read, *len is zero. */
+local void *load(const char *name, size_t *len)
+{
+    size_t size;
+    void *buf, *swap;
+    FILE *in;
+
+    *len = 0;
+    buf = malloc(size = 4096);
+    if (buf == NULL)
+        return NULL;
+    in = name == NULL ? stdin : fopen(name, "rb");
+    if (in != NULL) {
+        for (;;) {
+            *len += fread((char *)buf + *len, 1, size - *len, in);
+            if (*len < size) break;
+            size = bythirds(size);
+            if (size == *len || (swap = realloc(buf, size)) == NULL) {
+                free(buf);
+                buf = NULL;
+                break;
+            }
+            buf = swap;
+        }
+        fclose(in);
+    }
+    return buf;
+}
+
+int main(int argc, char **argv)
+{
+    int ret, put = 0, fail = 0;
+    unsigned skip = 0;
+    char *arg, *name = NULL;
+    unsigned char *source = NULL, *dest;
+    size_t len = 0;
+    unsigned long sourcelen, destlen;
+
+    /* process arguments */
+    while (arg = *++argv, --argc)
+        if (arg[0] == '-') {
+            if (arg[1] == 'w' && arg[2] == 0)
+                put = 1;
+            else if (arg[1] == 'f' && arg[2] == 0)
+                fail = 1, put = 1;
+            else if (arg[1] >= '0' && arg[1] <= '9')
+                skip = (unsigned)atoi(arg + 1);
+            else {
+                fprintf(stderr, "invalid option %s\n", arg);
+                return 3;
+            }
+        }
+        else if (name != NULL) {
+            fprintf(stderr, "only one file name allowed\n");
+            return 3;
+        }
+        else
+            name = arg;
+    source = load(name, &len);
+    if (source == NULL) {
+        fprintf(stderr, "memory allocation failure\n");
+        return 4;
+    }
+    if (len == 0) {
+        fprintf(stderr, "could not read %s, or it was empty\n",
+                name == NULL ? "<stdin>" : name);
+        free(source);
+        return 3;
+    }
+    if (skip >= len) {
+        fprintf(stderr, "skip request of %d leaves no input\n", skip);
+        free(source);
+        return 3;
+    }
+
+    /* test inflate data with offset skip */
+    len -= skip;
+    sourcelen = (unsigned long)len;
+    ret = puff(NIL, &destlen, source + skip, &sourcelen);
+    if (ret)
+        fprintf(stderr, "puff() failed with return code %d\n", ret);
+    else {
+        fprintf(stderr, "puff() succeeded uncompressing %lu bytes\n", destlen);
+        if (sourcelen < len) fprintf(stderr, "%lu compressed bytes unused\n",
+                                     len - sourcelen);
+    }
+
+    /* if requested, inflate again and write decompressd data to stdout */
+    if (put && ret == 0) {
+        if (fail)
+            destlen >>= 1;
+        dest = malloc(destlen);
+        if (dest == NULL) {
+            fprintf(stderr, "memory allocation failure\n");
+            free(source);
+            return 4;
+        }
+        puff(dest, &destlen, source + skip, &sourcelen);
+        SET_BINARY_MODE(stdout);
+        fwrite(dest, 1, destlen, stdout);
+        free(dest);
+    }
+
+    /* clean up */
+    free(source);
+    return ret;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/puff/zeros.raw
Binary file sys/src/ape/lib/z/contrib/puff/zeros.raw has changed
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/testzlib/testzlib.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/testzlib/testzlib.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,275 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <windows.h>
+
+#include "zlib.h"
+
+
+void MyDoMinus64(LARGE_INTEGER *R,LARGE_INTEGER A,LARGE_INTEGER B)
+{
+    R->HighPart = A.HighPart - B.HighPart;
+    if (A.LowPart >= B.LowPart)
+        R->LowPart = A.LowPart - B.LowPart;
+    else
+    {
+        R->LowPart = A.LowPart - B.LowPart;
+        R->HighPart --;
+    }
+}
+
+#ifdef _M_X64
+// see http://msdn2.microsoft.com/library/twchhe95(en-us,vs.80).aspx for __rdtsc
+unsigned __int64 __rdtsc(void);
+void BeginCountRdtsc(LARGE_INTEGER * pbeginTime64)
+{
+ //   printf("rdtsc = %I64x\n",__rdtsc());
+   pbeginTime64->QuadPart=__rdtsc();
+}
+
+LARGE_INTEGER GetResRdtsc(LARGE_INTEGER beginTime64,BOOL fComputeTimeQueryPerf)
+{
+    LARGE_INTEGER LIres;
+    unsigned _int64 res=__rdtsc()-((unsigned _int64)(beginTime64.QuadPart));
+    LIres.QuadPart=res;
+   // printf("rdtsc = %I64x\n",__rdtsc());
+    return LIres;
+}
+#else
+#ifdef _M_IX86
+void myGetRDTSC32(LARGE_INTEGER * pbeginTime64)
+{
+    DWORD dwEdx,dwEax;
+    _asm
+    {
+        rdtsc
+        mov dwEax,eax
+        mov dwEdx,edx
+    }
+    pbeginTime64->LowPart=dwEax;
+    pbeginTime64->HighPart=dwEdx;
+}
+
+void BeginCountRdtsc(LARGE_INTEGER * pbeginTime64)
+{
+    myGetRDTSC32(pbeginTime64);
+}
+
+LARGE_INTEGER GetResRdtsc(LARGE_INTEGER beginTime64,BOOL fComputeTimeQueryPerf)
+{
+    LARGE_INTEGER LIres,endTime64;
+    myGetRDTSC32(&endTime64);
+
+    LIres.LowPart=LIres.HighPart=0;
+    MyDoMinus64(&LIres,endTime64,beginTime64);
+    return LIres;
+}
+#else
+void myGetRDTSC32(LARGE_INTEGER * pbeginTime64)
+{
+}
+
+void BeginCountRdtsc(LARGE_INTEGER * pbeginTime64)
+{
+}
+
+LARGE_INTEGER GetResRdtsc(LARGE_INTEGER beginTime64,BOOL fComputeTimeQueryPerf)
+{
+    LARGE_INTEGER lr;
+    lr.QuadPart=0;
+    return lr;
+}
+#endif
+#endif
+
+void BeginCountPerfCounter(LARGE_INTEGER * pbeginTime64,BOOL fComputeTimeQueryPerf)
+{
+    if ((!fComputeTimeQueryPerf) || (!QueryPerformanceCounter(pbeginTime64)))
+    {
+        pbeginTime64->LowPart = GetTickCount();
+        pbeginTime64->HighPart = 0;
+    }
+}
+
+DWORD GetMsecSincePerfCounter(LARGE_INTEGER beginTime64,BOOL fComputeTimeQueryPerf)
+{
+    LARGE_INTEGER endTime64,ticksPerSecond,ticks;
+    DWORDLONG ticksShifted,tickSecShifted;
+    DWORD dwLog=16+0;
+    DWORD dwRet;
+    if ((!fComputeTimeQueryPerf) || (!QueryPerformanceCounter(&endTime64)))
+        dwRet = (GetTickCount() - beginTime64.LowPart)*1;
+    else
+    {
+        MyDoMinus64(&ticks,endTime64,beginTime64);
+        QueryPerformanceFrequency(&ticksPerSecond);
+
+
+        {
+            ticksShifted = Int64ShrlMod32(*(DWORDLONG*)&ticks,dwLog);
+            tickSecShifted = Int64ShrlMod32(*(DWORDLONG*)&ticksPerSecond,dwLog);
+
+        }
+
+        dwRet = (DWORD)((((DWORD)ticksShifted)*1000)/(DWORD)(tickSecShifted));
+        dwRet *=1;
+    }
+    return dwRet;
+}
+
+int ReadFileMemory(const char* filename,long* plFileSize,unsigned char** pFilePtr)
+{
+    FILE* stream;
+    unsigned char* ptr;
+    int retVal=1;
+    stream=fopen(filename, "rb");
+    if (stream==NULL)
+        return 0;
+
+    fseek(stream,0,SEEK_END);
+
+    *plFileSize=ftell(stream);
+    fseek(stream,0,SEEK_SET);
+    ptr=malloc((*plFileSize)+1);
+    if (ptr==NULL)
+        retVal=0;
+    else
+    {
+        if (fread(ptr, 1, *plFileSize,stream) != (*plFileSize))
+            retVal=0;
+    }
+    fclose(stream);
+    *pFilePtr=ptr;
+    return retVal;
+}
+
+int main(int argc, char *argv[])
+{
+    int BlockSizeCompress=0x8000;
+    int BlockSizeUncompress=0x8000;
+    int cprLevel=Z_DEFAULT_COMPRESSION ;
+    long lFileSize;
+    unsigned char* FilePtr;
+    long lBufferSizeCpr;
+    long lBufferSizeUncpr;
+    long lCompressedSize=0;
+    unsigned char* CprPtr;
+    unsigned char* UncprPtr;
+    long lSizeCpr,lSizeUncpr;
+    DWORD dwGetTick,dwMsecQP;
+    LARGE_INTEGER li_qp,li_rdtsc,dwResRdtsc;
+
+    if (argc<=1)
+    {
+        printf("run TestZlib <File> [BlockSizeCompress] [BlockSizeUncompress] [compres. level]\n");
+        return 0;
+    }
+
+    if (ReadFileMemory(argv[1],&lFileSize,&FilePtr)==0)
+    {
+        printf("error reading %s\n",argv[1]);
+        return 1;
+    }
+    else printf("file %s read, %u bytes\n",argv[1],lFileSize);
+
+    if (argc>=3)
+        BlockSizeCompress=atol(argv[2]);
+
+    if (argc>=4)
+        BlockSizeUncompress=atol(argv[3]);
+
+    if (argc>=5)
+        cprLevel=(int)atol(argv[4]);
+
+    lBufferSizeCpr = lFileSize + (lFileSize/0x10) + 0x200;
+    lBufferSizeUncpr = lBufferSizeCpr;
+
+    CprPtr=(unsigned char*)malloc(lBufferSizeCpr + BlockSizeCompress);
+
+    BeginCountPerfCounter(&li_qp,TRUE);
+    dwGetTick=GetTickCount();
+    BeginCountRdtsc(&li_rdtsc);
+    {
+        z_stream zcpr;
+        int ret=Z_OK;
+        long lOrigToDo = lFileSize;
+        long lOrigDone = 0;
+        int step=0;
+        memset(&zcpr,0,sizeof(z_stream));
+        deflateInit(&zcpr,cprLevel);
+
+        zcpr.next_in = FilePtr;
+        zcpr.next_out = CprPtr;
+
+
+        do
+        {
+            long all_read_before = zcpr.total_in;
+            zcpr.avail_in = min(lOrigToDo,BlockSizeCompress);
+            zcpr.avail_out = BlockSizeCompress;
+            ret=deflate(&zcpr,(zcpr.avail_in==lOrigToDo) ? Z_FINISH : Z_SYNC_FLUSH);
+            lOrigDone += (zcpr.total_in-all_read_before);
+            lOrigToDo -= (zcpr.total_in-all_read_before);
+            step++;
+        } while (ret==Z_OK);
+
+        lSizeCpr=zcpr.total_out;
+        deflateEnd(&zcpr);
+        dwGetTick=GetTickCount()-dwGetTick;
+        dwMsecQP=GetMsecSincePerfCounter(li_qp,TRUE);
+        dwResRdtsc=GetResRdtsc(li_rdtsc,TRUE);
+        printf("total compress size = %u, in %u step\n",lSizeCpr,step);
+        printf("time = %u msec = %f sec\n",dwGetTick,dwGetTick/(double)1000.);
+        printf("defcpr time QP = %u msec = %f sec\n",dwMsecQP,dwMsecQP/(double)1000.);
+        printf("defcpr result rdtsc = %I64x\n\n",dwResRdtsc.QuadPart);
+    }
+
+    CprPtr=(unsigned char*)realloc(CprPtr,lSizeCpr);
+    UncprPtr=(unsigned char*)malloc(lBufferSizeUncpr + BlockSizeUncompress);
+
+    BeginCountPerfCounter(&li_qp,TRUE);
+    dwGetTick=GetTickCount();
+    BeginCountRdtsc(&li_rdtsc);
+    {
+        z_stream zcpr;
+        int ret=Z_OK;
+        long lOrigToDo = lSizeCpr;
+        long lOrigDone = 0;
+        int step=0;
+        memset(&zcpr,0,sizeof(z_stream));
+        inflateInit(&zcpr);
+
+        zcpr.next_in = CprPtr;
+        zcpr.next_out = UncprPtr;
+
+
+        do
+        {
+            long all_read_before = zcpr.total_in;
+            zcpr.avail_in = min(lOrigToDo,BlockSizeUncompress);
+            zcpr.avail_out = BlockSizeUncompress;
+            ret=inflate(&zcpr,Z_SYNC_FLUSH);
+            lOrigDone += (zcpr.total_in-all_read_before);
+            lOrigToDo -= (zcpr.total_in-all_read_before);
+            step++;
+        } while (ret==Z_OK);
+
+        lSizeUncpr=zcpr.total_out;
+        inflateEnd(&zcpr);
+        dwGetTick=GetTickCount()-dwGetTick;
+        dwMsecQP=GetMsecSincePerfCounter(li_qp,TRUE);
+        dwResRdtsc=GetResRdtsc(li_rdtsc,TRUE);
+        printf("total uncompress size = %u, in %u step\n",lSizeUncpr,step);
+        printf("time = %u msec = %f sec\n",dwGetTick,dwGetTick/(double)1000.);
+        printf("uncpr  time QP = %u msec = %f sec\n",dwMsecQP,dwMsecQP/(double)1000.);
+        printf("uncpr  result rdtsc = %I64x\n\n",dwResRdtsc.QuadPart);
+    }
+
+    if (lSizeUncpr==lFileSize)
+    {
+        if (memcmp(FilePtr,UncprPtr,lFileSize)==0)
+            printf("compare ok\n");
+
+    }
+
+    return 0;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/testzlib/testzlib.txt
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/testzlib/testzlib.txt	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,10 @@
+To build testzLib with Visual Studio 2005:
+
+copy to a directory file from :
+- root of zLib tree
+- contrib/testzlib
+- contrib/masmx86
+- contrib/masmx64
+- contrib/vstudio/vc7
+
+and open testzlib8.sln
\ No newline at end of file
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/untgz/Makefile
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/untgz/Makefile	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,14 @@
+CC=cc
+CFLAGS=-g
+
+untgz: untgz.o ../../libz.a
+	$(CC) $(CFLAGS) -o untgz untgz.o -L../.. -lz
+
+untgz.o: untgz.c ../../zlib.h
+	$(CC) $(CFLAGS) -c -I../.. untgz.c
+
+../../libz.a:
+	cd ../..; ./configure; make
+
+clean:
+	rm -f untgz untgz.o *~
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/untgz/Makefile.msc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/untgz/Makefile.msc	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,17 @@
+CC=cl
+CFLAGS=-MD
+
+untgz.exe: untgz.obj ..\..\zlib.lib
+	$(CC) $(CFLAGS) untgz.obj ..\..\zlib.lib
+
+untgz.obj: untgz.c ..\..\zlib.h
+	$(CC) $(CFLAGS) -c -I..\.. untgz.c
+
+..\..\zlib.lib:
+	cd ..\..
+	$(MAKE) -f win32\makefile.msc
+	cd contrib\untgz
+
+clean:
+	-del untgz.obj
+	-del untgz.exe
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/contrib/untgz/untgz.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/contrib/untgz/untgz.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,674 @@
+/*
+ * untgz.c -- Display contents and extract files from a gzip'd TAR file
+ *
+ * written by Pedro A. Aranda Gutierrez <paag@tid.es>
+ * adaptation to Unix by Jean-loup Gailly <jloup@gzip.org>
+ * various fixes by Cosmin Truta <cosmint@cs.ubbcluj.ro>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <errno.h>
+
+#include "zlib.h"
+
+#ifdef unix
+#  include <unistd.h>
+#else
+#  include <direct.h>
+#  include <io.h>
+#endif
+
+#ifdef WIN32
+#include <windows.h>
+#  ifndef F_OK
+#    define F_OK  0
+#  endif
+#  define mkdir(dirname,mode)   _mkdir(dirname)
+#  ifdef _MSC_VER
+#    define access(path,mode)   _access(path,mode)
+#    define chmod(path,mode)    _chmod(path,mode)
+#    define strdup(str)         _strdup(str)
+#  endif
+#else
+#  include <utime.h>
+#endif
+
+
+/* values used in typeflag field */
+
+#define REGTYPE  '0'            /* regular file */
+#define AREGTYPE '\0'           /* regular file */
+#define LNKTYPE  '1'            /* link */
+#define SYMTYPE  '2'            /* reserved */
+#define CHRTYPE  '3'            /* character special */
+#define BLKTYPE  '4'            /* block special */
+#define DIRTYPE  '5'            /* directory */
+#define FIFOTYPE '6'            /* FIFO special */
+#define CONTTYPE '7'            /* reserved */
+
+/* GNU tar extensions */
+
+#define GNUTYPE_DUMPDIR  'D'    /* file names from dumped directory */
+#define GNUTYPE_LONGLINK 'K'    /* long link name */
+#define GNUTYPE_LONGNAME 'L'    /* long file name */
+#define GNUTYPE_MULTIVOL 'M'    /* continuation of file from another volume */
+#define GNUTYPE_NAMES    'N'    /* file name that does not fit into main hdr */
+#define GNUTYPE_SPARSE   'S'    /* sparse file */
+#define GNUTYPE_VOLHDR   'V'    /* tape/volume header */
+
+
+/* tar header */
+
+#define BLOCKSIZE     512
+#define SHORTNAMESIZE 100
+
+struct tar_header
+{                               /* byte offset */
+  char name[100];               /*   0 */
+  char mode[8];                 /* 100 */
+  char uid[8];                  /* 108 */
+  char gid[8];                  /* 116 */
+  char size[12];                /* 124 */
+  char mtime[12];               /* 136 */
+  char chksum[8];               /* 148 */
+  char typeflag;                /* 156 */
+  char linkname[100];           /* 157 */
+  char magic[6];                /* 257 */
+  char version[2];              /* 263 */
+  char uname[32];               /* 265 */
+  char gname[32];               /* 297 */
+  char devmajor[8];             /* 329 */
+  char devminor[8];             /* 337 */
+  char prefix[155];             /* 345 */
+                                /* 500 */
+};
+
+union tar_buffer
+{
+  char               buffer[BLOCKSIZE];
+  struct tar_header  header;
+};
+
+struct attr_item
+{
+  struct attr_item  *next;
+  char              *fname;
+  int                mode;
+  time_t             time;
+};
+
+enum { TGZ_EXTRACT, TGZ_LIST, TGZ_INVALID };
+
+char *TGZfname          OF((const char *));
+void TGZnotfound        OF((const char *));
+
+int getoct              OF((char *, int));
+char *strtime           OF((time_t *));
+int setfiletime         OF((char *, time_t));
+void push_attr          OF((struct attr_item **, char *, int, time_t));
+void restore_attr       OF((struct attr_item **));
+
+int ExprMatch           OF((char *, char *));
+
+int makedir             OF((char *));
+int matchname           OF((int, int, char **, char *));
+
+void error              OF((const char *));
+int tar                 OF((gzFile, int, int, int, char **));
+
+void help               OF((int));
+int main                OF((int, char **));
+
+char *prog;
+
+const char *TGZsuffix[] = { "\0", ".tar", ".tar.gz", ".taz", ".tgz", NULL };
+
+/* return the file name of the TGZ archive */
+/* or NULL if it does not exist */
+
+char *TGZfname (const char *arcname)
+{
+  static char buffer[1024];
+  int origlen,i;
+
+  strcpy(buffer,arcname);
+  origlen = strlen(buffer);
+
+  for (i=0; TGZsuffix[i]; i++)
+    {
+       strcpy(buffer+origlen,TGZsuffix[i]);
+       if (access(buffer,F_OK) == 0)
+         return buffer;
+    }
+  return NULL;
+}
+
+
+/* error message for the filename */
+
+void TGZnotfound (const char *arcname)
+{
+  int i;
+
+  fprintf(stderr,"%s: Couldn't find ",prog);
+  for (i=0;TGZsuffix[i];i++)
+    fprintf(stderr,(TGZsuffix[i+1]) ? "%s%s, " : "or %s%s\n",
+            arcname,
+            TGZsuffix[i]);
+  exit(1);
+}
+
+
+/* convert octal digits to int */
+/* on error return -1 */
+
+int getoct (char *p,int width)
+{
+  int result = 0;
+  char c;
+
+  while (width--)
+    {
+      c = *p++;
+      if (c == 0)
+        break;
+      if (c == ' ')
+        continue;
+      if (c < '0' || c > '7')
+        return -1;
+      result = result * 8 + (c - '0');
+    }
+  return result;
+}
+
+
+/* convert time_t to string */
+/* use the "YYYY/MM/DD hh:mm:ss" format */
+
+char *strtime (time_t *t)
+{
+  struct tm   *local;
+  static char result[32];
+
+  local = localtime(t);
+  sprintf(result,"%4d/%02d/%02d %02d:%02d:%02d",
+          local->tm_year+1900, local->tm_mon+1, local->tm_mday,
+          local->tm_hour, local->tm_min, local->tm_sec);
+  return result;
+}
+
+
+/* set file time */
+
+int setfiletime (char *fname,time_t ftime)
+{
+#ifdef WIN32
+  static int isWinNT = -1;
+  SYSTEMTIME st;
+  FILETIME locft, modft;
+  struct tm *loctm;
+  HANDLE hFile;
+  int result;
+
+  loctm = localtime(&ftime);
+  if (loctm == NULL)
+    return -1;
+
+  st.wYear         = (WORD)loctm->tm_year + 1900;
+  st.wMonth        = (WORD)loctm->tm_mon + 1;
+  st.wDayOfWeek    = (WORD)loctm->tm_wday;
+  st.wDay          = (WORD)loctm->tm_mday;
+  st.wHour         = (WORD)loctm->tm_hour;
+  st.wMinute       = (WORD)loctm->tm_min;
+  st.wSecond       = (WORD)loctm->tm_sec;
+  st.wMilliseconds = 0;
+  if (!SystemTimeToFileTime(&st, &locft) ||
+      !LocalFileTimeToFileTime(&locft, &modft))
+    return -1;
+
+  if (isWinNT < 0)
+    isWinNT = (GetVersion() < 0x80000000) ? 1 : 0;
+  hFile = CreateFile(fname, GENERIC_WRITE, 0, NULL, OPEN_EXISTING,
+                     (isWinNT ? FILE_FLAG_BACKUP_SEMANTICS : 0),
+                     NULL);
+  if (hFile == INVALID_HANDLE_VALUE)
+    return -1;
+  result = SetFileTime(hFile, NULL, NULL, &modft) ? 0 : -1;
+  CloseHandle(hFile);
+  return result;
+#else
+  struct utimbuf settime;
+
+  settime.actime = settime.modtime = ftime;
+  return utime(fname,&settime);
+#endif
+}
+
+
+/* push file attributes */
+
+void push_attr(struct attr_item **list,char *fname,int mode,time_t time)
+{
+  struct attr_item *item;
+
+  item = (struct attr_item *)malloc(sizeof(struct attr_item));
+  if (item == NULL)
+    error("Out of memory");
+  item->fname = strdup(fname);
+  item->mode  = mode;
+  item->time  = time;
+  item->next  = *list;
+  *list       = item;
+}
+
+
+/* restore file attributes */
+
+void restore_attr(struct attr_item **list)
+{
+  struct attr_item *item, *prev;
+
+  for (item = *list; item != NULL; )
+    {
+      setfiletime(item->fname,item->time);
+      chmod(item->fname,item->mode);
+      prev = item;
+      item = item->next;
+      free(prev);
+    }
+  *list = NULL;
+}
+
+
+/* match regular expression */
+
+#define ISSPECIAL(c) (((c) == '*') || ((c) == '/'))
+
+int ExprMatch (char *string,char *expr)
+{
+  while (1)
+    {
+      if (ISSPECIAL(*expr))
+        {
+          if (*expr == '/')
+            {
+              if (*string != '\\' && *string != '/')
+                return 0;
+              string ++; expr++;
+            }
+          else if (*expr == '*')
+            {
+              if (*expr ++ == 0)
+                return 1;
+              while (*++string != *expr)
+                if (*string == 0)
+                  return 0;
+            }
+        }
+      else
+        {
+          if (*string != *expr)
+            return 0;
+          if (*expr++ == 0)
+            return 1;
+          string++;
+        }
+    }
+}
+
+
+/* recursive mkdir */
+/* abort on ENOENT; ignore other errors like "directory already exists" */
+/* return 1 if OK */
+/*        0 on error */
+
+int makedir (char *newdir)
+{
+  char *buffer = strdup(newdir);
+  char *p;
+  int  len = strlen(buffer);
+
+  if (len <= 0) {
+    free(buffer);
+    return 0;
+  }
+  if (buffer[len-1] == '/') {
+    buffer[len-1] = '\0';
+  }
+  if (mkdir(buffer, 0755) == 0)
+    {
+      free(buffer);
+      return 1;
+    }
+
+  p = buffer+1;
+  while (1)
+    {
+      char hold;
+
+      while(*p && *p != '\\' && *p != '/')
+        p++;
+      hold = *p;
+      *p = 0;
+      if ((mkdir(buffer, 0755) == -1) && (errno == ENOENT))
+        {
+          fprintf(stderr,"%s: Couldn't create directory %s\n",prog,buffer);
+          free(buffer);
+          return 0;
+        }
+      if (hold == 0)
+        break;
+      *p++ = hold;
+    }
+  free(buffer);
+  return 1;
+}
+
+
+int matchname (int arg,int argc,char **argv,char *fname)
+{
+  if (arg == argc)      /* no arguments given (untgz tgzarchive) */
+    return 1;
+
+  while (arg < argc)
+    if (ExprMatch(fname,argv[arg++]))
+      return 1;
+
+  return 0; /* ignore this for the moment being */
+}
+
+
+/* tar file list or extract */
+
+int tar (gzFile in,int action,int arg,int argc,char **argv)
+{
+  union  tar_buffer buffer;
+  int    len;
+  int    err;
+  int    getheader = 1;
+  int    remaining = 0;
+  FILE   *outfile = NULL;
+  char   fname[BLOCKSIZE];
+  int    tarmode;
+  time_t tartime;
+  struct attr_item *attributes = NULL;
+
+  if (action == TGZ_LIST)
+    printf("    date      time     size                       file\n"
+           " ---------- -------- --------- -------------------------------------\n");
+  while (1)
+    {
+      len = gzread(in, &buffer, BLOCKSIZE);
+      if (len < 0)
+        error(gzerror(in, &err));
+      /*
+       * Always expect complete blocks to process
+       * the tar information.
+       */
+      if (len != BLOCKSIZE)
+        {
+          action = TGZ_INVALID; /* force error exit */
+          remaining = 0;        /* force I/O cleanup */
+        }
+
+      /*
+       * If we have to get a tar header
+       */
+      if (getheader >= 1)
+        {
+          /*
+           * if we met the end of the tar
+           * or the end-of-tar block,
+           * we are done
+           */
+          if (len == 0 || buffer.header.name[0] == 0)
+            break;
+
+          tarmode = getoct(buffer.header.mode,8);
+          tartime = (time_t)getoct(buffer.header.mtime,12);
+          if (tarmode == -1 || tartime == (time_t)-1)
+            {
+              buffer.header.name[0] = 0;
+              action = TGZ_INVALID;
+            }
+
+          if (getheader == 1)
+            {
+              strncpy(fname,buffer.header.name,SHORTNAMESIZE);
+              if (fname[SHORTNAMESIZE-1] != 0)
+                  fname[SHORTNAMESIZE] = 0;
+            }
+          else
+            {
+              /*
+               * The file name is longer than SHORTNAMESIZE
+               */
+              if (strncmp(fname,buffer.header.name,SHORTNAMESIZE-1) != 0)
+                  error("bad long name");
+              getheader = 1;
+            }
+
+          /*
+           * Act according to the type flag
+           */
+          switch (buffer.header.typeflag)
+            {
+            case DIRTYPE:
+              if (action == TGZ_LIST)
+                printf(" %s     <dir> %s\n",strtime(&tartime),fname);
+              if (action == TGZ_EXTRACT)
+                {
+                  makedir(fname);
+                  push_attr(&attributes,fname,tarmode,tartime);
+                }
+              break;
+            case REGTYPE:
+            case AREGTYPE:
+              remaining = getoct(buffer.header.size,12);
+              if (remaining == -1)
+                {
+                  action = TGZ_INVALID;
+                  break;
+                }
+              if (action == TGZ_LIST)
+                printf(" %s %9d %s\n",strtime(&tartime),remaining,fname);
+              else if (action == TGZ_EXTRACT)
+                {
+                  if (matchname(arg,argc,argv,fname))
+                    {
+                      outfile = fopen(fname,"wb");
+                      if (outfile == NULL) {
+                        /* try creating directory */
+                        char *p = strrchr(fname, '/');
+                        if (p != NULL) {
+                          *p = '\0';
+                          makedir(fname);
+                          *p = '/';
+                          outfile = fopen(fname,"wb");
+                        }
+                      }
+                      if (outfile != NULL)
+                        printf("Extracting %s\n",fname);
+                      else
+                        fprintf(stderr, "%s: Couldn't create %s",prog,fname);
+                    }
+                  else
+                    outfile = NULL;
+                }
+              getheader = 0;
+              break;
+            case GNUTYPE_LONGLINK:
+            case GNUTYPE_LONGNAME:
+              remaining = getoct(buffer.header.size,12);
+              if (remaining < 0 || remaining >= BLOCKSIZE)
+                {
+                  action = TGZ_INVALID;
+                  break;
+                }
+              len = gzread(in, fname, BLOCKSIZE);
+              if (len < 0)
+                error(gzerror(in, &err));
+              if (fname[BLOCKSIZE-1] != 0 || (int)strlen(fname) > remaining)
+                {
+                  action = TGZ_INVALID;
+                  break;
+                }
+              getheader = 2;
+              break;
+            default:
+              if (action == TGZ_LIST)
+                printf(" %s     <---> %s\n",strtime(&tartime),fname);
+              break;
+            }
+        }
+      else
+        {
+          unsigned int bytes = (remaining > BLOCKSIZE) ? BLOCKSIZE : remaining;
+
+          if (outfile != NULL)
+            {
+              if (fwrite(&buffer,sizeof(char),bytes,outfile) != bytes)
+                {
+                  fprintf(stderr,
+                    "%s: Error writing %s -- skipping\n",prog,fname);
+                  fclose(outfile);
+                  outfile = NULL;
+                  remove(fname);
+                }
+            }
+          remaining -= bytes;
+        }
+
+      if (remaining == 0)
+        {
+          getheader = 1;
+          if (outfile != NULL)
+            {
+              fclose(outfile);
+              outfile = NULL;
+              if (action != TGZ_INVALID)
+                push_attr(&attributes,fname,tarmode,tartime);
+            }
+        }
+
+      /*
+       * Abandon if errors are found
+       */
+      if (action == TGZ_INVALID)
+        {
+          error("broken archive");
+          break;
+        }
+    }
+
+  /*
+   * Restore file modes and time stamps
+   */
+  restore_attr(&attributes);
+
+  if (gzclose(in) != Z_OK)
+    error("failed gzclose");
+
+  return 0;
+}
+
+
+/* ============================================================ */
+
+void help(int exitval)
+{
+  printf("untgz version 0.2.1\n"
+         "  using zlib version %s\n\n",
+         zlibVersion());
+  printf("Usage: untgz file.tgz            extract all files\n"
+         "       untgz file.tgz fname ...  extract selected files\n"
+         "       untgz -l file.tgz         list archive contents\n"
+         "       untgz -h                  display this help\n");
+  exit(exitval);
+}
+
+void error(const char *msg)
+{
+  fprintf(stderr, "%s: %s\n", prog, msg);
+  exit(1);
+}
+
+
+/* ============================================================ */
+
+#if defined(WIN32) && defined(__GNUC__)
+int _CRT_glob = 0;      /* disable argument globbing in MinGW */
+#endif
+
+int main(int argc,char **argv)
+{
+    int         action = TGZ_EXTRACT;
+    int         arg = 1;
+    char        *TGZfile;
+    gzFile      *f;
+
+    prog = strrchr(argv[0],'\\');
+    if (prog == NULL)
+      {
+        prog = strrchr(argv[0],'/');
+        if (prog == NULL)
+          {
+            prog = strrchr(argv[0],':');
+            if (prog == NULL)
+              prog = argv[0];
+            else
+              prog++;
+          }
+        else
+          prog++;
+      }
+    else
+      prog++;
+
+    if (argc == 1)
+      help(0);
+
+    if (strcmp(argv[arg],"-l") == 0)
+      {
+        action = TGZ_LIST;
+        if (argc == ++arg)
+          help(0);
+      }
+    else if (strcmp(argv[arg],"-h") == 0)
+      {
+        help(0);
+      }
+
+    if ((TGZfile = TGZfname(argv[arg])) == NULL)
+      TGZnotfound(argv[arg]);
+
+    ++arg;
+    if ((action == TGZ_LIST) && (arg != argc))
+      help(1);
+
+/*
+ *  Process the TGZ file
+ */
+    switch(action)
+      {
+      case TGZ_LIST:
+      case TGZ_EXTRACT:
+        f = gzopen(TGZfile,"rb");
+        if (f == NULL)
+          {
+            fprintf(stderr,"%s: Couldn't gzopen %s\n",prog,TGZfile);
+            return 1;
+          }
+        exit(tar(f, action, arg, argc, argv));
+      break;
+
+      default:
+        error("Unknown option");
+        exit(1);
+      }
+
+    return 0;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/crc32.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/crc32.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,442 @@
+/* crc32.c -- compute the CRC-32 of a data stream
+ * Copyright (C) 1995-2006, 2010, 2011, 2012, 2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ *
+ * Thanks to Rodney Brown <rbrown64@csc.com.au> for his contribution of faster
+ * CRC methods: exclusive-oring 32 bits of data at a time, and pre-computing
+ * tables for updating the shift register in one step with three exclusive-ors
+ * instead of four steps with four exclusive-ors.  This results in about a
+ * factor of two increase in speed on a Power PC G4 (PPC7455) using gcc -O3.
+ */
+
+/* @(#) $Id$ */
+
+/*
+  Note on the use of DYNAMIC_CRC_TABLE: there is no mutex or semaphore
+  protection on the static variables used to control the first-use generation
+  of the crc tables.  Therefore, if you #define DYNAMIC_CRC_TABLE, you should
+  first call get_crc_table() to initialize the tables before allowing more than
+  one thread to use crc32().
+
+  DYNAMIC_CRC_TABLE and MAKECRCH can be #defined to write out crc32.h.
+ */
+
+#ifdef MAKECRCH
+#  include <stdio.h>
+#  ifndef DYNAMIC_CRC_TABLE
+#    define DYNAMIC_CRC_TABLE
+#  endif /* !DYNAMIC_CRC_TABLE */
+#endif /* MAKECRCH */
+
+#include "zutil.h"      /* for STDC and FAR definitions */
+
+/* Definitions for doing the crc four data bytes at a time. */
+#if !defined(NOBYFOUR) && defined(Z_U4)
+#  define BYFOUR
+#endif
+#ifdef BYFOUR
+   local unsigned long crc32_little OF((unsigned long,
+                        const unsigned char FAR *, z_size_t));
+   local unsigned long crc32_big OF((unsigned long,
+                        const unsigned char FAR *, z_size_t));
+#  define TBLS 8
+#else
+#  define TBLS 1
+#endif /* BYFOUR */
+
+/* Local functions for crc concatenation */
+local unsigned long gf2_matrix_times OF((unsigned long *mat,
+                                         unsigned long vec));
+local void gf2_matrix_square OF((unsigned long *square, unsigned long *mat));
+local uLong crc32_combine_ OF((uLong crc1, uLong crc2, z_off64_t len2));
+
+
+#ifdef DYNAMIC_CRC_TABLE
+
+local volatile int crc_table_empty = 1;
+local z_crc_t FAR crc_table[TBLS][256];
+local void make_crc_table OF((void));
+#ifdef MAKECRCH
+   local void write_table OF((FILE *, const z_crc_t FAR *));
+#endif /* MAKECRCH */
+/*
+  Generate tables for a byte-wise 32-bit CRC calculation on the polynomial:
+  x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x+1.
+
+  Polynomials over GF(2) are represented in binary, one bit per coefficient,
+  with the lowest powers in the most significant bit.  Then adding polynomials
+  is just exclusive-or, and multiplying a polynomial by x is a right shift by
+  one.  If we call the above polynomial p, and represent a byte as the
+  polynomial q, also with the lowest power in the most significant bit (so the
+  byte 0xb1 is the polynomial x^7+x^3+x+1), then the CRC is (q*x^32) mod p,
+  where a mod b means the remainder after dividing a by b.
+
+  This calculation is done using the shift-register method of multiplying and
+  taking the remainder.  The register is initialized to zero, and for each
+  incoming bit, x^32 is added mod p to the register if the bit is a one (where
+  x^32 mod p is p+x^32 = x^26+...+1), and the register is multiplied mod p by
+  x (which is shifting right by one and adding x^32 mod p if the bit shifted
+  out is a one).  We start with the highest power (least significant bit) of
+  q and repeat for all eight bits of q.
+
+  The first table is simply the CRC of all possible eight bit values.  This is
+  all the information needed to generate CRCs on data a byte at a time for all
+  combinations of CRC register values and incoming bytes.  The remaining tables
+  allow for word-at-a-time CRC calculation for both big-endian and little-
+  endian machines, where a word is four bytes.
+*/
+local void make_crc_table()
+{
+    z_crc_t c;
+    int n, k;
+    z_crc_t poly;                       /* polynomial exclusive-or pattern */
+    /* terms of polynomial defining this crc (except x^32): */
+    static volatile int first = 1;      /* flag to limit concurrent making */
+    static const unsigned char p[] = {0,1,2,4,5,7,8,10,11,12,16,22,23,26};
+
+    /* See if another task is already doing this (not thread-safe, but better
+       than nothing -- significantly reduces duration of vulnerability in
+       case the advice about DYNAMIC_CRC_TABLE is ignored) */
+    if (first) {
+        first = 0;
+
+        /* make exclusive-or pattern from polynomial (0xedb88320UL) */
+        poly = 0;
+        for (n = 0; n < (int)(sizeof(p)/sizeof(unsigned char)); n++)
+            poly |= (z_crc_t)1 << (31 - p[n]);
+
+        /* generate a crc for every 8-bit value */
+        for (n = 0; n < 256; n++) {
+            c = (z_crc_t)n;
+            for (k = 0; k < 8; k++)
+                c = c & 1 ? poly ^ (c >> 1) : c >> 1;
+            crc_table[0][n] = c;
+        }
+
+#ifdef BYFOUR
+        /* generate crc for each value followed by one, two, and three zeros,
+           and then the byte reversal of those as well as the first table */
+        for (n = 0; n < 256; n++) {
+            c = crc_table[0][n];
+            crc_table[4][n] = ZSWAP32(c);
+            for (k = 1; k < 4; k++) {
+                c = crc_table[0][c & 0xff] ^ (c >> 8);
+                crc_table[k][n] = c;
+                crc_table[k + 4][n] = ZSWAP32(c);
+            }
+        }
+#endif /* BYFOUR */
+
+        crc_table_empty = 0;
+    }
+    else {      /* not first */
+        /* wait for the other guy to finish (not efficient, but rare) */
+        while (crc_table_empty)
+            ;
+    }
+
+#ifdef MAKECRCH
+    /* write out CRC tables to crc32.h */
+    {
+        FILE *out;
+
+        out = fopen("crc32.h", "w");
+        if (out == NULL) return;
+        fprintf(out, "/* crc32.h -- tables for rapid CRC calculation\n");
+        fprintf(out, " * Generated automatically by crc32.c\n */\n\n");
+        fprintf(out, "local const z_crc_t FAR ");
+        fprintf(out, "crc_table[TBLS][256] =\n{\n  {\n");
+        write_table(out, crc_table[0]);
+#  ifdef BYFOUR
+        fprintf(out, "#ifdef BYFOUR\n");
+        for (k = 1; k < 8; k++) {
+            fprintf(out, "  },\n  {\n");
+            write_table(out, crc_table[k]);
+        }
+        fprintf(out, "#endif\n");
+#  endif /* BYFOUR */
+        fprintf(out, "  }\n};\n");
+        fclose(out);
+    }
+#endif /* MAKECRCH */
+}
+
+#ifdef MAKECRCH
+local void write_table(out, table)
+    FILE *out;
+    const z_crc_t FAR *table;
+{
+    int n;
+
+    for (n = 0; n < 256; n++)
+        fprintf(out, "%s0x%08lxUL%s", n % 5 ? "" : "    ",
+                (unsigned long)(table[n]),
+                n == 255 ? "\n" : (n % 5 == 4 ? ",\n" : ", "));
+}
+#endif /* MAKECRCH */
+
+#else /* !DYNAMIC_CRC_TABLE */
+/* ========================================================================
+ * Tables of CRC-32s of all single-byte values, made by make_crc_table().
+ */
+#include "crc32.h"
+#endif /* DYNAMIC_CRC_TABLE */
+
+/* =========================================================================
+ * This function can be used by asm versions of crc32()
+ */
+const z_crc_t FAR * ZEXPORT get_crc_table()
+{
+#ifdef DYNAMIC_CRC_TABLE
+    if (crc_table_empty)
+        make_crc_table();
+#endif /* DYNAMIC_CRC_TABLE */
+    return (const z_crc_t FAR *)crc_table;
+}
+
+/* ========================================================================= */
+#define DO1 crc = crc_table[0][((int)crc ^ (*buf++)) & 0xff] ^ (crc >> 8)
+#define DO8 DO1; DO1; DO1; DO1; DO1; DO1; DO1; DO1
+
+/* ========================================================================= */
+unsigned long ZEXPORT crc32_z(crc, buf, len)
+    unsigned long crc;
+    const unsigned char FAR *buf;
+    z_size_t len;
+{
+    if (buf == Z_NULL) return 0UL;
+
+#ifdef DYNAMIC_CRC_TABLE
+    if (crc_table_empty)
+        make_crc_table();
+#endif /* DYNAMIC_CRC_TABLE */
+
+#ifdef BYFOUR
+    if (sizeof(void *) == sizeof(ptrdiff_t)) {
+        z_crc_t endian;
+
+        endian = 1;
+        if (*((unsigned char *)(&endian)))
+            return crc32_little(crc, buf, len);
+        else
+            return crc32_big(crc, buf, len);
+    }
+#endif /* BYFOUR */
+    crc = crc ^ 0xffffffffUL;
+    while (len >= 8) {
+        DO8;
+        len -= 8;
+    }
+    if (len) do {
+        DO1;
+    } while (--len);
+    return crc ^ 0xffffffffUL;
+}
+
+/* ========================================================================= */
+unsigned long ZEXPORT crc32(crc, buf, len)
+    unsigned long crc;
+    const unsigned char FAR *buf;
+    uInt len;
+{
+    return crc32_z(crc, buf, len);
+}
+
+#ifdef BYFOUR
+
+/*
+   This BYFOUR code accesses the passed unsigned char * buffer with a 32-bit
+   integer pointer type. This violates the strict aliasing rule, where a
+   compiler can assume, for optimization purposes, that two pointers to
+   fundamentally different types won't ever point to the same memory. This can
+   manifest as a problem only if one of the pointers is written to. This code
+   only reads from those pointers. So long as this code remains isolated in
+   this compilation unit, there won't be a problem. For this reason, this code
+   should not be copied and pasted into a compilation unit in which other code
+   writes to the buffer that is passed to these routines.
+ */
+
+/* ========================================================================= */
+#define DOLIT4 c ^= *buf4++; \
+        c = crc_table[3][c & 0xff] ^ crc_table[2][(c >> 8) & 0xff] ^ \
+            crc_table[1][(c >> 16) & 0xff] ^ crc_table[0][c >> 24]
+#define DOLIT32 DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4
+
+/* ========================================================================= */
+local unsigned long crc32_little(crc, buf, len)
+    unsigned long crc;
+    const unsigned char FAR *buf;
+    z_size_t len;
+{
+    register z_crc_t c;
+    register const z_crc_t FAR *buf4;
+
+    c = (z_crc_t)crc;
+    c = ~c;
+    while (len && ((ptrdiff_t)buf & 3)) {
+        c = crc_table[0][(c ^ *buf++) & 0xff] ^ (c >> 8);
+        len--;
+    }
+
+    buf4 = (const z_crc_t FAR *)(const void FAR *)buf;
+    while (len >= 32) {
+        DOLIT32;
+        len -= 32;
+    }
+    while (len >= 4) {
+        DOLIT4;
+        len -= 4;
+    }
+    buf = (const unsigned char FAR *)buf4;
+
+    if (len) do {
+        c = crc_table[0][(c ^ *buf++) & 0xff] ^ (c >> 8);
+    } while (--len);
+    c = ~c;
+    return (unsigned long)c;
+}
+
+/* ========================================================================= */
+#define DOBIG4 c ^= *buf4++; \
+        c = crc_table[4][c & 0xff] ^ crc_table[5][(c >> 8) & 0xff] ^ \
+            crc_table[6][(c >> 16) & 0xff] ^ crc_table[7][c >> 24]
+#define DOBIG32 DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4
+
+/* ========================================================================= */
+local unsigned long crc32_big(crc, buf, len)
+    unsigned long crc;
+    const unsigned char FAR *buf;
+    z_size_t len;
+{
+    register z_crc_t c;
+    register const z_crc_t FAR *buf4;
+
+    c = ZSWAP32((z_crc_t)crc);
+    c = ~c;
+    while (len && ((ptrdiff_t)buf & 3)) {
+        c = crc_table[4][(c >> 24) ^ *buf++] ^ (c << 8);
+        len--;
+    }
+
+    buf4 = (const z_crc_t FAR *)(const void FAR *)buf;
+    while (len >= 32) {
+        DOBIG32;
+        len -= 32;
+    }
+    while (len >= 4) {
+        DOBIG4;
+        len -= 4;
+    }
+    buf = (const unsigned char FAR *)buf4;
+
+    if (len) do {
+        c = crc_table[4][(c >> 24) ^ *buf++] ^ (c << 8);
+    } while (--len);
+    c = ~c;
+    return (unsigned long)(ZSWAP32(c));
+}
+
+#endif /* BYFOUR */
+
+#define GF2_DIM 32      /* dimension of GF(2) vectors (length of CRC) */
+
+/* ========================================================================= */
+local unsigned long gf2_matrix_times(mat, vec)
+    unsigned long *mat;
+    unsigned long vec;
+{
+    unsigned long sum;
+
+    sum = 0;
+    while (vec) {
+        if (vec & 1)
+            sum ^= *mat;
+        vec >>= 1;
+        mat++;
+    }
+    return sum;
+}
+
+/* ========================================================================= */
+local void gf2_matrix_square(square, mat)
+    unsigned long *square;
+    unsigned long *mat;
+{
+    int n;
+
+    for (n = 0; n < GF2_DIM; n++)
+        square[n] = gf2_matrix_times(mat, mat[n]);
+}
+
+/* ========================================================================= */
+local uLong crc32_combine_(crc1, crc2, len2)
+    uLong crc1;
+    uLong crc2;
+    z_off64_t len2;
+{
+    int n;
+    unsigned long row;
+    unsigned long even[GF2_DIM];    /* even-power-of-two zeros operator */
+    unsigned long odd[GF2_DIM];     /* odd-power-of-two zeros operator */
+
+    /* degenerate case (also disallow negative lengths) */
+    if (len2 <= 0)
+        return crc1;
+
+    /* put operator for one zero bit in odd */
+    odd[0] = 0xedb88320UL;          /* CRC-32 polynomial */
+    row = 1;
+    for (n = 1; n < GF2_DIM; n++) {
+        odd[n] = row;
+        row <<= 1;
+    }
+
+    /* put operator for two zero bits in even */
+    gf2_matrix_square(even, odd);
+
+    /* put operator for four zero bits in odd */
+    gf2_matrix_square(odd, even);
+
+    /* apply len2 zeros to crc1 (first square will put the operator for one
+       zero byte, eight zero bits, in even) */
+    do {
+        /* apply zeros operator for this bit of len2 */
+        gf2_matrix_square(even, odd);
+        if (len2 & 1)
+            crc1 = gf2_matrix_times(even, crc1);
+        len2 >>= 1;
+
+        /* if no more bits set, then done */
+        if (len2 == 0)
+            break;
+
+        /* another iteration of the loop with odd and even swapped */
+        gf2_matrix_square(odd, even);
+        if (len2 & 1)
+            crc1 = gf2_matrix_times(odd, crc1);
+        len2 >>= 1;
+
+        /* if no more bits set, then done */
+    } while (len2 != 0);
+
+    /* return combined crc */
+    crc1 ^= crc2;
+    return crc1;
+}
+
+/* ========================================================================= */
+uLong ZEXPORT crc32_combine(crc1, crc2, len2)
+    uLong crc1;
+    uLong crc2;
+    z_off_t len2;
+{
+    return crc32_combine_(crc1, crc2, len2);
+}
+
+uLong ZEXPORT crc32_combine64(crc1, crc2, len2)
+    uLong crc1;
+    uLong crc2;
+    z_off64_t len2;
+{
+    return crc32_combine_(crc1, crc2, len2);
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/crc32.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/crc32.h	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,441 @@
+/* crc32.h -- tables for rapid CRC calculation
+ * Generated automatically by crc32.c
+ */
+
+local const z_crc_t FAR crc_table[TBLS][256] =
+{
+  {
+    0x00000000UL, 0x77073096UL, 0xee0e612cUL, 0x990951baUL, 0x076dc419UL,
+    0x706af48fUL, 0xe963a535UL, 0x9e6495a3UL, 0x0edb8832UL, 0x79dcb8a4UL,
+    0xe0d5e91eUL, 0x97d2d988UL, 0x09b64c2bUL, 0x7eb17cbdUL, 0xe7b82d07UL,
+    0x90bf1d91UL, 0x1db71064UL, 0x6ab020f2UL, 0xf3b97148UL, 0x84be41deUL,
+    0x1adad47dUL, 0x6ddde4ebUL, 0xf4d4b551UL, 0x83d385c7UL, 0x136c9856UL,
+    0x646ba8c0UL, 0xfd62f97aUL, 0x8a65c9ecUL, 0x14015c4fUL, 0x63066cd9UL,
+    0xfa0f3d63UL, 0x8d080df5UL, 0x3b6e20c8UL, 0x4c69105eUL, 0xd56041e4UL,
+    0xa2677172UL, 0x3c03e4d1UL, 0x4b04d447UL, 0xd20d85fdUL, 0xa50ab56bUL,
+    0x35b5a8faUL, 0x42b2986cUL, 0xdbbbc9d6UL, 0xacbcf940UL, 0x32d86ce3UL,
+    0x45df5c75UL, 0xdcd60dcfUL, 0xabd13d59UL, 0x26d930acUL, 0x51de003aUL,
+    0xc8d75180UL, 0xbfd06116UL, 0x21b4f4b5UL, 0x56b3c423UL, 0xcfba9599UL,
+    0xb8bda50fUL, 0x2802b89eUL, 0x5f058808UL, 0xc60cd9b2UL, 0xb10be924UL,
+    0x2f6f7c87UL, 0x58684c11UL, 0xc1611dabUL, 0xb6662d3dUL, 0x76dc4190UL,
+    0x01db7106UL, 0x98d220bcUL, 0xefd5102aUL, 0x71b18589UL, 0x06b6b51fUL,
+    0x9fbfe4a5UL, 0xe8b8d433UL, 0x7807c9a2UL, 0x0f00f934UL, 0x9609a88eUL,
+    0xe10e9818UL, 0x7f6a0dbbUL, 0x086d3d2dUL, 0x91646c97UL, 0xe6635c01UL,
+    0x6b6b51f4UL, 0x1c6c6162UL, 0x856530d8UL, 0xf262004eUL, 0x6c0695edUL,
+    0x1b01a57bUL, 0x8208f4c1UL, 0xf50fc457UL, 0x65b0d9c6UL, 0x12b7e950UL,
+    0x8bbeb8eaUL, 0xfcb9887cUL, 0x62dd1ddfUL, 0x15da2d49UL, 0x8cd37cf3UL,
+    0xfbd44c65UL, 0x4db26158UL, 0x3ab551ceUL, 0xa3bc0074UL, 0xd4bb30e2UL,
+    0x4adfa541UL, 0x3dd895d7UL, 0xa4d1c46dUL, 0xd3d6f4fbUL, 0x4369e96aUL,
+    0x346ed9fcUL, 0xad678846UL, 0xda60b8d0UL, 0x44042d73UL, 0x33031de5UL,
+    0xaa0a4c5fUL, 0xdd0d7cc9UL, 0x5005713cUL, 0x270241aaUL, 0xbe0b1010UL,
+    0xc90c2086UL, 0x5768b525UL, 0x206f85b3UL, 0xb966d409UL, 0xce61e49fUL,
+    0x5edef90eUL, 0x29d9c998UL, 0xb0d09822UL, 0xc7d7a8b4UL, 0x59b33d17UL,
+    0x2eb40d81UL, 0xb7bd5c3bUL, 0xc0ba6cadUL, 0xedb88320UL, 0x9abfb3b6UL,
+    0x03b6e20cUL, 0x74b1d29aUL, 0xead54739UL, 0x9dd277afUL, 0x04db2615UL,
+    0x73dc1683UL, 0xe3630b12UL, 0x94643b84UL, 0x0d6d6a3eUL, 0x7a6a5aa8UL,
+    0xe40ecf0bUL, 0x9309ff9dUL, 0x0a00ae27UL, 0x7d079eb1UL, 0xf00f9344UL,
+    0x8708a3d2UL, 0x1e01f268UL, 0x6906c2feUL, 0xf762575dUL, 0x806567cbUL,
+    0x196c3671UL, 0x6e6b06e7UL, 0xfed41b76UL, 0x89d32be0UL, 0x10da7a5aUL,
+    0x67dd4accUL, 0xf9b9df6fUL, 0x8ebeeff9UL, 0x17b7be43UL, 0x60b08ed5UL,
+    0xd6d6a3e8UL, 0xa1d1937eUL, 0x38d8c2c4UL, 0x4fdff252UL, 0xd1bb67f1UL,
+    0xa6bc5767UL, 0x3fb506ddUL, 0x48b2364bUL, 0xd80d2bdaUL, 0xaf0a1b4cUL,
+    0x36034af6UL, 0x41047a60UL, 0xdf60efc3UL, 0xa867df55UL, 0x316e8eefUL,
+    0x4669be79UL, 0xcb61b38cUL, 0xbc66831aUL, 0x256fd2a0UL, 0x5268e236UL,
+    0xcc0c7795UL, 0xbb0b4703UL, 0x220216b9UL, 0x5505262fUL, 0xc5ba3bbeUL,
+    0xb2bd0b28UL, 0x2bb45a92UL, 0x5cb36a04UL, 0xc2d7ffa7UL, 0xb5d0cf31UL,
+    0x2cd99e8bUL, 0x5bdeae1dUL, 0x9b64c2b0UL, 0xec63f226UL, 0x756aa39cUL,
+    0x026d930aUL, 0x9c0906a9UL, 0xeb0e363fUL, 0x72076785UL, 0x05005713UL,
+    0x95bf4a82UL, 0xe2b87a14UL, 0x7bb12baeUL, 0x0cb61b38UL, 0x92d28e9bUL,
+    0xe5d5be0dUL, 0x7cdcefb7UL, 0x0bdbdf21UL, 0x86d3d2d4UL, 0xf1d4e242UL,
+    0x68ddb3f8UL, 0x1fda836eUL, 0x81be16cdUL, 0xf6b9265bUL, 0x6fb077e1UL,
+    0x18b74777UL, 0x88085ae6UL, 0xff0f6a70UL, 0x66063bcaUL, 0x11010b5cUL,
+    0x8f659effUL, 0xf862ae69UL, 0x616bffd3UL, 0x166ccf45UL, 0xa00ae278UL,
+    0xd70dd2eeUL, 0x4e048354UL, 0x3903b3c2UL, 0xa7672661UL, 0xd06016f7UL,
+    0x4969474dUL, 0x3e6e77dbUL, 0xaed16a4aUL, 0xd9d65adcUL, 0x40df0b66UL,
+    0x37d83bf0UL, 0xa9bcae53UL, 0xdebb9ec5UL, 0x47b2cf7fUL, 0x30b5ffe9UL,
+    0xbdbdf21cUL, 0xcabac28aUL, 0x53b39330UL, 0x24b4a3a6UL, 0xbad03605UL,
+    0xcdd70693UL, 0x54de5729UL, 0x23d967bfUL, 0xb3667a2eUL, 0xc4614ab8UL,
+    0x5d681b02UL, 0x2a6f2b94UL, 0xb40bbe37UL, 0xc30c8ea1UL, 0x5a05df1bUL,
+    0x2d02ef8dUL
+#ifdef BYFOUR
+  },
+  {
+    0x00000000UL, 0x191b3141UL, 0x32366282UL, 0x2b2d53c3UL, 0x646cc504UL,
+    0x7d77f445UL, 0x565aa786UL, 0x4f4196c7UL, 0xc8d98a08UL, 0xd1c2bb49UL,
+    0xfaefe88aUL, 0xe3f4d9cbUL, 0xacb54f0cUL, 0xb5ae7e4dUL, 0x9e832d8eUL,
+    0x87981ccfUL, 0x4ac21251UL, 0x53d92310UL, 0x78f470d3UL, 0x61ef4192UL,
+    0x2eaed755UL, 0x37b5e614UL, 0x1c98b5d7UL, 0x05838496UL, 0x821b9859UL,
+    0x9b00a918UL, 0xb02dfadbUL, 0xa936cb9aUL, 0xe6775d5dUL, 0xff6c6c1cUL,
+    0xd4413fdfUL, 0xcd5a0e9eUL, 0x958424a2UL, 0x8c9f15e3UL, 0xa7b24620UL,
+    0xbea97761UL, 0xf1e8e1a6UL, 0xe8f3d0e7UL, 0xc3de8324UL, 0xdac5b265UL,
+    0x5d5daeaaUL, 0x44469febUL, 0x6f6bcc28UL, 0x7670fd69UL, 0x39316baeUL,
+    0x202a5aefUL, 0x0b07092cUL, 0x121c386dUL, 0xdf4636f3UL, 0xc65d07b2UL,
+    0xed705471UL, 0xf46b6530UL, 0xbb2af3f7UL, 0xa231c2b6UL, 0x891c9175UL,
+    0x9007a034UL, 0x179fbcfbUL, 0x0e848dbaUL, 0x25a9de79UL, 0x3cb2ef38UL,
+    0x73f379ffUL, 0x6ae848beUL, 0x41c51b7dUL, 0x58de2a3cUL, 0xf0794f05UL,
+    0xe9627e44UL, 0xc24f2d87UL, 0xdb541cc6UL, 0x94158a01UL, 0x8d0ebb40UL,
+    0xa623e883UL, 0xbf38d9c2UL, 0x38a0c50dUL, 0x21bbf44cUL, 0x0a96a78fUL,
+    0x138d96ceUL, 0x5ccc0009UL, 0x45d73148UL, 0x6efa628bUL, 0x77e153caUL,
+    0xbabb5d54UL, 0xa3a06c15UL, 0x888d3fd6UL, 0x91960e97UL, 0xded79850UL,
+    0xc7cca911UL, 0xece1fad2UL, 0xf5facb93UL, 0x7262d75cUL, 0x6b79e61dUL,
+    0x4054b5deUL, 0x594f849fUL, 0x160e1258UL, 0x0f152319UL, 0x243870daUL,
+    0x3d23419bUL, 0x65fd6ba7UL, 0x7ce65ae6UL, 0x57cb0925UL, 0x4ed03864UL,
+    0x0191aea3UL, 0x188a9fe2UL, 0x33a7cc21UL, 0x2abcfd60UL, 0xad24e1afUL,
+    0xb43fd0eeUL, 0x9f12832dUL, 0x8609b26cUL, 0xc94824abUL, 0xd05315eaUL,
+    0xfb7e4629UL, 0xe2657768UL, 0x2f3f79f6UL, 0x362448b7UL, 0x1d091b74UL,
+    0x04122a35UL, 0x4b53bcf2UL, 0x52488db3UL, 0x7965de70UL, 0x607eef31UL,
+    0xe7e6f3feUL, 0xfefdc2bfUL, 0xd5d0917cUL, 0xcccba03dUL, 0x838a36faUL,
+    0x9a9107bbUL, 0xb1bc5478UL, 0xa8a76539UL, 0x3b83984bUL, 0x2298a90aUL,
+    0x09b5fac9UL, 0x10aecb88UL, 0x5fef5d4fUL, 0x46f46c0eUL, 0x6dd93fcdUL,
+    0x74c20e8cUL, 0xf35a1243UL, 0xea412302UL, 0xc16c70c1UL, 0xd8774180UL,
+    0x9736d747UL, 0x8e2de606UL, 0xa500b5c5UL, 0xbc1b8484UL, 0x71418a1aUL,
+    0x685abb5bUL, 0x4377e898UL, 0x5a6cd9d9UL, 0x152d4f1eUL, 0x0c367e5fUL,
+    0x271b2d9cUL, 0x3e001cddUL, 0xb9980012UL, 0xa0833153UL, 0x8bae6290UL,
+    0x92b553d1UL, 0xddf4c516UL, 0xc4eff457UL, 0xefc2a794UL, 0xf6d996d5UL,
+    0xae07bce9UL, 0xb71c8da8UL, 0x9c31de6bUL, 0x852aef2aUL, 0xca6b79edUL,
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+  },
+  {
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+    0xbe9834edUL
+  },
+  {
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+    0xde0506f1UL
+  },
+  {
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+    0xeed20dd7UL, 0x5483044eUL, 0xc2b30339UL, 0x612667a7UL, 0xf71660d0UL,
+    0x4d476949UL, 0xdb776e3eUL, 0x4a6ad1aeUL, 0xdc5ad6d9UL, 0x660bdf40UL,
+    0xf03bd837UL, 0x53aebca9UL, 0xc59ebbdeUL, 0x7fcfb247UL, 0xe9ffb530UL,
+    0x1cf2bdbdUL, 0x8ac2bacaUL, 0x3093b353UL, 0xa6a3b424UL, 0x0536d0baUL,
+    0x9306d7cdUL, 0x2957de54UL, 0xbf67d923UL, 0x2e7a66b3UL, 0xb84a61c4UL,
+    0x021b685dUL, 0x942b6f2aUL, 0x37be0bb4UL, 0xa18e0cc3UL, 0x1bdf055aUL,
+    0x8def022dUL
+  },
+  {
+    0x00000000UL, 0x41311b19UL, 0x82623632UL, 0xc3532d2bUL, 0x04c56c64UL,
+    0x45f4777dUL, 0x86a75a56UL, 0xc796414fUL, 0x088ad9c8UL, 0x49bbc2d1UL,
+    0x8ae8effaUL, 0xcbd9f4e3UL, 0x0c4fb5acUL, 0x4d7eaeb5UL, 0x8e2d839eUL,
+    0xcf1c9887UL, 0x5112c24aUL, 0x1023d953UL, 0xd370f478UL, 0x9241ef61UL,
+    0x55d7ae2eUL, 0x14e6b537UL, 0xd7b5981cUL, 0x96848305UL, 0x59981b82UL,
+    0x18a9009bUL, 0xdbfa2db0UL, 0x9acb36a9UL, 0x5d5d77e6UL, 0x1c6c6cffUL,
+    0xdf3f41d4UL, 0x9e0e5acdUL, 0xa2248495UL, 0xe3159f8cUL, 0x2046b2a7UL,
+    0x6177a9beUL, 0xa6e1e8f1UL, 0xe7d0f3e8UL, 0x2483dec3UL, 0x65b2c5daUL,
+    0xaaae5d5dUL, 0xeb9f4644UL, 0x28cc6b6fUL, 0x69fd7076UL, 0xae6b3139UL,
+    0xef5a2a20UL, 0x2c09070bUL, 0x6d381c12UL, 0xf33646dfUL, 0xb2075dc6UL,
+    0x715470edUL, 0x30656bf4UL, 0xf7f32abbUL, 0xb6c231a2UL, 0x75911c89UL,
+    0x34a00790UL, 0xfbbc9f17UL, 0xba8d840eUL, 0x79dea925UL, 0x38efb23cUL,
+    0xff79f373UL, 0xbe48e86aUL, 0x7d1bc541UL, 0x3c2ade58UL, 0x054f79f0UL,
+    0x447e62e9UL, 0x872d4fc2UL, 0xc61c54dbUL, 0x018a1594UL, 0x40bb0e8dUL,
+    0x83e823a6UL, 0xc2d938bfUL, 0x0dc5a038UL, 0x4cf4bb21UL, 0x8fa7960aUL,
+    0xce968d13UL, 0x0900cc5cUL, 0x4831d745UL, 0x8b62fa6eUL, 0xca53e177UL,
+    0x545dbbbaUL, 0x156ca0a3UL, 0xd63f8d88UL, 0x970e9691UL, 0x5098d7deUL,
+    0x11a9ccc7UL, 0xd2fae1ecUL, 0x93cbfaf5UL, 0x5cd76272UL, 0x1de6796bUL,
+    0xdeb55440UL, 0x9f844f59UL, 0x58120e16UL, 0x1923150fUL, 0xda703824UL,
+    0x9b41233dUL, 0xa76bfd65UL, 0xe65ae67cUL, 0x2509cb57UL, 0x6438d04eUL,
+    0xa3ae9101UL, 0xe29f8a18UL, 0x21cca733UL, 0x60fdbc2aUL, 0xafe124adUL,
+    0xeed03fb4UL, 0x2d83129fUL, 0x6cb20986UL, 0xab2448c9UL, 0xea1553d0UL,
+    0x29467efbUL, 0x687765e2UL, 0xf6793f2fUL, 0xb7482436UL, 0x741b091dUL,
+    0x352a1204UL, 0xf2bc534bUL, 0xb38d4852UL, 0x70de6579UL, 0x31ef7e60UL,
+    0xfef3e6e7UL, 0xbfc2fdfeUL, 0x7c91d0d5UL, 0x3da0cbccUL, 0xfa368a83UL,
+    0xbb07919aUL, 0x7854bcb1UL, 0x3965a7a8UL, 0x4b98833bUL, 0x0aa99822UL,
+    0xc9fab509UL, 0x88cbae10UL, 0x4f5def5fUL, 0x0e6cf446UL, 0xcd3fd96dUL,
+    0x8c0ec274UL, 0x43125af3UL, 0x022341eaUL, 0xc1706cc1UL, 0x804177d8UL,
+    0x47d73697UL, 0x06e62d8eUL, 0xc5b500a5UL, 0x84841bbcUL, 0x1a8a4171UL,
+    0x5bbb5a68UL, 0x98e87743UL, 0xd9d96c5aUL, 0x1e4f2d15UL, 0x5f7e360cUL,
+    0x9c2d1b27UL, 0xdd1c003eUL, 0x120098b9UL, 0x533183a0UL, 0x9062ae8bUL,
+    0xd153b592UL, 0x16c5f4ddUL, 0x57f4efc4UL, 0x94a7c2efUL, 0xd596d9f6UL,
+    0xe9bc07aeUL, 0xa88d1cb7UL, 0x6bde319cUL, 0x2aef2a85UL, 0xed796bcaUL,
+    0xac4870d3UL, 0x6f1b5df8UL, 0x2e2a46e1UL, 0xe136de66UL, 0xa007c57fUL,
+    0x6354e854UL, 0x2265f34dUL, 0xe5f3b202UL, 0xa4c2a91bUL, 0x67918430UL,
+    0x26a09f29UL, 0xb8aec5e4UL, 0xf99fdefdUL, 0x3accf3d6UL, 0x7bfde8cfUL,
+    0xbc6ba980UL, 0xfd5ab299UL, 0x3e099fb2UL, 0x7f3884abUL, 0xb0241c2cUL,
+    0xf1150735UL, 0x32462a1eUL, 0x73773107UL, 0xb4e17048UL, 0xf5d06b51UL,
+    0x3683467aUL, 0x77b25d63UL, 0x4ed7facbUL, 0x0fe6e1d2UL, 0xccb5ccf9UL,
+    0x8d84d7e0UL, 0x4a1296afUL, 0x0b238db6UL, 0xc870a09dUL, 0x8941bb84UL,
+    0x465d2303UL, 0x076c381aUL, 0xc43f1531UL, 0x850e0e28UL, 0x42984f67UL,
+    0x03a9547eUL, 0xc0fa7955UL, 0x81cb624cUL, 0x1fc53881UL, 0x5ef42398UL,
+    0x9da70eb3UL, 0xdc9615aaUL, 0x1b0054e5UL, 0x5a314ffcUL, 0x996262d7UL,
+    0xd85379ceUL, 0x174fe149UL, 0x567efa50UL, 0x952dd77bUL, 0xd41ccc62UL,
+    0x138a8d2dUL, 0x52bb9634UL, 0x91e8bb1fUL, 0xd0d9a006UL, 0xecf37e5eUL,
+    0xadc26547UL, 0x6e91486cUL, 0x2fa05375UL, 0xe836123aUL, 0xa9070923UL,
+    0x6a542408UL, 0x2b653f11UL, 0xe479a796UL, 0xa548bc8fUL, 0x661b91a4UL,
+    0x272a8abdUL, 0xe0bccbf2UL, 0xa18dd0ebUL, 0x62defdc0UL, 0x23efe6d9UL,
+    0xbde1bc14UL, 0xfcd0a70dUL, 0x3f838a26UL, 0x7eb2913fUL, 0xb924d070UL,
+    0xf815cb69UL, 0x3b46e642UL, 0x7a77fd5bUL, 0xb56b65dcUL, 0xf45a7ec5UL,
+    0x370953eeUL, 0x763848f7UL, 0xb1ae09b8UL, 0xf09f12a1UL, 0x33cc3f8aUL,
+    0x72fd2493UL
+  },
+  {
+    0x00000000UL, 0x376ac201UL, 0x6ed48403UL, 0x59be4602UL, 0xdca80907UL,
+    0xebc2cb06UL, 0xb27c8d04UL, 0x85164f05UL, 0xb851130eUL, 0x8f3bd10fUL,
+    0xd685970dUL, 0xe1ef550cUL, 0x64f91a09UL, 0x5393d808UL, 0x0a2d9e0aUL,
+    0x3d475c0bUL, 0x70a3261cUL, 0x47c9e41dUL, 0x1e77a21fUL, 0x291d601eUL,
+    0xac0b2f1bUL, 0x9b61ed1aUL, 0xc2dfab18UL, 0xf5b56919UL, 0xc8f23512UL,
+    0xff98f713UL, 0xa626b111UL, 0x914c7310UL, 0x145a3c15UL, 0x2330fe14UL,
+    0x7a8eb816UL, 0x4de47a17UL, 0xe0464d38UL, 0xd72c8f39UL, 0x8e92c93bUL,
+    0xb9f80b3aUL, 0x3cee443fUL, 0x0b84863eUL, 0x523ac03cUL, 0x6550023dUL,
+    0x58175e36UL, 0x6f7d9c37UL, 0x36c3da35UL, 0x01a91834UL, 0x84bf5731UL,
+    0xb3d59530UL, 0xea6bd332UL, 0xdd011133UL, 0x90e56b24UL, 0xa78fa925UL,
+    0xfe31ef27UL, 0xc95b2d26UL, 0x4c4d6223UL, 0x7b27a022UL, 0x2299e620UL,
+    0x15f32421UL, 0x28b4782aUL, 0x1fdeba2bUL, 0x4660fc29UL, 0x710a3e28UL,
+    0xf41c712dUL, 0xc376b32cUL, 0x9ac8f52eUL, 0xada2372fUL, 0xc08d9a70UL,
+    0xf7e75871UL, 0xae591e73UL, 0x9933dc72UL, 0x1c259377UL, 0x2b4f5176UL,
+    0x72f11774UL, 0x459bd575UL, 0x78dc897eUL, 0x4fb64b7fUL, 0x16080d7dUL,
+    0x2162cf7cUL, 0xa4748079UL, 0x931e4278UL, 0xcaa0047aUL, 0xfdcac67bUL,
+    0xb02ebc6cUL, 0x87447e6dUL, 0xdefa386fUL, 0xe990fa6eUL, 0x6c86b56bUL,
+    0x5bec776aUL, 0x02523168UL, 0x3538f369UL, 0x087faf62UL, 0x3f156d63UL,
+    0x66ab2b61UL, 0x51c1e960UL, 0xd4d7a665UL, 0xe3bd6464UL, 0xba032266UL,
+    0x8d69e067UL, 0x20cbd748UL, 0x17a11549UL, 0x4e1f534bUL, 0x7975914aUL,
+    0xfc63de4fUL, 0xcb091c4eUL, 0x92b75a4cUL, 0xa5dd984dUL, 0x989ac446UL,
+    0xaff00647UL, 0xf64e4045UL, 0xc1248244UL, 0x4432cd41UL, 0x73580f40UL,
+    0x2ae64942UL, 0x1d8c8b43UL, 0x5068f154UL, 0x67023355UL, 0x3ebc7557UL,
+    0x09d6b756UL, 0x8cc0f853UL, 0xbbaa3a52UL, 0xe2147c50UL, 0xd57ebe51UL,
+    0xe839e25aUL, 0xdf53205bUL, 0x86ed6659UL, 0xb187a458UL, 0x3491eb5dUL,
+    0x03fb295cUL, 0x5a456f5eUL, 0x6d2fad5fUL, 0x801b35e1UL, 0xb771f7e0UL,
+    0xeecfb1e2UL, 0xd9a573e3UL, 0x5cb33ce6UL, 0x6bd9fee7UL, 0x3267b8e5UL,
+    0x050d7ae4UL, 0x384a26efUL, 0x0f20e4eeUL, 0x569ea2ecUL, 0x61f460edUL,
+    0xe4e22fe8UL, 0xd388ede9UL, 0x8a36abebUL, 0xbd5c69eaUL, 0xf0b813fdUL,
+    0xc7d2d1fcUL, 0x9e6c97feUL, 0xa90655ffUL, 0x2c101afaUL, 0x1b7ad8fbUL,
+    0x42c49ef9UL, 0x75ae5cf8UL, 0x48e900f3UL, 0x7f83c2f2UL, 0x263d84f0UL,
+    0x115746f1UL, 0x944109f4UL, 0xa32bcbf5UL, 0xfa958df7UL, 0xcdff4ff6UL,
+    0x605d78d9UL, 0x5737bad8UL, 0x0e89fcdaUL, 0x39e33edbUL, 0xbcf571deUL,
+    0x8b9fb3dfUL, 0xd221f5ddUL, 0xe54b37dcUL, 0xd80c6bd7UL, 0xef66a9d6UL,
+    0xb6d8efd4UL, 0x81b22dd5UL, 0x04a462d0UL, 0x33cea0d1UL, 0x6a70e6d3UL,
+    0x5d1a24d2UL, 0x10fe5ec5UL, 0x27949cc4UL, 0x7e2adac6UL, 0x494018c7UL,
+    0xcc5657c2UL, 0xfb3c95c3UL, 0xa282d3c1UL, 0x95e811c0UL, 0xa8af4dcbUL,
+    0x9fc58fcaUL, 0xc67bc9c8UL, 0xf1110bc9UL, 0x740744ccUL, 0x436d86cdUL,
+    0x1ad3c0cfUL, 0x2db902ceUL, 0x4096af91UL, 0x77fc6d90UL, 0x2e422b92UL,
+    0x1928e993UL, 0x9c3ea696UL, 0xab546497UL, 0xf2ea2295UL, 0xc580e094UL,
+    0xf8c7bc9fUL, 0xcfad7e9eUL, 0x9613389cUL, 0xa179fa9dUL, 0x246fb598UL,
+    0x13057799UL, 0x4abb319bUL, 0x7dd1f39aUL, 0x3035898dUL, 0x075f4b8cUL,
+    0x5ee10d8eUL, 0x698bcf8fUL, 0xec9d808aUL, 0xdbf7428bUL, 0x82490489UL,
+    0xb523c688UL, 0x88649a83UL, 0xbf0e5882UL, 0xe6b01e80UL, 0xd1dadc81UL,
+    0x54cc9384UL, 0x63a65185UL, 0x3a181787UL, 0x0d72d586UL, 0xa0d0e2a9UL,
+    0x97ba20a8UL, 0xce0466aaUL, 0xf96ea4abUL, 0x7c78ebaeUL, 0x4b1229afUL,
+    0x12ac6fadUL, 0x25c6adacUL, 0x1881f1a7UL, 0x2feb33a6UL, 0x765575a4UL,
+    0x413fb7a5UL, 0xc429f8a0UL, 0xf3433aa1UL, 0xaafd7ca3UL, 0x9d97bea2UL,
+    0xd073c4b5UL, 0xe71906b4UL, 0xbea740b6UL, 0x89cd82b7UL, 0x0cdbcdb2UL,
+    0x3bb10fb3UL, 0x620f49b1UL, 0x55658bb0UL, 0x6822d7bbUL, 0x5f4815baUL,
+    0x06f653b8UL, 0x319c91b9UL, 0xb48adebcUL, 0x83e01cbdUL, 0xda5e5abfUL,
+    0xed3498beUL
+  },
+  {
+    0x00000000UL, 0x6567bcb8UL, 0x8bc809aaUL, 0xeeafb512UL, 0x5797628fUL,
+    0x32f0de37UL, 0xdc5f6b25UL, 0xb938d79dUL, 0xef28b4c5UL, 0x8a4f087dUL,
+    0x64e0bd6fUL, 0x018701d7UL, 0xb8bfd64aUL, 0xddd86af2UL, 0x3377dfe0UL,
+    0x56106358UL, 0x9f571950UL, 0xfa30a5e8UL, 0x149f10faUL, 0x71f8ac42UL,
+    0xc8c07bdfUL, 0xada7c767UL, 0x43087275UL, 0x266fcecdUL, 0x707fad95UL,
+    0x1518112dUL, 0xfbb7a43fUL, 0x9ed01887UL, 0x27e8cf1aUL, 0x428f73a2UL,
+    0xac20c6b0UL, 0xc9477a08UL, 0x3eaf32a0UL, 0x5bc88e18UL, 0xb5673b0aUL,
+    0xd00087b2UL, 0x6938502fUL, 0x0c5fec97UL, 0xe2f05985UL, 0x8797e53dUL,
+    0xd1878665UL, 0xb4e03addUL, 0x5a4f8fcfUL, 0x3f283377UL, 0x8610e4eaUL,
+    0xe3775852UL, 0x0dd8ed40UL, 0x68bf51f8UL, 0xa1f82bf0UL, 0xc49f9748UL,
+    0x2a30225aUL, 0x4f579ee2UL, 0xf66f497fUL, 0x9308f5c7UL, 0x7da740d5UL,
+    0x18c0fc6dUL, 0x4ed09f35UL, 0x2bb7238dUL, 0xc518969fUL, 0xa07f2a27UL,
+    0x1947fdbaUL, 0x7c204102UL, 0x928ff410UL, 0xf7e848a8UL, 0x3d58149bUL,
+    0x583fa823UL, 0xb6901d31UL, 0xd3f7a189UL, 0x6acf7614UL, 0x0fa8caacUL,
+    0xe1077fbeUL, 0x8460c306UL, 0xd270a05eUL, 0xb7171ce6UL, 0x59b8a9f4UL,
+    0x3cdf154cUL, 0x85e7c2d1UL, 0xe0807e69UL, 0x0e2fcb7bUL, 0x6b4877c3UL,
+    0xa20f0dcbUL, 0xc768b173UL, 0x29c70461UL, 0x4ca0b8d9UL, 0xf5986f44UL,
+    0x90ffd3fcUL, 0x7e5066eeUL, 0x1b37da56UL, 0x4d27b90eUL, 0x284005b6UL,
+    0xc6efb0a4UL, 0xa3880c1cUL, 0x1ab0db81UL, 0x7fd76739UL, 0x9178d22bUL,
+    0xf41f6e93UL, 0x03f7263bUL, 0x66909a83UL, 0x883f2f91UL, 0xed589329UL,
+    0x546044b4UL, 0x3107f80cUL, 0xdfa84d1eUL, 0xbacff1a6UL, 0xecdf92feUL,
+    0x89b82e46UL, 0x67179b54UL, 0x027027ecUL, 0xbb48f071UL, 0xde2f4cc9UL,
+    0x3080f9dbUL, 0x55e74563UL, 0x9ca03f6bUL, 0xf9c783d3UL, 0x176836c1UL,
+    0x720f8a79UL, 0xcb375de4UL, 0xae50e15cUL, 0x40ff544eUL, 0x2598e8f6UL,
+    0x73888baeUL, 0x16ef3716UL, 0xf8408204UL, 0x9d273ebcUL, 0x241fe921UL,
+    0x41785599UL, 0xafd7e08bUL, 0xcab05c33UL, 0x3bb659edUL, 0x5ed1e555UL,
+    0xb07e5047UL, 0xd519ecffUL, 0x6c213b62UL, 0x094687daUL, 0xe7e932c8UL,
+    0x828e8e70UL, 0xd49eed28UL, 0xb1f95190UL, 0x5f56e482UL, 0x3a31583aUL,
+    0x83098fa7UL, 0xe66e331fUL, 0x08c1860dUL, 0x6da63ab5UL, 0xa4e140bdUL,
+    0xc186fc05UL, 0x2f294917UL, 0x4a4ef5afUL, 0xf3762232UL, 0x96119e8aUL,
+    0x78be2b98UL, 0x1dd99720UL, 0x4bc9f478UL, 0x2eae48c0UL, 0xc001fdd2UL,
+    0xa566416aUL, 0x1c5e96f7UL, 0x79392a4fUL, 0x97969f5dUL, 0xf2f123e5UL,
+    0x05196b4dUL, 0x607ed7f5UL, 0x8ed162e7UL, 0xebb6de5fUL, 0x528e09c2UL,
+    0x37e9b57aUL, 0xd9460068UL, 0xbc21bcd0UL, 0xea31df88UL, 0x8f566330UL,
+    0x61f9d622UL, 0x049e6a9aUL, 0xbda6bd07UL, 0xd8c101bfUL, 0x366eb4adUL,
+    0x53090815UL, 0x9a4e721dUL, 0xff29cea5UL, 0x11867bb7UL, 0x74e1c70fUL,
+    0xcdd91092UL, 0xa8beac2aUL, 0x46111938UL, 0x2376a580UL, 0x7566c6d8UL,
+    0x10017a60UL, 0xfeaecf72UL, 0x9bc973caUL, 0x22f1a457UL, 0x479618efUL,
+    0xa939adfdUL, 0xcc5e1145UL, 0x06ee4d76UL, 0x6389f1ceUL, 0x8d2644dcUL,
+    0xe841f864UL, 0x51792ff9UL, 0x341e9341UL, 0xdab12653UL, 0xbfd69aebUL,
+    0xe9c6f9b3UL, 0x8ca1450bUL, 0x620ef019UL, 0x07694ca1UL, 0xbe519b3cUL,
+    0xdb362784UL, 0x35999296UL, 0x50fe2e2eUL, 0x99b95426UL, 0xfcdee89eUL,
+    0x12715d8cUL, 0x7716e134UL, 0xce2e36a9UL, 0xab498a11UL, 0x45e63f03UL,
+    0x208183bbUL, 0x7691e0e3UL, 0x13f65c5bUL, 0xfd59e949UL, 0x983e55f1UL,
+    0x2106826cUL, 0x44613ed4UL, 0xaace8bc6UL, 0xcfa9377eUL, 0x38417fd6UL,
+    0x5d26c36eUL, 0xb389767cUL, 0xd6eecac4UL, 0x6fd61d59UL, 0x0ab1a1e1UL,
+    0xe41e14f3UL, 0x8179a84bUL, 0xd769cb13UL, 0xb20e77abUL, 0x5ca1c2b9UL,
+    0x39c67e01UL, 0x80fea99cUL, 0xe5991524UL, 0x0b36a036UL, 0x6e511c8eUL,
+    0xa7166686UL, 0xc271da3eUL, 0x2cde6f2cUL, 0x49b9d394UL, 0xf0810409UL,
+    0x95e6b8b1UL, 0x7b490da3UL, 0x1e2eb11bUL, 0x483ed243UL, 0x2d596efbUL,
+    0xc3f6dbe9UL, 0xa6916751UL, 0x1fa9b0ccUL, 0x7ace0c74UL, 0x9461b966UL,
+    0xf10605deUL
+#endif
+  }
+};
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/deflate.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/deflate.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,2163 @@
+/* deflate.c -- compress data using the deflation algorithm
+ * Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/*
+ *  ALGORITHM
+ *
+ *      The "deflation" process depends on being able to identify portions
+ *      of the input text which are identical to earlier input (within a
+ *      sliding window trailing behind the input currently being processed).
+ *
+ *      The most straightforward technique turns out to be the fastest for
+ *      most input files: try all possible matches and select the longest.
+ *      The key feature of this algorithm is that insertions into the string
+ *      dictionary are very simple and thus fast, and deletions are avoided
+ *      completely. Insertions are performed at each input character, whereas
+ *      string matches are performed only when the previous match ends. So it
+ *      is preferable to spend more time in matches to allow very fast string
+ *      insertions and avoid deletions. The matching algorithm for small
+ *      strings is inspired from that of Rabin & Karp. A brute force approach
+ *      is used to find longer strings when a small match has been found.
+ *      A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
+ *      (by Leonid Broukhis).
+ *         A previous version of this file used a more sophisticated algorithm
+ *      (by Fiala and Greene) which is guaranteed to run in linear amortized
+ *      time, but has a larger average cost, uses more memory and is patented.
+ *      However the F&G algorithm may be faster for some highly redundant
+ *      files if the parameter max_chain_length (described below) is too large.
+ *
+ *  ACKNOWLEDGEMENTS
+ *
+ *      The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
+ *      I found it in 'freeze' written by Leonid Broukhis.
+ *      Thanks to many people for bug reports and testing.
+ *
+ *  REFERENCES
+ *
+ *      Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
+ *      Available in http://tools.ietf.org/html/rfc1951
+ *
+ *      A description of the Rabin and Karp algorithm is given in the book
+ *         "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
+ *
+ *      Fiala,E.R., and Greene,D.H.
+ *         Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
+ *
+ */
+
+/* @(#) $Id$ */
+
+#include "deflate.h"
+
+const char deflate_copyright[] =
+   " deflate 1.2.11 Copyright 1995-2017 Jean-loup Gailly and Mark Adler ";
+/*
+  If you use the zlib library in a product, an acknowledgment is welcome
+  in the documentation of your product. If for some reason you cannot
+  include such an acknowledgment, I would appreciate that you keep this
+  copyright string in the executable of your product.
+ */
+
+/* ===========================================================================
+ *  Function prototypes.
+ */
+typedef enum {
+    need_more,      /* block not completed, need more input or more output */
+    block_done,     /* block flush performed */
+    finish_started, /* finish started, need only more output at next deflate */
+    finish_done     /* finish done, accept no more input or output */
+} block_state;
+
+typedef block_state (*compress_func) OF((deflate_state *s, int flush));
+/* Compression function. Returns the block state after the call. */
+
+local int deflateStateCheck      OF((z_streamp strm));
+local void slide_hash     OF((deflate_state *s));
+local void fill_window    OF((deflate_state *s));
+local block_state deflate_stored OF((deflate_state *s, int flush));
+local block_state deflate_fast   OF((deflate_state *s, int flush));
+#ifndef FASTEST
+local block_state deflate_slow   OF((deflate_state *s, int flush));
+#endif
+local block_state deflate_rle    OF((deflate_state *s, int flush));
+local block_state deflate_huff   OF((deflate_state *s, int flush));
+local void lm_init        OF((deflate_state *s));
+local void putShortMSB    OF((deflate_state *s, uInt b));
+local void flush_pending  OF((z_streamp strm));
+local unsigned read_buf   OF((z_streamp strm, Bytef *buf, unsigned size));
+#ifdef ASMV
+#  pragma message("Assembler code may have bugs -- use at your own risk")
+      void match_init OF((void)); /* asm code initialization */
+      uInt longest_match  OF((deflate_state *s, IPos cur_match));
+#else
+local uInt longest_match  OF((deflate_state *s, IPos cur_match));
+#endif
+
+#ifdef ZLIB_DEBUG
+local  void check_match OF((deflate_state *s, IPos start, IPos match,
+                            int length));
+#endif
+
+/* ===========================================================================
+ * Local data
+ */
+
+#define NIL 0
+/* Tail of hash chains */
+
+#ifndef TOO_FAR
+#  define TOO_FAR 4096
+#endif
+/* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
+
+/* Values for max_lazy_match, good_match and max_chain_length, depending on
+ * the desired pack level (0..9). The values given below have been tuned to
+ * exclude worst case performance for pathological files. Better values may be
+ * found for specific files.
+ */
+typedef struct config_s {
+   ush good_length; /* reduce lazy search above this match length */
+   ush max_lazy;    /* do not perform lazy search above this match length */
+   ush nice_length; /* quit search above this match length */
+   ush max_chain;
+   compress_func func;
+} config;
+
+#ifdef FASTEST
+local const config configuration_table[2] = {
+/*      good lazy nice chain */
+/* 0 */ {0,    0,  0,    0, deflate_stored},  /* store only */
+/* 1 */ {4,    4,  8,    4, deflate_fast}}; /* max speed, no lazy matches */
+#else
+local const config configuration_table[10] = {
+/*      good lazy nice chain */
+/* 0 */ {0,    0,  0,    0, deflate_stored},  /* store only */
+/* 1 */ {4,    4,  8,    4, deflate_fast}, /* max speed, no lazy matches */
+/* 2 */ {4,    5, 16,    8, deflate_fast},
+/* 3 */ {4,    6, 32,   32, deflate_fast},
+
+/* 4 */ {4,    4, 16,   16, deflate_slow},  /* lazy matches */
+/* 5 */ {8,   16, 32,   32, deflate_slow},
+/* 6 */ {8,   16, 128, 128, deflate_slow},
+/* 7 */ {8,   32, 128, 256, deflate_slow},
+/* 8 */ {32, 128, 258, 1024, deflate_slow},
+/* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* max compression */
+#endif
+
+/* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
+ * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
+ * meaning.
+ */
+
+/* rank Z_BLOCK between Z_NO_FLUSH and Z_PARTIAL_FLUSH */
+#define RANK(f) (((f) * 2) - ((f) > 4 ? 9 : 0))
+
+/* ===========================================================================
+ * Update a hash value with the given input byte
+ * IN  assertion: all calls to UPDATE_HASH are made with consecutive input
+ *    characters, so that a running hash key can be computed from the previous
+ *    key instead of complete recalculation each time.
+ */
+#define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
+
+
+/* ===========================================================================
+ * Insert string str in the dictionary and set match_head to the previous head
+ * of the hash chain (the most recent string with same hash key). Return
+ * the previous length of the hash chain.
+ * If this file is compiled with -DFASTEST, the compression level is forced
+ * to 1, and no hash chains are maintained.
+ * IN  assertion: all calls to INSERT_STRING are made with consecutive input
+ *    characters and the first MIN_MATCH bytes of str are valid (except for
+ *    the last MIN_MATCH-1 bytes of the input file).
+ */
+#ifdef FASTEST
+#define INSERT_STRING(s, str, match_head) \
+   (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
+    match_head = s->head[s->ins_h], \
+    s->head[s->ins_h] = (Pos)(str))
+#else
+#define INSERT_STRING(s, str, match_head) \
+   (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
+    match_head = s->prev[(str) & s->w_mask] = s->head[s->ins_h], \
+    s->head[s->ins_h] = (Pos)(str))
+#endif
+
+/* ===========================================================================
+ * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
+ * prev[] will be initialized on the fly.
+ */
+#define CLEAR_HASH(s) \
+    s->head[s->hash_size-1] = NIL; \
+    zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
+
+/* ===========================================================================
+ * Slide the hash table when sliding the window down (could be avoided with 32
+ * bit values at the expense of memory usage). We slide even when level == 0 to
+ * keep the hash table consistent if we switch back to level > 0 later.
+ */
+local void slide_hash(s)
+    deflate_state *s;
+{
+    unsigned n, m;
+    Posf *p;
+    uInt wsize = s->w_size;
+
+    n = s->hash_size;
+    p = &s->head[n];
+    do {
+        m = *--p;
+        *p = (Pos)(m >= wsize ? m - wsize : NIL);
+    } while (--n);
+    n = wsize;
+#ifndef FASTEST
+    p = &s->prev[n];
+    do {
+        m = *--p;
+        *p = (Pos)(m >= wsize ? m - wsize : NIL);
+        /* If n is not on any hash chain, prev[n] is garbage but
+         * its value will never be used.
+         */
+    } while (--n);
+#endif
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateInit_(strm, level, version, stream_size)
+    z_streamp strm;
+    int level;
+    const char *version;
+    int stream_size;
+{
+    return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
+                         Z_DEFAULT_STRATEGY, version, stream_size);
+    /* To do: ignore strm->next_in if we use it as window */
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
+                  version, stream_size)
+    z_streamp strm;
+    int  level;
+    int  method;
+    int  windowBits;
+    int  memLevel;
+    int  strategy;
+    const char *version;
+    int stream_size;
+{
+    deflate_state *s;
+    int wrap = 1;
+    static const char my_version[] = ZLIB_VERSION;
+
+    ushf *overlay;
+    /* We overlay pending_buf and d_buf+l_buf. This works since the average
+     * output size for (length,distance) codes is <= 24 bits.
+     */
+
+    if (version == Z_NULL || version[0] != my_version[0] ||
+        stream_size != sizeof(z_stream)) {
+        return Z_VERSION_ERROR;
+    }
+    if (strm == Z_NULL) return Z_STREAM_ERROR;
+
+    strm->msg = Z_NULL;
+    if (strm->zalloc == (alloc_func)0) {
+#ifdef Z_SOLO
+        return Z_STREAM_ERROR;
+#else
+        strm->zalloc = zcalloc;
+        strm->opaque = (voidpf)0;
+#endif
+    }
+    if (strm->zfree == (free_func)0)
+#ifdef Z_SOLO
+        return Z_STREAM_ERROR;
+#else
+        strm->zfree = zcfree;
+#endif
+
+#ifdef FASTEST
+    if (level != 0) level = 1;
+#else
+    if (level == Z_DEFAULT_COMPRESSION) level = 6;
+#endif
+
+    if (windowBits < 0) { /* suppress zlib wrapper */
+        wrap = 0;
+        windowBits = -windowBits;
+    }
+#ifdef GZIP
+    else if (windowBits > 15) {
+        wrap = 2;       /* write gzip wrapper instead */
+        windowBits -= 16;
+    }
+#endif
+    if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
+        windowBits < 8 || windowBits > 15 || level < 0 || level > 9 ||
+        strategy < 0 || strategy > Z_FIXED || (windowBits == 8 && wrap != 1)) {
+        return Z_STREAM_ERROR;
+    }
+    if (windowBits == 8) windowBits = 9;  /* until 256-byte window bug fixed */
+    s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
+    if (s == Z_NULL) return Z_MEM_ERROR;
+    strm->state = (struct internal_state FAR *)s;
+    s->strm = strm;
+    s->status = INIT_STATE;     /* to pass state test in deflateReset() */
+
+    s->wrap = wrap;
+    s->gzhead = Z_NULL;
+    s->w_bits = (uInt)windowBits;
+    s->w_size = 1 << s->w_bits;
+    s->w_mask = s->w_size - 1;
+
+    s->hash_bits = (uInt)memLevel + 7;
+    s->hash_size = 1 << s->hash_bits;
+    s->hash_mask = s->hash_size - 1;
+    s->hash_shift =  ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
+
+    s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
+    s->prev   = (Posf *)  ZALLOC(strm, s->w_size, sizeof(Pos));
+    s->head   = (Posf *)  ZALLOC(strm, s->hash_size, sizeof(Pos));
+
+    s->high_water = 0;      /* nothing written to s->window yet */
+
+    s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
+
+    overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
+    s->pending_buf = (uchf *) overlay;
+    s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
+
+    if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
+        s->pending_buf == Z_NULL) {
+        s->status = FINISH_STATE;
+        strm->msg = ERR_MSG(Z_MEM_ERROR);
+        deflateEnd (strm);
+        return Z_MEM_ERROR;
+    }
+    s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
+    s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
+
+    s->level = level;
+    s->strategy = strategy;
+    s->method = (Byte)method;
+
+    return deflateReset(strm);
+}
+
+/* =========================================================================
+ * Check for a valid deflate stream state. Return 0 if ok, 1 if not.
+ */
+local int deflateStateCheck (strm)
+    z_streamp strm;
+{
+    deflate_state *s;
+    if (strm == Z_NULL ||
+        strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
+        return 1;
+    s = strm->state;
+    if (s == Z_NULL || s->strm != strm || (s->status != INIT_STATE &&
+#ifdef GZIP
+                                           s->status != GZIP_STATE &&
+#endif
+                                           s->status != EXTRA_STATE &&
+                                           s->status != NAME_STATE &&
+                                           s->status != COMMENT_STATE &&
+                                           s->status != HCRC_STATE &&
+                                           s->status != BUSY_STATE &&
+                                           s->status != FINISH_STATE))
+        return 1;
+    return 0;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength)
+    z_streamp strm;
+    const Bytef *dictionary;
+    uInt  dictLength;
+{
+    deflate_state *s;
+    uInt str, n;
+    int wrap;
+    unsigned avail;
+    z_const unsigned char *next;
+
+    if (deflateStateCheck(strm) || dictionary == Z_NULL)
+        return Z_STREAM_ERROR;
+    s = strm->state;
+    wrap = s->wrap;
+    if (wrap == 2 || (wrap == 1 && s->status != INIT_STATE) || s->lookahead)
+        return Z_STREAM_ERROR;
+
+    /* when using zlib wrappers, compute Adler-32 for provided dictionary */
+    if (wrap == 1)
+        strm->adler = adler32(strm->adler, dictionary, dictLength);
+    s->wrap = 0;                    /* avoid computing Adler-32 in read_buf */
+
+    /* if dictionary would fill window, just replace the history */
+    if (dictLength >= s->w_size) {
+        if (wrap == 0) {            /* already empty otherwise */
+            CLEAR_HASH(s);
+            s->strstart = 0;
+            s->block_start = 0L;
+            s->insert = 0;
+        }
+        dictionary += dictLength - s->w_size;  /* use the tail */
+        dictLength = s->w_size;
+    }
+
+    /* insert dictionary into window and hash */
+    avail = strm->avail_in;
+    next = strm->next_in;
+    strm->avail_in = dictLength;
+    strm->next_in = (z_const Bytef *)dictionary;
+    fill_window(s);
+    while (s->lookahead >= MIN_MATCH) {
+        str = s->strstart;
+        n = s->lookahead - (MIN_MATCH-1);
+        do {
+            UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]);
+#ifndef FASTEST
+            s->prev[str & s->w_mask] = s->head[s->ins_h];
+#endif
+            s->head[s->ins_h] = (Pos)str;
+            str++;
+        } while (--n);
+        s->strstart = str;
+        s->lookahead = MIN_MATCH-1;
+        fill_window(s);
+    }
+    s->strstart += s->lookahead;
+    s->block_start = (long)s->strstart;
+    s->insert = s->lookahead;
+    s->lookahead = 0;
+    s->match_length = s->prev_length = MIN_MATCH-1;
+    s->match_available = 0;
+    strm->next_in = next;
+    strm->avail_in = avail;
+    s->wrap = wrap;
+    return Z_OK;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateGetDictionary (strm, dictionary, dictLength)
+    z_streamp strm;
+    Bytef *dictionary;
+    uInt  *dictLength;
+{
+    deflate_state *s;
+    uInt len;
+
+    if (deflateStateCheck(strm))
+        return Z_STREAM_ERROR;
+    s = strm->state;
+    len = s->strstart + s->lookahead;
+    if (len > s->w_size)
+        len = s->w_size;
+    if (dictionary != Z_NULL && len)
+        zmemcpy(dictionary, s->window + s->strstart + s->lookahead - len, len);
+    if (dictLength != Z_NULL)
+        *dictLength = len;
+    return Z_OK;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateResetKeep (strm)
+    z_streamp strm;
+{
+    deflate_state *s;
+
+    if (deflateStateCheck(strm)) {
+        return Z_STREAM_ERROR;
+    }
+
+    strm->total_in = strm->total_out = 0;
+    strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
+    strm->data_type = Z_UNKNOWN;
+
+    s = (deflate_state *)strm->state;
+    s->pending = 0;
+    s->pending_out = s->pending_buf;
+
+    if (s->wrap < 0) {
+        s->wrap = -s->wrap; /* was made negative by deflate(..., Z_FINISH); */
+    }
+    s->status =
+#ifdef GZIP
+        s->wrap == 2 ? GZIP_STATE :
+#endif
+        s->wrap ? INIT_STATE : BUSY_STATE;
+    strm->adler =
+#ifdef GZIP
+        s->wrap == 2 ? crc32(0L, Z_NULL, 0) :
+#endif
+        adler32(0L, Z_NULL, 0);
+    s->last_flush = Z_NO_FLUSH;
+
+    _tr_init(s);
+
+    return Z_OK;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateReset (strm)
+    z_streamp strm;
+{
+    int ret;
+
+    ret = deflateResetKeep(strm);
+    if (ret == Z_OK)
+        lm_init(strm->state);
+    return ret;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateSetHeader (strm, head)
+    z_streamp strm;
+    gz_headerp head;
+{
+    if (deflateStateCheck(strm) || strm->state->wrap != 2)
+        return Z_STREAM_ERROR;
+    strm->state->gzhead = head;
+    return Z_OK;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflatePending (strm, pending, bits)
+    unsigned *pending;
+    int *bits;
+    z_streamp strm;
+{
+    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
+    if (pending != Z_NULL)
+        *pending = strm->state->pending;
+    if (bits != Z_NULL)
+        *bits = strm->state->bi_valid;
+    return Z_OK;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflatePrime (strm, bits, value)
+    z_streamp strm;
+    int bits;
+    int value;
+{
+    deflate_state *s;
+    int put;
+
+    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
+    s = strm->state;
+    if ((Bytef *)(s->d_buf) < s->pending_out + ((Buf_size + 7) >> 3))
+        return Z_BUF_ERROR;
+    do {
+        put = Buf_size - s->bi_valid;
+        if (put > bits)
+            put = bits;
+        s->bi_buf |= (ush)((value & ((1 << put) - 1)) << s->bi_valid);
+        s->bi_valid += put;
+        _tr_flush_bits(s);
+        value >>= put;
+        bits -= put;
+    } while (bits);
+    return Z_OK;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateParams(strm, level, strategy)
+    z_streamp strm;
+    int level;
+    int strategy;
+{
+    deflate_state *s;
+    compress_func func;
+
+    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
+    s = strm->state;
+
+#ifdef FASTEST
+    if (level != 0) level = 1;
+#else
+    if (level == Z_DEFAULT_COMPRESSION) level = 6;
+#endif
+    if (level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) {
+        return Z_STREAM_ERROR;
+    }
+    func = configuration_table[s->level].func;
+
+    if ((strategy != s->strategy || func != configuration_table[level].func) &&
+        s->high_water) {
+        /* Flush the last buffer: */
+        int err = deflate(strm, Z_BLOCK);
+        if (err == Z_STREAM_ERROR)
+            return err;
+        if (strm->avail_out == 0)
+            return Z_BUF_ERROR;
+    }
+    if (s->level != level) {
+        if (s->level == 0 && s->matches != 0) {
+            if (s->matches == 1)
+                slide_hash(s);
+            else
+                CLEAR_HASH(s);
+            s->matches = 0;
+        }
+        s->level = level;
+        s->max_lazy_match   = configuration_table[level].max_lazy;
+        s->good_match       = configuration_table[level].good_length;
+        s->nice_match       = configuration_table[level].nice_length;
+        s->max_chain_length = configuration_table[level].max_chain;
+    }
+    s->strategy = strategy;
+    return Z_OK;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateTune(strm, good_length, max_lazy, nice_length, max_chain)
+    z_streamp strm;
+    int good_length;
+    int max_lazy;
+    int nice_length;
+    int max_chain;
+{
+    deflate_state *s;
+
+    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
+    s = strm->state;
+    s->good_match = (uInt)good_length;
+    s->max_lazy_match = (uInt)max_lazy;
+    s->nice_match = nice_length;
+    s->max_chain_length = (uInt)max_chain;
+    return Z_OK;
+}
+
+/* =========================================================================
+ * For the default windowBits of 15 and memLevel of 8, this function returns
+ * a close to exact, as well as small, upper bound on the compressed size.
+ * They are coded as constants here for a reason--if the #define's are
+ * changed, then this function needs to be changed as well.  The return
+ * value for 15 and 8 only works for those exact settings.
+ *
+ * For any setting other than those defaults for windowBits and memLevel,
+ * the value returned is a conservative worst case for the maximum expansion
+ * resulting from using fixed blocks instead of stored blocks, which deflate
+ * can emit on compressed data for some combinations of the parameters.
+ *
+ * This function could be more sophisticated to provide closer upper bounds for
+ * every combination of windowBits and memLevel.  But even the conservative
+ * upper bound of about 14% expansion does not seem onerous for output buffer
+ * allocation.
+ */
+uLong ZEXPORT deflateBound(strm, sourceLen)
+    z_streamp strm;
+    uLong sourceLen;
+{
+    deflate_state *s;
+    uLong complen, wraplen;
+
+    /* conservative upper bound for compressed data */
+    complen = sourceLen +
+              ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5;
+
+    /* if can't get parameters, return conservative bound plus zlib wrapper */
+    if (deflateStateCheck(strm))
+        return complen + 6;
+
+    /* compute wrapper length */
+    s = strm->state;
+    switch (s->wrap) {
+    case 0:                                 /* raw deflate */
+        wraplen = 0;
+        break;
+    case 1:                                 /* zlib wrapper */
+        wraplen = 6 + (s->strstart ? 4 : 0);
+        break;
+#ifdef GZIP
+    case 2:                                 /* gzip wrapper */
+        wraplen = 18;
+        if (s->gzhead != Z_NULL) {          /* user-supplied gzip header */
+            Bytef *str;
+            if (s->gzhead->extra != Z_NULL)
+                wraplen += 2 + s->gzhead->extra_len;
+            str = s->gzhead->name;
+            if (str != Z_NULL)
+                do {
+                    wraplen++;
+                } while (*str++);
+            str = s->gzhead->comment;
+            if (str != Z_NULL)
+                do {
+                    wraplen++;
+                } while (*str++);
+            if (s->gzhead->hcrc)
+                wraplen += 2;
+        }
+        break;
+#endif
+    default:                                /* for compiler happiness */
+        wraplen = 6;
+    }
+
+    /* if not default parameters, return conservative bound */
+    if (s->w_bits != 15 || s->hash_bits != 8 + 7)
+        return complen + wraplen;
+
+    /* default settings: return tight bound for that case */
+    return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) +
+           (sourceLen >> 25) + 13 - 6 + wraplen;
+}
+
+/* =========================================================================
+ * Put a short in the pending buffer. The 16-bit value is put in MSB order.
+ * IN assertion: the stream state is correct and there is enough room in
+ * pending_buf.
+ */
+local void putShortMSB (s, b)
+    deflate_state *s;
+    uInt b;
+{
+    put_byte(s, (Byte)(b >> 8));
+    put_byte(s, (Byte)(b & 0xff));
+}
+
+/* =========================================================================
+ * Flush as much pending output as possible. All deflate() output, except for
+ * some deflate_stored() output, goes through this function so some
+ * applications may wish to modify it to avoid allocating a large
+ * strm->next_out buffer and copying into it. (See also read_buf()).
+ */
+local void flush_pending(strm)
+    z_streamp strm;
+{
+    unsigned len;
+    deflate_state *s = strm->state;
+
+    _tr_flush_bits(s);
+    len = s->pending;
+    if (len > strm->avail_out) len = strm->avail_out;
+    if (len == 0) return;
+
+    zmemcpy(strm->next_out, s->pending_out, len);
+    strm->next_out  += len;
+    s->pending_out  += len;
+    strm->total_out += len;
+    strm->avail_out -= len;
+    s->pending      -= len;
+    if (s->pending == 0) {
+        s->pending_out = s->pending_buf;
+    }
+}
+
+/* ===========================================================================
+ * Update the header CRC with the bytes s->pending_buf[beg..s->pending - 1].
+ */
+#define HCRC_UPDATE(beg) \
+    do { \
+        if (s->gzhead->hcrc && s->pending > (beg)) \
+            strm->adler = crc32(strm->adler, s->pending_buf + (beg), \
+                                s->pending - (beg)); \
+    } while (0)
+
+/* ========================================================================= */
+int ZEXPORT deflate (strm, flush)
+    z_streamp strm;
+    int flush;
+{
+    int old_flush; /* value of flush param for previous deflate call */
+    deflate_state *s;
+
+    if (deflateStateCheck(strm) || flush > Z_BLOCK || flush < 0) {
+        return Z_STREAM_ERROR;
+    }
+    s = strm->state;
+
+    if (strm->next_out == Z_NULL ||
+        (strm->avail_in != 0 && strm->next_in == Z_NULL) ||
+        (s->status == FINISH_STATE && flush != Z_FINISH)) {
+        ERR_RETURN(strm, Z_STREAM_ERROR);
+    }
+    if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
+
+    old_flush = s->last_flush;
+    s->last_flush = flush;
+
+    /* Flush as much pending output as possible */
+    if (s->pending != 0) {
+        flush_pending(strm);
+        if (strm->avail_out == 0) {
+            /* Since avail_out is 0, deflate will be called again with
+             * more output space, but possibly with both pending and
+             * avail_in equal to zero. There won't be anything to do,
+             * but this is not an error situation so make sure we
+             * return OK instead of BUF_ERROR at next call of deflate:
+             */
+            s->last_flush = -1;
+            return Z_OK;
+        }
+
+    /* Make sure there is something to do and avoid duplicate consecutive
+     * flushes. For repeated and useless calls with Z_FINISH, we keep
+     * returning Z_STREAM_END instead of Z_BUF_ERROR.
+     */
+    } else if (strm->avail_in == 0 && RANK(flush) <= RANK(old_flush) &&
+               flush != Z_FINISH) {
+        ERR_RETURN(strm, Z_BUF_ERROR);
+    }
+
+    /* User must not provide more input after the first FINISH: */
+    if (s->status == FINISH_STATE && strm->avail_in != 0) {
+        ERR_RETURN(strm, Z_BUF_ERROR);
+    }
+
+    /* Write the header */
+    if (s->status == INIT_STATE) {
+        /* zlib header */
+        uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
+        uInt level_flags;
+
+        if (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2)
+            level_flags = 0;
+        else if (s->level < 6)
+            level_flags = 1;
+        else if (s->level == 6)
+            level_flags = 2;
+        else
+            level_flags = 3;
+        header |= (level_flags << 6);
+        if (s->strstart != 0) header |= PRESET_DICT;
+        header += 31 - (header % 31);
+
+        putShortMSB(s, header);
+
+        /* Save the adler32 of the preset dictionary: */
+        if (s->strstart != 0) {
+            putShortMSB(s, (uInt)(strm->adler >> 16));
+            putShortMSB(s, (uInt)(strm->adler & 0xffff));
+        }
+        strm->adler = adler32(0L, Z_NULL, 0);
+        s->status = BUSY_STATE;
+
+        /* Compression must start with an empty pending buffer */
+        flush_pending(strm);
+        if (s->pending != 0) {
+            s->last_flush = -1;
+            return Z_OK;
+        }
+    }
+#ifdef GZIP
+    if (s->status == GZIP_STATE) {
+        /* gzip header */
+        strm->adler = crc32(0L, Z_NULL, 0);
+        put_byte(s, 31);
+        put_byte(s, 139);
+        put_byte(s, 8);
+        if (s->gzhead == Z_NULL) {
+            put_byte(s, 0);
+            put_byte(s, 0);
+            put_byte(s, 0);
+            put_byte(s, 0);
+            put_byte(s, 0);
+            put_byte(s, s->level == 9 ? 2 :
+                     (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
+                      4 : 0));
+            put_byte(s, OS_CODE);
+            s->status = BUSY_STATE;
+
+            /* Compression must start with an empty pending buffer */
+            flush_pending(strm);
+            if (s->pending != 0) {
+                s->last_flush = -1;
+                return Z_OK;
+            }
+        }
+        else {
+            put_byte(s, (s->gzhead->text ? 1 : 0) +
+                     (s->gzhead->hcrc ? 2 : 0) +
+                     (s->gzhead->extra == Z_NULL ? 0 : 4) +
+                     (s->gzhead->name == Z_NULL ? 0 : 8) +
+                     (s->gzhead->comment == Z_NULL ? 0 : 16)
+                     );
+            put_byte(s, (Byte)(s->gzhead->time & 0xff));
+            put_byte(s, (Byte)((s->gzhead->time >> 8) & 0xff));
+            put_byte(s, (Byte)((s->gzhead->time >> 16) & 0xff));
+            put_byte(s, (Byte)((s->gzhead->time >> 24) & 0xff));
+            put_byte(s, s->level == 9 ? 2 :
+                     (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
+                      4 : 0));
+            put_byte(s, s->gzhead->os & 0xff);
+            if (s->gzhead->extra != Z_NULL) {
+                put_byte(s, s->gzhead->extra_len & 0xff);
+                put_byte(s, (s->gzhead->extra_len >> 8) & 0xff);
+            }
+            if (s->gzhead->hcrc)
+                strm->adler = crc32(strm->adler, s->pending_buf,
+                                    s->pending);
+            s->gzindex = 0;
+            s->status = EXTRA_STATE;
+        }
+    }
+    if (s->status == EXTRA_STATE) {
+        if (s->gzhead->extra != Z_NULL) {
+            ulg beg = s->pending;   /* start of bytes to update crc */
+            uInt left = (s->gzhead->extra_len & 0xffff) - s->gzindex;
+            while (s->pending + left > s->pending_buf_size) {
+                uInt copy = s->pending_buf_size - s->pending;
+                zmemcpy(s->pending_buf + s->pending,
+                        s->gzhead->extra + s->gzindex, copy);
+                s->pending = s->pending_buf_size;
+                HCRC_UPDATE(beg);
+                s->gzindex += copy;
+                flush_pending(strm);
+                if (s->pending != 0) {
+                    s->last_flush = -1;
+                    return Z_OK;
+                }
+                beg = 0;
+                left -= copy;
+            }
+            zmemcpy(s->pending_buf + s->pending,
+                    s->gzhead->extra + s->gzindex, left);
+            s->pending += left;
+            HCRC_UPDATE(beg);
+            s->gzindex = 0;
+        }
+        s->status = NAME_STATE;
+    }
+    if (s->status == NAME_STATE) {
+        if (s->gzhead->name != Z_NULL) {
+            ulg beg = s->pending;   /* start of bytes to update crc */
+            int val;
+            do {
+                if (s->pending == s->pending_buf_size) {
+                    HCRC_UPDATE(beg);
+                    flush_pending(strm);
+                    if (s->pending != 0) {
+                        s->last_flush = -1;
+                        return Z_OK;
+                    }
+                    beg = 0;
+                }
+                val = s->gzhead->name[s->gzindex++];
+                put_byte(s, val);
+            } while (val != 0);
+            HCRC_UPDATE(beg);
+            s->gzindex = 0;
+        }
+        s->status = COMMENT_STATE;
+    }
+    if (s->status == COMMENT_STATE) {
+        if (s->gzhead->comment != Z_NULL) {
+            ulg beg = s->pending;   /* start of bytes to update crc */
+            int val;
+            do {
+                if (s->pending == s->pending_buf_size) {
+                    HCRC_UPDATE(beg);
+                    flush_pending(strm);
+                    if (s->pending != 0) {
+                        s->last_flush = -1;
+                        return Z_OK;
+                    }
+                    beg = 0;
+                }
+                val = s->gzhead->comment[s->gzindex++];
+                put_byte(s, val);
+            } while (val != 0);
+            HCRC_UPDATE(beg);
+        }
+        s->status = HCRC_STATE;
+    }
+    if (s->status == HCRC_STATE) {
+        if (s->gzhead->hcrc) {
+            if (s->pending + 2 > s->pending_buf_size) {
+                flush_pending(strm);
+                if (s->pending != 0) {
+                    s->last_flush = -1;
+                    return Z_OK;
+                }
+            }
+            put_byte(s, (Byte)(strm->adler & 0xff));
+            put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
+            strm->adler = crc32(0L, Z_NULL, 0);
+        }
+        s->status = BUSY_STATE;
+
+        /* Compression must start with an empty pending buffer */
+        flush_pending(strm);
+        if (s->pending != 0) {
+            s->last_flush = -1;
+            return Z_OK;
+        }
+    }
+#endif
+
+    /* Start a new block or continue the current one.
+     */
+    if (strm->avail_in != 0 || s->lookahead != 0 ||
+        (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
+        block_state bstate;
+
+        bstate = s->level == 0 ? deflate_stored(s, flush) :
+                 s->strategy == Z_HUFFMAN_ONLY ? deflate_huff(s, flush) :
+                 s->strategy == Z_RLE ? deflate_rle(s, flush) :
+                 (*(configuration_table[s->level].func))(s, flush);
+
+        if (bstate == finish_started || bstate == finish_done) {
+            s->status = FINISH_STATE;
+        }
+        if (bstate == need_more || bstate == finish_started) {
+            if (strm->avail_out == 0) {
+                s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
+            }
+            return Z_OK;
+            /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
+             * of deflate should use the same flush parameter to make sure
+             * that the flush is complete. So we don't have to output an
+             * empty block here, this will be done at next call. This also
+             * ensures that for a very small output buffer, we emit at most
+             * one empty block.
+             */
+        }
+        if (bstate == block_done) {
+            if (flush == Z_PARTIAL_FLUSH) {
+                _tr_align(s);
+            } else if (flush != Z_BLOCK) { /* FULL_FLUSH or SYNC_FLUSH */
+                _tr_stored_block(s, (char*)0, 0L, 0);
+                /* For a full flush, this empty block will be recognized
+                 * as a special marker by inflate_sync().
+                 */
+                if (flush == Z_FULL_FLUSH) {
+                    CLEAR_HASH(s);             /* forget history */
+                    if (s->lookahead == 0) {
+                        s->strstart = 0;
+                        s->block_start = 0L;
+                        s->insert = 0;
+                    }
+                }
+            }
+            flush_pending(strm);
+            if (strm->avail_out == 0) {
+              s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
+              return Z_OK;
+            }
+        }
+    }
+
+    if (flush != Z_FINISH) return Z_OK;
+    if (s->wrap <= 0) return Z_STREAM_END;
+
+    /* Write the trailer */
+#ifdef GZIP
+    if (s->wrap == 2) {
+        put_byte(s, (Byte)(strm->adler & 0xff));
+        put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
+        put_byte(s, (Byte)((strm->adler >> 16) & 0xff));
+        put_byte(s, (Byte)((strm->adler >> 24) & 0xff));
+        put_byte(s, (Byte)(strm->total_in & 0xff));
+        put_byte(s, (Byte)((strm->total_in >> 8) & 0xff));
+        put_byte(s, (Byte)((strm->total_in >> 16) & 0xff));
+        put_byte(s, (Byte)((strm->total_in >> 24) & 0xff));
+    }
+    else
+#endif
+    {
+        putShortMSB(s, (uInt)(strm->adler >> 16));
+        putShortMSB(s, (uInt)(strm->adler & 0xffff));
+    }
+    flush_pending(strm);
+    /* If avail_out is zero, the application will call deflate again
+     * to flush the rest.
+     */
+    if (s->wrap > 0) s->wrap = -s->wrap; /* write the trailer only once! */
+    return s->pending != 0 ? Z_OK : Z_STREAM_END;
+}
+
+/* ========================================================================= */
+int ZEXPORT deflateEnd (strm)
+    z_streamp strm;
+{
+    int status;
+
+    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
+
+    status = strm->state->status;
+
+    /* Deallocate in reverse order of allocations: */
+    TRY_FREE(strm, strm->state->pending_buf);
+    TRY_FREE(strm, strm->state->head);
+    TRY_FREE(strm, strm->state->prev);
+    TRY_FREE(strm, strm->state->window);
+
+    ZFREE(strm, strm->state);
+    strm->state = Z_NULL;
+
+    return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
+}
+
+/* =========================================================================
+ * Copy the source state to the destination state.
+ * To simplify the source, this is not supported for 16-bit MSDOS (which
+ * doesn't have enough memory anyway to duplicate compression states).
+ */
+int ZEXPORT deflateCopy (dest, source)
+    z_streamp dest;
+    z_streamp source;
+{
+#ifdef MAXSEG_64K
+    return Z_STREAM_ERROR;
+#else
+    deflate_state *ds;
+    deflate_state *ss;
+    ushf *overlay;
+
+
+    if (deflateStateCheck(source) || dest == Z_NULL) {
+        return Z_STREAM_ERROR;
+    }
+
+    ss = source->state;
+
+    zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream));
+
+    ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
+    if (ds == Z_NULL) return Z_MEM_ERROR;
+    dest->state = (struct internal_state FAR *) ds;
+    zmemcpy((voidpf)ds, (voidpf)ss, sizeof(deflate_state));
+    ds->strm = dest;
+
+    ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
+    ds->prev   = (Posf *)  ZALLOC(dest, ds->w_size, sizeof(Pos));
+    ds->head   = (Posf *)  ZALLOC(dest, ds->hash_size, sizeof(Pos));
+    overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
+    ds->pending_buf = (uchf *) overlay;
+
+    if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
+        ds->pending_buf == Z_NULL) {
+        deflateEnd (dest);
+        return Z_MEM_ERROR;
+    }
+    /* following zmemcpy do not work for 16-bit MSDOS */
+    zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
+    zmemcpy((voidpf)ds->prev, (voidpf)ss->prev, ds->w_size * sizeof(Pos));
+    zmemcpy((voidpf)ds->head, (voidpf)ss->head, ds->hash_size * sizeof(Pos));
+    zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
+
+    ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
+    ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
+    ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
+
+    ds->l_desc.dyn_tree = ds->dyn_ltree;
+    ds->d_desc.dyn_tree = ds->dyn_dtree;
+    ds->bl_desc.dyn_tree = ds->bl_tree;
+
+    return Z_OK;
+#endif /* MAXSEG_64K */
+}
+
+/* ===========================================================================
+ * Read a new buffer from the current input stream, update the adler32
+ * and total number of bytes read.  All deflate() input goes through
+ * this function so some applications may wish to modify it to avoid
+ * allocating a large strm->next_in buffer and copying from it.
+ * (See also flush_pending()).
+ */
+local unsigned read_buf(strm, buf, size)
+    z_streamp strm;
+    Bytef *buf;
+    unsigned size;
+{
+    unsigned len = strm->avail_in;
+
+    if (len > size) len = size;
+    if (len == 0) return 0;
+
+    strm->avail_in  -= len;
+
+    zmemcpy(buf, strm->next_in, len);
+    if (strm->state->wrap == 1) {
+        strm->adler = adler32(strm->adler, buf, len);
+    }
+#ifdef GZIP
+    else if (strm->state->wrap == 2) {
+        strm->adler = crc32(strm->adler, buf, len);
+    }
+#endif
+    strm->next_in  += len;
+    strm->total_in += len;
+
+    return len;
+}
+
+/* ===========================================================================
+ * Initialize the "longest match" routines for a new zlib stream
+ */
+local void lm_init (s)
+    deflate_state *s;
+{
+    s->window_size = (ulg)2L*s->w_size;
+
+    CLEAR_HASH(s);
+
+    /* Set the default configuration parameters:
+     */
+    s->max_lazy_match   = configuration_table[s->level].max_lazy;
+    s->good_match       = configuration_table[s->level].good_length;
+    s->nice_match       = configuration_table[s->level].nice_length;
+    s->max_chain_length = configuration_table[s->level].max_chain;
+
+    s->strstart = 0;
+    s->block_start = 0L;
+    s->lookahead = 0;
+    s->insert = 0;
+    s->match_length = s->prev_length = MIN_MATCH-1;
+    s->match_available = 0;
+    s->ins_h = 0;
+#ifndef FASTEST
+#ifdef ASMV
+    match_init(); /* initialize the asm code */
+#endif
+#endif
+}
+
+#ifndef FASTEST
+/* ===========================================================================
+ * Set match_start to the longest match starting at the given string and
+ * return its length. Matches shorter or equal to prev_length are discarded,
+ * in which case the result is equal to prev_length and match_start is
+ * garbage.
+ * IN assertions: cur_match is the head of the hash chain for the current
+ *   string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
+ * OUT assertion: the match length is not greater than s->lookahead.
+ */
+#ifndef ASMV
+/* For 80x86 and 680x0, an optimized version will be provided in match.asm or
+ * match.S. The code will be functionally equivalent.
+ */
+local uInt longest_match(s, cur_match)
+    deflate_state *s;
+    IPos cur_match;                             /* current match */
+{
+    unsigned chain_length = s->max_chain_length;/* max hash chain length */
+    register Bytef *scan = s->window + s->strstart; /* current string */
+    register Bytef *match;                      /* matched string */
+    register int len;                           /* length of current match */
+    int best_len = (int)s->prev_length;         /* best match length so far */
+    int nice_match = s->nice_match;             /* stop if match long enough */
+    IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
+        s->strstart - (IPos)MAX_DIST(s) : NIL;
+    /* Stop when cur_match becomes <= limit. To simplify the code,
+     * we prevent matches with the string of window index 0.
+     */
+    Posf *prev = s->prev;
+    uInt wmask = s->w_mask;
+
+#ifdef UNALIGNED_OK
+    /* Compare two bytes at a time. Note: this is not always beneficial.
+     * Try with and without -DUNALIGNED_OK to check.
+     */
+    register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
+    register ush scan_start = *(ushf*)scan;
+    register ush scan_end   = *(ushf*)(scan+best_len-1);
+#else
+    register Bytef *strend = s->window + s->strstart + MAX_MATCH;
+    register Byte scan_end1  = scan[best_len-1];
+    register Byte scan_end   = scan[best_len];
+#endif
+
+    /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
+     * It is easy to get rid of this optimization if necessary.
+     */
+    Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
+
+    /* Do not waste too much time if we already have a good match: */
+    if (s->prev_length >= s->good_match) {
+        chain_length >>= 2;
+    }
+    /* Do not look for matches beyond the end of the input. This is necessary
+     * to make deflate deterministic.
+     */
+    if ((uInt)nice_match > s->lookahead) nice_match = (int)s->lookahead;
+
+    Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
+
+    do {
+        Assert(cur_match < s->strstart, "no future");
+        match = s->window + cur_match;
+
+        /* Skip to next match if the match length cannot increase
+         * or if the match length is less than 2.  Note that the checks below
+         * for insufficient lookahead only occur occasionally for performance
+         * reasons.  Therefore uninitialized memory will be accessed, and
+         * conditional jumps will be made that depend on those values.
+         * However the length of the match is limited to the lookahead, so
+         * the output of deflate is not affected by the uninitialized values.
+         */
+#if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
+        /* This code assumes sizeof(unsigned short) == 2. Do not use
+         * UNALIGNED_OK if your compiler uses a different size.
+         */
+        if (*(ushf*)(match+best_len-1) != scan_end ||
+            *(ushf*)match != scan_start) continue;
+
+        /* It is not necessary to compare scan[2] and match[2] since they are
+         * always equal when the other bytes match, given that the hash keys
+         * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
+         * strstart+3, +5, ... up to strstart+257. We check for insufficient
+         * lookahead only every 4th comparison; the 128th check will be made
+         * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
+         * necessary to put more guard bytes at the end of the window, or
+         * to check more often for insufficient lookahead.
+         */
+        Assert(scan[2] == match[2], "scan[2]?");
+        scan++, match++;
+        do {
+        } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
+                 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
+                 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
+                 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
+                 scan < strend);
+        /* The funny "do {}" generates better code on most compilers */
+
+        /* Here, scan <= window+strstart+257 */
+        Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
+        if (*scan == *match) scan++;
+
+        len = (MAX_MATCH - 1) - (int)(strend-scan);
+        scan = strend - (MAX_MATCH-1);
+
+#else /* UNALIGNED_OK */
+
+        if (match[best_len]   != scan_end  ||
+            match[best_len-1] != scan_end1 ||
+            *match            != *scan     ||
+            *++match          != scan[1])      continue;
+
+        /* The check at best_len-1 can be removed because it will be made
+         * again later. (This heuristic is not always a win.)
+         * It is not necessary to compare scan[2] and match[2] since they
+         * are always equal when the other bytes match, given that
+         * the hash keys are equal and that HASH_BITS >= 8.
+         */
+        scan += 2, match++;
+        Assert(*scan == *match, "match[2]?");
+
+        /* We check for insufficient lookahead only every 8th comparison;
+         * the 256th check will be made at strstart+258.
+         */
+        do {
+        } while (*++scan == *++match && *++scan == *++match &&
+                 *++scan == *++match && *++scan == *++match &&
+                 *++scan == *++match && *++scan == *++match &&
+                 *++scan == *++match && *++scan == *++match &&
+                 scan < strend);
+
+        Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
+
+        len = MAX_MATCH - (int)(strend - scan);
+        scan = strend - MAX_MATCH;
+
+#endif /* UNALIGNED_OK */
+
+        if (len > best_len) {
+            s->match_start = cur_match;
+            best_len = len;
+            if (len >= nice_match) break;
+#ifdef UNALIGNED_OK
+            scan_end = *(ushf*)(scan+best_len-1);
+#else
+            scan_end1  = scan[best_len-1];
+            scan_end   = scan[best_len];
+#endif
+        }
+    } while ((cur_match = prev[cur_match & wmask]) > limit
+             && --chain_length != 0);
+
+    if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
+    return s->lookahead;
+}
+#endif /* ASMV */
+
+#else /* FASTEST */
+
+/* ---------------------------------------------------------------------------
+ * Optimized version for FASTEST only
+ */
+local uInt longest_match(s, cur_match)
+    deflate_state *s;
+    IPos cur_match;                             /* current match */
+{
+    register Bytef *scan = s->window + s->strstart; /* current string */
+    register Bytef *match;                       /* matched string */
+    register int len;                           /* length of current match */
+    register Bytef *strend = s->window + s->strstart + MAX_MATCH;
+
+    /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
+     * It is easy to get rid of this optimization if necessary.
+     */
+    Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
+
+    Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
+
+    Assert(cur_match < s->strstart, "no future");
+
+    match = s->window + cur_match;
+
+    /* Return failure if the match length is less than 2:
+     */
+    if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1;
+
+    /* The check at best_len-1 can be removed because it will be made
+     * again later. (This heuristic is not always a win.)
+     * It is not necessary to compare scan[2] and match[2] since they
+     * are always equal when the other bytes match, given that
+     * the hash keys are equal and that HASH_BITS >= 8.
+     */
+    scan += 2, match += 2;
+    Assert(*scan == *match, "match[2]?");
+
+    /* We check for insufficient lookahead only every 8th comparison;
+     * the 256th check will be made at strstart+258.
+     */
+    do {
+    } while (*++scan == *++match && *++scan == *++match &&
+             *++scan == *++match && *++scan == *++match &&
+             *++scan == *++match && *++scan == *++match &&
+             *++scan == *++match && *++scan == *++match &&
+             scan < strend);
+
+    Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
+
+    len = MAX_MATCH - (int)(strend - scan);
+
+    if (len < MIN_MATCH) return MIN_MATCH - 1;
+
+    s->match_start = cur_match;
+    return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead;
+}
+
+#endif /* FASTEST */
+
+#ifdef ZLIB_DEBUG
+
+#define EQUAL 0
+/* result of memcmp for equal strings */
+
+/* ===========================================================================
+ * Check that the match at match_start is indeed a match.
+ */
+local void check_match(s, start, match, length)
+    deflate_state *s;
+    IPos start, match;
+    int length;
+{
+    /* check that the match is indeed a match */
+    if (zmemcmp(s->window + match,
+                s->window + start, length) != EQUAL) {
+        fprintf(stderr, " start %u, match %u, length %d\n",
+                start, match, length);
+        do {
+            fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
+        } while (--length != 0);
+        z_error("invalid match");
+    }
+    if (z_verbose > 1) {
+        fprintf(stderr,"\\[%d,%d]", start-match, length);
+        do { putc(s->window[start++], stderr); } while (--length != 0);
+    }
+}
+#else
+#  define check_match(s, start, match, length)
+#endif /* ZLIB_DEBUG */
+
+/* ===========================================================================
+ * Fill the window when the lookahead becomes insufficient.
+ * Updates strstart and lookahead.
+ *
+ * IN assertion: lookahead < MIN_LOOKAHEAD
+ * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
+ *    At least one byte has been read, or avail_in == 0; reads are
+ *    performed for at least two bytes (required for the zip translate_eol
+ *    option -- not supported here).
+ */
+local void fill_window(s)
+    deflate_state *s;
+{
+    unsigned n;
+    unsigned more;    /* Amount of free space at the end of the window. */
+    uInt wsize = s->w_size;
+
+    Assert(s->lookahead < MIN_LOOKAHEAD, "already enough lookahead");
+
+    do {
+        more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
+
+        /* Deal with !@#$% 64K limit: */
+        if (sizeof(int) <= 2) {
+            if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
+                more = wsize;
+
+            } else if (more == (unsigned)(-1)) {
+                /* Very unlikely, but possible on 16 bit machine if
+                 * strstart == 0 && lookahead == 1 (input done a byte at time)
+                 */
+                more--;
+            }
+        }
+
+        /* If the window is almost full and there is insufficient lookahead,
+         * move the upper half to the lower one to make room in the upper half.
+         */
+        if (s->strstart >= wsize+MAX_DIST(s)) {
+
+            zmemcpy(s->window, s->window+wsize, (unsigned)wsize - more);
+            s->match_start -= wsize;
+            s->strstart    -= wsize; /* we now have strstart >= MAX_DIST */
+            s->block_start -= (long) wsize;
+            slide_hash(s);
+            more += wsize;
+        }
+        if (s->strm->avail_in == 0) break;
+
+        /* If there was no sliding:
+         *    strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
+         *    more == window_size - lookahead - strstart
+         * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
+         * => more >= window_size - 2*WSIZE + 2
+         * In the BIG_MEM or MMAP case (not yet supported),
+         *   window_size == input_size + MIN_LOOKAHEAD  &&
+         *   strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
+         * Otherwise, window_size == 2*WSIZE so more >= 2.
+         * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
+         */
+        Assert(more >= 2, "more < 2");
+
+        n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more);
+        s->lookahead += n;
+
+        /* Initialize the hash value now that we have some input: */
+        if (s->lookahead + s->insert >= MIN_MATCH) {
+            uInt str = s->strstart - s->insert;
+            s->ins_h = s->window[str];
+            UPDATE_HASH(s, s->ins_h, s->window[str + 1]);
+#if MIN_MATCH != 3
+            Call UPDATE_HASH() MIN_MATCH-3 more times
+#endif
+            while (s->insert) {
+                UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]);
+#ifndef FASTEST
+                s->prev[str & s->w_mask] = s->head[s->ins_h];
+#endif
+                s->head[s->ins_h] = (Pos)str;
+                str++;
+                s->insert--;
+                if (s->lookahead + s->insert < MIN_MATCH)
+                    break;
+            }
+        }
+        /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
+         * but this is not important since only literal bytes will be emitted.
+         */
+
+    } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
+
+    /* If the WIN_INIT bytes after the end of the current data have never been
+     * written, then zero those bytes in order to avoid memory check reports of
+     * the use of uninitialized (or uninitialised as Julian writes) bytes by
+     * the longest match routines.  Update the high water mark for the next
+     * time through here.  WIN_INIT is set to MAX_MATCH since the longest match
+     * routines allow scanning to strstart + MAX_MATCH, ignoring lookahead.
+     */
+    if (s->high_water < s->window_size) {
+        ulg curr = s->strstart + (ulg)(s->lookahead);
+        ulg init;
+
+        if (s->high_water < curr) {
+            /* Previous high water mark below current data -- zero WIN_INIT
+             * bytes or up to end of window, whichever is less.
+             */
+            init = s->window_size - curr;
+            if (init > WIN_INIT)
+                init = WIN_INIT;
+            zmemzero(s->window + curr, (unsigned)init);
+            s->high_water = curr + init;
+        }
+        else if (s->high_water < (ulg)curr + WIN_INIT) {
+            /* High water mark at or above current data, but below current data
+             * plus WIN_INIT -- zero out to current data plus WIN_INIT, or up
+             * to end of window, whichever is less.
+             */
+            init = (ulg)curr + WIN_INIT - s->high_water;
+            if (init > s->window_size - s->high_water)
+                init = s->window_size - s->high_water;
+            zmemzero(s->window + s->high_water, (unsigned)init);
+            s->high_water += init;
+        }
+    }
+
+    Assert((ulg)s->strstart <= s->window_size - MIN_LOOKAHEAD,
+           "not enough room for search");
+}
+
+/* ===========================================================================
+ * Flush the current block, with given end-of-file flag.
+ * IN assertion: strstart is set to the end of the current match.
+ */
+#define FLUSH_BLOCK_ONLY(s, last) { \
+   _tr_flush_block(s, (s->block_start >= 0L ? \
+                   (charf *)&s->window[(unsigned)s->block_start] : \
+                   (charf *)Z_NULL), \
+                (ulg)((long)s->strstart - s->block_start), \
+                (last)); \
+   s->block_start = s->strstart; \
+   flush_pending(s->strm); \
+   Tracev((stderr,"[FLUSH]")); \
+}
+
+/* Same but force premature exit if necessary. */
+#define FLUSH_BLOCK(s, last) { \
+   FLUSH_BLOCK_ONLY(s, last); \
+   if (s->strm->avail_out == 0) return (last) ? finish_started : need_more; \
+}
+
+/* Maximum stored block length in deflate format (not including header). */
+#define MAX_STORED 65535
+
+/* Minimum of a and b. */
+#define MIN(a, b) ((a) > (b) ? (b) : (a))
+
+/* ===========================================================================
+ * Copy without compression as much as possible from the input stream, return
+ * the current block state.
+ *
+ * In case deflateParams() is used to later switch to a non-zero compression
+ * level, s->matches (otherwise unused when storing) keeps track of the number
+ * of hash table slides to perform. If s->matches is 1, then one hash table
+ * slide will be done when switching. If s->matches is 2, the maximum value
+ * allowed here, then the hash table will be cleared, since two or more slides
+ * is the same as a clear.
+ *
+ * deflate_stored() is written to minimize the number of times an input byte is
+ * copied. It is most efficient with large input and output buffers, which
+ * maximizes the opportunites to have a single copy from next_in to next_out.
+ */
+local block_state deflate_stored(s, flush)
+    deflate_state *s;
+    int flush;
+{
+    /* Smallest worthy block size when not flushing or finishing. By default
+     * this is 32K. This can be as small as 507 bytes for memLevel == 1. For
+     * large input and output buffers, the stored block size will be larger.
+     */
+    unsigned min_block = MIN(s->pending_buf_size - 5, s->w_size);
+
+    /* Copy as many min_block or larger stored blocks directly to next_out as
+     * possible. If flushing, copy the remaining available input to next_out as
+     * stored blocks, if there is enough space.
+     */
+    unsigned len, left, have, last = 0;
+    unsigned used = s->strm->avail_in;
+    do {
+        /* Set len to the maximum size block that we can copy directly with the
+         * available input data and output space. Set left to how much of that
+         * would be copied from what's left in the window.
+         */
+        len = MAX_STORED;       /* maximum deflate stored block length */
+        have = (s->bi_valid + 42) >> 3;         /* number of header bytes */
+        if (s->strm->avail_out < have)          /* need room for header */
+            break;
+            /* maximum stored block length that will fit in avail_out: */
+        have = s->strm->avail_out - have;
+        left = s->strstart - s->block_start;    /* bytes left in window */
+        if (len > (ulg)left + s->strm->avail_in)
+            len = left + s->strm->avail_in;     /* limit len to the input */
+        if (len > have)
+            len = have;                         /* limit len to the output */
+
+        /* If the stored block would be less than min_block in length, or if
+         * unable to copy all of the available input when flushing, then try
+         * copying to the window and the pending buffer instead. Also don't
+         * write an empty block when flushing -- deflate() does that.
+         */
+        if (len < min_block && ((len == 0 && flush != Z_FINISH) ||
+                                flush == Z_NO_FLUSH ||
+                                len != left + s->strm->avail_in))
+            break;
+
+        /* Make a dummy stored block in pending to get the header bytes,
+         * including any pending bits. This also updates the debugging counts.
+         */
+        last = flush == Z_FINISH && len == left + s->strm->avail_in ? 1 : 0;
+        _tr_stored_block(s, (char *)0, 0L, last);
+
+        /* Replace the lengths in the dummy stored block with len. */
+        s->pending_buf[s->pending - 4] = len;
+        s->pending_buf[s->pending - 3] = len >> 8;
+        s->pending_buf[s->pending - 2] = ~len;
+        s->pending_buf[s->pending - 1] = ~len >> 8;
+
+        /* Write the stored block header bytes. */
+        flush_pending(s->strm);
+
+#ifdef ZLIB_DEBUG
+        /* Update debugging counts for the data about to be copied. */
+        s->compressed_len += len << 3;
+        s->bits_sent += len << 3;
+#endif
+
+        /* Copy uncompressed bytes from the window to next_out. */
+        if (left) {
+            if (left > len)
+                left = len;
+            zmemcpy(s->strm->next_out, s->window + s->block_start, left);
+            s->strm->next_out += left;
+            s->strm->avail_out -= left;
+            s->strm->total_out += left;
+            s->block_start += left;
+            len -= left;
+        }
+
+        /* Copy uncompressed bytes directly from next_in to next_out, updating
+         * the check value.
+         */
+        if (len) {
+            read_buf(s->strm, s->strm->next_out, len);
+            s->strm->next_out += len;
+            s->strm->avail_out -= len;
+            s->strm->total_out += len;
+        }
+    } while (last == 0);
+
+    /* Update the sliding window with the last s->w_size bytes of the copied
+     * data, or append all of the copied data to the existing window if less
+     * than s->w_size bytes were copied. Also update the number of bytes to
+     * insert in the hash tables, in the event that deflateParams() switches to
+     * a non-zero compression level.
+     */
+    used -= s->strm->avail_in;      /* number of input bytes directly copied */
+    if (used) {
+        /* If any input was used, then no unused input remains in the window,
+         * therefore s->block_start == s->strstart.
+         */
+        if (used >= s->w_size) {    /* supplant the previous history */
+            s->matches = 2;         /* clear hash */
+            zmemcpy(s->window, s->strm->next_in - s->w_size, s->w_size);
+            s->strstart = s->w_size;
+        }
+        else {
+            if (s->window_size - s->strstart <= used) {
+                /* Slide the window down. */
+                s->strstart -= s->w_size;
+                zmemcpy(s->window, s->window + s->w_size, s->strstart);
+                if (s->matches < 2)
+                    s->matches++;   /* add a pending slide_hash() */
+            }
+            zmemcpy(s->window + s->strstart, s->strm->next_in - used, used);
+            s->strstart += used;
+        }
+        s->block_start = s->strstart;
+        s->insert += MIN(used, s->w_size - s->insert);
+    }
+    if (s->high_water < s->strstart)
+        s->high_water = s->strstart;
+
+    /* If the last block was written to next_out, then done. */
+    if (last)
+        return finish_done;
+
+    /* If flushing and all input has been consumed, then done. */
+    if (flush != Z_NO_FLUSH && flush != Z_FINISH &&
+        s->strm->avail_in == 0 && (long)s->strstart == s->block_start)
+        return block_done;
+
+    /* Fill the window with any remaining input. */
+    have = s->window_size - s->strstart - 1;
+    if (s->strm->avail_in > have && s->block_start >= (long)s->w_size) {
+        /* Slide the window down. */
+        s->block_start -= s->w_size;
+        s->strstart -= s->w_size;
+        zmemcpy(s->window, s->window + s->w_size, s->strstart);
+        if (s->matches < 2)
+            s->matches++;           /* add a pending slide_hash() */
+        have += s->w_size;          /* more space now */
+    }
+    if (have > s->strm->avail_in)
+        have = s->strm->avail_in;
+    if (have) {
+        read_buf(s->strm, s->window + s->strstart, have);
+        s->strstart += have;
+    }
+    if (s->high_water < s->strstart)
+        s->high_water = s->strstart;
+
+    /* There was not enough avail_out to write a complete worthy or flushed
+     * stored block to next_out. Write a stored block to pending instead, if we
+     * have enough input for a worthy block, or if flushing and there is enough
+     * room for the remaining input as a stored block in the pending buffer.
+     */
+    have = (s->bi_valid + 42) >> 3;         /* number of header bytes */
+        /* maximum stored block length that will fit in pending: */
+    have = MIN(s->pending_buf_size - have, MAX_STORED);
+    min_block = MIN(have, s->w_size);
+    left = s->strstart - s->block_start;
+    if (left >= min_block ||
+        ((left || flush == Z_FINISH) && flush != Z_NO_FLUSH &&
+         s->strm->avail_in == 0 && left <= have)) {
+        len = MIN(left, have);
+        last = flush == Z_FINISH && s->strm->avail_in == 0 &&
+               len == left ? 1 : 0;
+        _tr_stored_block(s, (charf *)s->window + s->block_start, len, last);
+        s->block_start += len;
+        flush_pending(s->strm);
+    }
+
+    /* We've done all we can with the available input and output. */
+    return last ? finish_started : need_more;
+}
+
+/* ===========================================================================
+ * Compress as much as possible from the input stream, return the current
+ * block state.
+ * This function does not perform lazy evaluation of matches and inserts
+ * new strings in the dictionary only for unmatched strings or for short
+ * matches. It is used only for the fast compression options.
+ */
+local block_state deflate_fast(s, flush)
+    deflate_state *s;
+    int flush;
+{
+    IPos hash_head;       /* head of the hash chain */
+    int bflush;           /* set if current block must be flushed */
+
+    for (;;) {
+        /* Make sure that we always have enough lookahead, except
+         * at the end of the input file. We need MAX_MATCH bytes
+         * for the next match, plus MIN_MATCH bytes to insert the
+         * string following the next match.
+         */
+        if (s->lookahead < MIN_LOOKAHEAD) {
+            fill_window(s);
+            if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
+                return need_more;
+            }
+            if (s->lookahead == 0) break; /* flush the current block */
+        }
+
+        /* Insert the string window[strstart .. strstart+2] in the
+         * dictionary, and set hash_head to the head of the hash chain:
+         */
+        hash_head = NIL;
+        if (s->lookahead >= MIN_MATCH) {
+            INSERT_STRING(s, s->strstart, hash_head);
+        }
+
+        /* Find the longest match, discarding those <= prev_length.
+         * At this point we have always match_length < MIN_MATCH
+         */
+        if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
+            /* To simplify the code, we prevent matches with the string
+             * of window index 0 (in particular we have to avoid a match
+             * of the string with itself at the start of the input file).
+             */
+            s->match_length = longest_match (s, hash_head);
+            /* longest_match() sets match_start */
+        }
+        if (s->match_length >= MIN_MATCH) {
+            check_match(s, s->strstart, s->match_start, s->match_length);
+
+            _tr_tally_dist(s, s->strstart - s->match_start,
+                           s->match_length - MIN_MATCH, bflush);
+
+            s->lookahead -= s->match_length;
+
+            /* Insert new strings in the hash table only if the match length
+             * is not too large. This saves time but degrades compression.
+             */
+#ifndef FASTEST
+            if (s->match_length <= s->max_insert_length &&
+                s->lookahead >= MIN_MATCH) {
+                s->match_length--; /* string at strstart already in table */
+                do {
+                    s->strstart++;
+                    INSERT_STRING(s, s->strstart, hash_head);
+                    /* strstart never exceeds WSIZE-MAX_MATCH, so there are
+                     * always MIN_MATCH bytes ahead.
+                     */
+                } while (--s->match_length != 0);
+                s->strstart++;
+            } else
+#endif
+            {
+                s->strstart += s->match_length;
+                s->match_length = 0;
+                s->ins_h = s->window[s->strstart];
+                UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
+#if MIN_MATCH != 3
+                Call UPDATE_HASH() MIN_MATCH-3 more times
+#endif
+                /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
+                 * matter since it will be recomputed at next deflate call.
+                 */
+            }
+        } else {
+            /* No match, output a literal byte */
+            Tracevv((stderr,"%c", s->window[s->strstart]));
+            _tr_tally_lit (s, s->window[s->strstart], bflush);
+            s->lookahead--;
+            s->strstart++;
+        }
+        if (bflush) FLUSH_BLOCK(s, 0);
+    }
+    s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1;
+    if (flush == Z_FINISH) {
+        FLUSH_BLOCK(s, 1);
+        return finish_done;
+    }
+    if (s->last_lit)
+        FLUSH_BLOCK(s, 0);
+    return block_done;
+}
+
+#ifndef FASTEST
+/* ===========================================================================
+ * Same as above, but achieves better compression. We use a lazy
+ * evaluation for matches: a match is finally adopted only if there is
+ * no better match at the next window position.
+ */
+local block_state deflate_slow(s, flush)
+    deflate_state *s;
+    int flush;
+{
+    IPos hash_head;          /* head of hash chain */
+    int bflush;              /* set if current block must be flushed */
+
+    /* Process the input block. */
+    for (;;) {
+        /* Make sure that we always have enough lookahead, except
+         * at the end of the input file. We need MAX_MATCH bytes
+         * for the next match, plus MIN_MATCH bytes to insert the
+         * string following the next match.
+         */
+        if (s->lookahead < MIN_LOOKAHEAD) {
+            fill_window(s);
+            if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
+                return need_more;
+            }
+            if (s->lookahead == 0) break; /* flush the current block */
+        }
+
+        /* Insert the string window[strstart .. strstart+2] in the
+         * dictionary, and set hash_head to the head of the hash chain:
+         */
+        hash_head = NIL;
+        if (s->lookahead >= MIN_MATCH) {
+            INSERT_STRING(s, s->strstart, hash_head);
+        }
+
+        /* Find the longest match, discarding those <= prev_length.
+         */
+        s->prev_length = s->match_length, s->prev_match = s->match_start;
+        s->match_length = MIN_MATCH-1;
+
+        if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
+            s->strstart - hash_head <= MAX_DIST(s)) {
+            /* To simplify the code, we prevent matches with the string
+             * of window index 0 (in particular we have to avoid a match
+             * of the string with itself at the start of the input file).
+             */
+            s->match_length = longest_match (s, hash_head);
+            /* longest_match() sets match_start */
+
+            if (s->match_length <= 5 && (s->strategy == Z_FILTERED
+#if TOO_FAR <= 32767
+                || (s->match_length == MIN_MATCH &&
+                    s->strstart - s->match_start > TOO_FAR)
+#endif
+                )) {
+
+                /* If prev_match is also MIN_MATCH, match_start is garbage
+                 * but we will ignore the current match anyway.
+                 */
+                s->match_length = MIN_MATCH-1;
+            }
+        }
+        /* If there was a match at the previous step and the current
+         * match is not better, output the previous match:
+         */
+        if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
+            uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
+            /* Do not insert strings in hash table beyond this. */
+
+            check_match(s, s->strstart-1, s->prev_match, s->prev_length);
+
+            _tr_tally_dist(s, s->strstart -1 - s->prev_match,
+                           s->prev_length - MIN_MATCH, bflush);
+
+            /* Insert in hash table all strings up to the end of the match.
+             * strstart-1 and strstart are already inserted. If there is not
+             * enough lookahead, the last two strings are not inserted in
+             * the hash table.
+             */
+            s->lookahead -= s->prev_length-1;
+            s->prev_length -= 2;
+            do {
+                if (++s->strstart <= max_insert) {
+                    INSERT_STRING(s, s->strstart, hash_head);
+                }
+            } while (--s->prev_length != 0);
+            s->match_available = 0;
+            s->match_length = MIN_MATCH-1;
+            s->strstart++;
+
+            if (bflush) FLUSH_BLOCK(s, 0);
+
+        } else if (s->match_available) {
+            /* If there was no match at the previous position, output a
+             * single literal. If there was a match but the current match
+             * is longer, truncate the previous match to a single literal.
+             */
+            Tracevv((stderr,"%c", s->window[s->strstart-1]));
+            _tr_tally_lit(s, s->window[s->strstart-1], bflush);
+            if (bflush) {
+                FLUSH_BLOCK_ONLY(s, 0);
+            }
+            s->strstart++;
+            s->lookahead--;
+            if (s->strm->avail_out == 0) return need_more;
+        } else {
+            /* There is no previous match to compare with, wait for
+             * the next step to decide.
+             */
+            s->match_available = 1;
+            s->strstart++;
+            s->lookahead--;
+        }
+    }
+    Assert (flush != Z_NO_FLUSH, "no flush?");
+    if (s->match_available) {
+        Tracevv((stderr,"%c", s->window[s->strstart-1]));
+        _tr_tally_lit(s, s->window[s->strstart-1], bflush);
+        s->match_available = 0;
+    }
+    s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1;
+    if (flush == Z_FINISH) {
+        FLUSH_BLOCK(s, 1);
+        return finish_done;
+    }
+    if (s->last_lit)
+        FLUSH_BLOCK(s, 0);
+    return block_done;
+}
+#endif /* FASTEST */
+
+/* ===========================================================================
+ * For Z_RLE, simply look for runs of bytes, generate matches only of distance
+ * one.  Do not maintain a hash table.  (It will be regenerated if this run of
+ * deflate switches away from Z_RLE.)
+ */
+local block_state deflate_rle(s, flush)
+    deflate_state *s;
+    int flush;
+{
+    int bflush;             /* set if current block must be flushed */
+    uInt prev;              /* byte at distance one to match */
+    Bytef *scan, *strend;   /* scan goes up to strend for length of run */
+
+    for (;;) {
+        /* Make sure that we always have enough lookahead, except
+         * at the end of the input file. We need MAX_MATCH bytes
+         * for the longest run, plus one for the unrolled loop.
+         */
+        if (s->lookahead <= MAX_MATCH) {
+            fill_window(s);
+            if (s->lookahead <= MAX_MATCH && flush == Z_NO_FLUSH) {
+                return need_more;
+            }
+            if (s->lookahead == 0) break; /* flush the current block */
+        }
+
+        /* See how many times the previous byte repeats */
+        s->match_length = 0;
+        if (s->lookahead >= MIN_MATCH && s->strstart > 0) {
+            scan = s->window + s->strstart - 1;
+            prev = *scan;
+            if (prev == *++scan && prev == *++scan && prev == *++scan) {
+                strend = s->window + s->strstart + MAX_MATCH;
+                do {
+                } while (prev == *++scan && prev == *++scan &&
+                         prev == *++scan && prev == *++scan &&
+                         prev == *++scan && prev == *++scan &&
+                         prev == *++scan && prev == *++scan &&
+                         scan < strend);
+                s->match_length = MAX_MATCH - (uInt)(strend - scan);
+                if (s->match_length > s->lookahead)
+                    s->match_length = s->lookahead;
+            }
+            Assert(scan <= s->window+(uInt)(s->window_size-1), "wild scan");
+        }
+
+        /* Emit match if have run of MIN_MATCH or longer, else emit literal */
+        if (s->match_length >= MIN_MATCH) {
+            check_match(s, s->strstart, s->strstart - 1, s->match_length);
+
+            _tr_tally_dist(s, 1, s->match_length - MIN_MATCH, bflush);
+
+            s->lookahead -= s->match_length;
+            s->strstart += s->match_length;
+            s->match_length = 0;
+        } else {
+            /* No match, output a literal byte */
+            Tracevv((stderr,"%c", s->window[s->strstart]));
+            _tr_tally_lit (s, s->window[s->strstart], bflush);
+            s->lookahead--;
+            s->strstart++;
+        }
+        if (bflush) FLUSH_BLOCK(s, 0);
+    }
+    s->insert = 0;
+    if (flush == Z_FINISH) {
+        FLUSH_BLOCK(s, 1);
+        return finish_done;
+    }
+    if (s->last_lit)
+        FLUSH_BLOCK(s, 0);
+    return block_done;
+}
+
+/* ===========================================================================
+ * For Z_HUFFMAN_ONLY, do not look for matches.  Do not maintain a hash table.
+ * (It will be regenerated if this run of deflate switches away from Huffman.)
+ */
+local block_state deflate_huff(s, flush)
+    deflate_state *s;
+    int flush;
+{
+    int bflush;             /* set if current block must be flushed */
+
+    for (;;) {
+        /* Make sure that we have a literal to write. */
+        if (s->lookahead == 0) {
+            fill_window(s);
+            if (s->lookahead == 0) {
+                if (flush == Z_NO_FLUSH)
+                    return need_more;
+                break;      /* flush the current block */
+            }
+        }
+
+        /* Output a literal byte */
+        s->match_length = 0;
+        Tracevv((stderr,"%c", s->window[s->strstart]));
+        _tr_tally_lit (s, s->window[s->strstart], bflush);
+        s->lookahead--;
+        s->strstart++;
+        if (bflush) FLUSH_BLOCK(s, 0);
+    }
+    s->insert = 0;
+    if (flush == Z_FINISH) {
+        FLUSH_BLOCK(s, 1);
+        return finish_done;
+    }
+    if (s->last_lit)
+        FLUSH_BLOCK(s, 0);
+    return block_done;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/deflate.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/deflate.h	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,349 @@
+/* deflate.h -- internal compression state
+ * Copyright (C) 1995-2016 Jean-loup Gailly
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+/* @(#) $Id$ */
+
+#ifndef DEFLATE_H
+#define DEFLATE_H
+
+#include "zutil.h"
+
+/* define NO_GZIP when compiling if you want to disable gzip header and
+   trailer creation by deflate().  NO_GZIP would be used to avoid linking in
+   the crc code when it is not needed.  For shared libraries, gzip encoding
+   should be left enabled. */
+#ifndef NO_GZIP
+#  define GZIP
+#endif
+
+/* ===========================================================================
+ * Internal compression state.
+ */
+
+#define LENGTH_CODES 29
+/* number of length codes, not counting the special END_BLOCK code */
+
+#define LITERALS  256
+/* number of literal bytes 0..255 */
+
+#define L_CODES (LITERALS+1+LENGTH_CODES)
+/* number of Literal or Length codes, including the END_BLOCK code */
+
+#define D_CODES   30
+/* number of distance codes */
+
+#define BL_CODES  19
+/* number of codes used to transfer the bit lengths */
+
+#define HEAP_SIZE (2*L_CODES+1)
+/* maximum heap size */
+
+#define MAX_BITS 15
+/* All codes must not exceed MAX_BITS bits */
+
+#define Buf_size 16
+/* size of bit buffer in bi_buf */
+
+#define INIT_STATE    42    /* zlib header -> BUSY_STATE */
+#ifdef GZIP
+#  define GZIP_STATE  57    /* gzip header -> BUSY_STATE | EXTRA_STATE */
+#endif
+#define EXTRA_STATE   69    /* gzip extra block -> NAME_STATE */
+#define NAME_STATE    73    /* gzip file name -> COMMENT_STATE */
+#define COMMENT_STATE 91    /* gzip comment -> HCRC_STATE */
+#define HCRC_STATE   103    /* gzip header CRC -> BUSY_STATE */
+#define BUSY_STATE   113    /* deflate -> FINISH_STATE */
+#define FINISH_STATE 666    /* stream complete */
+/* Stream status */
+
+
+/* Data structure describing a single value and its code string. */
+typedef struct ct_data_s {
+    union {
+        ush  freq;       /* frequency count */
+        ush  code;       /* bit string */
+    } fc;
+    union {
+        ush  dad;        /* father node in Huffman tree */
+        ush  len;        /* length of bit string */
+    } dl;
+} FAR ct_data;
+
+#define Freq fc.freq
+#define Code fc.code
+#define Dad  dl.dad
+#define Len  dl.len
+
+typedef struct static_tree_desc_s  static_tree_desc;
+
+typedef struct tree_desc_s {
+    ct_data *dyn_tree;           /* the dynamic tree */
+    int     max_code;            /* largest code with non zero frequency */
+    const static_tree_desc *stat_desc;  /* the corresponding static tree */
+} FAR tree_desc;
+
+typedef ush Pos;
+typedef Pos FAR Posf;
+typedef unsigned IPos;
+
+/* A Pos is an index in the character window. We use short instead of int to
+ * save space in the various tables. IPos is used only for parameter passing.
+ */
+
+typedef struct internal_state {
+    z_streamp strm;      /* pointer back to this zlib stream */
+    int   status;        /* as the name implies */
+    Bytef *pending_buf;  /* output still pending */
+    ulg   pending_buf_size; /* size of pending_buf */
+    Bytef *pending_out;  /* next pending byte to output to the stream */
+    ulg   pending;       /* nb of bytes in the pending buffer */
+    int   wrap;          /* bit 0 true for zlib, bit 1 true for gzip */
+    gz_headerp  gzhead;  /* gzip header information to write */
+    ulg   gzindex;       /* where in extra, name, or comment */
+    Byte  method;        /* can only be DEFLATED */
+    int   last_flush;    /* value of flush param for previous deflate call */
+
+                /* used by deflate.c: */
+
+    uInt  w_size;        /* LZ77 window size (32K by default) */
+    uInt  w_bits;        /* log2(w_size)  (8..16) */
+    uInt  w_mask;        /* w_size - 1 */
+
+    Bytef *window;
+    /* Sliding window. Input bytes are read into the second half of the window,
+     * and move to the first half later to keep a dictionary of at least wSize
+     * bytes. With this organization, matches are limited to a distance of
+     * wSize-MAX_MATCH bytes, but this ensures that IO is always
+     * performed with a length multiple of the block size. Also, it limits
+     * the window size to 64K, which is quite useful on MSDOS.
+     * To do: use the user input buffer as sliding window.
+     */
+
+    ulg window_size;
+    /* Actual size of window: 2*wSize, except when the user input buffer
+     * is directly used as sliding window.
+     */
+
+    Posf *prev;
+    /* Link to older string with same hash index. To limit the size of this
+     * array to 64K, this link is maintained only for the last 32K strings.
+     * An index in this array is thus a window index modulo 32K.
+     */
+
+    Posf *head; /* Heads of the hash chains or NIL. */
+
+    uInt  ins_h;          /* hash index of string to be inserted */
+    uInt  hash_size;      /* number of elements in hash table */
+    uInt  hash_bits;      /* log2(hash_size) */
+    uInt  hash_mask;      /* hash_size-1 */
+
+    uInt  hash_shift;
+    /* Number of bits by which ins_h must be shifted at each input
+     * step. It must be such that after MIN_MATCH steps, the oldest
+     * byte no longer takes part in the hash key, that is:
+     *   hash_shift * MIN_MATCH >= hash_bits
+     */
+
+    long block_start;
+    /* Window position at the beginning of the current output block. Gets
+     * negative when the window is moved backwards.
+     */
+
+    uInt match_length;           /* length of best match */
+    IPos prev_match;             /* previous match */
+    int match_available;         /* set if previous match exists */
+    uInt strstart;               /* start of string to insert */
+    uInt match_start;            /* start of matching string */
+    uInt lookahead;              /* number of valid bytes ahead in window */
+
+    uInt prev_length;
+    /* Length of the best match at previous step. Matches not greater than this
+     * are discarded. This is used in the lazy match evaluation.
+     */
+
+    uInt max_chain_length;
+    /* To speed up deflation, hash chains are never searched beyond this
+     * length.  A higher limit improves compression ratio but degrades the
+     * speed.
+     */
+
+    uInt max_lazy_match;
+    /* Attempt to find a better match only when the current match is strictly
+     * smaller than this value. This mechanism is used only for compression
+     * levels >= 4.
+     */
+#   define max_insert_length  max_lazy_match
+    /* Insert new strings in the hash table only if the match length is not
+     * greater than this length. This saves time but degrades compression.
+     * max_insert_length is used only for compression levels <= 3.
+     */
+
+    int level;    /* compression level (1..9) */
+    int strategy; /* favor or force Huffman coding*/
+
+    uInt good_match;
+    /* Use a faster search when the previous match is longer than this */
+
+    int nice_match; /* Stop searching when current match exceeds this */
+
+                /* used by trees.c: */
+    /* Didn't use ct_data typedef below to suppress compiler warning */
+    struct ct_data_s dyn_ltree[HEAP_SIZE];   /* literal and length tree */
+    struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
+    struct ct_data_s bl_tree[2*BL_CODES+1];  /* Huffman tree for bit lengths */
+
+    struct tree_desc_s l_desc;               /* desc. for literal tree */
+    struct tree_desc_s d_desc;               /* desc. for distance tree */
+    struct tree_desc_s bl_desc;              /* desc. for bit length tree */
+
+    ush bl_count[MAX_BITS+1];
+    /* number of codes at each bit length for an optimal tree */
+
+    int heap[2*L_CODES+1];      /* heap used to build the Huffman trees */
+    int heap_len;               /* number of elements in the heap */
+    int heap_max;               /* element of largest frequency */
+    /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
+     * The same heap array is used to build all trees.
+     */
+
+    uch depth[2*L_CODES+1];
+    /* Depth of each subtree used as tie breaker for trees of equal frequency
+     */
+
+    uchf *l_buf;          /* buffer for literals or lengths */
+
+    uInt  lit_bufsize;
+    /* Size of match buffer for literals/lengths.  There are 4 reasons for
+     * limiting lit_bufsize to 64K:
+     *   - frequencies can be kept in 16 bit counters
+     *   - if compression is not successful for the first block, all input
+     *     data is still in the window so we can still emit a stored block even
+     *     when input comes from standard input.  (This can also be done for
+     *     all blocks if lit_bufsize is not greater than 32K.)
+     *   - if compression is not successful for a file smaller than 64K, we can
+     *     even emit a stored file instead of a stored block (saving 5 bytes).
+     *     This is applicable only for zip (not gzip or zlib).
+     *   - creating new Huffman trees less frequently may not provide fast
+     *     adaptation to changes in the input data statistics. (Take for
+     *     example a binary file with poorly compressible code followed by
+     *     a highly compressible string table.) Smaller buffer sizes give
+     *     fast adaptation but have of course the overhead of transmitting
+     *     trees more frequently.
+     *   - I can't count above 4
+     */
+
+    uInt last_lit;      /* running index in l_buf */
+
+    ushf *d_buf;
+    /* Buffer for distances. To simplify the code, d_buf and l_buf have
+     * the same number of elements. To use different lengths, an extra flag
+     * array would be necessary.
+     */
+
+    ulg opt_len;        /* bit length of current block with optimal trees */
+    ulg static_len;     /* bit length of current block with static trees */
+    uInt matches;       /* number of string matches in current block */
+    uInt insert;        /* bytes at end of window left to insert */
+
+#ifdef ZLIB_DEBUG
+    ulg compressed_len; /* total bit length of compressed file mod 2^32 */
+    ulg bits_sent;      /* bit length of compressed data sent mod 2^32 */
+#endif
+
+    ush bi_buf;
+    /* Output buffer. bits are inserted starting at the bottom (least
+     * significant bits).
+     */
+    int bi_valid;
+    /* Number of valid bits in bi_buf.  All bits above the last valid bit
+     * are always zero.
+     */
+
+    ulg high_water;
+    /* High water mark offset in window for initialized bytes -- bytes above
+     * this are set to zero in order to avoid memory check warnings when
+     * longest match routines access bytes past the input.  This is then
+     * updated to the new high water mark.
+     */
+
+} FAR deflate_state;
+
+/* Output a byte on the stream.
+ * IN assertion: there is enough room in pending_buf.
+ */
+#define put_byte(s, c) {s->pending_buf[s->pending++] = (Bytef)(c);}
+
+
+#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
+/* Minimum amount of lookahead, except at the end of the input file.
+ * See deflate.c for comments about the MIN_MATCH+1.
+ */
+
+#define MAX_DIST(s)  ((s)->w_size-MIN_LOOKAHEAD)
+/* In order to simplify the code, particularly on 16 bit machines, match
+ * distances are limited to MAX_DIST instead of WSIZE.
+ */
+
+#define WIN_INIT MAX_MATCH
+/* Number of bytes after end of data in window to initialize in order to avoid
+   memory checker errors from longest match routines */
+
+        /* in trees.c */
+void ZLIB_INTERNAL _tr_init OF((deflate_state *s));
+int ZLIB_INTERNAL _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc));
+void ZLIB_INTERNAL _tr_flush_block OF((deflate_state *s, charf *buf,
+                        ulg stored_len, int last));
+void ZLIB_INTERNAL _tr_flush_bits OF((deflate_state *s));
+void ZLIB_INTERNAL _tr_align OF((deflate_state *s));
+void ZLIB_INTERNAL _tr_stored_block OF((deflate_state *s, charf *buf,
+                        ulg stored_len, int last));
+
+#define d_code(dist) \
+   ((dist) < 256 ? _dist_code[dist] : _dist_code[256+((dist)>>7)])
+/* Mapping from a distance to a distance code. dist is the distance - 1 and
+ * must not have side effects. _dist_code[256] and _dist_code[257] are never
+ * used.
+ */
+
+#ifndef ZLIB_DEBUG
+/* Inline versions of _tr_tally for speed: */
+
+#if defined(GEN_TREES_H) || !defined(STDC)
+  extern uch ZLIB_INTERNAL _length_code[];
+  extern uch ZLIB_INTERNAL _dist_code[];
+#else
+  extern const uch ZLIB_INTERNAL _length_code[];
+  extern const uch ZLIB_INTERNAL _dist_code[];
+#endif
+
+# define _tr_tally_lit(s, c, flush) \
+  { uch cc = (c); \
+    s->d_buf[s->last_lit] = 0; \
+    s->l_buf[s->last_lit++] = cc; \
+    s->dyn_ltree[cc].Freq++; \
+    flush = (s->last_lit == s->lit_bufsize-1); \
+   }
+# define _tr_tally_dist(s, distance, length, flush) \
+  { uch len = (uch)(length); \
+    ush dist = (ush)(distance); \
+    s->d_buf[s->last_lit] = dist; \
+    s->l_buf[s->last_lit++] = len; \
+    dist--; \
+    s->dyn_ltree[_length_code[len]+LITERALS+1].Freq++; \
+    s->dyn_dtree[d_code(dist)].Freq++; \
+    flush = (s->last_lit == s->lit_bufsize-1); \
+  }
+#else
+# define _tr_tally_lit(s, c, flush) flush = _tr_tally(s, 0, c)
+# define _tr_tally_dist(s, distance, length, flush) \
+              flush = _tr_tally(s, distance, length)
+#endif
+
+#endif /* DEFLATE_H */
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/doc/algorithm.txt
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/doc/algorithm.txt	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,209 @@
+1. Compression algorithm (deflate)
+
+The deflation algorithm used by gzip (also zip and zlib) is a variation of
+LZ77 (Lempel-Ziv 1977, see reference below). It finds duplicated strings in
+the input data.  The second occurrence of a string is replaced by a
+pointer to the previous string, in the form of a pair (distance,
+length).  Distances are limited to 32K bytes, and lengths are limited
+to 258 bytes. When a string does not occur anywhere in the previous
+32K bytes, it is emitted as a sequence of literal bytes.  (In this
+description, `string' must be taken as an arbitrary sequence of bytes,
+and is not restricted to printable characters.)
+
+Literals or match lengths are compressed with one Huffman tree, and
+match distances are compressed with another tree. The trees are stored
+in a compact form at the start of each block. The blocks can have any
+size (except that the compressed data for one block must fit in
+available memory). A block is terminated when deflate() determines that
+it would be useful to start another block with fresh trees. (This is
+somewhat similar to the behavior of LZW-based _compress_.)
+
+Duplicated strings are found using a hash table. All input strings of
+length 3 are inserted in the hash table. A hash index is computed for
+the next 3 bytes. If the hash chain for this index is not empty, all
+strings in the chain are compared with the current input string, and
+the longest match is selected.
+
+The hash chains are searched starting with the most recent strings, to
+favor small distances and thus take advantage of the Huffman encoding.
+The hash chains are singly linked. There are no deletions from the
+hash chains, the algorithm simply discards matches that are too old.
+
+To avoid a worst-case situation, very long hash chains are arbitrarily
+truncated at a certain length, determined by a runtime option (level
+parameter of deflateInit). So deflate() does not always find the longest
+possible match but generally finds a match which is long enough.
+
+deflate() also defers the selection of matches with a lazy evaluation
+mechanism. After a match of length N has been found, deflate() searches for
+a longer match at the next input byte. If a longer match is found, the
+previous match is truncated to a length of one (thus producing a single
+literal byte) and the process of lazy evaluation begins again. Otherwise,
+the original match is kept, and the next match search is attempted only N
+steps later.
+
+The lazy match evaluation is also subject to a runtime parameter. If
+the current match is long enough, deflate() reduces the search for a longer
+match, thus speeding up the whole process. If compression ratio is more
+important than speed, deflate() attempts a complete second search even if
+the first match is already long enough.
+
+The lazy match evaluation is not performed for the fastest compression
+modes (level parameter 1 to 3). For these fast modes, new strings
+are inserted in the hash table only when no match was found, or
+when the match is not too long. This degrades the compression ratio
+but saves time since there are both fewer insertions and fewer searches.
+
+
+2. Decompression algorithm (inflate)
+
+2.1 Introduction
+
+The key question is how to represent a Huffman code (or any prefix code) so
+that you can decode fast.  The most important characteristic is that shorter
+codes are much more common than longer codes, so pay attention to decoding the
+short codes fast, and let the long codes take longer to decode.
+
+inflate() sets up a first level table that covers some number of bits of
+input less than the length of longest code.  It gets that many bits from the
+stream, and looks it up in the table.  The table will tell if the next
+code is that many bits or less and how many, and if it is, it will tell
+the value, else it will point to the next level table for which inflate()
+grabs more bits and tries to decode a longer code.
+
+How many bits to make the first lookup is a tradeoff between the time it
+takes to decode and the time it takes to build the table.  If building the
+table took no time (and if you had infinite memory), then there would only
+be a first level table to cover all the way to the longest code.  However,
+building the table ends up taking a lot longer for more bits since short
+codes are replicated many times in such a table.  What inflate() does is
+simply to make the number of bits in the first table a variable, and  then
+to set that variable for the maximum speed.
+
+For inflate, which has 286 possible codes for the literal/length tree, the size
+of the first table is nine bits.  Also the distance trees have 30 possible
+values, and the size of the first table is six bits.  Note that for each of
+those cases, the table ended up one bit longer than the ``average'' code
+length, i.e. the code length of an approximately flat code which would be a
+little more than eight bits for 286 symbols and a little less than five bits
+for 30 symbols.
+
+
+2.2 More details on the inflate table lookup
+
+Ok, you want to know what this cleverly obfuscated inflate tree actually
+looks like.  You are correct that it's not a Huffman tree.  It is simply a
+lookup table for the first, let's say, nine bits of a Huffman symbol.  The
+symbol could be as short as one bit or as long as 15 bits.  If a particular
+symbol is shorter than nine bits, then that symbol's translation is duplicated
+in all those entries that start with that symbol's bits.  For example, if the
+symbol is four bits, then it's duplicated 32 times in a nine-bit table.  If a
+symbol is nine bits long, it appears in the table once.
+
+If the symbol is longer than nine bits, then that entry in the table points
+to another similar table for the remaining bits.  Again, there are duplicated
+entries as needed.  The idea is that most of the time the symbol will be short
+and there will only be one table look up.  (That's whole idea behind data
+compression in the first place.)  For the less frequent long symbols, there
+will be two lookups.  If you had a compression method with really long
+symbols, you could have as many levels of lookups as is efficient.  For
+inflate, two is enough.
+
+So a table entry either points to another table (in which case nine bits in
+the above example are gobbled), or it contains the translation for the symbol
+and the number of bits to gobble.  Then you start again with the next
+ungobbled bit.
+
+You may wonder: why not just have one lookup table for how ever many bits the
+longest symbol is?  The reason is that if you do that, you end up spending
+more time filling in duplicate symbol entries than you do actually decoding.
+At least for deflate's output that generates new trees every several 10's of
+kbytes.  You can imagine that filling in a 2^15 entry table for a 15-bit code
+would take too long if you're only decoding several thousand symbols.  At the
+other extreme, you could make a new table for every bit in the code.  In fact,
+that's essentially a Huffman tree.  But then you spend too much time
+traversing the tree while decoding, even for short symbols.
+
+So the number of bits for the first lookup table is a trade of the time to
+fill out the table vs. the time spent looking at the second level and above of
+the table.
+
+Here is an example, scaled down:
+
+The code being decoded, with 10 symbols, from 1 to 6 bits long:
+
+A: 0
+B: 10
+C: 1100
+D: 11010
+E: 11011
+F: 11100
+G: 11101
+H: 11110
+I: 111110
+J: 111111
+
+Let's make the first table three bits long (eight entries):
+
+000: A,1
+001: A,1
+010: A,1
+011: A,1
+100: B,2
+101: B,2
+110: -> table X (gobble 3 bits)
+111: -> table Y (gobble 3 bits)
+
+Each entry is what the bits decode as and how many bits that is, i.e. how
+many bits to gobble.  Or the entry points to another table, with the number of
+bits to gobble implicit in the size of the table.
+
+Table X is two bits long since the longest code starting with 110 is five bits
+long:
+
+00: C,1
+01: C,1
+10: D,2
+11: E,2
+
+Table Y is three bits long since the longest code starting with 111 is six
+bits long:
+
+000: F,2
+001: F,2
+010: G,2
+011: G,2
+100: H,2
+101: H,2
+110: I,3
+111: J,3
+
+So what we have here are three tables with a total of 20 entries that had to
+be constructed.  That's compared to 64 entries for a single table.  Or
+compared to 16 entries for a Huffman tree (six two entry tables and one four
+entry table).  Assuming that the code ideally represents the probability of
+the symbols, it takes on the average 1.25 lookups per symbol.  That's compared
+to one lookup for the single table, or 1.66 lookups per symbol for the
+Huffman tree.
+
+There, I think that gives you a picture of what's going on.  For inflate, the
+meaning of a particular symbol is often more than just a letter.  It can be a
+byte (a "literal"), or it can be either a length or a distance which
+indicates a base value and a number of bits to fetch after the code that is
+added to the base value.  Or it might be the special end-of-block code.  The
+data structures created in inftrees.c try to encode all that information
+compactly in the tables.
+
+
+Jean-loup Gailly        Mark Adler
+jloup@gzip.org          madler@alumni.caltech.edu
+
+
+References:
+
+[LZ77] Ziv J., Lempel A., ``A Universal Algorithm for Sequential Data
+Compression,'' IEEE Transactions on Information Theory, Vol. 23, No. 3,
+pp. 337-343.
+
+``DEFLATE Compressed Data Format Specification'' available in
+http://tools.ietf.org/html/rfc1951
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/doc/rfc1950.txt
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/doc/rfc1950.txt	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,619 @@
+
+
+
+
+
+
+Network Working Group                                         P. Deutsch
+Request for Comments: 1950                           Aladdin Enterprises
+Category: Informational                                      J-L. Gailly
+                                                                Info-ZIP
+                                                                May 1996
+
+
+         ZLIB Compressed Data Format Specification version 3.3
+
+Status of This Memo
+
+   This memo provides information for the Internet community.  This memo
+   does not specify an Internet standard of any kind.  Distribution of
+   this memo is unlimited.
+
+IESG Note:
+
+   The IESG takes no position on the validity of any Intellectual
+   Property Rights statements contained in this document.
+
+Notices
+
+   Copyright (c) 1996 L. Peter Deutsch and Jean-Loup Gailly
+
+   Permission is granted to copy and distribute this document for any
+   purpose and without charge, including translations into other
+   languages and incorporation into compilations, provided that the
+   copyright notice and this notice are preserved, and that any
+   substantive changes or deletions from the original are clearly
+   marked.
+
+   A pointer to the latest version of this and related documentation in
+   HTML format can be found at the URL
+   <ftp://ftp.uu.net/graphics/png/documents/zlib/zdoc-index.html>.
+
+Abstract
+
+   This specification defines a lossless compressed data format.  The
+   data can be produced or consumed, even for an arbitrarily long
+   sequentially presented input data stream, using only an a priori
+   bounded amount of intermediate storage.  The format presently uses
+   the DEFLATE compression method but can be easily extended to use
+   other compression methods.  It can be implemented readily in a manner
+   not covered by patents.  This specification also defines the ADLER-32
+   checksum (an extension and improvement of the Fletcher checksum),
+   used for detection of data corruption, and provides an algorithm for
+   computing it.
+
+
+
+
+Deutsch & Gailly             Informational                      [Page 1]
+\f
+RFC 1950       ZLIB Compressed Data Format Specification        May 1996
+
+
+Table of Contents
+
+   1. Introduction ................................................... 2
+      1.1. Purpose ................................................... 2
+      1.2. Intended audience ......................................... 3
+      1.3. Scope ..................................................... 3
+      1.4. Compliance ................................................ 3
+      1.5.  Definitions of terms and conventions used ................ 3
+      1.6. Changes from previous versions ............................ 3
+   2. Detailed specification ......................................... 3
+      2.1. Overall conventions ....................................... 3
+      2.2. Data format ............................................... 4
+      2.3. Compliance ................................................ 7
+   3. References ..................................................... 7
+   4. Source code .................................................... 8
+   5. Security Considerations ........................................ 8
+   6. Acknowledgements ............................................... 8
+   7. Authors' Addresses ............................................. 8
+   8. Appendix: Rationale ............................................ 9
+   9. Appendix: Sample code ..........................................10
+
+1. Introduction
+
+   1.1. Purpose
+
+      The purpose of this specification is to define a lossless
+      compressed data format that:
+
+          * Is independent of CPU type, operating system, file system,
+            and character set, and hence can be used for interchange;
+
+          * Can be produced or consumed, even for an arbitrarily long
+            sequentially presented input data stream, using only an a
+            priori bounded amount of intermediate storage, and hence can
+            be used in data communications or similar structures such as
+            Unix filters;
+
+          * Can use a number of different compression methods;
+
+          * Can be implemented readily in a manner not covered by
+            patents, and hence can be practiced freely.
+
+      The data format defined by this specification does not attempt to
+      allow random access to compressed data.
+
+
+
+
+
+
+
+Deutsch & Gailly             Informational                      [Page 2]
+\f
+RFC 1950       ZLIB Compressed Data Format Specification        May 1996
+
+
+   1.2. Intended audience
+
+      This specification is intended for use by implementors of software
+      to compress data into zlib format and/or decompress data from zlib
+      format.
+
+      The text of the specification assumes a basic background in
+      programming at the level of bits and other primitive data
+      representations.
+
+   1.3. Scope
+
+      The specification specifies a compressed data format that can be
+      used for in-memory compression of a sequence of arbitrary bytes.
+
+   1.4. Compliance
+
+      Unless otherwise indicated below, a compliant decompressor must be
+      able to accept and decompress any data set that conforms to all
+      the specifications presented here; a compliant compressor must
+      produce data sets that conform to all the specifications presented
+      here.
+
+   1.5.  Definitions of terms and conventions used
+
+      byte: 8 bits stored or transmitted as a unit (same as an octet).
+      (For this specification, a byte is exactly 8 bits, even on
+      machines which store a character on a number of bits different
+      from 8.) See below, for the numbering of bits within a byte.
+
+   1.6. Changes from previous versions
+
+      Version 3.1 was the first public release of this specification.
+      In version 3.2, some terminology was changed and the Adler-32
+      sample code was rewritten for clarity.  In version 3.3, the
+      support for a preset dictionary was introduced, and the
+      specification was converted to RFC style.
+
+2. Detailed specification
+
+   2.1. Overall conventions
+
+      In the diagrams below, a box like this:
+
+         +---+
+         |   | <-- the vertical bars might be missing
+         +---+
+
+
+
+
+Deutsch & Gailly             Informational                      [Page 3]
+\f
+RFC 1950       ZLIB Compressed Data Format Specification        May 1996
+
+
+      represents one byte; a box like this:
+
+         +==============+
+         |              |
+         +==============+
+
+      represents a variable number of bytes.
+
+      Bytes stored within a computer do not have a "bit order", since
+      they are always treated as a unit.  However, a byte considered as
+      an integer between 0 and 255 does have a most- and least-
+      significant bit, and since we write numbers with the most-
+      significant digit on the left, we also write bytes with the most-
+      significant bit on the left.  In the diagrams below, we number the
+      bits of a byte so that bit 0 is the least-significant bit, i.e.,
+      the bits are numbered:
+
+         +--------+
+         |76543210|
+         +--------+
+
+      Within a computer, a number may occupy multiple bytes.  All
+      multi-byte numbers in the format described here are stored with
+      the MOST-significant byte first (at the lower memory address).
+      For example, the decimal number 520 is stored as:
+
+             0     1
+         +--------+--------+
+         |00000010|00001000|
+         +--------+--------+
+          ^        ^
+          |        |
+          |        + less significant byte = 8
+          + more significant byte = 2 x 256
+
+   2.2. Data format
+
+      A zlib stream has the following structure:
+
+           0   1
+         +---+---+
+         |CMF|FLG|   (more-->)
+         +---+---+
+
+
+
+
+
+
+
+
+Deutsch & Gailly             Informational                      [Page 4]
+\f
+RFC 1950       ZLIB Compressed Data Format Specification        May 1996
+
+
+      (if FLG.FDICT set)
+
+           0   1   2   3
+         +---+---+---+---+
+         |     DICTID    |   (more-->)
+         +---+---+---+---+
+
+         +=====================+---+---+---+---+
+         |...compressed data...|    ADLER32    |
+         +=====================+---+---+---+---+
+
+      Any data which may appear after ADLER32 are not part of the zlib
+      stream.
+
+      CMF (Compression Method and flags)
+         This byte is divided into a 4-bit compression method and a 4-
+         bit information field depending on the compression method.
+
+            bits 0 to 3  CM     Compression method
+            bits 4 to 7  CINFO  Compression info
+
+      CM (Compression method)
+         This identifies the compression method used in the file. CM = 8
+         denotes the "deflate" compression method with a window size up
+         to 32K.  This is the method used by gzip and PNG (see
+         references [1] and [2] in Chapter 3, below, for the reference
+         documents).  CM = 15 is reserved.  It might be used in a future
+         version of this specification to indicate the presence of an
+         extra field before the compressed data.
+
+      CINFO (Compression info)
+         For CM = 8, CINFO is the base-2 logarithm of the LZ77 window
+         size, minus eight (CINFO=7 indicates a 32K window size). Values
+         of CINFO above 7 are not allowed in this version of the
+         specification.  CINFO is not defined in this specification for
+         CM not equal to 8.
+
+      FLG (FLaGs)
+         This flag byte is divided as follows:
+
+            bits 0 to 4  FCHECK  (check bits for CMF and FLG)
+            bit  5       FDICT   (preset dictionary)
+            bits 6 to 7  FLEVEL  (compression level)
+
+         The FCHECK value must be such that CMF and FLG, when viewed as
+         a 16-bit unsigned integer stored in MSB order (CMF*256 + FLG),
+         is a multiple of 31.
+
+
+
+
+Deutsch & Gailly             Informational                      [Page 5]
+\f
+RFC 1950       ZLIB Compressed Data Format Specification        May 1996
+
+
+      FDICT (Preset dictionary)
+         If FDICT is set, a DICT dictionary identifier is present
+         immediately after the FLG byte. The dictionary is a sequence of
+         bytes which are initially fed to the compressor without
+         producing any compressed output. DICT is the Adler-32 checksum
+         of this sequence of bytes (see the definition of ADLER32
+         below).  The decompressor can use this identifier to determine
+         which dictionary has been used by the compressor.
+
+      FLEVEL (Compression level)
+         These flags are available for use by specific compression
+         methods.  The "deflate" method (CM = 8) sets these flags as
+         follows:
+
+            0 - compressor used fastest algorithm
+            1 - compressor used fast algorithm
+            2 - compressor used default algorithm
+            3 - compressor used maximum compression, slowest algorithm
+
+         The information in FLEVEL is not needed for decompression; it
+         is there to indicate if recompression might be worthwhile.
+
+      compressed data
+         For compression method 8, the compressed data is stored in the
+         deflate compressed data format as described in the document
+         "DEFLATE Compressed Data Format Specification" by L. Peter
+         Deutsch. (See reference [3] in Chapter 3, below)
+
+         Other compressed data formats are not specified in this version
+         of the zlib specification.
+
+      ADLER32 (Adler-32 checksum)
+         This contains a checksum value of the uncompressed data
+         (excluding any dictionary data) computed according to Adler-32
+         algorithm. This algorithm is a 32-bit extension and improvement
+         of the Fletcher algorithm, used in the ITU-T X.224 / ISO 8073
+         standard. See references [4] and [5] in Chapter 3, below)
+
+         Adler-32 is composed of two sums accumulated per byte: s1 is
+         the sum of all bytes, s2 is the sum of all s1 values. Both sums
+         are done modulo 65521. s1 is initialized to 1, s2 to zero.  The
+         Adler-32 checksum is stored as s2*65536 + s1 in most-
+         significant-byte first (network) order.
+
+
+
+
+
+
+
+
+Deutsch & Gailly             Informational                      [Page 6]
+\f
+RFC 1950       ZLIB Compressed Data Format Specification        May 1996
+
+
+   2.3. Compliance
+
+      A compliant compressor must produce streams with correct CMF, FLG
+      and ADLER32, but need not support preset dictionaries.  When the
+      zlib data format is used as part of another standard data format,
+      the compressor may use only preset dictionaries that are specified
+      by this other data format.  If this other format does not use the
+      preset dictionary feature, the compressor must not set the FDICT
+      flag.
+
+      A compliant decompressor must check CMF, FLG, and ADLER32, and
+      provide an error indication if any of these have incorrect values.
+      A compliant decompressor must give an error indication if CM is
+      not one of the values defined in this specification (only the
+      value 8 is permitted in this version), since another value could
+      indicate the presence of new features that would cause subsequent
+      data to be interpreted incorrectly.  A compliant decompressor must
+      give an error indication if FDICT is set and DICTID is not the
+      identifier of a known preset dictionary.  A decompressor may
+      ignore FLEVEL and still be compliant.  When the zlib data format
+      is being used as a part of another standard format, a compliant
+      decompressor must support all the preset dictionaries specified by
+      the other format. When the other format does not use the preset
+      dictionary feature, a compliant decompressor must reject any
+      stream in which the FDICT flag is set.
+
+3. References
+
+   [1] Deutsch, L.P.,"GZIP Compressed Data Format Specification",
+       available in ftp://ftp.uu.net/pub/archiving/zip/doc/
+
+   [2] Thomas Boutell, "PNG (Portable Network Graphics) specification",
+       available in ftp://ftp.uu.net/graphics/png/documents/
+
+   [3] Deutsch, L.P.,"DEFLATE Compressed Data Format Specification",
+       available in ftp://ftp.uu.net/pub/archiving/zip/doc/
+
+   [4] Fletcher, J. G., "An Arithmetic Checksum for Serial
+       Transmissions," IEEE Transactions on Communications, Vol. COM-30,
+       No. 1, January 1982, pp. 247-252.
+
+   [5] ITU-T Recommendation X.224, Annex D, "Checksum Algorithms,"
+       November, 1993, pp. 144, 145. (Available from
+       gopher://info.itu.ch). ITU-T X.244 is also the same as ISO 8073.
+
+
+
+
+
+
+
+Deutsch & Gailly             Informational                      [Page 7]
+\f
+RFC 1950       ZLIB Compressed Data Format Specification        May 1996
+
+
+4. Source code
+
+   Source code for a C language implementation of a "zlib" compliant
+   library is available at ftp://ftp.uu.net/pub/archiving/zip/zlib/.
+
+5. Security Considerations
+
+   A decoder that fails to check the ADLER32 checksum value may be
+   subject to undetected data corruption.
+
+6. Acknowledgements
+
+   Trademarks cited in this document are the property of their
+   respective owners.
+
+   Jean-Loup Gailly and Mark Adler designed the zlib format and wrote
+   the related software described in this specification.  Glenn
+   Randers-Pehrson converted this document to RFC and HTML format.
+
+7. Authors' Addresses
+
+   L. Peter Deutsch
+   Aladdin Enterprises
+   203 Santa Margarita Ave.
+   Menlo Park, CA 94025
+
+   Phone: (415) 322-0103 (AM only)
+   FAX:   (415) 322-1734
+   EMail: <ghost@aladdin.com>
+
+
+   Jean-Loup Gailly
+
+   EMail: <gzip@prep.ai.mit.edu>
+
+   Questions about the technical content of this specification can be
+   sent by email to
+
+   Jean-Loup Gailly <gzip@prep.ai.mit.edu> and
+   Mark Adler <madler@alumni.caltech.edu>
+
+   Editorial comments on this specification can be sent by email to
+
+   L. Peter Deutsch <ghost@aladdin.com> and
+   Glenn Randers-Pehrson <randeg@alumni.rpi.edu>
+
+
+
+
+
+
+Deutsch & Gailly             Informational                      [Page 8]
+\f
+RFC 1950       ZLIB Compressed Data Format Specification        May 1996
+
+
+8. Appendix: Rationale
+
+   8.1. Preset dictionaries
+
+      A preset dictionary is specially useful to compress short input
+      sequences. The compressor can take advantage of the dictionary
+      context to encode the input in a more compact manner. The
+      decompressor can be initialized with the appropriate context by
+      virtually decompressing a compressed version of the dictionary
+      without producing any output. However for certain compression
+      algorithms such as the deflate algorithm this operation can be
+      achieved without actually performing any decompression.
+
+      The compressor and the decompressor must use exactly the same
+      dictionary. The dictionary may be fixed or may be chosen among a
+      certain number of predefined dictionaries, according to the kind
+      of input data. The decompressor can determine which dictionary has
+      been chosen by the compressor by checking the dictionary
+      identifier. This document does not specify the contents of
+      predefined dictionaries, since the optimal dictionaries are
+      application specific. Standard data formats using this feature of
+      the zlib specification must precisely define the allowed
+      dictionaries.
+
+   8.2. The Adler-32 algorithm
+
+      The Adler-32 algorithm is much faster than the CRC32 algorithm yet
+      still provides an extremely low probability of undetected errors.
+
+      The modulo on unsigned long accumulators can be delayed for 5552
+      bytes, so the modulo operation time is negligible.  If the bytes
+      are a, b, c, the second sum is 3a + 2b + c + 3, and so is position
+      and order sensitive, unlike the first sum, which is just a
+      checksum.  That 65521 is prime is important to avoid a possible
+      large class of two-byte errors that leave the check unchanged.
+      (The Fletcher checksum uses 255, which is not prime and which also
+      makes the Fletcher check insensitive to single byte changes 0 <->
+      255.)
+
+      The sum s1 is initialized to 1 instead of zero to make the length
+      of the sequence part of s2, so that the length does not have to be
+      checked separately. (Any sequence of zeroes has a Fletcher
+      checksum of zero.)
+
+
+
+
+
+
+
+
+Deutsch & Gailly             Informational                      [Page 9]
+\f
+RFC 1950       ZLIB Compressed Data Format Specification        May 1996
+
+
+9. Appendix: Sample code
+
+   The following C code computes the Adler-32 checksum of a data buffer.
+   It is written for clarity, not for speed.  The sample code is in the
+   ANSI C programming language. Non C users may find it easier to read
+   with these hints:
+
+      &      Bitwise AND operator.
+      >>     Bitwise right shift operator. When applied to an
+             unsigned quantity, as here, right shift inserts zero bit(s)
+             at the left.
+      <<     Bitwise left shift operator. Left shift inserts zero
+             bit(s) at the right.
+      ++     "n++" increments the variable n.
+      %      modulo operator: a % b is the remainder of a divided by b.
+
+      #define BASE 65521 /* largest prime smaller than 65536 */
+
+      /*
+         Update a running Adler-32 checksum with the bytes buf[0..len-1]
+       and return the updated checksum. The Adler-32 checksum should be
+       initialized to 1.
+
+       Usage example:
+
+         unsigned long adler = 1L;
+
+         while (read_buffer(buffer, length) != EOF) {
+           adler = update_adler32(adler, buffer, length);
+         }
+         if (adler != original_adler) error();
+      */
+      unsigned long update_adler32(unsigned long adler,
+         unsigned char *buf, int len)
+      {
+        unsigned long s1 = adler & 0xffff;
+        unsigned long s2 = (adler >> 16) & 0xffff;
+        int n;
+
+        for (n = 0; n < len; n++) {
+          s1 = (s1 + buf[n]) % BASE;
+          s2 = (s2 + s1)     % BASE;
+        }
+        return (s2 << 16) + s1;
+      }
+
+      /* Return the adler32 of the bytes buf[0..len-1] */
+
+
+
+
+Deutsch & Gailly             Informational                     [Page 10]
+\f
+RFC 1950       ZLIB Compressed Data Format Specification        May 1996
+
+
+      unsigned long adler32(unsigned char *buf, int len)
+      {
+        return update_adler32(1L, buf, len);
+      }
+
+
+
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+Deutsch & Gailly             Informational                     [Page 11]
+\f
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/doc/rfc1951.txt
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/doc/rfc1951.txt	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,955 @@
+
+
+
+
+
+
+Network Working Group                                         P. Deutsch
+Request for Comments: 1951                           Aladdin Enterprises
+Category: Informational                                         May 1996
+
+
+        DEFLATE Compressed Data Format Specification version 1.3
+
+Status of This Memo
+
+   This memo provides information for the Internet community.  This memo
+   does not specify an Internet standard of any kind.  Distribution of
+   this memo is unlimited.
+
+IESG Note:
+
+   The IESG takes no position on the validity of any Intellectual
+   Property Rights statements contained in this document.
+
+Notices
+
+   Copyright (c) 1996 L. Peter Deutsch
+
+   Permission is granted to copy and distribute this document for any
+   purpose and without charge, including translations into other
+   languages and incorporation into compilations, provided that the
+   copyright notice and this notice are preserved, and that any
+   substantive changes or deletions from the original are clearly
+   marked.
+
+   A pointer to the latest version of this and related documentation in
+   HTML format can be found at the URL
+   <ftp://ftp.uu.net/graphics/png/documents/zlib/zdoc-index.html>.
+
+Abstract
+
+   This specification defines a lossless compressed data format that
+   compresses data using a combination of the LZ77 algorithm and Huffman
+   coding, with efficiency comparable to the best currently available
+   general-purpose compression methods.  The data can be produced or
+   consumed, even for an arbitrarily long sequentially presented input
+   data stream, using only an a priori bounded amount of intermediate
+   storage.  The format can be implemented readily in a manner not
+   covered by patents.
+
+
+
+
+
+
+
+
+Deutsch                      Informational                      [Page 1]
+\f
+RFC 1951      DEFLATE Compressed Data Format Specification      May 1996
+
+
+Table of Contents
+
+   1. Introduction ................................................... 2
+      1.1. Purpose ................................................... 2
+      1.2. Intended audience ......................................... 3
+      1.3. Scope ..................................................... 3
+      1.4. Compliance ................................................ 3
+      1.5.  Definitions of terms and conventions used ................ 3
+      1.6. Changes from previous versions ............................ 4
+   2. Compressed representation overview ............................. 4
+   3. Detailed specification ......................................... 5
+      3.1. Overall conventions ....................................... 5
+          3.1.1. Packing into bytes .................................. 5
+      3.2. Compressed block format ................................... 6
+          3.2.1. Synopsis of prefix and Huffman coding ............... 6
+          3.2.2. Use of Huffman coding in the "deflate" format ....... 7
+          3.2.3. Details of block format ............................. 9
+          3.2.4. Non-compressed blocks (BTYPE=00) ................... 11
+          3.2.5. Compressed blocks (length and distance codes) ...... 11
+          3.2.6. Compression with fixed Huffman codes (BTYPE=01) .... 12
+          3.2.7. Compression with dynamic Huffman codes (BTYPE=10) .. 13
+      3.3. Compliance ............................................... 14
+   4. Compression algorithm details ................................. 14
+   5. References .................................................... 16
+   6. Security Considerations ....................................... 16
+   7. Source code ................................................... 16
+   8. Acknowledgements .............................................. 16
+   9. Author's Address .............................................. 17
+
+1. Introduction
+
+   1.1. Purpose
+
+      The purpose of this specification is to define a lossless
+      compressed data format that:
+          * Is independent of CPU type, operating system, file system,
+            and character set, and hence can be used for interchange;
+          * Can be produced or consumed, even for an arbitrarily long
+            sequentially presented input data stream, using only an a
+            priori bounded amount of intermediate storage, and hence
+            can be used in data communications or similar structures
+            such as Unix filters;
+          * Compresses data with efficiency comparable to the best
+            currently available general-purpose compression methods,
+            and in particular considerably better than the "compress"
+            program;
+          * Can be implemented readily in a manner not covered by
+            patents, and hence can be practiced freely;
+
+
+
+Deutsch                      Informational                      [Page 2]
+\f
+RFC 1951      DEFLATE Compressed Data Format Specification      May 1996
+
+
+          * Is compatible with the file format produced by the current
+            widely used gzip utility, in that conforming decompressors
+            will be able to read data produced by the existing gzip
+            compressor.
+
+      The data format defined by this specification does not attempt to:
+
+          * Allow random access to compressed data;
+          * Compress specialized data (e.g., raster graphics) as well
+            as the best currently available specialized algorithms.
+
+      A simple counting argument shows that no lossless compression
+      algorithm can compress every possible input data set.  For the
+      format defined here, the worst case expansion is 5 bytes per 32K-
+      byte block, i.e., a size increase of 0.015% for large data sets.
+      English text usually compresses by a factor of 2.5 to 3;
+      executable files usually compress somewhat less; graphical data
+      such as raster images may compress much more.
+
+   1.2. Intended audience
+
+      This specification is intended for use by implementors of software
+      to compress data into "deflate" format and/or decompress data from
+      "deflate" format.
+
+      The text of the specification assumes a basic background in
+      programming at the level of bits and other primitive data
+      representations.  Familiarity with the technique of Huffman coding
+      is helpful but not required.
+
+   1.3. Scope
+
+      The specification specifies a method for representing a sequence
+      of bytes as a (usually shorter) sequence of bits, and a method for
+      packing the latter bit sequence into bytes.
+
+   1.4. Compliance
+
+      Unless otherwise indicated below, a compliant decompressor must be
+      able to accept and decompress any data set that conforms to all
+      the specifications presented here; a compliant compressor must
+      produce data sets that conform to all the specifications presented
+      here.
+
+   1.5.  Definitions of terms and conventions used
+
+      Byte: 8 bits stored or transmitted as a unit (same as an octet).
+      For this specification, a byte is exactly 8 bits, even on machines
+
+
+
+Deutsch                      Informational                      [Page 3]
+\f
+RFC 1951      DEFLATE Compressed Data Format Specification      May 1996
+
+
+      which store a character on a number of bits different from eight.
+      See below, for the numbering of bits within a byte.
+
+      String: a sequence of arbitrary bytes.
+
+   1.6. Changes from previous versions
+
+      There have been no technical changes to the deflate format since
+      version 1.1 of this specification.  In version 1.2, some
+      terminology was changed.  Version 1.3 is a conversion of the
+      specification to RFC style.
+
+2. Compressed representation overview
+
+   A compressed data set consists of a series of blocks, corresponding
+   to successive blocks of input data.  The block sizes are arbitrary,
+   except that non-compressible blocks are limited to 65,535 bytes.
+
+   Each block is compressed using a combination of the LZ77 algorithm
+   and Huffman coding. The Huffman trees for each block are independent
+   of those for previous or subsequent blocks; the LZ77 algorithm may
+   use a reference to a duplicated string occurring in a previous block,
+   up to 32K input bytes before.
+
+   Each block consists of two parts: a pair of Huffman code trees that
+   describe the representation of the compressed data part, and a
+   compressed data part.  (The Huffman trees themselves are compressed
+   using Huffman encoding.)  The compressed data consists of a series of
+   elements of two types: literal bytes (of strings that have not been
+   detected as duplicated within the previous 32K input bytes), and
+   pointers to duplicated strings, where a pointer is represented as a
+   pair <length, backward distance>.  The representation used in the
+   "deflate" format limits distances to 32K bytes and lengths to 258
+   bytes, but does not limit the size of a block, except for
+   uncompressible blocks, which are limited as noted above.
+
+   Each type of value (literals, distances, and lengths) in the
+   compressed data is represented using a Huffman code, using one code
+   tree for literals and lengths and a separate code tree for distances.
+   The code trees for each block appear in a compact form just before
+   the compressed data for that block.
+
+
+
+
+
+
+
+
+
+
+Deutsch                      Informational                      [Page 4]
+\f
+RFC 1951      DEFLATE Compressed Data Format Specification      May 1996
+
+
+3. Detailed specification
+
+   3.1. Overall conventions In the diagrams below, a box like this:
+
+         +---+
+         |   | <-- the vertical bars might be missing
+         +---+
+
+      represents one byte; a box like this:
+
+         +==============+
+         |              |
+         +==============+
+
+      represents a variable number of bytes.
+
+      Bytes stored within a computer do not have a "bit order", since
+      they are always treated as a unit.  However, a byte considered as
+      an integer between 0 and 255 does have a most- and least-
+      significant bit, and since we write numbers with the most-
+      significant digit on the left, we also write bytes with the most-
+      significant bit on the left.  In the diagrams below, we number the
+      bits of a byte so that bit 0 is the least-significant bit, i.e.,
+      the bits are numbered:
+
+         +--------+
+         |76543210|
+         +--------+
+
+      Within a computer, a number may occupy multiple bytes.  All
+      multi-byte numbers in the format described here are stored with
+      the least-significant byte first (at the lower memory address).
+      For example, the decimal number 520 is stored as:
+
+             0        1
+         +--------+--------+
+         |00001000|00000010|
+         +--------+--------+
+          ^        ^
+          |        |
+          |        + more significant byte = 2 x 256
+          + less significant byte = 8
+
+      3.1.1. Packing into bytes
+
+         This document does not address the issue of the order in which
+         bits of a byte are transmitted on a bit-sequential medium,
+         since the final data format described here is byte- rather than
+
+
+
+Deutsch                      Informational                      [Page 5]
+\f
+RFC 1951      DEFLATE Compressed Data Format Specification      May 1996
+
+
+         bit-oriented.  However, we describe the compressed block format
+         in below, as a sequence of data elements of various bit
+         lengths, not a sequence of bytes.  We must therefore specify
+         how to pack these data elements into bytes to form the final
+         compressed byte sequence:
+
+             * Data elements are packed into bytes in order of
+               increasing bit number within the byte, i.e., starting
+               with the least-significant bit of the byte.
+             * Data elements other than Huffman codes are packed
+               starting with the least-significant bit of the data
+               element.
+             * Huffman codes are packed starting with the most-
+               significant bit of the code.
+
+         In other words, if one were to print out the compressed data as
+         a sequence of bytes, starting with the first byte at the
+         *right* margin and proceeding to the *left*, with the most-
+         significant bit of each byte on the left as usual, one would be
+         able to parse the result from right to left, with fixed-width
+         elements in the correct MSB-to-LSB order and Huffman codes in
+         bit-reversed order (i.e., with the first bit of the code in the
+         relative LSB position).
+
+   3.2. Compressed block format
+
+      3.2.1. Synopsis of prefix and Huffman coding
+
+         Prefix coding represents symbols from an a priori known
+         alphabet by bit sequences (codes), one code for each symbol, in
+         a manner such that different symbols may be represented by bit
+         sequences of different lengths, but a parser can always parse
+         an encoded string unambiguously symbol-by-symbol.
+
+         We define a prefix code in terms of a binary tree in which the
+         two edges descending from each non-leaf node are labeled 0 and
+         1 and in which the leaf nodes correspond one-for-one with (are
+         labeled with) the symbols of the alphabet; then the code for a
+         symbol is the sequence of 0's and 1's on the edges leading from
+         the root to the leaf labeled with that symbol.  For example:
+
+
+
+
+
+
+
+
+
+
+
+Deutsch                      Informational                      [Page 6]
+\f
+RFC 1951      DEFLATE Compressed Data Format Specification      May 1996
+
+
+                          /\              Symbol    Code
+                         0  1             ------    ----
+                        /    \                A      00
+                       /\     B               B       1
+                      0  1                    C     011
+                     /    \                   D     010
+                    A     /\
+                         0  1
+                        /    \
+                       D      C
+
+         A parser can decode the next symbol from an encoded input
+         stream by walking down the tree from the root, at each step
+         choosing the edge corresponding to the next input bit.
+
+         Given an alphabet with known symbol frequencies, the Huffman
+         algorithm allows the construction of an optimal prefix code
+         (one which represents strings with those symbol frequencies
+         using the fewest bits of any possible prefix codes for that
+         alphabet).  Such a code is called a Huffman code.  (See
+         reference [1] in Chapter 5, references for additional
+         information on Huffman codes.)
+
+         Note that in the "deflate" format, the Huffman codes for the
+         various alphabets must not exceed certain maximum code lengths.
+         This constraint complicates the algorithm for computing code
+         lengths from symbol frequencies.  Again, see Chapter 5,
+         references for details.
+
+      3.2.2. Use of Huffman coding in the "deflate" format
+
+         The Huffman codes used for each alphabet in the "deflate"
+         format have two additional rules:
+
+             * All codes of a given bit length have lexicographically
+               consecutive values, in the same order as the symbols
+               they represent;
+
+             * Shorter codes lexicographically precede longer codes.
+
+
+
+
+
+
+
+
+
+
+
+
+Deutsch                      Informational                      [Page 7]
+\f
+RFC 1951      DEFLATE Compressed Data Format Specification      May 1996
+
+
+         We could recode the example above to follow this rule as
+         follows, assuming that the order of the alphabet is ABCD:
+
+            Symbol  Code
+            ------  ----
+            A       10
+            B       0
+            C       110
+            D       111
+
+         I.e., 0 precedes 10 which precedes 11x, and 110 and 111 are
+         lexicographically consecutive.
+
+         Given this rule, we can define the Huffman code for an alphabet
+         just by giving the bit lengths of the codes for each symbol of
+         the alphabet in order; this is sufficient to determine the
+         actual codes.  In our example, the code is completely defined
+         by the sequence of bit lengths (2, 1, 3, 3).  The following
+         algorithm generates the codes as integers, intended to be read
+         from most- to least-significant bit.  The code lengths are
+         initially in tree[I].Len; the codes are produced in
+         tree[I].Code.
+
+         1)  Count the number of codes for each code length.  Let
+             bl_count[N] be the number of codes of length N, N >= 1.
+
+         2)  Find the numerical value of the smallest code for each
+             code length:
+
+                code = 0;
+                bl_count[0] = 0;
+                for (bits = 1; bits <= MAX_BITS; bits++) {
+                    code = (code + bl_count[bits-1]) << 1;
+                    next_code[bits] = code;
+                }
+
+         3)  Assign numerical values to all codes, using consecutive
+             values for all codes of the same length with the base
+             values determined at step 2. Codes that are never used
+             (which have a bit length of zero) must not be assigned a
+             value.
+
+                for (n = 0;  n <= max_code; n++) {
+                    len = tree[n].Len;
+                    if (len != 0) {
+                        tree[n].Code = next_code[len];
+                        next_code[len]++;
+                    }
+
+
+
+Deutsch                      Informational                      [Page 8]
+\f
+RFC 1951      DEFLATE Compressed Data Format Specification      May 1996
+
+
+                }
+
+         Example:
+
+         Consider the alphabet ABCDEFGH, with bit lengths (3, 3, 3, 3,
+         3, 2, 4, 4).  After step 1, we have:
+
+            N      bl_count[N]
+            -      -----------
+            2      1
+            3      5
+            4      2
+
+         Step 2 computes the following next_code values:
+
+            N      next_code[N]
+            -      ------------
+            1      0
+            2      0
+            3      2
+            4      14
+
+         Step 3 produces the following code values:
+
+            Symbol Length   Code
+            ------ ------   ----
+            A       3        010
+            B       3        011
+            C       3        100
+            D       3        101
+            E       3        110
+            F       2         00
+            G       4       1110
+            H       4       1111
+
+      3.2.3. Details of block format
+
+         Each block of compressed data begins with 3 header bits
+         containing the following data:
+
+            first bit       BFINAL
+            next 2 bits     BTYPE
+
+         Note that the header bits do not necessarily begin on a byte
+         boundary, since a block does not necessarily occupy an integral
+         number of bytes.
+
+
+
+
+
+Deutsch                      Informational                      [Page 9]
+\f
+RFC 1951      DEFLATE Compressed Data Format Specification      May 1996
+
+
+         BFINAL is set if and only if this is the last block of the data
+         set.
+
+         BTYPE specifies how the data are compressed, as follows:
+
+            00 - no compression
+            01 - compressed with fixed Huffman codes
+            10 - compressed with dynamic Huffman codes
+            11 - reserved (error)
+
+         The only difference between the two compressed cases is how the
+         Huffman codes for the literal/length and distance alphabets are
+         defined.
+
+         In all cases, the decoding algorithm for the actual data is as
+         follows:
+
+            do
+               read block header from input stream.
+               if stored with no compression
+                  skip any remaining bits in current partially
+                     processed byte
+                  read LEN and NLEN (see next section)
+                  copy LEN bytes of data to output
+               otherwise
+                  if compressed with dynamic Huffman codes
+                     read representation of code trees (see
+                        subsection below)
+                  loop (until end of block code recognized)
+                     decode literal/length value from input stream
+                     if value < 256
+                        copy value (literal byte) to output stream
+                     otherwise
+                        if value = end of block (256)
+                           break from loop
+                        otherwise (value = 257..285)
+                           decode distance from input stream
+
+                           move backwards distance bytes in the output
+                           stream, and copy length bytes from this
+                           position to the output stream.
+                  end loop
+            while not last block
+
+         Note that a duplicated string reference may refer to a string
+         in a previous block; i.e., the backward distance may cross one
+         or more block boundaries.  However a distance cannot refer past
+         the beginning of the output stream.  (An application using a
+
+
+
+Deutsch                      Informational                     [Page 10]
+\f
+RFC 1951      DEFLATE Compressed Data Format Specification      May 1996
+
+
+         preset dictionary might discard part of the output stream; a
+         distance can refer to that part of the output stream anyway)
+         Note also that the referenced string may overlap the current
+         position; for example, if the last 2 bytes decoded have values
+         X and Y, a string reference with <length = 5, distance = 2>
+         adds X,Y,X,Y,X to the output stream.
+
+         We now specify each compression method in turn.
+
+      3.2.4. Non-compressed blocks (BTYPE=00)
+
+         Any bits of input up to the next byte boundary are ignored.
+         The rest of the block consists of the following information:
+
+              0   1   2   3   4...
+            +---+---+---+---+================================+
+            |  LEN  | NLEN  |... LEN bytes of literal data...|
+            +---+---+---+---+================================+
+
+         LEN is the number of data bytes in the block.  NLEN is the
+         one's complement of LEN.
+
+      3.2.5. Compressed blocks (length and distance codes)
+
+         As noted above, encoded data blocks in the "deflate" format
+         consist of sequences of symbols drawn from three conceptually
+         distinct alphabets: either literal bytes, from the alphabet of
+         byte values (0..255), or <length, backward distance> pairs,
+         where the length is drawn from (3..258) and the distance is
+         drawn from (1..32,768).  In fact, the literal and length
+         alphabets are merged into a single alphabet (0..285), where
+         values 0..255 represent literal bytes, the value 256 indicates
+         end-of-block, and values 257..285 represent length codes
+         (possibly in conjunction with extra bits following the symbol
+         code) as follows:
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Deutsch                      Informational                     [Page 11]
+\f
+RFC 1951      DEFLATE Compressed Data Format Specification      May 1996
+
+
+                 Extra               Extra               Extra
+            Code Bits Length(s) Code Bits Lengths   Code Bits Length(s)
+            ---- ---- ------     ---- ---- -------   ---- ---- -------
+             257   0     3       267   1   15,16     277   4   67-82
+             258   0     4       268   1   17,18     278   4   83-98
+             259   0     5       269   2   19-22     279   4   99-114
+             260   0     6       270   2   23-26     280   4  115-130
+             261   0     7       271   2   27-30     281   5  131-162
+             262   0     8       272   2   31-34     282   5  163-194
+             263   0     9       273   3   35-42     283   5  195-226
+             264   0    10       274   3   43-50     284   5  227-257
+             265   1  11,12      275   3   51-58     285   0    258
+             266   1  13,14      276   3   59-66
+
+         The extra bits should be interpreted as a machine integer
+         stored with the most-significant bit first, e.g., bits 1110
+         represent the value 14.
+
+                  Extra           Extra               Extra
+             Code Bits Dist  Code Bits   Dist     Code Bits Distance
+             ---- ---- ----  ---- ----  ------    ---- ---- --------
+               0   0    1     10   4     33-48    20    9   1025-1536
+               1   0    2     11   4     49-64    21    9   1537-2048
+               2   0    3     12   5     65-96    22   10   2049-3072
+               3   0    4     13   5     97-128   23   10   3073-4096
+               4   1   5,6    14   6    129-192   24   11   4097-6144
+               5   1   7,8    15   6    193-256   25   11   6145-8192
+               6   2   9-12   16   7    257-384   26   12  8193-12288
+               7   2  13-16   17   7    385-512   27   12 12289-16384
+               8   3  17-24   18   8    513-768   28   13 16385-24576
+               9   3  25-32   19   8   769-1024   29   13 24577-32768
+
+      3.2.6. Compression with fixed Huffman codes (BTYPE=01)
+
+         The Huffman codes for the two alphabets are fixed, and are not
+         represented explicitly in the data.  The Huffman code lengths
+         for the literal/length alphabet are:
+
+                   Lit Value    Bits        Codes
+                   ---------    ----        -----
+                     0 - 143     8          00110000 through
+                                            10111111
+                   144 - 255     9          110010000 through
+                                            111111111
+                   256 - 279     7          0000000 through
+                                            0010111
+                   280 - 287     8          11000000 through
+                                            11000111
+
+
+
+Deutsch                      Informational                     [Page 12]
+\f
+RFC 1951      DEFLATE Compressed Data Format Specification      May 1996
+
+
+         The code lengths are sufficient to generate the actual codes,
+         as described above; we show the codes in the table for added
+         clarity.  Literal/length values 286-287 will never actually
+         occur in the compressed data, but participate in the code
+         construction.
+
+         Distance codes 0-31 are represented by (fixed-length) 5-bit
+         codes, with possible additional bits as shown in the table
+         shown in Paragraph 3.2.5, above.  Note that distance codes 30-
+         31 will never actually occur in the compressed data.
+
+      3.2.7. Compression with dynamic Huffman codes (BTYPE=10)
+
+         The Huffman codes for the two alphabets appear in the block
+         immediately after the header bits and before the actual
+         compressed data, first the literal/length code and then the
+         distance code.  Each code is defined by a sequence of code
+         lengths, as discussed in Paragraph 3.2.2, above.  For even
+         greater compactness, the code length sequences themselves are
+         compressed using a Huffman code.  The alphabet for code lengths
+         is as follows:
+
+               0 - 15: Represent code lengths of 0 - 15
+                   16: Copy the previous code length 3 - 6 times.
+                       The next 2 bits indicate repeat length
+                             (0 = 3, ... , 3 = 6)
+                          Example:  Codes 8, 16 (+2 bits 11),
+                                    16 (+2 bits 10) will expand to
+                                    12 code lengths of 8 (1 + 6 + 5)
+                   17: Repeat a code length of 0 for 3 - 10 times.
+                       (3 bits of length)
+                   18: Repeat a code length of 0 for 11 - 138 times
+                       (7 bits of length)
+
+         A code length of 0 indicates that the corresponding symbol in
+         the literal/length or distance alphabet will not occur in the
+         block, and should not participate in the Huffman code
+         construction algorithm given earlier.  If only one distance
+         code is used, it is encoded using one bit, not zero bits; in
+         this case there is a single code length of one, with one unused
+         code.  One distance code of zero bits means that there are no
+         distance codes used at all (the data is all literals).
+
+         We can now define the format of the block:
+
+               5 Bits: HLIT, # of Literal/Length codes - 257 (257 - 286)
+               5 Bits: HDIST, # of Distance codes - 1        (1 - 32)
+               4 Bits: HCLEN, # of Code Length codes - 4     (4 - 19)
+
+
+
+Deutsch                      Informational                     [Page 13]
+\f
+RFC 1951      DEFLATE Compressed Data Format Specification      May 1996
+
+
+               (HCLEN + 4) x 3 bits: code lengths for the code length
+                  alphabet given just above, in the order: 16, 17, 18,
+                  0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
+
+                  These code lengths are interpreted as 3-bit integers
+                  (0-7); as above, a code length of 0 means the
+                  corresponding symbol (literal/length or distance code
+                  length) is not used.
+
+               HLIT + 257 code lengths for the literal/length alphabet,
+                  encoded using the code length Huffman code
+
+               HDIST + 1 code lengths for the distance alphabet,
+                  encoded using the code length Huffman code
+
+               The actual compressed data of the block,
+                  encoded using the literal/length and distance Huffman
+                  codes
+
+               The literal/length symbol 256 (end of data),
+                  encoded using the literal/length Huffman code
+
+         The code length repeat codes can cross from HLIT + 257 to the
+         HDIST + 1 code lengths.  In other words, all code lengths form
+         a single sequence of HLIT + HDIST + 258 values.
+
+   3.3. Compliance
+
+      A compressor may limit further the ranges of values specified in
+      the previous section and still be compliant; for example, it may
+      limit the range of backward pointers to some value smaller than
+      32K.  Similarly, a compressor may limit the size of blocks so that
+      a compressible block fits in memory.
+
+      A compliant decompressor must accept the full range of possible
+      values defined in the previous section, and must accept blocks of
+      arbitrary size.
+
+4. Compression algorithm details
+
+   While it is the intent of this document to define the "deflate"
+   compressed data format without reference to any particular
+   compression algorithm, the format is related to the compressed
+   formats produced by LZ77 (Lempel-Ziv 1977, see reference [2] below);
+   since many variations of LZ77 are patented, it is strongly
+   recommended that the implementor of a compressor follow the general
+   algorithm presented here, which is known not to be patented per se.
+   The material in this section is not part of the definition of the
+
+
+
+Deutsch                      Informational                     [Page 14]
+\f
+RFC 1951      DEFLATE Compressed Data Format Specification      May 1996
+
+
+   specification per se, and a compressor need not follow it in order to
+   be compliant.
+
+   The compressor terminates a block when it determines that starting a
+   new block with fresh trees would be useful, or when the block size
+   fills up the compressor's block buffer.
+
+   The compressor uses a chained hash table to find duplicated strings,
+   using a hash function that operates on 3-byte sequences.  At any
+   given point during compression, let XYZ be the next 3 input bytes to
+   be examined (not necessarily all different, of course).  First, the
+   compressor examines the hash chain for XYZ.  If the chain is empty,
+   the compressor simply writes out X as a literal byte and advances one
+   byte in the input.  If the hash chain is not empty, indicating that
+   the sequence XYZ (or, if we are unlucky, some other 3 bytes with the
+   same hash function value) has occurred recently, the compressor
+   compares all strings on the XYZ hash chain with the actual input data
+   sequence starting at the current point, and selects the longest
+   match.
+
+   The compressor searches the hash chains starting with the most recent
+   strings, to favor small distances and thus take advantage of the
+   Huffman encoding.  The hash chains are singly linked. There are no
+   deletions from the hash chains; the algorithm simply discards matches
+   that are too old.  To avoid a worst-case situation, very long hash
+   chains are arbitrarily truncated at a certain length, determined by a
+   run-time parameter.
+
+   To improve overall compression, the compressor optionally defers the
+   selection of matches ("lazy matching"): after a match of length N has
+   been found, the compressor searches for a longer match starting at
+   the next input byte.  If it finds a longer match, it truncates the
+   previous match to a length of one (thus producing a single literal
+   byte) and then emits the longer match.  Otherwise, it emits the
+   original match, and, as described above, advances N bytes before
+   continuing.
+
+   Run-time parameters also control this "lazy match" procedure.  If
+   compression ratio is most important, the compressor attempts a
+   complete second search regardless of the length of the first match.
+   In the normal case, if the current match is "long enough", the
+   compressor reduces the search for a longer match, thus speeding up
+   the process.  If speed is most important, the compressor inserts new
+   strings in the hash table only when no match was found, or when the
+   match is not "too long".  This degrades the compression ratio but
+   saves time since there are both fewer insertions and fewer searches.
+
+
+
+
+
+Deutsch                      Informational                     [Page 15]
+\f
+RFC 1951      DEFLATE Compressed Data Format Specification      May 1996
+
+
+5. References
+
+   [1] Huffman, D. A., "A Method for the Construction of Minimum
+       Redundancy Codes", Proceedings of the Institute of Radio
+       Engineers, September 1952, Volume 40, Number 9, pp. 1098-1101.
+
+   [2] Ziv J., Lempel A., "A Universal Algorithm for Sequential Data
+       Compression", IEEE Transactions on Information Theory, Vol. 23,
+       No. 3, pp. 337-343.
+
+   [3] Gailly, J.-L., and Adler, M., ZLIB documentation and sources,
+       available in ftp://ftp.uu.net/pub/archiving/zip/doc/
+
+   [4] Gailly, J.-L., and Adler, M., GZIP documentation and sources,
+       available as gzip-*.tar in ftp://prep.ai.mit.edu/pub/gnu/
+
+   [5] Schwartz, E. S., and Kallick, B. "Generating a canonical prefix
+       encoding." Comm. ACM, 7,3 (Mar. 1964), pp. 166-169.
+
+   [6] Hirschberg and Lelewer, "Efficient decoding of prefix codes,"
+       Comm. ACM, 33,4, April 1990, pp. 449-459.
+
+6. Security Considerations
+
+   Any data compression method involves the reduction of redundancy in
+   the data.  Consequently, any corruption of the data is likely to have
+   severe effects and be difficult to correct.  Uncompressed text, on
+   the other hand, will probably still be readable despite the presence
+   of some corrupted bytes.
+
+   It is recommended that systems using this data format provide some
+   means of validating the integrity of the compressed data.  See
+   reference [3], for example.
+
+7. Source code
+
+   Source code for a C language implementation of a "deflate" compliant
+   compressor and decompressor is available within the zlib package at
+   ftp://ftp.uu.net/pub/archiving/zip/zlib/.
+
+8. Acknowledgements
+
+   Trademarks cited in this document are the property of their
+   respective owners.
+
+   Phil Katz designed the deflate format.  Jean-Loup Gailly and Mark
+   Adler wrote the related software described in this specification.
+   Glenn Randers-Pehrson converted this document to RFC and HTML format.
+
+
+
+Deutsch                      Informational                     [Page 16]
+\f
+RFC 1951      DEFLATE Compressed Data Format Specification      May 1996
+
+
+9. Author's Address
+
+   L. Peter Deutsch
+   Aladdin Enterprises
+   203 Santa Margarita Ave.
+   Menlo Park, CA 94025
+
+   Phone: (415) 322-0103 (AM only)
+   FAX:   (415) 322-1734
+   EMail: <ghost@aladdin.com>
+
+   Questions about the technical content of this specification can be
+   sent by email to:
+
+   Jean-Loup Gailly <gzip@prep.ai.mit.edu> and
+   Mark Adler <madler@alumni.caltech.edu>
+
+   Editorial comments on this specification can be sent by email to:
+
+   L. Peter Deutsch <ghost@aladdin.com> and
+   Glenn Randers-Pehrson <randeg@alumni.rpi.edu>
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Deutsch                      Informational                     [Page 17]
+\f
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/doc/rfc1952.txt
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/doc/rfc1952.txt	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,675 @@
+
+
+
+
+
+
+Network Working Group                                         P. Deutsch
+Request for Comments: 1952                           Aladdin Enterprises
+Category: Informational                                         May 1996
+
+
+               GZIP file format specification version 4.3
+
+Status of This Memo
+
+   This memo provides information for the Internet community.  This memo
+   does not specify an Internet standard of any kind.  Distribution of
+   this memo is unlimited.
+
+IESG Note:
+
+   The IESG takes no position on the validity of any Intellectual
+   Property Rights statements contained in this document.
+
+Notices
+
+   Copyright (c) 1996 L. Peter Deutsch
+
+   Permission is granted to copy and distribute this document for any
+   purpose and without charge, including translations into other
+   languages and incorporation into compilations, provided that the
+   copyright notice and this notice are preserved, and that any
+   substantive changes or deletions from the original are clearly
+   marked.
+
+   A pointer to the latest version of this and related documentation in
+   HTML format can be found at the URL
+   <ftp://ftp.uu.net/graphics/png/documents/zlib/zdoc-index.html>.
+
+Abstract
+
+   This specification defines a lossless compressed data format that is
+   compatible with the widely used GZIP utility.  The format includes a
+   cyclic redundancy check value for detecting data corruption.  The
+   format presently uses the DEFLATE method of compression but can be
+   easily extended to use other compression methods.  The format can be
+   implemented readily in a manner not covered by patents.
+
+
+
+
+
+
+
+
+
+
+Deutsch                      Informational                      [Page 1]
+\f
+RFC 1952             GZIP File Format Specification             May 1996
+
+
+Table of Contents
+
+   1. Introduction ................................................... 2
+      1.1. Purpose ................................................... 2
+      1.2. Intended audience ......................................... 3
+      1.3. Scope ..................................................... 3
+      1.4. Compliance ................................................ 3
+      1.5. Definitions of terms and conventions used ................. 3
+      1.6. Changes from previous versions ............................ 3
+   2. Detailed specification ......................................... 4
+      2.1. Overall conventions ....................................... 4
+      2.2. File format ............................................... 5
+      2.3. Member format ............................................. 5
+          2.3.1. Member header and trailer ........................... 6
+              2.3.1.1. Extra field ................................... 8
+              2.3.1.2. Compliance .................................... 9
+      3. References .................................................. 9
+      4. Security Considerations .................................... 10
+      5. Acknowledgements ........................................... 10
+      6. Author's Address ........................................... 10
+      7. Appendix: Jean-Loup Gailly's gzip utility .................. 11
+      8. Appendix: Sample CRC Code .................................. 11
+
+1. Introduction
+
+   1.1. Purpose
+
+      The purpose of this specification is to define a lossless
+      compressed data format that:
+
+          * Is independent of CPU type, operating system, file system,
+            and character set, and hence can be used for interchange;
+          * Can compress or decompress a data stream (as opposed to a
+            randomly accessible file) to produce another data stream,
+            using only an a priori bounded amount of intermediate
+            storage, and hence can be used in data communications or
+            similar structures such as Unix filters;
+          * Compresses data with efficiency comparable to the best
+            currently available general-purpose compression methods,
+            and in particular considerably better than the "compress"
+            program;
+          * Can be implemented readily in a manner not covered by
+            patents, and hence can be practiced freely;
+          * Is compatible with the file format produced by the current
+            widely used gzip utility, in that conforming decompressors
+            will be able to read data produced by the existing gzip
+            compressor.
+
+
+
+
+Deutsch                      Informational                      [Page 2]
+\f
+RFC 1952             GZIP File Format Specification             May 1996
+
+
+      The data format defined by this specification does not attempt to:
+
+          * Provide random access to compressed data;
+          * Compress specialized data (e.g., raster graphics) as well as
+            the best currently available specialized algorithms.
+
+   1.2. Intended audience
+
+      This specification is intended for use by implementors of software
+      to compress data into gzip format and/or decompress data from gzip
+      format.
+
+      The text of the specification assumes a basic background in
+      programming at the level of bits and other primitive data
+      representations.
+
+   1.3. Scope
+
+      The specification specifies a compression method and a file format
+      (the latter assuming only that a file can store a sequence of
+      arbitrary bytes).  It does not specify any particular interface to
+      a file system or anything about character sets or encodings
+      (except for file names and comments, which are optional).
+
+   1.4. Compliance
+
+      Unless otherwise indicated below, a compliant decompressor must be
+      able to accept and decompress any file that conforms to all the
+      specifications presented here; a compliant compressor must produce
+      files that conform to all the specifications presented here.  The
+      material in the appendices is not part of the specification per se
+      and is not relevant to compliance.
+
+   1.5. Definitions of terms and conventions used
+
+      byte: 8 bits stored or transmitted as a unit (same as an octet).
+      (For this specification, a byte is exactly 8 bits, even on
+      machines which store a character on a number of bits different
+      from 8.)  See below for the numbering of bits within a byte.
+
+   1.6. Changes from previous versions
+
+      There have been no technical changes to the gzip format since
+      version 4.1 of this specification.  In version 4.2, some
+      terminology was changed, and the sample CRC code was rewritten for
+      clarity and to eliminate the requirement for the caller to do pre-
+      and post-conditioning.  Version 4.3 is a conversion of the
+      specification to RFC style.
+
+
+
+Deutsch                      Informational                      [Page 3]
+\f
+RFC 1952             GZIP File Format Specification             May 1996
+
+
+2. Detailed specification
+
+   2.1. Overall conventions
+
+      In the diagrams below, a box like this:
+
+         +---+
+         |   | <-- the vertical bars might be missing
+         +---+
+
+      represents one byte; a box like this:
+
+         +==============+
+         |              |
+         +==============+
+
+      represents a variable number of bytes.
+
+      Bytes stored within a computer do not have a "bit order", since
+      they are always treated as a unit.  However, a byte considered as
+      an integer between 0 and 255 does have a most- and least-
+      significant bit, and since we write numbers with the most-
+      significant digit on the left, we also write bytes with the most-
+      significant bit on the left.  In the diagrams below, we number the
+      bits of a byte so that bit 0 is the least-significant bit, i.e.,
+      the bits are numbered:
+
+         +--------+
+         |76543210|
+         +--------+
+
+      This document does not address the issue of the order in which
+      bits of a byte are transmitted on a bit-sequential medium, since
+      the data format described here is byte- rather than bit-oriented.
+
+      Within a computer, a number may occupy multiple bytes.  All
+      multi-byte numbers in the format described here are stored with
+      the least-significant byte first (at the lower memory address).
+      For example, the decimal number 520 is stored as:
+
+             0        1
+         +--------+--------+
+         |00001000|00000010|
+         +--------+--------+
+          ^        ^
+          |        |
+          |        + more significant byte = 2 x 256
+          + less significant byte = 8
+
+
+
+Deutsch                      Informational                      [Page 4]
+\f
+RFC 1952             GZIP File Format Specification             May 1996
+
+
+   2.2. File format
+
+      A gzip file consists of a series of "members" (compressed data
+      sets).  The format of each member is specified in the following
+      section.  The members simply appear one after another in the file,
+      with no additional information before, between, or after them.
+
+   2.3. Member format
+
+      Each member has the following structure:
+
+         +---+---+---+---+---+---+---+---+---+---+
+         |ID1|ID2|CM |FLG|     MTIME     |XFL|OS | (more-->)
+         +---+---+---+---+---+---+---+---+---+---+
+
+      (if FLG.FEXTRA set)
+
+         +---+---+=================================+
+         | XLEN  |...XLEN bytes of "extra field"...| (more-->)
+         +---+---+=================================+
+
+      (if FLG.FNAME set)
+
+         +=========================================+
+         |...original file name, zero-terminated...| (more-->)
+         +=========================================+
+
+      (if FLG.FCOMMENT set)
+
+         +===================================+
+         |...file comment, zero-terminated...| (more-->)
+         +===================================+
+
+      (if FLG.FHCRC set)
+
+         +---+---+
+         | CRC16 |
+         +---+---+
+
+         +=======================+
+         |...compressed blocks...| (more-->)
+         +=======================+
+
+           0   1   2   3   4   5   6   7
+         +---+---+---+---+---+---+---+---+
+         |     CRC32     |     ISIZE     |
+         +---+---+---+---+---+---+---+---+
+
+
+
+
+Deutsch                      Informational                      [Page 5]
+\f
+RFC 1952             GZIP File Format Specification             May 1996
+
+
+      2.3.1. Member header and trailer
+
+         ID1 (IDentification 1)
+         ID2 (IDentification 2)
+            These have the fixed values ID1 = 31 (0x1f, \037), ID2 = 139
+            (0x8b, \213), to identify the file as being in gzip format.
+
+         CM (Compression Method)
+            This identifies the compression method used in the file.  CM
+            = 0-7 are reserved.  CM = 8 denotes the "deflate"
+            compression method, which is the one customarily used by
+            gzip and which is documented elsewhere.
+
+         FLG (FLaGs)
+            This flag byte is divided into individual bits as follows:
+
+               bit 0   FTEXT
+               bit 1   FHCRC
+               bit 2   FEXTRA
+               bit 3   FNAME
+               bit 4   FCOMMENT
+               bit 5   reserved
+               bit 6   reserved
+               bit 7   reserved
+
+            If FTEXT is set, the file is probably ASCII text.  This is
+            an optional indication, which the compressor may set by
+            checking a small amount of the input data to see whether any
+            non-ASCII characters are present.  In case of doubt, FTEXT
+            is cleared, indicating binary data. For systems which have
+            different file formats for ascii text and binary data, the
+            decompressor can use FTEXT to choose the appropriate format.
+            We deliberately do not specify the algorithm used to set
+            this bit, since a compressor always has the option of
+            leaving it cleared and a decompressor always has the option
+            of ignoring it and letting some other program handle issues
+            of data conversion.
+
+            If FHCRC is set, a CRC16 for the gzip header is present,
+            immediately before the compressed data. The CRC16 consists
+            of the two least significant bytes of the CRC32 for all
+            bytes of the gzip header up to and not including the CRC16.
+            [The FHCRC bit was never set by versions of gzip up to
+            1.2.4, even though it was documented with a different
+            meaning in gzip 1.2.4.]
+
+            If FEXTRA is set, optional extra fields are present, as
+            described in a following section.
+
+
+
+Deutsch                      Informational                      [Page 6]
+\f
+RFC 1952             GZIP File Format Specification             May 1996
+
+
+            If FNAME is set, an original file name is present,
+            terminated by a zero byte.  The name must consist of ISO
+            8859-1 (LATIN-1) characters; on operating systems using
+            EBCDIC or any other character set for file names, the name
+            must be translated to the ISO LATIN-1 character set.  This
+            is the original name of the file being compressed, with any
+            directory components removed, and, if the file being
+            compressed is on a file system with case insensitive names,
+            forced to lower case. There is no original file name if the
+            data was compressed from a source other than a named file;
+            for example, if the source was stdin on a Unix system, there
+            is no file name.
+
+            If FCOMMENT is set, a zero-terminated file comment is
+            present.  This comment is not interpreted; it is only
+            intended for human consumption.  The comment must consist of
+            ISO 8859-1 (LATIN-1) characters.  Line breaks should be
+            denoted by a single line feed character (10 decimal).
+
+            Reserved FLG bits must be zero.
+
+         MTIME (Modification TIME)
+            This gives the most recent modification time of the original
+            file being compressed.  The time is in Unix format, i.e.,
+            seconds since 00:00:00 GMT, Jan.  1, 1970.  (Note that this
+            may cause problems for MS-DOS and other systems that use
+            local rather than Universal time.)  If the compressed data
+            did not come from a file, MTIME is set to the time at which
+            compression started.  MTIME = 0 means no time stamp is
+            available.
+
+         XFL (eXtra FLags)
+            These flags are available for use by specific compression
+            methods.  The "deflate" method (CM = 8) sets these flags as
+            follows:
+
+               XFL = 2 - compressor used maximum compression,
+                         slowest algorithm
+               XFL = 4 - compressor used fastest algorithm
+
+         OS (Operating System)
+            This identifies the type of file system on which compression
+            took place.  This may be useful in determining end-of-line
+            convention for text files.  The currently defined values are
+            as follows:
+
+
+
+
+
+
+Deutsch                      Informational                      [Page 7]
+\f
+RFC 1952             GZIP File Format Specification             May 1996
+
+
+                 0 - FAT filesystem (MS-DOS, OS/2, NT/Win32)
+                 1 - Amiga
+                 2 - VMS (or OpenVMS)
+                 3 - Unix
+                 4 - VM/CMS
+                 5 - Atari TOS
+                 6 - HPFS filesystem (OS/2, NT)
+                 7 - Macintosh
+                 8 - Z-System
+                 9 - CP/M
+                10 - TOPS-20
+                11 - NTFS filesystem (NT)
+                12 - QDOS
+                13 - Acorn RISCOS
+               255 - unknown
+
+         XLEN (eXtra LENgth)
+            If FLG.FEXTRA is set, this gives the length of the optional
+            extra field.  See below for details.
+
+         CRC32 (CRC-32)
+            This contains a Cyclic Redundancy Check value of the
+            uncompressed data computed according to CRC-32 algorithm
+            used in the ISO 3309 standard and in section 8.1.1.6.2 of
+            ITU-T recommendation V.42.  (See http://www.iso.ch for
+            ordering ISO documents. See gopher://info.itu.ch for an
+            online version of ITU-T V.42.)
+
+         ISIZE (Input SIZE)
+            This contains the size of the original (uncompressed) input
+            data modulo 2^32.
+
+      2.3.1.1. Extra field
+
+         If the FLG.FEXTRA bit is set, an "extra field" is present in
+         the header, with total length XLEN bytes.  It consists of a
+         series of subfields, each of the form:
+
+            +---+---+---+---+==================================+
+            |SI1|SI2|  LEN  |... LEN bytes of subfield data ...|
+            +---+---+---+---+==================================+
+
+         SI1 and SI2 provide a subfield ID, typically two ASCII letters
+         with some mnemonic value.  Jean-Loup Gailly
+         <gzip@prep.ai.mit.edu> is maintaining a registry of subfield
+         IDs; please send him any subfield ID you wish to use.  Subfield
+         IDs with SI2 = 0 are reserved for future use.  The following
+         IDs are currently defined:
+
+
+
+Deutsch                      Informational                      [Page 8]
+\f
+RFC 1952             GZIP File Format Specification             May 1996
+
+
+            SI1         SI2         Data
+            ----------  ----------  ----
+            0x41 ('A')  0x70 ('P')  Apollo file type information
+
+         LEN gives the length of the subfield data, excluding the 4
+         initial bytes.
+
+      2.3.1.2. Compliance
+
+         A compliant compressor must produce files with correct ID1,
+         ID2, CM, CRC32, and ISIZE, but may set all the other fields in
+         the fixed-length part of the header to default values (255 for
+         OS, 0 for all others).  The compressor must set all reserved
+         bits to zero.
+
+         A compliant decompressor must check ID1, ID2, and CM, and
+         provide an error indication if any of these have incorrect
+         values.  It must examine FEXTRA/XLEN, FNAME, FCOMMENT and FHCRC
+         at least so it can skip over the optional fields if they are
+         present.  It need not examine any other part of the header or
+         trailer; in particular, a decompressor may ignore FTEXT and OS
+         and always produce binary output, and still be compliant.  A
+         compliant decompressor must give an error indication if any
+         reserved bit is non-zero, since such a bit could indicate the
+         presence of a new field that would cause subsequent data to be
+         interpreted incorrectly.
+
+3. References
+
+   [1] "Information Processing - 8-bit single-byte coded graphic
+       character sets - Part 1: Latin alphabet No.1" (ISO 8859-1:1987).
+       The ISO 8859-1 (Latin-1) character set is a superset of 7-bit
+       ASCII. Files defining this character set are available as
+       iso_8859-1.* in ftp://ftp.uu.net/graphics/png/documents/
+
+   [2] ISO 3309
+
+   [3] ITU-T recommendation V.42
+
+   [4] Deutsch, L.P.,"DEFLATE Compressed Data Format Specification",
+       available in ftp://ftp.uu.net/pub/archiving/zip/doc/
+
+   [5] Gailly, J.-L., GZIP documentation, available as gzip-*.tar in
+       ftp://prep.ai.mit.edu/pub/gnu/
+
+   [6] Sarwate, D.V., "Computation of Cyclic Redundancy Checks via Table
+       Look-Up", Communications of the ACM, 31(8), pp.1008-1013.
+
+
+
+
+Deutsch                      Informational                      [Page 9]
+\f
+RFC 1952             GZIP File Format Specification             May 1996
+
+
+   [7] Schwaderer, W.D., "CRC Calculation", April 85 PC Tech Journal,
+       pp.118-133.
+
+   [8] ftp://ftp.adelaide.edu.au/pub/rocksoft/papers/crc_v3.txt,
+       describing the CRC concept.
+
+4. Security Considerations
+
+   Any data compression method involves the reduction of redundancy in
+   the data.  Consequently, any corruption of the data is likely to have
+   severe effects and be difficult to correct.  Uncompressed text, on
+   the other hand, will probably still be readable despite the presence
+   of some corrupted bytes.
+
+   It is recommended that systems using this data format provide some
+   means of validating the integrity of the compressed data, such as by
+   setting and checking the CRC-32 check value.
+
+5. Acknowledgements
+
+   Trademarks cited in this document are the property of their
+   respective owners.
+
+   Jean-Loup Gailly designed the gzip format and wrote, with Mark Adler,
+   the related software described in this specification.  Glenn
+   Randers-Pehrson converted this document to RFC and HTML format.
+
+6. Author's Address
+
+   L. Peter Deutsch
+   Aladdin Enterprises
+   203 Santa Margarita Ave.
+   Menlo Park, CA 94025
+
+   Phone: (415) 322-0103 (AM only)
+   FAX:   (415) 322-1734
+   EMail: <ghost@aladdin.com>
+
+   Questions about the technical content of this specification can be
+   sent by email to:
+
+   Jean-Loup Gailly <gzip@prep.ai.mit.edu> and
+   Mark Adler <madler@alumni.caltech.edu>
+
+   Editorial comments on this specification can be sent by email to:
+
+   L. Peter Deutsch <ghost@aladdin.com> and
+   Glenn Randers-Pehrson <randeg@alumni.rpi.edu>
+
+
+
+Deutsch                      Informational                     [Page 10]
+\f
+RFC 1952             GZIP File Format Specification             May 1996
+
+
+7. Appendix: Jean-Loup Gailly's gzip utility
+
+   The most widely used implementation of gzip compression, and the
+   original documentation on which this specification is based, were
+   created by Jean-Loup Gailly <gzip@prep.ai.mit.edu>.  Since this
+   implementation is a de facto standard, we mention some more of its
+   features here.  Again, the material in this section is not part of
+   the specification per se, and implementations need not follow it to
+   be compliant.
+
+   When compressing or decompressing a file, gzip preserves the
+   protection, ownership, and modification time attributes on the local
+   file system, since there is no provision for representing protection
+   attributes in the gzip file format itself.  Since the file format
+   includes a modification time, the gzip decompressor provides a
+   command line switch that assigns the modification time from the file,
+   rather than the local modification time of the compressed input, to
+   the decompressed output.
+
+8. Appendix: Sample CRC Code
+
+   The following sample code represents a practical implementation of
+   the CRC (Cyclic Redundancy Check). (See also ISO 3309 and ITU-T V.42
+   for a formal specification.)
+
+   The sample code is in the ANSI C programming language. Non C users
+   may find it easier to read with these hints:
+
+      &      Bitwise AND operator.
+      ^      Bitwise exclusive-OR operator.
+      >>     Bitwise right shift operator. When applied to an
+             unsigned quantity, as here, right shift inserts zero
+             bit(s) at the left.
+      !      Logical NOT operator.
+      ++     "n++" increments the variable n.
+      0xNNN  0x introduces a hexadecimal (base 16) constant.
+             Suffix L indicates a long value (at least 32 bits).
+
+      /* Table of CRCs of all 8-bit messages. */
+      unsigned long crc_table[256];
+
+      /* Flag: has the table been computed? Initially false. */
+      int crc_table_computed = 0;
+
+      /* Make the table for a fast CRC. */
+      void make_crc_table(void)
+      {
+        unsigned long c;
+
+
+
+Deutsch                      Informational                     [Page 11]
+\f
+RFC 1952             GZIP File Format Specification             May 1996
+
+
+        int n, k;
+        for (n = 0; n < 256; n++) {
+          c = (unsigned long) n;
+          for (k = 0; k < 8; k++) {
+            if (c & 1) {
+              c = 0xedb88320L ^ (c >> 1);
+            } else {
+              c = c >> 1;
+            }
+          }
+          crc_table[n] = c;
+        }
+        crc_table_computed = 1;
+      }
+
+      /*
+         Update a running crc with the bytes buf[0..len-1] and return
+       the updated crc. The crc should be initialized to zero. Pre- and
+       post-conditioning (one's complement) is performed within this
+       function so it shouldn't be done by the caller. Usage example:
+
+         unsigned long crc = 0L;
+
+         while (read_buffer(buffer, length) != EOF) {
+           crc = update_crc(crc, buffer, length);
+         }
+         if (crc != original_crc) error();
+      */
+      unsigned long update_crc(unsigned long crc,
+                      unsigned char *buf, int len)
+      {
+        unsigned long c = crc ^ 0xffffffffL;
+        int n;
+
+        if (!crc_table_computed)
+          make_crc_table();
+        for (n = 0; n < len; n++) {
+          c = crc_table[(c ^ buf[n]) & 0xff] ^ (c >> 8);
+        }
+        return c ^ 0xffffffffL;
+      }
+
+      /* Return the CRC of the bytes buf[0..len-1]. */
+      unsigned long crc(unsigned char *buf, int len)
+      {
+        return update_crc(0L, buf, len);
+      }
+
+
+
+
+Deutsch                      Informational                     [Page 12]
+\f
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/doc/txtvsbin.txt
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/doc/txtvsbin.txt	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,107 @@
+A Fast Method for Identifying Plain Text Files
+==============================================
+
+
+Introduction
+------------
+
+Given a file coming from an unknown source, it is sometimes desirable
+to find out whether the format of that file is plain text.  Although
+this may appear like a simple task, a fully accurate detection of the
+file type requires heavy-duty semantic analysis on the file contents.
+It is, however, possible to obtain satisfactory results by employing
+various heuristics.
+
+Previous versions of PKZip and other zip-compatible compression tools
+were using a crude detection scheme: if more than 80% (4/5) of the bytes
+found in a certain buffer are within the range [7..127], the file is
+labeled as plain text, otherwise it is labeled as binary.  A prominent
+limitation of this scheme is the restriction to Latin-based alphabets.
+Other alphabets, like Greek, Cyrillic or Asian, make extensive use of
+the bytes within the range [128..255], and texts using these alphabets
+are most often misidentified by this scheme; in other words, the rate
+of false negatives is sometimes too high, which means that the recall
+is low.  Another weakness of this scheme is a reduced precision, due to
+the false positives that may occur when binary files containing large
+amounts of textual characters are misidentified as plain text.
+
+In this article we propose a new, simple detection scheme that features
+a much increased precision and a near-100% recall.  This scheme is
+designed to work on ASCII, Unicode and other ASCII-derived alphabets,
+and it handles single-byte encodings (ISO-8859, MacRoman, KOI8, etc.)
+and variable-sized encodings (ISO-2022, UTF-8, etc.).  Wider encodings
+(UCS-2/UTF-16 and UCS-4/UTF-32) are not handled, however.
+
+
+The Algorithm
+-------------
+
+The algorithm works by dividing the set of bytecodes [0..255] into three
+categories:
+- The white list of textual bytecodes:
+  9 (TAB), 10 (LF), 13 (CR), 32 (SPACE) to 255.
+- The gray list of tolerated bytecodes:
+  7 (BEL), 8 (BS), 11 (VT), 12 (FF), 26 (SUB), 27 (ESC).
+- The black list of undesired, non-textual bytecodes:
+  0 (NUL) to 6, 14 to 31.
+
+If a file contains at least one byte that belongs to the white list and
+no byte that belongs to the black list, then the file is categorized as
+plain text; otherwise, it is categorized as binary.  (The boundary case,
+when the file is empty, automatically falls into the latter category.)
+
+
+Rationale
+---------
+
+The idea behind this algorithm relies on two observations.
+
+The first observation is that, although the full range of 7-bit codes
+[0..127] is properly specified by the ASCII standard, most control
+characters in the range [0..31] are not used in practice.  The only
+widely-used, almost universally-portable control codes are 9 (TAB),
+10 (LF) and 13 (CR).  There are a few more control codes that are
+recognized on a reduced range of platforms and text viewers/editors:
+7 (BEL), 8 (BS), 11 (VT), 12 (FF), 26 (SUB) and 27 (ESC); but these
+codes are rarely (if ever) used alone, without being accompanied by
+some printable text.  Even the newer, portable text formats such as
+XML avoid using control characters outside the list mentioned here.
+
+The second observation is that most of the binary files tend to contain
+control characters, especially 0 (NUL).  Even though the older text
+detection schemes observe the presence of non-ASCII codes from the range
+[128..255], the precision rarely has to suffer if this upper range is
+labeled as textual, because the files that are genuinely binary tend to
+contain both control characters and codes from the upper range.  On the
+other hand, the upper range needs to be labeled as textual, because it
+is used by virtually all ASCII extensions.  In particular, this range is
+used for encoding non-Latin scripts.
+
+Since there is no counting involved, other than simply observing the
+presence or the absence of some byte values, the algorithm produces
+consistent results, regardless what alphabet encoding is being used.
+(If counting were involved, it could be possible to obtain different
+results on a text encoded, say, using ISO-8859-16 versus UTF-8.)
+
+There is an extra category of plain text files that are "polluted" with
+one or more black-listed codes, either by mistake or by peculiar design
+considerations.  In such cases, a scheme that tolerates a small fraction
+of black-listed codes would provide an increased recall (i.e. more true
+positives).  This, however, incurs a reduced precision overall, since
+false positives are more likely to appear in binary files that contain
+large chunks of textual data.  Furthermore, "polluted" plain text should
+be regarded as binary by general-purpose text detection schemes, because
+general-purpose text processing algorithms might not be applicable.
+Under this premise, it is safe to say that our detection method provides
+a near-100% recall.
+
+Experiments have been run on many files coming from various platforms
+and applications.  We tried plain text files, system logs, source code,
+formatted office documents, compiled object code, etc.  The results
+confirm the optimistic assumptions about the capabilities of this
+algorithm.
+
+
+--
+Cosmin Truta
+Last updated: 2006-May-28
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/examples/README.examples
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/examples/README.examples	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,49 @@
+This directory contains examples of the use of zlib and other relevant
+programs and documentation.
+
+enough.c
+    calculation and justification of ENOUGH parameter in inftrees.h
+    - calculates the maximum table space used in inflate tree
+      construction over all possible Huffman codes
+
+fitblk.c
+    compress just enough input to nearly fill a requested output size
+    - zlib isn't designed to do this, but fitblk does it anyway
+
+gun.c
+    uncompress a gzip file
+    - illustrates the use of inflateBack() for high speed file-to-file
+      decompression using call-back functions
+    - is approximately twice as fast as gzip -d
+    - also provides Unix uncompress functionality, again twice as fast
+
+gzappend.c
+    append to a gzip file
+    - illustrates the use of the Z_BLOCK flush parameter for inflate()
+    - illustrates the use of deflatePrime() to start at any bit
+
+gzjoin.c
+    join gzip files without recalculating the crc or recompressing
+    - illustrates the use of the Z_BLOCK flush parameter for inflate()
+    - illustrates the use of crc32_combine()
+
+gzlog.c
+gzlog.h
+    efficiently and robustly maintain a message log file in gzip format
+    - illustrates use of raw deflate, Z_PARTIAL_FLUSH, deflatePrime(),
+      and deflateSetDictionary()
+    - illustrates use of a gzip header extra field
+
+zlib_how.html
+    painfully comprehensive description of zpipe.c (see below)
+    - describes in excruciating detail the use of deflate() and inflate()
+
+zpipe.c
+    reads and writes zlib streams from stdin to stdout
+    - illustrates the proper use of deflate() and inflate()
+    - deeply commented in zlib_how.html (see above)
+
+zran.c
+    index a zlib or gzip stream and randomly access it
+    - illustrates the use of Z_BLOCK, inflatePrime(), and
+      inflateSetDictionary() to provide random access
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/examples/enough.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/examples/enough.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,572 @@
+/* enough.c -- determine the maximum size of inflate's Huffman code tables over
+ * all possible valid and complete Huffman codes, subject to a length limit.
+ * Copyright (C) 2007, 2008, 2012 Mark Adler
+ * Version 1.4  18 August 2012  Mark Adler
+ */
+
+/* Version history:
+   1.0   3 Jan 2007  First version (derived from codecount.c version 1.4)
+   1.1   4 Jan 2007  Use faster incremental table usage computation
+                     Prune examine() search on previously visited states
+   1.2   5 Jan 2007  Comments clean up
+                     As inflate does, decrease root for short codes
+                     Refuse cases where inflate would increase root
+   1.3  17 Feb 2008  Add argument for initial root table size
+                     Fix bug for initial root table size == max - 1
+                     Use a macro to compute the history index
+   1.4  18 Aug 2012  Avoid shifts more than bits in type (caused endless loop!)
+                     Clean up comparisons of different types
+                     Clean up code indentation
+ */
+
+/*
+   Examine all possible Huffman codes for a given number of symbols and a
+   maximum code length in bits to determine the maximum table size for zilb's
+   inflate.  Only complete Huffman codes are counted.
+
+   Two codes are considered distinct if the vectors of the number of codes per
+   length are not identical.  So permutations of the symbol assignments result
+   in the same code for the counting, as do permutations of the assignments of
+   the bit values to the codes (i.e. only canonical codes are counted).
+
+   We build a code from shorter to longer lengths, determining how many symbols
+   are coded at each length.  At each step, we have how many symbols remain to
+   be coded, what the last code length used was, and how many bit patterns of
+   that length remain unused. Then we add one to the code length and double the
+   number of unused patterns to graduate to the next code length.  We then
+   assign all portions of the remaining symbols to that code length that
+   preserve the properties of a correct and eventually complete code.  Those
+   properties are: we cannot use more bit patterns than are available; and when
+   all the symbols are used, there are exactly zero possible bit patterns
+   remaining.
+
+   The inflate Huffman decoding algorithm uses two-level lookup tables for
+   speed.  There is a single first-level table to decode codes up to root bits
+   in length (root == 9 in the current inflate implementation).  The table
+   has 1 << root entries and is indexed by the next root bits of input.  Codes
+   shorter than root bits have replicated table entries, so that the correct
+   entry is pointed to regardless of the bits that follow the short code.  If
+   the code is longer than root bits, then the table entry points to a second-
+   level table.  The size of that table is determined by the longest code with
+   that root-bit prefix.  If that longest code has length len, then the table
+   has size 1 << (len - root), to index the remaining bits in that set of
+   codes.  Each subsequent root-bit prefix then has its own sub-table.  The
+   total number of table entries required by the code is calculated
+   incrementally as the number of codes at each bit length is populated.  When
+   all of the codes are shorter than root bits, then root is reduced to the
+   longest code length, resulting in a single, smaller, one-level table.
+
+   The inflate algorithm also provides for small values of root (relative to
+   the log2 of the number of symbols), where the shortest code has more bits
+   than root.  In that case, root is increased to the length of the shortest
+   code.  This program, by design, does not handle that case, so it is verified
+   that the number of symbols is less than 2^(root + 1).
+
+   In order to speed up the examination (by about ten orders of magnitude for
+   the default arguments), the intermediate states in the build-up of a code
+   are remembered and previously visited branches are pruned.  The memory
+   required for this will increase rapidly with the total number of symbols and
+   the maximum code length in bits.  However this is a very small price to pay
+   for the vast speedup.
+
+   First, all of the possible Huffman codes are counted, and reachable
+   intermediate states are noted by a non-zero count in a saved-results array.
+   Second, the intermediate states that lead to (root + 1) bit or longer codes
+   are used to look at all sub-codes from those junctures for their inflate
+   memory usage.  (The amount of memory used is not affected by the number of
+   codes of root bits or less in length.)  Third, the visited states in the
+   construction of those sub-codes and the associated calculation of the table
+   size is recalled in order to avoid recalculating from the same juncture.
+   Beginning the code examination at (root + 1) bit codes, which is enabled by
+   identifying the reachable nodes, accounts for about six of the orders of
+   magnitude of improvement for the default arguments.  About another four
+   orders of magnitude come from not revisiting previous states.  Out of
+   approximately 2x10^16 possible Huffman codes, only about 2x10^6 sub-codes
+   need to be examined to cover all of the possible table memory usage cases
+   for the default arguments of 286 symbols limited to 15-bit codes.
+
+   Note that an unsigned long long type is used for counting.  It is quite easy
+   to exceed the capacity of an eight-byte integer with a large number of
+   symbols and a large maximum code length, so multiple-precision arithmetic
+   would need to replace the unsigned long long arithmetic in that case.  This
+   program will abort if an overflow occurs.  The big_t type identifies where
+   the counting takes place.
+
+   An unsigned long long type is also used for calculating the number of
+   possible codes remaining at the maximum length.  This limits the maximum
+   code length to the number of bits in a long long minus the number of bits
+   needed to represent the symbols in a flat code.  The code_t type identifies
+   where the bit pattern counting takes place.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#define local static
+
+/* special data types */
+typedef unsigned long long big_t;   /* type for code counting */
+typedef unsigned long long code_t;  /* type for bit pattern counting */
+struct tab {                        /* type for been here check */
+    size_t len;         /* length of bit vector in char's */
+    char *vec;          /* allocated bit vector */
+};
+
+/* The array for saving results, num[], is indexed with this triplet:
+
+      syms: number of symbols remaining to code
+      left: number of available bit patterns at length len
+      len: number of bits in the codes currently being assigned
+
+   Those indices are constrained thusly when saving results:
+
+      syms: 3..totsym (totsym == total symbols to code)
+      left: 2..syms - 1, but only the evens (so syms == 8 -> 2, 4, 6)
+      len: 1..max - 1 (max == maximum code length in bits)
+
+   syms == 2 is not saved since that immediately leads to a single code.  left
+   must be even, since it represents the number of available bit patterns at
+   the current length, which is double the number at the previous length.
+   left ends at syms-1 since left == syms immediately results in a single code.
+   (left > sym is not allowed since that would result in an incomplete code.)
+   len is less than max, since the code completes immediately when len == max.
+
+   The offset into the array is calculated for the three indices with the
+   first one (syms) being outermost, and the last one (len) being innermost.
+   We build the array with length max-1 lists for the len index, with syms-3
+   of those for each symbol.  There are totsym-2 of those, with each one
+   varying in length as a function of sym.  See the calculation of index in
+   count() for the index, and the calculation of size in main() for the size
+   of the array.
+
+   For the deflate example of 286 symbols limited to 15-bit codes, the array
+   has 284,284 entries, taking up 2.17 MB for an 8-byte big_t.  More than
+   half of the space allocated for saved results is actually used -- not all
+   possible triplets are reached in the generation of valid Huffman codes.
+ */
+
+/* The array for tracking visited states, done[], is itself indexed identically
+   to the num[] array as described above for the (syms, left, len) triplet.
+   Each element in the array is further indexed by the (mem, rem) doublet,
+   where mem is the amount of inflate table space used so far, and rem is the
+   remaining unused entries in the current inflate sub-table.  Each indexed
+   element is simply one bit indicating whether the state has been visited or
+   not.  Since the ranges for mem and rem are not known a priori, each bit
+   vector is of a variable size, and grows as needed to accommodate the visited
+   states.  mem and rem are used to calculate a single index in a triangular
+   array.  Since the range of mem is expected in the default case to be about
+   ten times larger than the range of rem, the array is skewed to reduce the
+   memory usage, with eight times the range for mem than for rem.  See the
+   calculations for offset and bit in beenhere() for the details.
+
+   For the deflate example of 286 symbols limited to 15-bit codes, the bit
+   vectors grow to total approximately 21 MB, in addition to the 4.3 MB done[]
+   array itself.
+ */
+
+/* Globals to avoid propagating constants or constant pointers recursively */
+local int max;          /* maximum allowed bit length for the codes */
+local int root;         /* size of base code table in bits */
+local int large;        /* largest code table so far */
+local size_t size;      /* number of elements in num and done */
+local int *code;        /* number of symbols assigned to each bit length */
+local big_t *num;       /* saved results array for code counting */
+local struct tab *done; /* states already evaluated array */
+
+/* Index function for num[] and done[] */
+#define INDEX(i,j,k) (((size_t)((i-1)>>1)*((i-2)>>1)+(j>>1)-1)*(max-1)+k-1)
+
+/* Free allocated space.  Uses globals code, num, and done. */
+local void cleanup(void)
+{
+    size_t n;
+
+    if (done != NULL) {
+        for (n = 0; n < size; n++)
+            if (done[n].len)
+                free(done[n].vec);
+        free(done);
+    }
+    if (num != NULL)
+        free(num);
+    if (code != NULL)
+        free(code);
+}
+
+/* Return the number of possible Huffman codes using bit patterns of lengths
+   len through max inclusive, coding syms symbols, with left bit patterns of
+   length len unused -- return -1 if there is an overflow in the counting.
+   Keep a record of previous results in num to prevent repeating the same
+   calculation.  Uses the globals max and num. */
+local big_t count(int syms, int len, int left)
+{
+    big_t sum;          /* number of possible codes from this juncture */
+    big_t got;          /* value returned from count() */
+    int least;          /* least number of syms to use at this juncture */
+    int most;           /* most number of syms to use at this juncture */
+    int use;            /* number of bit patterns to use in next call */
+    size_t index;       /* index of this case in *num */
+
+    /* see if only one possible code */
+    if (syms == left)
+        return 1;
+
+    /* note and verify the expected state */
+    assert(syms > left && left > 0 && len < max);
+
+    /* see if we've done this one already */
+    index = INDEX(syms, left, len);
+    got = num[index];
+    if (got)
+        return got;         /* we have -- return the saved result */
+
+    /* we need to use at least this many bit patterns so that the code won't be
+       incomplete at the next length (more bit patterns than symbols) */
+    least = (left << 1) - syms;
+    if (least < 0)
+        least = 0;
+
+    /* we can use at most this many bit patterns, lest there not be enough
+       available for the remaining symbols at the maximum length (if there were
+       no limit to the code length, this would become: most = left - 1) */
+    most = (((code_t)left << (max - len)) - syms) /
+            (((code_t)1 << (max - len)) - 1);
+
+    /* count all possible codes from this juncture and add them up */
+    sum = 0;
+    for (use = least; use <= most; use++) {
+        got = count(syms - use, len + 1, (left - use) << 1);
+        sum += got;
+        if (got == (big_t)0 - 1 || sum < got)   /* overflow */
+            return (big_t)0 - 1;
+    }
+
+    /* verify that all recursive calls are productive */
+    assert(sum != 0);
+
+    /* save the result and return it */
+    num[index] = sum;
+    return sum;
+}
+
+/* Return true if we've been here before, set to true if not.  Set a bit in a
+   bit vector to indicate visiting this state.  Each (syms,len,left) state
+   has a variable size bit vector indexed by (mem,rem).  The bit vector is
+   lengthened if needed to allow setting the (mem,rem) bit. */
+local int beenhere(int syms, int len, int left, int mem, int rem)
+{
+    size_t index;       /* index for this state's bit vector */
+    size_t offset;      /* offset in this state's bit vector */
+    int bit;            /* mask for this state's bit */
+    size_t length;      /* length of the bit vector in bytes */
+    char *vector;       /* new or enlarged bit vector */
+
+    /* point to vector for (syms,left,len), bit in vector for (mem,rem) */
+    index = INDEX(syms, left, len);
+    mem -= 1 << root;
+    offset = (mem >> 3) + rem;
+    offset = ((offset * (offset + 1)) >> 1) + rem;
+    bit = 1 << (mem & 7);
+
+    /* see if we've been here */
+    length = done[index].len;
+    if (offset < length && (done[index].vec[offset] & bit) != 0)
+        return 1;       /* done this! */
+
+    /* we haven't been here before -- set the bit to show we have now */
+
+    /* see if we need to lengthen the vector in order to set the bit */
+    if (length <= offset) {
+        /* if we have one already, enlarge it, zero out the appended space */
+        if (length) {
+            do {
+                length <<= 1;
+            } while (length <= offset);
+            vector = realloc(done[index].vec, length);
+            if (vector != NULL)
+                memset(vector + done[index].len, 0, length - done[index].len);
+        }
+
+        /* otherwise we need to make a new vector and zero it out */
+        else {
+            length = 1 << (len - root);
+            while (length <= offset)
+                length <<= 1;
+            vector = calloc(length, sizeof(char));
+        }
+
+        /* in either case, bail if we can't get the memory */
+        if (vector == NULL) {
+            fputs("abort: unable to allocate enough memory\n", stderr);
+            cleanup();
+            exit(1);
+        }
+
+        /* install the new vector */
+        done[index].len = length;
+        done[index].vec = vector;
+    }
+
+    /* set the bit */
+    done[index].vec[offset] |= bit;
+    return 0;
+}
+
+/* Examine all possible codes from the given node (syms, len, left).  Compute
+   the amount of memory required to build inflate's decoding tables, where the
+   number of code structures used so far is mem, and the number remaining in
+   the current sub-table is rem.  Uses the globals max, code, root, large, and
+   done. */
+local void examine(int syms, int len, int left, int mem, int rem)
+{
+    int least;          /* least number of syms to use at this juncture */
+    int most;           /* most number of syms to use at this juncture */
+    int use;            /* number of bit patterns to use in next call */
+
+    /* see if we have a complete code */
+    if (syms == left) {
+        /* set the last code entry */
+        code[len] = left;
+
+        /* complete computation of memory used by this code */
+        while (rem < left) {
+            left -= rem;
+            rem = 1 << (len - root);
+            mem += rem;
+        }
+        assert(rem == left);
+
+        /* if this is a new maximum, show the entries used and the sub-code */
+        if (mem > large) {
+            large = mem;
+            printf("max %d: ", mem);
+            for (use = root + 1; use <= max; use++)
+                if (code[use])
+                    printf("%d[%d] ", code[use], use);
+            putchar('\n');
+            fflush(stdout);
+        }
+
+        /* remove entries as we drop back down in the recursion */
+        code[len] = 0;
+        return;
+    }
+
+    /* prune the tree if we can */
+    if (beenhere(syms, len, left, mem, rem))
+        return;
+
+    /* we need to use at least this many bit patterns so that the code won't be
+       incomplete at the next length (more bit patterns than symbols) */
+    least = (left << 1) - syms;
+    if (least < 0)
+        least = 0;
+
+    /* we can use at most this many bit patterns, lest there not be enough
+       available for the remaining symbols at the maximum length (if there were
+       no limit to the code length, this would become: most = left - 1) */
+    most = (((code_t)left << (max - len)) - syms) /
+            (((code_t)1 << (max - len)) - 1);
+
+    /* occupy least table spaces, creating new sub-tables as needed */
+    use = least;
+    while (rem < use) {
+        use -= rem;
+        rem = 1 << (len - root);
+        mem += rem;
+    }
+    rem -= use;
+
+    /* examine codes from here, updating table space as we go */
+    for (use = least; use <= most; use++) {
+        code[len] = use;
+        examine(syms - use, len + 1, (left - use) << 1,
+                mem + (rem ? 1 << (len - root) : 0), rem << 1);
+        if (rem == 0) {
+            rem = 1 << (len - root);
+            mem += rem;
+        }
+        rem--;
+    }
+
+    /* remove entries as we drop back down in the recursion */
+    code[len] = 0;
+}
+
+/* Look at all sub-codes starting with root + 1 bits.  Look at only the valid
+   intermediate code states (syms, left, len).  For each completed code,
+   calculate the amount of memory required by inflate to build the decoding
+   tables. Find the maximum amount of memory required and show the code that
+   requires that maximum.  Uses the globals max, root, and num. */
+local void enough(int syms)
+{
+    int n;              /* number of remaing symbols for this node */
+    int left;           /* number of unused bit patterns at this length */
+    size_t index;       /* index of this case in *num */
+
+    /* clear code */
+    for (n = 0; n <= max; n++)
+        code[n] = 0;
+
+    /* look at all (root + 1) bit and longer codes */
+    large = 1 << root;              /* base table */
+    if (root < max)                 /* otherwise, there's only a base table */
+        for (n = 3; n <= syms; n++)
+            for (left = 2; left < n; left += 2)
+            {
+                /* look at all reachable (root + 1) bit nodes, and the
+                   resulting codes (complete at root + 2 or more) */
+                index = INDEX(n, left, root + 1);
+                if (root + 1 < max && num[index])       /* reachable node */
+                    examine(n, root + 1, left, 1 << root, 0);
+
+                /* also look at root bit codes with completions at root + 1
+                   bits (not saved in num, since complete), just in case */
+                if (num[index - 1] && n <= left << 1)
+                    examine((n - left) << 1, root + 1, (n - left) << 1,
+                            1 << root, 0);
+            }
+
+    /* done */
+    printf("done: maximum of %d table entries\n", large);
+}
+
+/*
+   Examine and show the total number of possible Huffman codes for a given
+   maximum number of symbols, initial root table size, and maximum code length
+   in bits -- those are the command arguments in that order.  The default
+   values are 286, 9, and 15 respectively, for the deflate literal/length code.
+   The possible codes are counted for each number of coded symbols from two to
+   the maximum.  The counts for each of those and the total number of codes are
+   shown.  The maximum number of inflate table entires is then calculated
+   across all possible codes.  Each new maximum number of table entries and the
+   associated sub-code (starting at root + 1 == 10 bits) is shown.
+
+   To count and examine Huffman codes that are not length-limited, provide a
+   maximum length equal to the number of symbols minus one.
+
+   For the deflate literal/length code, use "enough".  For the deflate distance
+   code, use "enough 30 6".
+
+   This uses the %llu printf format to print big_t numbers, which assumes that
+   big_t is an unsigned long long.  If the big_t type is changed (for example
+   to a multiple precision type), the method of printing will also need to be
+   updated.
+ */
+int main(int argc, char **argv)
+{
+    int syms;           /* total number of symbols to code */
+    int n;              /* number of symbols to code for this run */
+    big_t got;          /* return value of count() */
+    big_t sum;          /* accumulated number of codes over n */
+    code_t word;        /* for counting bits in code_t */
+
+    /* set up globals for cleanup() */
+    code = NULL;
+    num = NULL;
+    done = NULL;
+
+    /* get arguments -- default to the deflate literal/length code */
+    syms = 286;
+    root = 9;
+    max = 15;
+    if (argc > 1) {
+        syms = atoi(argv[1]);
+        if (argc > 2) {
+            root = atoi(argv[2]);
+            if (argc > 3)
+                max = atoi(argv[3]);
+        }
+    }
+    if (argc > 4 || syms < 2 || root < 1 || max < 1) {
+        fputs("invalid arguments, need: [sym >= 2 [root >= 1 [max >= 1]]]\n",
+              stderr);
+        return 1;
+    }
+
+    /* if not restricting the code length, the longest is syms - 1 */
+    if (max > syms - 1)
+        max = syms - 1;
+
+    /* determine the number of bits in a code_t */
+    for (n = 0, word = 1; word; n++, word <<= 1)
+        ;
+
+    /* make sure that the calculation of most will not overflow */
+    if (max > n || (code_t)(syms - 2) >= (((code_t)0 - 1) >> (max - 1))) {
+        fputs("abort: code length too long for internal types\n", stderr);
+        return 1;
+    }
+
+    /* reject impossible code requests */
+    if ((code_t)(syms - 1) > ((code_t)1 << max) - 1) {
+        fprintf(stderr, "%d symbols cannot be coded in %d bits\n",
+                syms, max);
+        return 1;
+    }
+
+    /* allocate code vector */
+    code = calloc(max + 1, sizeof(int));
+    if (code == NULL) {
+        fputs("abort: unable to allocate enough memory\n", stderr);
+        return 1;
+    }
+
+    /* determine size of saved results array, checking for overflows,
+       allocate and clear the array (set all to zero with calloc()) */
+    if (syms == 2)              /* iff max == 1 */
+        num = NULL;             /* won't be saving any results */
+    else {
+        size = syms >> 1;
+        if (size > ((size_t)0 - 1) / (n = (syms - 1) >> 1) ||
+                (size *= n, size > ((size_t)0 - 1) / (n = max - 1)) ||
+                (size *= n, size > ((size_t)0 - 1) / sizeof(big_t)) ||
+                (num = calloc(size, sizeof(big_t))) == NULL) {
+            fputs("abort: unable to allocate enough memory\n", stderr);
+            cleanup();
+            return 1;
+        }
+    }
+
+    /* count possible codes for all numbers of symbols, add up counts */
+    sum = 0;
+    for (n = 2; n <= syms; n++) {
+        got = count(n, 1, 2);
+        sum += got;
+        if (got == (big_t)0 - 1 || sum < got) {     /* overflow */
+            fputs("abort: can't count that high!\n", stderr);
+            cleanup();
+            return 1;
+        }
+        printf("%llu %d-codes\n", got, n);
+    }
+    printf("%llu total codes for 2 to %d symbols", sum, syms);
+    if (max < syms - 1)
+        printf(" (%d-bit length limit)\n", max);
+    else
+        puts(" (no length limit)");
+
+    /* allocate and clear done array for beenhere() */
+    if (syms == 2)
+        done = NULL;
+    else if (size > ((size_t)0 - 1) / sizeof(struct tab) ||
+             (done = calloc(size, sizeof(struct tab))) == NULL) {
+        fputs("abort: unable to allocate enough memory\n", stderr);
+        cleanup();
+        return 1;
+    }
+
+    /* find and show maximum inflate table usage */
+    if (root > max)                 /* reduce root to max length */
+        root = max;
+    if ((code_t)syms < ((code_t)1 << (root + 1)))
+        enough(syms);
+    else
+        puts("cannot handle minimum code lengths > root");
+
+    /* done */
+    cleanup();
+    return 0;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/examples/fitblk.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/examples/fitblk.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,233 @@
+/* fitblk.c: example of fitting compressed output to a specified size
+   Not copyrighted -- provided to the public domain
+   Version 1.1  25 November 2004  Mark Adler */
+
+/* Version history:
+   1.0  24 Nov 2004  First version
+   1.1  25 Nov 2004  Change deflateInit2() to deflateInit()
+                     Use fixed-size, stack-allocated raw buffers
+                     Simplify code moving compression to subroutines
+                     Use assert() for internal errors
+                     Add detailed description of approach
+ */
+
+/* Approach to just fitting a requested compressed size:
+
+   fitblk performs three compression passes on a portion of the input
+   data in order to determine how much of that input will compress to
+   nearly the requested output block size.  The first pass generates
+   enough deflate blocks to produce output to fill the requested
+   output size plus a specfied excess amount (see the EXCESS define
+   below).  The last deflate block may go quite a bit past that, but
+   is discarded.  The second pass decompresses and recompresses just
+   the compressed data that fit in the requested plus excess sized
+   buffer.  The deflate process is terminated after that amount of
+   input, which is less than the amount consumed on the first pass.
+   The last deflate block of the result will be of a comparable size
+   to the final product, so that the header for that deflate block and
+   the compression ratio for that block will be about the same as in
+   the final product.  The third compression pass decompresses the
+   result of the second step, but only the compressed data up to the
+   requested size minus an amount to allow the compressed stream to
+   complete (see the MARGIN define below).  That will result in a
+   final compressed stream whose length is less than or equal to the
+   requested size.  Assuming sufficient input and a requested size
+   greater than a few hundred bytes, the shortfall will typically be
+   less than ten bytes.
+
+   If the input is short enough that the first compression completes
+   before filling the requested output size, then that compressed
+   stream is return with no recompression.
+
+   EXCESS is chosen to be just greater than the shortfall seen in a
+   two pass approach similar to the above.  That shortfall is due to
+   the last deflate block compressing more efficiently with a smaller
+   header on the second pass.  EXCESS is set to be large enough so
+   that there is enough uncompressed data for the second pass to fill
+   out the requested size, and small enough so that the final deflate
+   block of the second pass will be close in size to the final deflate
+   block of the third and final pass.  MARGIN is chosen to be just
+   large enough to assure that the final compression has enough room
+   to complete in all cases.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include "zlib.h"
+
+#define local static
+
+/* print nastygram and leave */
+local void quit(char *why)
+{
+    fprintf(stderr, "fitblk abort: %s\n", why);
+    exit(1);
+}
+
+#define RAWLEN 4096    /* intermediate uncompressed buffer size */
+
+/* compress from file to def until provided buffer is full or end of
+   input reached; return last deflate() return value, or Z_ERRNO if
+   there was read error on the file */
+local int partcompress(FILE *in, z_streamp def)
+{
+    int ret, flush;
+    unsigned char raw[RAWLEN];
+
+    flush = Z_NO_FLUSH;
+    do {
+        def->avail_in = fread(raw, 1, RAWLEN, in);
+        if (ferror(in))
+            return Z_ERRNO;
+        def->next_in = raw;
+        if (feof(in))
+            flush = Z_FINISH;
+        ret = deflate(def, flush);
+        assert(ret != Z_STREAM_ERROR);
+    } while (def->avail_out != 0 && flush == Z_NO_FLUSH);
+    return ret;
+}
+
+/* recompress from inf's input to def's output; the input for inf and
+   the output for def are set in those structures before calling;
+   return last deflate() return value, or Z_MEM_ERROR if inflate()
+   was not able to allocate enough memory when it needed to */
+local int recompress(z_streamp inf, z_streamp def)
+{
+    int ret, flush;
+    unsigned char raw[RAWLEN];
+
+    flush = Z_NO_FLUSH;
+    do {
+        /* decompress */
+        inf->avail_out = RAWLEN;
+        inf->next_out = raw;
+        ret = inflate(inf, Z_NO_FLUSH);
+        assert(ret != Z_STREAM_ERROR && ret != Z_DATA_ERROR &&
+               ret != Z_NEED_DICT);
+        if (ret == Z_MEM_ERROR)
+            return ret;
+
+        /* compress what was decompresed until done or no room */
+        def->avail_in = RAWLEN - inf->avail_out;
+        def->next_in = raw;
+        if (inf->avail_out != 0)
+            flush = Z_FINISH;
+        ret = deflate(def, flush);
+        assert(ret != Z_STREAM_ERROR);
+    } while (ret != Z_STREAM_END && def->avail_out != 0);
+    return ret;
+}
+
+#define EXCESS 256      /* empirically determined stream overage */
+#define MARGIN 8        /* amount to back off for completion */
+
+/* compress from stdin to fixed-size block on stdout */
+int main(int argc, char **argv)
+{
+    int ret;                /* return code */
+    unsigned size;          /* requested fixed output block size */
+    unsigned have;          /* bytes written by deflate() call */
+    unsigned char *blk;     /* intermediate and final stream */
+    unsigned char *tmp;     /* close to desired size stream */
+    z_stream def, inf;      /* zlib deflate and inflate states */
+
+    /* get requested output size */
+    if (argc != 2)
+        quit("need one argument: size of output block");
+    ret = strtol(argv[1], argv + 1, 10);
+    if (argv[1][0] != 0)
+        quit("argument must be a number");
+    if (ret < 8)            /* 8 is minimum zlib stream size */
+        quit("need positive size of 8 or greater");
+    size = (unsigned)ret;
+
+    /* allocate memory for buffers and compression engine */
+    blk = malloc(size + EXCESS);
+    def.zalloc = Z_NULL;
+    def.zfree = Z_NULL;
+    def.opaque = Z_NULL;
+    ret = deflateInit(&def, Z_DEFAULT_COMPRESSION);
+    if (ret != Z_OK || blk == NULL)
+        quit("out of memory");
+
+    /* compress from stdin until output full, or no more input */
+    def.avail_out = size + EXCESS;
+    def.next_out = blk;
+    ret = partcompress(stdin, &def);
+    if (ret == Z_ERRNO)
+        quit("error reading input");
+
+    /* if it all fit, then size was undersubscribed -- done! */
+    if (ret == Z_STREAM_END && def.avail_out >= EXCESS) {
+        /* write block to stdout */
+        have = size + EXCESS - def.avail_out;
+        if (fwrite(blk, 1, have, stdout) != have || ferror(stdout))
+            quit("error writing output");
+
+        /* clean up and print results to stderr */
+        ret = deflateEnd(&def);
+        assert(ret != Z_STREAM_ERROR);
+        free(blk);
+        fprintf(stderr,
+                "%u bytes unused out of %u requested (all input)\n",
+                size - have, size);
+        return 0;
+    }
+
+    /* it didn't all fit -- set up for recompression */
+    inf.zalloc = Z_NULL;
+    inf.zfree = Z_NULL;
+    inf.opaque = Z_NULL;
+    inf.avail_in = 0;
+    inf.next_in = Z_NULL;
+    ret = inflateInit(&inf);
+    tmp = malloc(size + EXCESS);
+    if (ret != Z_OK || tmp == NULL)
+        quit("out of memory");
+    ret = deflateReset(&def);
+    assert(ret != Z_STREAM_ERROR);
+
+    /* do first recompression close to the right amount */
+    inf.avail_in = size + EXCESS;
+    inf.next_in = blk;
+    def.avail_out = size + EXCESS;
+    def.next_out = tmp;
+    ret = recompress(&inf, &def);
+    if (ret == Z_MEM_ERROR)
+        quit("out of memory");
+
+    /* set up for next reocmpression */
+    ret = inflateReset(&inf);
+    assert(ret != Z_STREAM_ERROR);
+    ret = deflateReset(&def);
+    assert(ret != Z_STREAM_ERROR);
+
+    /* do second and final recompression (third compression) */
+    inf.avail_in = size - MARGIN;   /* assure stream will complete */
+    inf.next_in = tmp;
+    def.avail_out = size;
+    def.next_out = blk;
+    ret = recompress(&inf, &def);
+    if (ret == Z_MEM_ERROR)
+        quit("out of memory");
+    assert(ret == Z_STREAM_END);    /* otherwise MARGIN too small */
+
+    /* done -- write block to stdout */
+    have = size - def.avail_out;
+    if (fwrite(blk, 1, have, stdout) != have || ferror(stdout))
+        quit("error writing output");
+
+    /* clean up and print results to stderr */
+    free(tmp);
+    ret = inflateEnd(&inf);
+    assert(ret != Z_STREAM_ERROR);
+    ret = deflateEnd(&def);
+    assert(ret != Z_STREAM_ERROR);
+    free(blk);
+    fprintf(stderr,
+            "%u bytes unused out of %u requested (%lu input)\n",
+            size - have, size, def.total_in);
+    return 0;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/examples/gun.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/examples/gun.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,702 @@
+/* gun.c -- simple gunzip to give an example of the use of inflateBack()
+ * Copyright (C) 2003, 2005, 2008, 2010, 2012 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+   Version 1.7  12 August 2012  Mark Adler */
+
+/* Version history:
+   1.0  16 Feb 2003  First version for testing of inflateBack()
+   1.1  21 Feb 2005  Decompress concatenated gzip streams
+                     Remove use of "this" variable (C++ keyword)
+                     Fix return value for in()
+                     Improve allocation failure checking
+                     Add typecasting for void * structures
+                     Add -h option for command version and usage
+                     Add a bunch of comments
+   1.2  20 Mar 2005  Add Unix compress (LZW) decompression
+                     Copy file attributes from input file to output file
+   1.3  12 Jun 2005  Add casts for error messages [Oberhumer]
+   1.4   8 Dec 2006  LZW decompression speed improvements
+   1.5   9 Feb 2008  Avoid warning in latest version of gcc
+   1.6  17 Jan 2010  Avoid signed/unsigned comparison warnings
+   1.7  12 Aug 2012  Update for z_const usage in zlib 1.2.8
+ */
+
+/*
+   gun [ -t ] [ name ... ]
+
+   decompresses the data in the named gzip files.  If no arguments are given,
+   gun will decompress from stdin to stdout.  The names must end in .gz, -gz,
+   .z, -z, _z, or .Z.  The uncompressed data will be written to a file name
+   with the suffix stripped.  On success, the original file is deleted.  On
+   failure, the output file is deleted.  For most failures, the command will
+   continue to process the remaining names on the command line.  A memory
+   allocation failure will abort the command.  If -t is specified, then the
+   listed files or stdin will be tested as gzip files for integrity (without
+   checking for a proper suffix), no output will be written, and no files
+   will be deleted.
+
+   Like gzip, gun allows concatenated gzip streams and will decompress them,
+   writing all of the uncompressed data to the output.  Unlike gzip, gun allows
+   an empty file on input, and will produce no error writing an empty output
+   file.
+
+   gun will also decompress files made by Unix compress, which uses LZW
+   compression.  These files are automatically detected by virtue of their
+   magic header bytes.  Since the end of Unix compress stream is marked by the
+   end-of-file, they cannot be concantenated.  If a Unix compress stream is
+   encountered in an input file, it is the last stream in that file.
+
+   Like gunzip and uncompress, the file attributes of the original compressed
+   file are maintained in the final uncompressed file, to the extent that the
+   user permissions allow it.
+
+   On my Mac OS X PowerPC G4, gun is almost twice as fast as gunzip (version
+   1.2.4) is on the same file, when gun is linked with zlib 1.2.2.  Also the
+   LZW decompression provided by gun is about twice as fast as the standard
+   Unix uncompress command.
+ */
+
+/* external functions and related types and constants */
+#include <stdio.h>          /* fprintf() */
+#include <stdlib.h>         /* malloc(), free() */
+#include <string.h>         /* strerror(), strcmp(), strlen(), memcpy() */
+#include <errno.h>          /* errno */
+#include <fcntl.h>          /* open() */
+#include <unistd.h>         /* read(), write(), close(), chown(), unlink() */
+#include <sys/types.h>
+#include <sys/stat.h>       /* stat(), chmod() */
+#include <utime.h>          /* utime() */
+#include "zlib.h"           /* inflateBackInit(), inflateBack(), */
+                            /* inflateBackEnd(), crc32() */
+
+/* function declaration */
+#define local static
+
+/* buffer constants */
+#define SIZE 32768U         /* input and output buffer sizes */
+#define PIECE 16384         /* limits i/o chunks for 16-bit int case */
+
+/* structure for infback() to pass to input function in() -- it maintains the
+   input file and a buffer of size SIZE */
+struct ind {
+    int infile;
+    unsigned char *inbuf;
+};
+
+/* Load input buffer, assumed to be empty, and return bytes loaded and a
+   pointer to them.  read() is called until the buffer is full, or until it
+   returns end-of-file or error.  Return 0 on error. */
+local unsigned in(void *in_desc, z_const unsigned char **buf)
+{
+    int ret;
+    unsigned len;
+    unsigned char *next;
+    struct ind *me = (struct ind *)in_desc;
+
+    next = me->inbuf;
+    *buf = next;
+    len = 0;
+    do {
+        ret = PIECE;
+        if ((unsigned)ret > SIZE - len)
+            ret = (int)(SIZE - len);
+        ret = (int)read(me->infile, next, ret);
+        if (ret == -1) {
+            len = 0;
+            break;
+        }
+        next += ret;
+        len += ret;
+    } while (ret != 0 && len < SIZE);
+    return len;
+}
+
+/* structure for infback() to pass to output function out() -- it maintains the
+   output file, a running CRC-32 check on the output and the total number of
+   bytes output, both for checking against the gzip trailer.  (The length in
+   the gzip trailer is stored modulo 2^32, so it's ok if a long is 32 bits and
+   the output is greater than 4 GB.) */
+struct outd {
+    int outfile;
+    int check;                  /* true if checking crc and total */
+    unsigned long crc;
+    unsigned long total;
+};
+
+/* Write output buffer and update the CRC-32 and total bytes written.  write()
+   is called until all of the output is written or an error is encountered.
+   On success out() returns 0.  For a write failure, out() returns 1.  If the
+   output file descriptor is -1, then nothing is written.
+ */
+local int out(void *out_desc, unsigned char *buf, unsigned len)
+{
+    int ret;
+    struct outd *me = (struct outd *)out_desc;
+
+    if (me->check) {
+        me->crc = crc32(me->crc, buf, len);
+        me->total += len;
+    }
+    if (me->outfile != -1)
+        do {
+            ret = PIECE;
+            if ((unsigned)ret > len)
+                ret = (int)len;
+            ret = (int)write(me->outfile, buf, ret);
+            if (ret == -1)
+                return 1;
+            buf += ret;
+            len -= ret;
+        } while (len != 0);
+    return 0;
+}
+
+/* next input byte macro for use inside lunpipe() and gunpipe() */
+#define NEXT() (have ? 0 : (have = in(indp, &next)), \
+                last = have ? (have--, (int)(*next++)) : -1)
+
+/* memory for gunpipe() and lunpipe() --
+   the first 256 entries of prefix[] and suffix[] are never used, could
+   have offset the index, but it's faster to waste the memory */
+unsigned char inbuf[SIZE];              /* input buffer */
+unsigned char outbuf[SIZE];             /* output buffer */
+unsigned short prefix[65536];           /* index to LZW prefix string */
+unsigned char suffix[65536];            /* one-character LZW suffix */
+unsigned char match[65280 + 2];         /* buffer for reversed match or gzip
+                                           32K sliding window */
+
+/* throw out what's left in the current bits byte buffer (this is a vestigial
+   aspect of the compressed data format derived from an implementation that
+   made use of a special VAX machine instruction!) */
+#define FLUSHCODE() \
+    do { \
+        left = 0; \
+        rem = 0; \
+        if (chunk > have) { \
+            chunk -= have; \
+            have = 0; \
+            if (NEXT() == -1) \
+                break; \
+            chunk--; \
+            if (chunk > have) { \
+                chunk = have = 0; \
+                break; \
+            } \
+        } \
+        have -= chunk; \
+        next += chunk; \
+        chunk = 0; \
+    } while (0)
+
+/* Decompress a compress (LZW) file from indp to outfile.  The compress magic
+   header (two bytes) has already been read and verified.  There are have bytes
+   of buffered input at next.  strm is used for passing error information back
+   to gunpipe().
+
+   lunpipe() will return Z_OK on success, Z_BUF_ERROR for an unexpected end of
+   file, read error, or write error (a write error indicated by strm->next_in
+   not equal to Z_NULL), or Z_DATA_ERROR for invalid input.
+ */
+local int lunpipe(unsigned have, z_const unsigned char *next, struct ind *indp,
+                  int outfile, z_stream *strm)
+{
+    int last;                   /* last byte read by NEXT(), or -1 if EOF */
+    unsigned chunk;             /* bytes left in current chunk */
+    int left;                   /* bits left in rem */
+    unsigned rem;               /* unused bits from input */
+    int bits;                   /* current bits per code */
+    unsigned code;              /* code, table traversal index */
+    unsigned mask;              /* mask for current bits codes */
+    int max;                    /* maximum bits per code for this stream */
+    unsigned flags;             /* compress flags, then block compress flag */
+    unsigned end;               /* last valid entry in prefix/suffix tables */
+    unsigned temp;              /* current code */
+    unsigned prev;              /* previous code */
+    unsigned final;             /* last character written for previous code */
+    unsigned stack;             /* next position for reversed string */
+    unsigned outcnt;            /* bytes in output buffer */
+    struct outd outd;           /* output structure */
+    unsigned char *p;
+
+    /* set up output */
+    outd.outfile = outfile;
+    outd.check = 0;
+
+    /* process remainder of compress header -- a flags byte */
+    flags = NEXT();
+    if (last == -1)
+        return Z_BUF_ERROR;
+    if (flags & 0x60) {
+        strm->msg = (char *)"unknown lzw flags set";
+        return Z_DATA_ERROR;
+    }
+    max = flags & 0x1f;
+    if (max < 9 || max > 16) {
+        strm->msg = (char *)"lzw bits out of range";
+        return Z_DATA_ERROR;
+    }
+    if (max == 9)                           /* 9 doesn't really mean 9 */
+        max = 10;
+    flags &= 0x80;                          /* true if block compress */
+
+    /* clear table */
+    bits = 9;
+    mask = 0x1ff;
+    end = flags ? 256 : 255;
+
+    /* set up: get first 9-bit code, which is the first decompressed byte, but
+       don't create a table entry until the next code */
+    if (NEXT() == -1)                       /* no compressed data is ok */
+        return Z_OK;
+    final = prev = (unsigned)last;          /* low 8 bits of code */
+    if (NEXT() == -1)                       /* missing a bit */
+        return Z_BUF_ERROR;
+    if (last & 1) {                         /* code must be < 256 */
+        strm->msg = (char *)"invalid lzw code";
+        return Z_DATA_ERROR;
+    }
+    rem = (unsigned)last >> 1;              /* remaining 7 bits */
+    left = 7;
+    chunk = bits - 2;                       /* 7 bytes left in this chunk */
+    outbuf[0] = (unsigned char)final;       /* write first decompressed byte */
+    outcnt = 1;
+
+    /* decode codes */
+    stack = 0;
+    for (;;) {
+        /* if the table will be full after this, increment the code size */
+        if (end >= mask && bits < max) {
+            FLUSHCODE();
+            bits++;
+            mask <<= 1;
+            mask++;
+        }
+
+        /* get a code of length bits */
+        if (chunk == 0)                     /* decrement chunk modulo bits */
+            chunk = bits;
+        code = rem;                         /* low bits of code */
+        if (NEXT() == -1) {                 /* EOF is end of compressed data */
+            /* write remaining buffered output */
+            if (outcnt && out(&outd, outbuf, outcnt)) {
+                strm->next_in = outbuf;     /* signal write error */
+                return Z_BUF_ERROR;
+            }
+            return Z_OK;
+        }
+        code += (unsigned)last << left;     /* middle (or high) bits of code */
+        left += 8;
+        chunk--;
+        if (bits > left) {                  /* need more bits */
+            if (NEXT() == -1)               /* can't end in middle of code */
+                return Z_BUF_ERROR;
+            code += (unsigned)last << left; /* high bits of code */
+            left += 8;
+            chunk--;
+        }
+        code &= mask;                       /* mask to current code length */
+        left -= bits;                       /* number of unused bits */
+        rem = (unsigned)last >> (8 - left); /* unused bits from last byte */
+
+        /* process clear code (256) */
+        if (code == 256 && flags) {
+            FLUSHCODE();
+            bits = 9;                       /* initialize bits and mask */
+            mask = 0x1ff;
+            end = 255;                      /* empty table */
+            continue;                       /* get next code */
+        }
+
+        /* special code to reuse last match */
+        temp = code;                        /* save the current code */
+        if (code > end) {
+            /* Be picky on the allowed code here, and make sure that the code
+               we drop through (prev) will be a valid index so that random
+               input does not cause an exception.  The code != end + 1 check is
+               empirically derived, and not checked in the original uncompress
+               code.  If this ever causes a problem, that check could be safely
+               removed.  Leaving this check in greatly improves gun's ability
+               to detect random or corrupted input after a compress header.
+               In any case, the prev > end check must be retained. */
+            if (code != end + 1 || prev > end) {
+                strm->msg = (char *)"invalid lzw code";
+                return Z_DATA_ERROR;
+            }
+            match[stack++] = (unsigned char)final;
+            code = prev;
+        }
+
+        /* walk through linked list to generate output in reverse order */
+        p = match + stack;
+        while (code >= 256) {
+            *p++ = suffix[code];
+            code = prefix[code];
+        }
+        stack = p - match;
+        match[stack++] = (unsigned char)code;
+        final = code;
+
+        /* link new table entry */
+        if (end < mask) {
+            end++;
+            prefix[end] = (unsigned short)prev;
+            suffix[end] = (unsigned char)final;
+        }
+
+        /* set previous code for next iteration */
+        prev = temp;
+
+        /* write output in forward order */
+        while (stack > SIZE - outcnt) {
+            while (outcnt < SIZE)
+                outbuf[outcnt++] = match[--stack];
+            if (out(&outd, outbuf, outcnt)) {
+                strm->next_in = outbuf; /* signal write error */
+                return Z_BUF_ERROR;
+            }
+            outcnt = 0;
+        }
+        p = match + stack;
+        do {
+            outbuf[outcnt++] = *--p;
+        } while (p > match);
+        stack = 0;
+
+        /* loop for next code with final and prev as the last match, rem and
+           left provide the first 0..7 bits of the next code, end is the last
+           valid table entry */
+    }
+}
+
+/* Decompress a gzip file from infile to outfile.  strm is assumed to have been
+   successfully initialized with inflateBackInit().  The input file may consist
+   of a series of gzip streams, in which case all of them will be decompressed
+   to the output file.  If outfile is -1, then the gzip stream(s) integrity is
+   checked and nothing is written.
+
+   The return value is a zlib error code: Z_MEM_ERROR if out of memory,
+   Z_DATA_ERROR if the header or the compressed data is invalid, or if the
+   trailer CRC-32 check or length doesn't match, Z_BUF_ERROR if the input ends
+   prematurely or a write error occurs, or Z_ERRNO if junk (not a another gzip
+   stream) follows a valid gzip stream.
+ */
+local int gunpipe(z_stream *strm, int infile, int outfile)
+{
+    int ret, first, last;
+    unsigned have, flags, len;
+    z_const unsigned char *next = NULL;
+    struct ind ind, *indp;
+    struct outd outd;
+
+    /* setup input buffer */
+    ind.infile = infile;
+    ind.inbuf = inbuf;
+    indp = &ind;
+
+    /* decompress concatenated gzip streams */
+    have = 0;                               /* no input data read in yet */
+    first = 1;                              /* looking for first gzip header */
+    strm->next_in = Z_NULL;                 /* so Z_BUF_ERROR means EOF */
+    for (;;) {
+        /* look for the two magic header bytes for a gzip stream */
+        if (NEXT() == -1) {
+            ret = Z_OK;
+            break;                          /* empty gzip stream is ok */
+        }
+        if (last != 31 || (NEXT() != 139 && last != 157)) {
+            strm->msg = (char *)"incorrect header check";
+            ret = first ? Z_DATA_ERROR : Z_ERRNO;
+            break;                          /* not a gzip or compress header */
+        }
+        first = 0;                          /* next non-header is junk */
+
+        /* process a compress (LZW) file -- can't be concatenated after this */
+        if (last == 157) {
+            ret = lunpipe(have, next, indp, outfile, strm);
+            break;
+        }
+
+        /* process remainder of gzip header */
+        ret = Z_BUF_ERROR;
+        if (NEXT() != 8) {                  /* only deflate method allowed */
+            if (last == -1) break;
+            strm->msg = (char *)"unknown compression method";
+            ret = Z_DATA_ERROR;
+            break;
+        }
+        flags = NEXT();                     /* header flags */
+        NEXT();                             /* discard mod time, xflgs, os */
+        NEXT();
+        NEXT();
+        NEXT();
+        NEXT();
+        NEXT();
+        if (last == -1) break;
+        if (flags & 0xe0) {
+            strm->msg = (char *)"unknown header flags set";
+            ret = Z_DATA_ERROR;
+            break;
+        }
+        if (flags & 4) {                    /* extra field */
+            len = NEXT();
+            len += (unsigned)(NEXT()) << 8;
+            if (last == -1) break;
+            while (len > have) {
+                len -= have;
+                have = 0;
+                if (NEXT() == -1) break;
+                len--;
+            }
+            if (last == -1) break;
+            have -= len;
+            next += len;
+        }
+        if (flags & 8)                      /* file name */
+            while (NEXT() != 0 && last != -1)
+                ;
+        if (flags & 16)                     /* comment */
+            while (NEXT() != 0 && last != -1)
+                ;
+        if (flags & 2) {                    /* header crc */
+            NEXT();
+            NEXT();
+        }
+        if (last == -1) break;
+
+        /* set up output */
+        outd.outfile = outfile;
+        outd.check = 1;
+        outd.crc = crc32(0L, Z_NULL, 0);
+        outd.total = 0;
+
+        /* decompress data to output */
+        strm->next_in = next;
+        strm->avail_in = have;
+        ret = inflateBack(strm, in, indp, out, &outd);
+        if (ret != Z_STREAM_END) break;
+        next = strm->next_in;
+        have = strm->avail_in;
+        strm->next_in = Z_NULL;             /* so Z_BUF_ERROR means EOF */
+
+        /* check trailer */
+        ret = Z_BUF_ERROR;
+        if (NEXT() != (int)(outd.crc & 0xff) ||
+            NEXT() != (int)((outd.crc >> 8) & 0xff) ||
+            NEXT() != (int)((outd.crc >> 16) & 0xff) ||
+            NEXT() != (int)((outd.crc >> 24) & 0xff)) {
+            /* crc error */
+            if (last != -1) {
+                strm->msg = (char *)"incorrect data check";
+                ret = Z_DATA_ERROR;
+            }
+            break;
+        }
+        if (NEXT() != (int)(outd.total & 0xff) ||
+            NEXT() != (int)((outd.total >> 8) & 0xff) ||
+            NEXT() != (int)((outd.total >> 16) & 0xff) ||
+            NEXT() != (int)((outd.total >> 24) & 0xff)) {
+            /* length error */
+            if (last != -1) {
+                strm->msg = (char *)"incorrect length check";
+                ret = Z_DATA_ERROR;
+            }
+            break;
+        }
+
+        /* go back and look for another gzip stream */
+    }
+
+    /* clean up and return */
+    return ret;
+}
+
+/* Copy file attributes, from -> to, as best we can.  This is best effort, so
+   no errors are reported.  The mode bits, including suid, sgid, and the sticky
+   bit are copied (if allowed), the owner's user id and group id are copied
+   (again if allowed), and the access and modify times are copied. */
+local void copymeta(char *from, char *to)
+{
+    struct stat was;
+    struct utimbuf when;
+
+    /* get all of from's Unix meta data, return if not a regular file */
+    if (stat(from, &was) != 0 || (was.st_mode & S_IFMT) != S_IFREG)
+        return;
+
+    /* set to's mode bits, ignore errors */
+    (void)chmod(to, was.st_mode & 07777);
+
+    /* copy owner's user and group, ignore errors */
+    (void)chown(to, was.st_uid, was.st_gid);
+
+    /* copy access and modify times, ignore errors */
+    when.actime = was.st_atime;
+    when.modtime = was.st_mtime;
+    (void)utime(to, &when);
+}
+
+/* Decompress the file inname to the file outnname, of if test is true, just
+   decompress without writing and check the gzip trailer for integrity.  If
+   inname is NULL or an empty string, read from stdin.  If outname is NULL or
+   an empty string, write to stdout.  strm is a pre-initialized inflateBack
+   structure.  When appropriate, copy the file attributes from inname to
+   outname.
+
+   gunzip() returns 1 if there is an out-of-memory error or an unexpected
+   return code from gunpipe().  Otherwise it returns 0.
+ */
+local int gunzip(z_stream *strm, char *inname, char *outname, int test)
+{
+    int ret;
+    int infile, outfile;
+
+    /* open files */
+    if (inname == NULL || *inname == 0) {
+        inname = "-";
+        infile = 0;     /* stdin */
+    }
+    else {
+        infile = open(inname, O_RDONLY, 0);
+        if (infile == -1) {
+            fprintf(stderr, "gun cannot open %s\n", inname);
+            return 0;
+        }
+    }
+    if (test)
+        outfile = -1;
+    else if (outname == NULL || *outname == 0) {
+        outname = "-";
+        outfile = 1;    /* stdout */
+    }
+    else {
+        outfile = open(outname, O_CREAT | O_TRUNC | O_WRONLY, 0666);
+        if (outfile == -1) {
+            close(infile);
+            fprintf(stderr, "gun cannot create %s\n", outname);
+            return 0;
+        }
+    }
+    errno = 0;
+
+    /* decompress */
+    ret = gunpipe(strm, infile, outfile);
+    if (outfile > 2) close(outfile);
+    if (infile > 2) close(infile);
+
+    /* interpret result */
+    switch (ret) {
+    case Z_OK:
+    case Z_ERRNO:
+        if (infile > 2 && outfile > 2) {
+            copymeta(inname, outname);          /* copy attributes */
+            unlink(inname);
+        }
+        if (ret == Z_ERRNO)
+            fprintf(stderr, "gun warning: trailing garbage ignored in %s\n",
+                    inname);
+        break;
+    case Z_DATA_ERROR:
+        if (outfile > 2) unlink(outname);
+        fprintf(stderr, "gun data error on %s: %s\n", inname, strm->msg);
+        break;
+    case Z_MEM_ERROR:
+        if (outfile > 2) unlink(outname);
+        fprintf(stderr, "gun out of memory error--aborting\n");
+        return 1;
+    case Z_BUF_ERROR:
+        if (outfile > 2) unlink(outname);
+        if (strm->next_in != Z_NULL) {
+            fprintf(stderr, "gun write error on %s: %s\n",
+                    outname, strerror(errno));
+        }
+        else if (errno) {
+            fprintf(stderr, "gun read error on %s: %s\n",
+                    inname, strerror(errno));
+        }
+        else {
+            fprintf(stderr, "gun unexpected end of file on %s\n",
+                    inname);
+        }
+        break;
+    default:
+        if (outfile > 2) unlink(outname);
+        fprintf(stderr, "gun internal error--aborting\n");
+        return 1;
+    }
+    return 0;
+}
+
+/* Process the gun command line arguments.  See the command syntax near the
+   beginning of this source file. */
+int main(int argc, char **argv)
+{
+    int ret, len, test;
+    char *outname;
+    unsigned char *window;
+    z_stream strm;
+
+    /* initialize inflateBack state for repeated use */
+    window = match;                         /* reuse LZW match buffer */
+    strm.zalloc = Z_NULL;
+    strm.zfree = Z_NULL;
+    strm.opaque = Z_NULL;
+    ret = inflateBackInit(&strm, 15, window);
+    if (ret != Z_OK) {
+        fprintf(stderr, "gun out of memory error--aborting\n");
+        return 1;
+    }
+
+    /* decompress each file to the same name with the suffix removed */
+    argc--;
+    argv++;
+    test = 0;
+    if (argc && strcmp(*argv, "-h") == 0) {
+        fprintf(stderr, "gun 1.6 (17 Jan 2010)\n");
+        fprintf(stderr, "Copyright (C) 2003-2010 Mark Adler\n");
+        fprintf(stderr, "usage: gun [-t] [file1.gz [file2.Z ...]]\n");
+        return 0;
+    }
+    if (argc && strcmp(*argv, "-t") == 0) {
+        test = 1;
+        argc--;
+        argv++;
+    }
+    if (argc)
+        do {
+            if (test)
+                outname = NULL;
+            else {
+                len = (int)strlen(*argv);
+                if (strcmp(*argv + len - 3, ".gz") == 0 ||
+                    strcmp(*argv + len - 3, "-gz") == 0)
+                    len -= 3;
+                else if (strcmp(*argv + len - 2, ".z") == 0 ||
+                    strcmp(*argv + len - 2, "-z") == 0 ||
+                    strcmp(*argv + len - 2, "_z") == 0 ||
+                    strcmp(*argv + len - 2, ".Z") == 0)
+                    len -= 2;
+                else {
+                    fprintf(stderr, "gun error: no gz type on %s--skipping\n",
+                            *argv);
+                    continue;
+                }
+                outname = malloc(len + 1);
+                if (outname == NULL) {
+                    fprintf(stderr, "gun out of memory error--aborting\n");
+                    ret = 1;
+                    break;
+                }
+                memcpy(outname, *argv, len);
+                outname[len] = 0;
+            }
+            ret = gunzip(&strm, *argv, outname, test);
+            if (outname != NULL) free(outname);
+            if (ret) break;
+        } while (argv++, --argc);
+    else
+        ret = gunzip(&strm, NULL, NULL, test);
+
+    /* clean up */
+    inflateBackEnd(&strm);
+    return ret;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/examples/gzappend.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/examples/gzappend.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,504 @@
+/* gzappend -- command to append to a gzip file
+
+  Copyright (C) 2003, 2012 Mark Adler, all rights reserved
+  version 1.2, 11 Oct 2012
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the author be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  Mark Adler    madler@alumni.caltech.edu
+ */
+
+/*
+ * Change history:
+ *
+ * 1.0  19 Oct 2003     - First version
+ * 1.1   4 Nov 2003     - Expand and clarify some comments and notes
+ *                      - Add version and copyright to help
+ *                      - Send help to stdout instead of stderr
+ *                      - Add some preemptive typecasts
+ *                      - Add L to constants in lseek() calls
+ *                      - Remove some debugging information in error messages
+ *                      - Use new data_type definition for zlib 1.2.1
+ *                      - Simplfy and unify file operations
+ *                      - Finish off gzip file in gztack()
+ *                      - Use deflatePrime() instead of adding empty blocks
+ *                      - Keep gzip file clean on appended file read errors
+ *                      - Use in-place rotate instead of auxiliary buffer
+ *                        (Why you ask?  Because it was fun to write!)
+ * 1.2  11 Oct 2012     - Fix for proper z_const usage
+ *                      - Check for input buffer malloc failure
+ */
+
+/*
+   gzappend takes a gzip file and appends to it, compressing files from the
+   command line or data from stdin.  The gzip file is written to directly, to
+   avoid copying that file, in case it's large.  Note that this results in the
+   unfriendly behavior that if gzappend fails, the gzip file is corrupted.
+
+   This program was written to illustrate the use of the new Z_BLOCK option of
+   zlib 1.2.x's inflate() function.  This option returns from inflate() at each
+   block boundary to facilitate locating and modifying the last block bit at
+   the start of the final deflate block.  Also whether using Z_BLOCK or not,
+   another required feature of zlib 1.2.x is that inflate() now provides the
+   number of unusued bits in the last input byte used.  gzappend will not work
+   with versions of zlib earlier than 1.2.1.
+
+   gzappend first decompresses the gzip file internally, discarding all but
+   the last 32K of uncompressed data, and noting the location of the last block
+   bit and the number of unused bits in the last byte of the compressed data.
+   The gzip trailer containing the CRC-32 and length of the uncompressed data
+   is verified.  This trailer will be later overwritten.
+
+   Then the last block bit is cleared by seeking back in the file and rewriting
+   the byte that contains it.  Seeking forward, the last byte of the compressed
+   data is saved along with the number of unused bits to initialize deflate.
+
+   A deflate process is initialized, using the last 32K of the uncompressed
+   data from the gzip file to initialize the dictionary.  If the total
+   uncompressed data was less than 32K, then all of it is used to initialize
+   the dictionary.  The deflate output bit buffer is also initialized with the
+   last bits from the original deflate stream.  From here on, the data to
+   append is simply compressed using deflate, and written to the gzip file.
+   When that is complete, the new CRC-32 and uncompressed length are written
+   as the trailer of the gzip file.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include "zlib.h"
+
+#define local static
+#define LGCHUNK 14
+#define CHUNK (1U << LGCHUNK)
+#define DSIZE 32768U
+
+/* print an error message and terminate with extreme prejudice */
+local void bye(char *msg1, char *msg2)
+{
+    fprintf(stderr, "gzappend error: %s%s\n", msg1, msg2);
+    exit(1);
+}
+
+/* return the greatest common divisor of a and b using Euclid's algorithm,
+   modified to be fast when one argument much greater than the other, and
+   coded to avoid unnecessary swapping */
+local unsigned gcd(unsigned a, unsigned b)
+{
+    unsigned c;
+
+    while (a && b)
+        if (a > b) {
+            c = b;
+            while (a - c >= c)
+                c <<= 1;
+            a -= c;
+        }
+        else {
+            c = a;
+            while (b - c >= c)
+                c <<= 1;
+            b -= c;
+        }
+    return a + b;
+}
+
+/* rotate list[0..len-1] left by rot positions, in place */
+local void rotate(unsigned char *list, unsigned len, unsigned rot)
+{
+    unsigned char tmp;
+    unsigned cycles;
+    unsigned char *start, *last, *to, *from;
+
+    /* normalize rot and handle degenerate cases */
+    if (len < 2) return;
+    if (rot >= len) rot %= len;
+    if (rot == 0) return;
+
+    /* pointer to last entry in list */
+    last = list + (len - 1);
+
+    /* do simple left shift by one */
+    if (rot == 1) {
+        tmp = *list;
+        memcpy(list, list + 1, len - 1);
+        *last = tmp;
+        return;
+    }
+
+    /* do simple right shift by one */
+    if (rot == len - 1) {
+        tmp = *last;
+        memmove(list + 1, list, len - 1);
+        *list = tmp;
+        return;
+    }
+
+    /* otherwise do rotate as a set of cycles in place */
+    cycles = gcd(len, rot);             /* number of cycles */
+    do {
+        start = from = list + cycles;   /* start index is arbitrary */
+        tmp = *from;                    /* save entry to be overwritten */
+        for (;;) {
+            to = from;                  /* next step in cycle */
+            from += rot;                /* go right rot positions */
+            if (from > last) from -= len;   /* (pointer better not wrap) */
+            if (from == start) break;   /* all but one shifted */
+            *to = *from;                /* shift left */
+        }
+        *to = tmp;                      /* complete the circle */
+    } while (--cycles);
+}
+
+/* structure for gzip file read operations */
+typedef struct {
+    int fd;                     /* file descriptor */
+    int size;                   /* 1 << size is bytes in buf */
+    unsigned left;              /* bytes available at next */
+    unsigned char *buf;         /* buffer */
+    z_const unsigned char *next;    /* next byte in buffer */
+    char *name;                 /* file name for error messages */
+} file;
+
+/* reload buffer */
+local int readin(file *in)
+{
+    int len;
+
+    len = read(in->fd, in->buf, 1 << in->size);
+    if (len == -1) bye("error reading ", in->name);
+    in->left = (unsigned)len;
+    in->next = in->buf;
+    return len;
+}
+
+/* read from file in, exit if end-of-file */
+local int readmore(file *in)
+{
+    if (readin(in) == 0) bye("unexpected end of ", in->name);
+    return 0;
+}
+
+#define read1(in) (in->left == 0 ? readmore(in) : 0, \
+                   in->left--, *(in->next)++)
+
+/* skip over n bytes of in */
+local void skip(file *in, unsigned n)
+{
+    unsigned bypass;
+
+    if (n > in->left) {
+        n -= in->left;
+        bypass = n & ~((1U << in->size) - 1);
+        if (bypass) {
+            if (lseek(in->fd, (off_t)bypass, SEEK_CUR) == -1)
+                bye("seeking ", in->name);
+            n -= bypass;
+        }
+        readmore(in);
+        if (n > in->left)
+            bye("unexpected end of ", in->name);
+    }
+    in->left -= n;
+    in->next += n;
+}
+
+/* read a four-byte unsigned integer, little-endian, from in */
+unsigned long read4(file *in)
+{
+    unsigned long val;
+
+    val = read1(in);
+    val += (unsigned)read1(in) << 8;
+    val += (unsigned long)read1(in) << 16;
+    val += (unsigned long)read1(in) << 24;
+    return val;
+}
+
+/* skip over gzip header */
+local void gzheader(file *in)
+{
+    int flags;
+    unsigned n;
+
+    if (read1(in) != 31 || read1(in) != 139) bye(in->name, " not a gzip file");
+    if (read1(in) != 8) bye("unknown compression method in", in->name);
+    flags = read1(in);
+    if (flags & 0xe0) bye("unknown header flags set in", in->name);
+    skip(in, 6);
+    if (flags & 4) {
+        n = read1(in);
+        n += (unsigned)(read1(in)) << 8;
+        skip(in, n);
+    }
+    if (flags & 8) while (read1(in) != 0) ;
+    if (flags & 16) while (read1(in) != 0) ;
+    if (flags & 2) skip(in, 2);
+}
+
+/* decompress gzip file "name", return strm with a deflate stream ready to
+   continue compression of the data in the gzip file, and return a file
+   descriptor pointing to where to write the compressed data -- the deflate
+   stream is initialized to compress using level "level" */
+local int gzscan(char *name, z_stream *strm, int level)
+{
+    int ret, lastbit, left, full;
+    unsigned have;
+    unsigned long crc, tot;
+    unsigned char *window;
+    off_t lastoff, end;
+    file gz;
+
+    /* open gzip file */
+    gz.name = name;
+    gz.fd = open(name, O_RDWR, 0);
+    if (gz.fd == -1) bye("cannot open ", name);
+    gz.buf = malloc(CHUNK);
+    if (gz.buf == NULL) bye("out of memory", "");
+    gz.size = LGCHUNK;
+    gz.left = 0;
+
+    /* skip gzip header */
+    gzheader(&gz);
+
+    /* prepare to decompress */
+    window = malloc(DSIZE);
+    if (window == NULL) bye("out of memory", "");
+    strm->zalloc = Z_NULL;
+    strm->zfree = Z_NULL;
+    strm->opaque = Z_NULL;
+    ret = inflateInit2(strm, -15);
+    if (ret != Z_OK) bye("out of memory", " or library mismatch");
+
+    /* decompress the deflate stream, saving append information */
+    lastbit = 0;
+    lastoff = lseek(gz.fd, 0L, SEEK_CUR) - gz.left;
+    left = 0;
+    strm->avail_in = gz.left;
+    strm->next_in = gz.next;
+    crc = crc32(0L, Z_NULL, 0);
+    have = full = 0;
+    do {
+        /* if needed, get more input */
+        if (strm->avail_in == 0) {
+            readmore(&gz);
+            strm->avail_in = gz.left;
+            strm->next_in = gz.next;
+        }
+
+        /* set up output to next available section of sliding window */
+        strm->avail_out = DSIZE - have;
+        strm->next_out = window + have;
+
+        /* inflate and check for errors */
+        ret = inflate(strm, Z_BLOCK);
+        if (ret == Z_STREAM_ERROR) bye("internal stream error!", "");
+        if (ret == Z_MEM_ERROR) bye("out of memory", "");
+        if (ret == Z_DATA_ERROR)
+            bye("invalid compressed data--format violated in", name);
+
+        /* update crc and sliding window pointer */
+        crc = crc32(crc, window + have, DSIZE - have - strm->avail_out);
+        if (strm->avail_out)
+            have = DSIZE - strm->avail_out;
+        else {
+            have = 0;
+            full = 1;
+        }
+
+        /* process end of block */
+        if (strm->data_type & 128) {
+            if (strm->data_type & 64)
+                left = strm->data_type & 0x1f;
+            else {
+                lastbit = strm->data_type & 0x1f;
+                lastoff = lseek(gz.fd, 0L, SEEK_CUR) - strm->avail_in;
+            }
+        }
+    } while (ret != Z_STREAM_END);
+    inflateEnd(strm);
+    gz.left = strm->avail_in;
+    gz.next = strm->next_in;
+
+    /* save the location of the end of the compressed data */
+    end = lseek(gz.fd, 0L, SEEK_CUR) - gz.left;
+
+    /* check gzip trailer and save total for deflate */
+    if (crc != read4(&gz))
+        bye("invalid compressed data--crc mismatch in ", name);
+    tot = strm->total_out;
+    if ((tot & 0xffffffffUL) != read4(&gz))
+        bye("invalid compressed data--length mismatch in", name);
+
+    /* if not at end of file, warn */
+    if (gz.left || readin(&gz))
+        fprintf(stderr,
+            "gzappend warning: junk at end of gzip file overwritten\n");
+
+    /* clear last block bit */
+    lseek(gz.fd, lastoff - (lastbit != 0), SEEK_SET);
+    if (read(gz.fd, gz.buf, 1) != 1) bye("reading after seek on ", name);
+    *gz.buf = (unsigned char)(*gz.buf ^ (1 << ((8 - lastbit) & 7)));
+    lseek(gz.fd, -1L, SEEK_CUR);
+    if (write(gz.fd, gz.buf, 1) != 1) bye("writing after seek to ", name);
+
+    /* if window wrapped, build dictionary from window by rotating */
+    if (full) {
+        rotate(window, DSIZE, have);
+        have = DSIZE;
+    }
+
+    /* set up deflate stream with window, crc, total_in, and leftover bits */
+    ret = deflateInit2(strm, level, Z_DEFLATED, -15, 8, Z_DEFAULT_STRATEGY);
+    if (ret != Z_OK) bye("out of memory", "");
+    deflateSetDictionary(strm, window, have);
+    strm->adler = crc;
+    strm->total_in = tot;
+    if (left) {
+        lseek(gz.fd, --end, SEEK_SET);
+        if (read(gz.fd, gz.buf, 1) != 1) bye("reading after seek on ", name);
+        deflatePrime(strm, 8 - left, *gz.buf);
+    }
+    lseek(gz.fd, end, SEEK_SET);
+
+    /* clean up and return */
+    free(window);
+    free(gz.buf);
+    return gz.fd;
+}
+
+/* append file "name" to gzip file gd using deflate stream strm -- if last
+   is true, then finish off the deflate stream at the end */
+local void gztack(char *name, int gd, z_stream *strm, int last)
+{
+    int fd, len, ret;
+    unsigned left;
+    unsigned char *in, *out;
+
+    /* open file to compress and append */
+    fd = 0;
+    if (name != NULL) {
+        fd = open(name, O_RDONLY, 0);
+        if (fd == -1)
+            fprintf(stderr, "gzappend warning: %s not found, skipping ...\n",
+                    name);
+    }
+
+    /* allocate buffers */
+    in = malloc(CHUNK);
+    out = malloc(CHUNK);
+    if (in == NULL || out == NULL) bye("out of memory", "");
+
+    /* compress input file and append to gzip file */
+    do {
+        /* get more input */
+        len = read(fd, in, CHUNK);
+        if (len == -1) {
+            fprintf(stderr,
+                    "gzappend warning: error reading %s, skipping rest ...\n",
+                    name);
+            len = 0;
+        }
+        strm->avail_in = (unsigned)len;
+        strm->next_in = in;
+        if (len) strm->adler = crc32(strm->adler, in, (unsigned)len);
+
+        /* compress and write all available output */
+        do {
+            strm->avail_out = CHUNK;
+            strm->next_out = out;
+            ret = deflate(strm, last && len == 0 ? Z_FINISH : Z_NO_FLUSH);
+            left = CHUNK - strm->avail_out;
+            while (left) {
+                len = write(gd, out + CHUNK - strm->avail_out - left, left);
+                if (len == -1) bye("writing gzip file", "");
+                left -= (unsigned)len;
+            }
+        } while (strm->avail_out == 0 && ret != Z_STREAM_END);
+    } while (len != 0);
+
+    /* write trailer after last entry */
+    if (last) {
+        deflateEnd(strm);
+        out[0] = (unsigned char)(strm->adler);
+        out[1] = (unsigned char)(strm->adler >> 8);
+        out[2] = (unsigned char)(strm->adler >> 16);
+        out[3] = (unsigned char)(strm->adler >> 24);
+        out[4] = (unsigned char)(strm->total_in);
+        out[5] = (unsigned char)(strm->total_in >> 8);
+        out[6] = (unsigned char)(strm->total_in >> 16);
+        out[7] = (unsigned char)(strm->total_in >> 24);
+        len = 8;
+        do {
+            ret = write(gd, out + 8 - len, len);
+            if (ret == -1) bye("writing gzip file", "");
+            len -= ret;
+        } while (len);
+        close(gd);
+    }
+
+    /* clean up and return */
+    free(out);
+    free(in);
+    if (fd > 0) close(fd);
+}
+
+/* process the compression level option if present, scan the gzip file, and
+   append the specified files, or append the data from stdin if no other file
+   names are provided on the command line -- the gzip file must be writable
+   and seekable */
+int main(int argc, char **argv)
+{
+    int gd, level;
+    z_stream strm;
+
+    /* ignore command name */
+    argc--; argv++;
+
+    /* provide usage if no arguments */
+    if (*argv == NULL) {
+        printf(
+            "gzappend 1.2 (11 Oct 2012) Copyright (C) 2003, 2012 Mark Adler\n"
+               );
+        printf(
+            "usage: gzappend [-level] file.gz [ addthis [ andthis ... ]]\n");
+        return 0;
+    }
+
+    /* set compression level */
+    level = Z_DEFAULT_COMPRESSION;
+    if (argv[0][0] == '-') {
+        if (argv[0][1] < '0' || argv[0][1] > '9' || argv[0][2] != 0)
+            bye("invalid compression level", "");
+        level = argv[0][1] - '0';
+        if (*++argv == NULL) bye("no gzip file name after options", "");
+    }
+
+    /* prepare to append to gzip file */
+    gd = gzscan(*argv++, &strm, level);
+
+    /* append files on command line, or from stdin if none */
+    if (*argv == NULL)
+        gztack(NULL, gd, &strm, 1);
+    else
+        do {
+            gztack(*argv, gd, &strm, argv[1] == NULL);
+        } while (*++argv != NULL);
+    return 0;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/examples/gzjoin.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/examples/gzjoin.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,449 @@
+/* gzjoin -- command to join gzip files into one gzip file
+
+  Copyright (C) 2004, 2005, 2012 Mark Adler, all rights reserved
+  version 1.2, 14 Aug 2012
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the author be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  Mark Adler    madler@alumni.caltech.edu
+ */
+
+/*
+ * Change history:
+ *
+ * 1.0  11 Dec 2004     - First version
+ * 1.1  12 Jun 2005     - Changed ssize_t to long for portability
+ * 1.2  14 Aug 2012     - Clean up for z_const usage
+ */
+
+/*
+   gzjoin takes one or more gzip files on the command line and writes out a
+   single gzip file that will uncompress to the concatenation of the
+   uncompressed data from the individual gzip files.  gzjoin does this without
+   having to recompress any of the data and without having to calculate a new
+   crc32 for the concatenated uncompressed data.  gzjoin does however have to
+   decompress all of the input data in order to find the bits in the compressed
+   data that need to be modified to concatenate the streams.
+
+   gzjoin does not do an integrity check on the input gzip files other than
+   checking the gzip header and decompressing the compressed data.  They are
+   otherwise assumed to be complete and correct.
+
+   Each joint between gzip files removes at least 18 bytes of previous trailer
+   and subsequent header, and inserts an average of about three bytes to the
+   compressed data in order to connect the streams.  The output gzip file
+   has a minimal ten-byte gzip header with no file name or modification time.
+
+   This program was written to illustrate the use of the Z_BLOCK option of
+   inflate() and the crc32_combine() function.  gzjoin will not compile with
+   versions of zlib earlier than 1.2.3.
+ */
+
+#include <stdio.h>      /* fputs(), fprintf(), fwrite(), putc() */
+#include <stdlib.h>     /* exit(), malloc(), free() */
+#include <fcntl.h>      /* open() */
+#include <unistd.h>     /* close(), read(), lseek() */
+#include "zlib.h"
+    /* crc32(), crc32_combine(), inflateInit2(), inflate(), inflateEnd() */
+
+#define local static
+
+/* exit with an error (return a value to allow use in an expression) */
+local int bail(char *why1, char *why2)
+{
+    fprintf(stderr, "gzjoin error: %s%s, output incomplete\n", why1, why2);
+    exit(1);
+    return 0;
+}
+
+/* -- simple buffered file input with access to the buffer -- */
+
+#define CHUNK 32768         /* must be a power of two and fit in unsigned */
+
+/* bin buffered input file type */
+typedef struct {
+    char *name;             /* name of file for error messages */
+    int fd;                 /* file descriptor */
+    unsigned left;          /* bytes remaining at next */
+    unsigned char *next;    /* next byte to read */
+    unsigned char *buf;     /* allocated buffer of length CHUNK */
+} bin;
+
+/* close a buffered file and free allocated memory */
+local void bclose(bin *in)
+{
+    if (in != NULL) {
+        if (in->fd != -1)
+            close(in->fd);
+        if (in->buf != NULL)
+            free(in->buf);
+        free(in);
+    }
+}
+
+/* open a buffered file for input, return a pointer to type bin, or NULL on
+   failure */
+local bin *bopen(char *name)
+{
+    bin *in;
+
+    in = malloc(sizeof(bin));
+    if (in == NULL)
+        return NULL;
+    in->buf = malloc(CHUNK);
+    in->fd = open(name, O_RDONLY, 0);
+    if (in->buf == NULL || in->fd == -1) {
+        bclose(in);
+        return NULL;
+    }
+    in->left = 0;
+    in->next = in->buf;
+    in->name = name;
+    return in;
+}
+
+/* load buffer from file, return -1 on read error, 0 or 1 on success, with
+   1 indicating that end-of-file was reached */
+local int bload(bin *in)
+{
+    long len;
+
+    if (in == NULL)
+        return -1;
+    if (in->left != 0)
+        return 0;
+    in->next = in->buf;
+    do {
+        len = (long)read(in->fd, in->buf + in->left, CHUNK - in->left);
+        if (len < 0)
+            return -1;
+        in->left += (unsigned)len;
+    } while (len != 0 && in->left < CHUNK);
+    return len == 0 ? 1 : 0;
+}
+
+/* get a byte from the file, bail if end of file */
+#define bget(in) (in->left ? 0 : bload(in), \
+                  in->left ? (in->left--, *(in->next)++) : \
+                    bail("unexpected end of file on ", in->name))
+
+/* get a four-byte little-endian unsigned integer from file */
+local unsigned long bget4(bin *in)
+{
+    unsigned long val;
+
+    val = bget(in);
+    val += (unsigned long)(bget(in)) << 8;
+    val += (unsigned long)(bget(in)) << 16;
+    val += (unsigned long)(bget(in)) << 24;
+    return val;
+}
+
+/* skip bytes in file */
+local void bskip(bin *in, unsigned skip)
+{
+    /* check pointer */
+    if (in == NULL)
+        return;
+
+    /* easy case -- skip bytes in buffer */
+    if (skip <= in->left) {
+        in->left -= skip;
+        in->next += skip;
+        return;
+    }
+
+    /* skip what's in buffer, discard buffer contents */
+    skip -= in->left;
+    in->left = 0;
+
+    /* seek past multiples of CHUNK bytes */
+    if (skip > CHUNK) {
+        unsigned left;
+
+        left = skip & (CHUNK - 1);
+        if (left == 0) {
+            /* exact number of chunks: seek all the way minus one byte to check
+               for end-of-file with a read */
+            lseek(in->fd, skip - 1, SEEK_CUR);
+            if (read(in->fd, in->buf, 1) != 1)
+                bail("unexpected end of file on ", in->name);
+            return;
+        }
+
+        /* skip the integral chunks, update skip with remainder */
+        lseek(in->fd, skip - left, SEEK_CUR);
+        skip = left;
+    }
+
+    /* read more input and skip remainder */
+    bload(in);
+    if (skip > in->left)
+        bail("unexpected end of file on ", in->name);
+    in->left -= skip;
+    in->next += skip;
+}
+
+/* -- end of buffered input functions -- */
+
+/* skip the gzip header from file in */
+local void gzhead(bin *in)
+{
+    int flags;
+
+    /* verify gzip magic header and compression method */
+    if (bget(in) != 0x1f || bget(in) != 0x8b || bget(in) != 8)
+        bail(in->name, " is not a valid gzip file");
+
+    /* get and verify flags */
+    flags = bget(in);
+    if ((flags & 0xe0) != 0)
+        bail("unknown reserved bits set in ", in->name);
+
+    /* skip modification time, extra flags, and os */
+    bskip(in, 6);
+
+    /* skip extra field if present */
+    if (flags & 4) {
+        unsigned len;
+
+        len = bget(in);
+        len += (unsigned)(bget(in)) << 8;
+        bskip(in, len);
+    }
+
+    /* skip file name if present */
+    if (flags & 8)
+        while (bget(in) != 0)
+            ;
+
+    /* skip comment if present */
+    if (flags & 16)
+        while (bget(in) != 0)
+            ;
+
+    /* skip header crc if present */
+    if (flags & 2)
+        bskip(in, 2);
+}
+
+/* write a four-byte little-endian unsigned integer to out */
+local void put4(unsigned long val, FILE *out)
+{
+    putc(val & 0xff, out);
+    putc((val >> 8) & 0xff, out);
+    putc((val >> 16) & 0xff, out);
+    putc((val >> 24) & 0xff, out);
+}
+
+/* Load up zlib stream from buffered input, bail if end of file */
+local void zpull(z_streamp strm, bin *in)
+{
+    if (in->left == 0)
+        bload(in);
+    if (in->left == 0)
+        bail("unexpected end of file on ", in->name);
+    strm->avail_in = in->left;
+    strm->next_in = in->next;
+}
+
+/* Write header for gzip file to out and initialize trailer. */
+local void gzinit(unsigned long *crc, unsigned long *tot, FILE *out)
+{
+    fwrite("\x1f\x8b\x08\0\0\0\0\0\0\xff", 1, 10, out);
+    *crc = crc32(0L, Z_NULL, 0);
+    *tot = 0;
+}
+
+/* Copy the compressed data from name, zeroing the last block bit of the last
+   block if clr is true, and adding empty blocks as needed to get to a byte
+   boundary.  If clr is false, then the last block becomes the last block of
+   the output, and the gzip trailer is written.  crc and tot maintains the
+   crc and length (modulo 2^32) of the output for the trailer.  The resulting
+   gzip file is written to out.  gzinit() must be called before the first call
+   of gzcopy() to write the gzip header and to initialize crc and tot. */
+local void gzcopy(char *name, int clr, unsigned long *crc, unsigned long *tot,
+                  FILE *out)
+{
+    int ret;                /* return value from zlib functions */
+    int pos;                /* where the "last block" bit is in byte */
+    int last;               /* true if processing the last block */
+    bin *in;                /* buffered input file */
+    unsigned char *start;   /* start of compressed data in buffer */
+    unsigned char *junk;    /* buffer for uncompressed data -- discarded */
+    z_off_t len;            /* length of uncompressed data (support > 4 GB) */
+    z_stream strm;          /* zlib inflate stream */
+
+    /* open gzip file and skip header */
+    in = bopen(name);
+    if (in == NULL)
+        bail("could not open ", name);
+    gzhead(in);
+
+    /* allocate buffer for uncompressed data and initialize raw inflate
+       stream */
+    junk = malloc(CHUNK);
+    strm.zalloc = Z_NULL;
+    strm.zfree = Z_NULL;
+    strm.opaque = Z_NULL;
+    strm.avail_in = 0;
+    strm.next_in = Z_NULL;
+    ret = inflateInit2(&strm, -15);
+    if (junk == NULL || ret != Z_OK)
+        bail("out of memory", "");
+
+    /* inflate and copy compressed data, clear last-block bit if requested */
+    len = 0;
+    zpull(&strm, in);
+    start = in->next;
+    last = start[0] & 1;
+    if (last && clr)
+        start[0] &= ~1;
+    strm.avail_out = 0;
+    for (;;) {
+        /* if input used and output done, write used input and get more */
+        if (strm.avail_in == 0 && strm.avail_out != 0) {
+            fwrite(start, 1, strm.next_in - start, out);
+            start = in->buf;
+            in->left = 0;
+            zpull(&strm, in);
+        }
+
+        /* decompress -- return early when end-of-block reached */
+        strm.avail_out = CHUNK;
+        strm.next_out = junk;
+        ret = inflate(&strm, Z_BLOCK);
+        switch (ret) {
+        case Z_MEM_ERROR:
+            bail("out of memory", "");
+        case Z_DATA_ERROR:
+            bail("invalid compressed data in ", in->name);
+        }
+
+        /* update length of uncompressed data */
+        len += CHUNK - strm.avail_out;
+
+        /* check for block boundary (only get this when block copied out) */
+        if (strm.data_type & 128) {
+            /* if that was the last block, then done */
+            if (last)
+                break;
+
+            /* number of unused bits in last byte */
+            pos = strm.data_type & 7;
+
+            /* find the next last-block bit */
+            if (pos != 0) {
+                /* next last-block bit is in last used byte */
+                pos = 0x100 >> pos;
+                last = strm.next_in[-1] & pos;
+                if (last && clr)
+                    in->buf[strm.next_in - in->buf - 1] &= ~pos;
+            }
+            else {
+                /* next last-block bit is in next unused byte */
+                if (strm.avail_in == 0) {
+                    /* don't have that byte yet -- get it */
+                    fwrite(start, 1, strm.next_in - start, out);
+                    start = in->buf;
+                    in->left = 0;
+                    zpull(&strm, in);
+                }
+                last = strm.next_in[0] & 1;
+                if (last && clr)
+                    in->buf[strm.next_in - in->buf] &= ~1;
+            }
+        }
+    }
+
+    /* update buffer with unused input */
+    in->left = strm.avail_in;
+    in->next = in->buf + (strm.next_in - in->buf);
+
+    /* copy used input, write empty blocks to get to byte boundary */
+    pos = strm.data_type & 7;
+    fwrite(start, 1, in->next - start - 1, out);
+    last = in->next[-1];
+    if (pos == 0 || !clr)
+        /* already at byte boundary, or last file: write last byte */
+        putc(last, out);
+    else {
+        /* append empty blocks to last byte */
+        last &= ((0x100 >> pos) - 1);       /* assure unused bits are zero */
+        if (pos & 1) {
+            /* odd -- append an empty stored block */
+            putc(last, out);
+            if (pos == 1)
+                putc(0, out);               /* two more bits in block header */
+            fwrite("\0\0\xff\xff", 1, 4, out);
+        }
+        else {
+            /* even -- append 1, 2, or 3 empty fixed blocks */
+            switch (pos) {
+            case 6:
+                putc(last | 8, out);
+                last = 0;
+            case 4:
+                putc(last | 0x20, out);
+                last = 0;
+            case 2:
+                putc(last | 0x80, out);
+                putc(0, out);
+            }
+        }
+    }
+
+    /* update crc and tot */
+    *crc = crc32_combine(*crc, bget4(in), len);
+    *tot += (unsigned long)len;
+
+    /* clean up */
+    inflateEnd(&strm);
+    free(junk);
+    bclose(in);
+
+    /* write trailer if this is the last gzip file */
+    if (!clr) {
+        put4(*crc, out);
+        put4(*tot, out);
+    }
+}
+
+/* join the gzip files on the command line, write result to stdout */
+int main(int argc, char **argv)
+{
+    unsigned long crc, tot;     /* running crc and total uncompressed length */
+
+    /* skip command name */
+    argc--;
+    argv++;
+
+    /* show usage if no arguments */
+    if (argc == 0) {
+        fputs("gzjoin usage: gzjoin f1.gz [f2.gz [f3.gz ...]] > fjoin.gz\n",
+              stderr);
+        return 0;
+    }
+
+    /* join gzip files on command line and write to stdout */
+    gzinit(&crc, &tot, stdout);
+    while (argc--)
+        gzcopy(*argv++, argc, &crc, &tot, stdout);
+
+    /* done */
+    return 0;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/examples/gzlog.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/examples/gzlog.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,1059 @@
+/*
+ * gzlog.c
+ * Copyright (C) 2004, 2008, 2012, 2016 Mark Adler, all rights reserved
+ * For conditions of distribution and use, see copyright notice in gzlog.h
+ * version 2.2, 14 Aug 2012
+ */
+
+/*
+   gzlog provides a mechanism for frequently appending short strings to a gzip
+   file that is efficient both in execution time and compression ratio.  The
+   strategy is to write the short strings in an uncompressed form to the end of
+   the gzip file, only compressing when the amount of uncompressed data has
+   reached a given threshold.
+
+   gzlog also provides protection against interruptions in the process due to
+   system crashes.  The status of the operation is recorded in an extra field
+   in the gzip file, and is only updated once the gzip file is brought to a
+   valid state.  The last data to be appended or compressed is saved in an
+   auxiliary file, so that if the operation is interrupted, it can be completed
+   the next time an append operation is attempted.
+
+   gzlog maintains another auxiliary file with the last 32K of data from the
+   compressed portion, which is preloaded for the compression of the subsequent
+   data.  This minimizes the impact to the compression ratio of appending.
+ */
+
+/*
+   Operations Concept:
+
+   Files (log name "foo"):
+   foo.gz -- gzip file with the complete log
+   foo.add -- last message to append or last data to compress
+   foo.dict -- dictionary of the last 32K of data for next compression
+   foo.temp -- temporary dictionary file for compression after this one
+   foo.lock -- lock file for reading and writing the other files
+   foo.repairs -- log file for log file recovery operations (not compressed)
+
+   gzip file structure:
+   - fixed-length (no file name) header with extra field (see below)
+   - compressed data ending initially with empty stored block
+   - uncompressed data filling out originally empty stored block and
+     subsequent stored blocks as needed (16K max each)
+   - gzip trailer
+   - no junk at end (no other gzip streams)
+
+   When appending data, the information in the first three items above plus the
+   foo.add file are sufficient to recover an interrupted append operation.  The
+   extra field has the necessary information to restore the start of the last
+   stored block and determine where to append the data in the foo.add file, as
+   well as the crc and length of the gzip data before the append operation.
+
+   The foo.add file is created before the gzip file is marked for append, and
+   deleted after the gzip file is marked as complete.  So if the append
+   operation is interrupted, the data to add will still be there.  If due to
+   some external force, the foo.add file gets deleted between when the append
+   operation was interrupted and when recovery is attempted, the gzip file will
+   still be restored, but without the appended data.
+
+   When compressing data, the information in the first two items above plus the
+   foo.add file are sufficient to recover an interrupted compress operation.
+   The extra field has the necessary information to find the end of the
+   compressed data, and contains both the crc and length of just the compressed
+   data and of the complete set of data including the contents of the foo.add
+   file.
+
+   Again, the foo.add file is maintained during the compress operation in case
+   of an interruption.  If in the unlikely event the foo.add file with the data
+   to be compressed is missing due to some external force, a gzip file with
+   just the previous compressed data will be reconstructed.  In this case, all
+   of the data that was to be compressed is lost (approximately one megabyte).
+   This will not occur if all that happened was an interruption of the compress
+   operation.
+
+   The third state that is marked is the replacement of the old dictionary with
+   the new dictionary after a compress operation.  Once compression is
+   complete, the gzip file is marked as being in the replace state.  This
+   completes the gzip file, so an interrupt after being so marked does not
+   result in recompression.  Then the dictionary file is replaced, and the gzip
+   file is marked as completed.  This state prevents the possibility of
+   restarting compression with the wrong dictionary file.
+
+   All three operations are wrapped by a lock/unlock procedure.  In order to
+   gain exclusive access to the log files, first a foo.lock file must be
+   exclusively created.  When all operations are complete, the lock is
+   released by deleting the foo.lock file.  If when attempting to create the
+   lock file, it already exists and the modify time of the lock file is more
+   than five minutes old (set by the PATIENCE define below), then the old
+   lock file is considered stale and deleted, and the exclusive creation of
+   the lock file is retried.  To assure that there are no false assessments
+   of the staleness of the lock file, the operations periodically touch the
+   lock file to update the modified date.
+
+   Following is the definition of the extra field with all of the information
+   required to enable the above append and compress operations and their
+   recovery if interrupted.  Multi-byte values are stored little endian
+   (consistent with the gzip format).  File pointers are eight bytes long.
+   The crc's and lengths for the gzip trailer are four bytes long.  (Note that
+   the length at the end of a gzip file is used for error checking only, and
+   for large files is actually the length modulo 2^32.)  The stored block
+   length is two bytes long.  The gzip extra field two-byte identification is
+   "ap" for append.  It is assumed that writing the extra field to the file is
+   an "atomic" operation.  That is, either all of the extra field is written
+   to the file, or none of it is, if the operation is interrupted right at the
+   point of updating the extra field.  This is a reasonable assumption, since
+   the extra field is within the first 52 bytes of the file, which is smaller
+   than any expected block size for a mass storage device (usually 512 bytes or
+   larger).
+
+   Extra field (35 bytes):
+   - Pointer to first stored block length -- this points to the two-byte length
+     of the first stored block, which is followed by the two-byte, one's
+     complement of that length.  The stored block length is preceded by the
+     three-bit header of the stored block, which is the actual start of the
+     stored block in the deflate format.  See the bit offset field below.
+   - Pointer to the last stored block length.  This is the same as above, but
+     for the last stored block of the uncompressed data in the gzip file.
+     Initially this is the same as the first stored block length pointer.
+     When the stored block gets to 16K (see the MAX_STORE define), then a new
+     stored block as added, at which point the last stored block length pointer
+     is different from the first stored block length pointer.  When they are
+     different, the first bit of the last stored block header is eight bits, or
+     one byte back from the block length.
+   - Compressed data crc and length.  This is the crc and length of the data
+     that is in the compressed portion of the deflate stream.  These are used
+     only in the event that the foo.add file containing the data to compress is
+     lost after a compress operation is interrupted.
+   - Total data crc and length.  This is the crc and length of all of the data
+     stored in the gzip file, compressed and uncompressed.  It is used to
+     reconstruct the gzip trailer when compressing, as well as when recovering
+     interrupted operations.
+   - Final stored block length.  This is used to quickly find where to append,
+     and allows the restoration of the original final stored block state when
+     an append operation is interrupted.
+   - First stored block start as the number of bits back from the final stored
+     block first length byte.  This value is in the range of 3..10, and is
+     stored as the low three bits of the final byte of the extra field after
+     subtracting three (0..7).  This allows the last-block bit of the stored
+     block header to be updated when a new stored block is added, for the case
+     when the first stored block and the last stored block are the same.  (When
+     they are different, the numbers of bits back is known to be eight.)  This
+     also allows for new compressed data to be appended to the old compressed
+     data in the compress operation, overwriting the previous first stored
+     block, or for the compressed data to be terminated and a valid gzip file
+     reconstructed on the off chance that a compression operation was
+     interrupted and the data to compress in the foo.add file was deleted.
+   - The operation in process.  This is the next two bits in the last byte (the
+     bits under the mask 0x18).  The are interpreted as 0: nothing in process,
+     1: append in process, 2: compress in process, 3: replace in process.
+   - The top three bits of the last byte in the extra field are reserved and
+     are currently set to zero.
+
+   Main procedure:
+   - Exclusively create the foo.lock file using the O_CREAT and O_EXCL modes of
+     the system open() call.  If the modify time of an existing lock file is
+     more than PATIENCE seconds old, then the lock file is deleted and the
+     exclusive create is retried.
+   - Load the extra field from the foo.gz file, and see if an operation was in
+     progress but not completed.  If so, apply the recovery procedure below.
+   - Perform the append procedure with the provided data.
+   - If the uncompressed data in the foo.gz file is 1MB or more, apply the
+     compress procedure.
+   - Delete the foo.lock file.
+
+   Append procedure:
+   - Put what to append in the foo.add file so that the operation can be
+     restarted if this procedure is interrupted.
+   - Mark the foo.gz extra field with the append operation in progress.
+   + Restore the original last-block bit and stored block length of the last
+     stored block from the information in the extra field, in case a previous
+     append operation was interrupted.
+   - Append the provided data to the last stored block, creating new stored
+     blocks as needed and updating the stored blocks last-block bits and
+     lengths.
+   - Update the crc and length with the new data, and write the gzip trailer.
+   - Write over the extra field (with a single write operation) with the new
+     pointers, lengths, and crc's, and mark the gzip file as not in process.
+     Though there is still a foo.add file, it will be ignored since nothing
+     is in process.  If a foo.add file is leftover from a previously
+     completed operation, it is truncated when writing new data to it.
+   - Delete the foo.add file.
+
+   Compress and replace procedures:
+   - Read all of the uncompressed data in the stored blocks in foo.gz and write
+     it to foo.add.  Also write foo.temp with the last 32K of that data to
+     provide a dictionary for the next invocation of this procedure.
+   - Rewrite the extra field marking foo.gz with a compression in process.
+   * If there is no data provided to compress (due to a missing foo.add file
+     when recovering), reconstruct and truncate the foo.gz file to contain
+     only the previous compressed data and proceed to the step after the next
+     one.  Otherwise ...
+   - Compress the data with the dictionary in foo.dict, and write to the
+     foo.gz file starting at the bit immediately following the last previously
+     compressed block.  If there is no foo.dict, proceed anyway with the
+     compression at slightly reduced efficiency.  (For the foo.dict file to be
+     missing requires some external failure beyond simply the interruption of
+     a compress operation.)  During this process, the foo.lock file is
+     periodically touched to assure that that file is not considered stale by
+     another process before we're done.  The deflation is terminated with a
+     non-last empty static block (10 bits long), that is then located and
+     written over by a last-bit-set empty stored block.
+   - Append the crc and length of the data in the gzip file (previously
+     calculated during the append operations).
+   - Write over the extra field with the updated stored block offsets, bits
+     back, crc's, and lengths, and mark foo.gz as in process for a replacement
+     of the dictionary.
+   @ Delete the foo.add file.
+   - Replace foo.dict with foo.temp.
+   - Write over the extra field, marking foo.gz as complete.
+
+   Recovery procedure:
+   - If not a replace recovery, read in the foo.add file, and provide that data
+     to the appropriate recovery below.  If there is no foo.add file, provide
+     a zero data length to the recovery.  In that case, the append recovery
+     restores the foo.gz to the previous compressed + uncompressed data state.
+     For the the compress recovery, a missing foo.add file results in foo.gz
+     being restored to the previous compressed-only data state.
+   - Append recovery:
+     - Pick up append at + step above
+   - Compress recovery:
+     - Pick up compress at * step above
+   - Replace recovery:
+     - Pick up compress at @ step above
+   - Log the repair with a date stamp in foo.repairs
+ */
+
+#include <sys/types.h>
+#include <stdio.h>      /* rename, fopen, fprintf, fclose */
+#include <stdlib.h>     /* malloc, free */
+#include <string.h>     /* strlen, strrchr, strcpy, strncpy, strcmp */
+#include <fcntl.h>      /* open */
+#include <unistd.h>     /* lseek, read, write, close, unlink, sleep, */
+                        /* ftruncate, fsync */
+#include <errno.h>      /* errno */
+#include <time.h>       /* time, ctime */
+#include <sys/stat.h>   /* stat */
+#include <sys/time.h>   /* utimes */
+#include "zlib.h"       /* crc32 */
+
+#include "gzlog.h"      /* header for external access */
+
+#define local static
+typedef unsigned int uint;
+typedef unsigned long ulong;
+
+/* Macro for debugging to deterministically force recovery operations */
+#ifdef GZLOG_DEBUG
+    #include <setjmp.h>         /* longjmp */
+    jmp_buf gzlog_jump;         /* where to go back to */
+    int gzlog_bail = 0;         /* which point to bail at (1..8) */
+    int gzlog_count = -1;       /* number of times through to wait */
+#   define BAIL(n) do { if (n == gzlog_bail && gzlog_count-- == 0) \
+                            longjmp(gzlog_jump, gzlog_bail); } while (0)
+#else
+#   define BAIL(n)
+#endif
+
+/* how old the lock file can be in seconds before considering it stale */
+#define PATIENCE 300
+
+/* maximum stored block size in Kbytes -- must be in 1..63 */
+#define MAX_STORE 16
+
+/* number of stored Kbytes to trigger compression (must be >= 32 to allow
+   dictionary construction, and <= 204 * MAX_STORE, in order for >> 10 to
+   discard the stored block headers contribution of five bytes each) */
+#define TRIGGER 1024
+
+/* size of a deflate dictionary (this cannot be changed) */
+#define DICT 32768U
+
+/* values for the operation (2 bits) */
+#define NO_OP 0
+#define APPEND_OP 1
+#define COMPRESS_OP 2
+#define REPLACE_OP 3
+
+/* macros to extract little-endian integers from an unsigned byte buffer */
+#define PULL2(p) ((p)[0]+((uint)((p)[1])<<8))
+#define PULL4(p) (PULL2(p)+((ulong)PULL2(p+2)<<16))
+#define PULL8(p) (PULL4(p)+((off_t)PULL4(p+4)<<32))
+
+/* macros to store integers into a byte buffer in little-endian order */
+#define PUT2(p,a) do {(p)[0]=a;(p)[1]=(a)>>8;} while(0)
+#define PUT4(p,a) do {PUT2(p,a);PUT2(p+2,a>>16);} while(0)
+#define PUT8(p,a) do {PUT4(p,a);PUT4(p+4,a>>32);} while(0)
+
+/* internal structure for log information */
+#define LOGID "\106\035\172"    /* should be three non-zero characters */
+struct log {
+    char id[4];     /* contains LOGID to detect inadvertent overwrites */
+    int fd;         /* file descriptor for .gz file, opened read/write */
+    char *path;     /* allocated path, e.g. "/var/log/foo" or "foo" */
+    char *end;      /* end of path, for appending suffices such as ".gz" */
+    off_t first;    /* offset of first stored block first length byte */
+    int back;       /* location of first block id in bits back from first */
+    uint stored;    /* bytes currently in last stored block */
+    off_t last;     /* offset of last stored block first length byte */
+    ulong ccrc;     /* crc of compressed data */
+    ulong clen;     /* length (modulo 2^32) of compressed data */
+    ulong tcrc;     /* crc of total data */
+    ulong tlen;     /* length (modulo 2^32) of total data */
+    time_t lock;    /* last modify time of our lock file */
+};
+
+/* gzip header for gzlog */
+local unsigned char log_gzhead[] = {
+    0x1f, 0x8b,                 /* magic gzip id */
+    8,                          /* compression method is deflate */
+    4,                          /* there is an extra field (no file name) */
+    0, 0, 0, 0,                 /* no modification time provided */
+    0, 0xff,                    /* no extra flags, no OS specified */
+    39, 0, 'a', 'p', 35, 0      /* extra field with "ap" subfield */
+                                /* 35 is EXTRA, 39 is EXTRA + 4 */
+};
+
+#define HEAD sizeof(log_gzhead)     /* should be 16 */
+
+/* initial gzip extra field content (52 == HEAD + EXTRA + 1) */
+local unsigned char log_gzext[] = {
+    52, 0, 0, 0, 0, 0, 0, 0,    /* offset of first stored block length */
+    52, 0, 0, 0, 0, 0, 0, 0,    /* offset of last stored block length */
+    0, 0, 0, 0, 0, 0, 0, 0,     /* compressed data crc and length */
+    0, 0, 0, 0, 0, 0, 0, 0,     /* total data crc and length */
+    0, 0,                       /* final stored block data length */
+    5                           /* op is NO_OP, last bit 8 bits back */
+};
+
+#define EXTRA sizeof(log_gzext)     /* should be 35 */
+
+/* initial gzip data and trailer */
+local unsigned char log_gzbody[] = {
+    1, 0, 0, 0xff, 0xff,        /* empty stored block (last) */
+    0, 0, 0, 0,                 /* crc */
+    0, 0, 0, 0                  /* uncompressed length */
+};
+
+#define BODY sizeof(log_gzbody)
+
+/* Exclusively create foo.lock in order to negotiate exclusive access to the
+   foo.* files.  If the modify time of an existing lock file is greater than
+   PATIENCE seconds in the past, then consider the lock file to have been
+   abandoned, delete it, and try the exclusive create again.  Save the lock
+   file modify time for verification of ownership.  Return 0 on success, or -1
+   on failure, usually due to an access restriction or invalid path.  Note that
+   if stat() or unlink() fails, it may be due to another process noticing the
+   abandoned lock file a smidge sooner and deleting it, so those are not
+   flagged as an error. */
+local int log_lock(struct log *log)
+{
+    int fd;
+    struct stat st;
+
+    strcpy(log->end, ".lock");
+    while ((fd = open(log->path, O_CREAT | O_EXCL, 0644)) < 0) {
+        if (errno != EEXIST)
+            return -1;
+        if (stat(log->path, &st) == 0 && time(NULL) - st.st_mtime > PATIENCE) {
+            unlink(log->path);
+            continue;
+        }
+        sleep(2);       /* relinquish the CPU for two seconds while waiting */
+    }
+    close(fd);
+    if (stat(log->path, &st) == 0)
+        log->lock = st.st_mtime;
+    return 0;
+}
+
+/* Update the modify time of the lock file to now, in order to prevent another
+   task from thinking that the lock is stale.  Save the lock file modify time
+   for verification of ownership. */
+local void log_touch(struct log *log)
+{
+    struct stat st;
+
+    strcpy(log->end, ".lock");
+    utimes(log->path, NULL);
+    if (stat(log->path, &st) == 0)
+        log->lock = st.st_mtime;
+}
+
+/* Check the log file modify time against what is expected.  Return true if
+   this is not our lock.  If it is our lock, touch it to keep it. */
+local int log_check(struct log *log)
+{
+    struct stat st;
+
+    strcpy(log->end, ".lock");
+    if (stat(log->path, &st) || st.st_mtime != log->lock)
+        return 1;
+    log_touch(log);
+    return 0;
+}
+
+/* Unlock a previously acquired lock, but only if it's ours. */
+local void log_unlock(struct log *log)
+{
+    if (log_check(log))
+        return;
+    strcpy(log->end, ".lock");
+    unlink(log->path);
+    log->lock = 0;
+}
+
+/* Check the gzip header and read in the extra field, filling in the values in
+   the log structure.  Return op on success or -1 if the gzip header was not as
+   expected.  op is the current operation in progress last written to the extra
+   field.  This assumes that the gzip file has already been opened, with the
+   file descriptor log->fd. */
+local int log_head(struct log *log)
+{
+    int op;
+    unsigned char buf[HEAD + EXTRA];
+
+    if (lseek(log->fd, 0, SEEK_SET) < 0 ||
+        read(log->fd, buf, HEAD + EXTRA) != HEAD + EXTRA ||
+        memcmp(buf, log_gzhead, HEAD)) {
+        return -1;
+    }
+    log->first = PULL8(buf + HEAD);
+    log->last = PULL8(buf + HEAD + 8);
+    log->ccrc = PULL4(buf + HEAD + 16);
+    log->clen = PULL4(buf + HEAD + 20);
+    log->tcrc = PULL4(buf + HEAD + 24);
+    log->tlen = PULL4(buf + HEAD + 28);
+    log->stored = PULL2(buf + HEAD + 32);
+    log->back = 3 + (buf[HEAD + 34] & 7);
+    op = (buf[HEAD + 34] >> 3) & 3;
+    return op;
+}
+
+/* Write over the extra field contents, marking the operation as op.  Use fsync
+   to assure that the device is written to, and in the requested order.  This
+   operation, and only this operation, is assumed to be atomic in order to
+   assure that the log is recoverable in the event of an interruption at any
+   point in the process.  Return -1 if the write to foo.gz failed. */
+local int log_mark(struct log *log, int op)
+{
+    int ret;
+    unsigned char ext[EXTRA];
+
+    PUT8(ext, log->first);
+    PUT8(ext + 8, log->last);
+    PUT4(ext + 16, log->ccrc);
+    PUT4(ext + 20, log->clen);
+    PUT4(ext + 24, log->tcrc);
+    PUT4(ext + 28, log->tlen);
+    PUT2(ext + 32, log->stored);
+    ext[34] = log->back - 3 + (op << 3);
+    fsync(log->fd);
+    ret = lseek(log->fd, HEAD, SEEK_SET) < 0 ||
+          write(log->fd, ext, EXTRA) != EXTRA ? -1 : 0;
+    fsync(log->fd);
+    return ret;
+}
+
+/* Rewrite the last block header bits and subsequent zero bits to get to a byte
+   boundary, setting the last block bit if last is true, and then write the
+   remainder of the stored block header (length and one's complement).  Leave
+   the file pointer after the end of the last stored block data.  Return -1 if
+   there is a read or write failure on the foo.gz file */
+local int log_last(struct log *log, int last)
+{
+    int back, len, mask;
+    unsigned char buf[6];
+
+    /* determine the locations of the bytes and bits to modify */
+    back = log->last == log->first ? log->back : 8;
+    len = back > 8 ? 2 : 1;                 /* bytes back from log->last */
+    mask = 0x80 >> ((back - 1) & 7);        /* mask for block last-bit */
+
+    /* get the byte to modify (one or two back) into buf[0] -- don't need to
+       read the byte if the last-bit is eight bits back, since in that case
+       the entire byte will be modified */
+    buf[0] = 0;
+    if (back != 8 && (lseek(log->fd, log->last - len, SEEK_SET) < 0 ||
+                      read(log->fd, buf, 1) != 1))
+        return -1;
+
+    /* change the last-bit of the last stored block as requested -- note
+       that all bits above the last-bit are set to zero, per the type bits
+       of a stored block being 00 and per the convention that the bits to
+       bring the stream to a byte boundary are also zeros */
+    buf[1] = 0;
+    buf[2 - len] = (*buf & (mask - 1)) + (last ? mask : 0);
+
+    /* write the modified stored block header and lengths, move the file
+       pointer to after the last stored block data */
+    PUT2(buf + 2, log->stored);
+    PUT2(buf + 4, log->stored ^ 0xffff);
+    return lseek(log->fd, log->last - len, SEEK_SET) < 0 ||
+           write(log->fd, buf + 2 - len, len + 4) != len + 4 ||
+           lseek(log->fd, log->stored, SEEK_CUR) < 0 ? -1 : 0;
+}
+
+/* Append len bytes from data to the locked and open log file.  len may be zero
+   if recovering and no .add file was found.  In that case, the previous state
+   of the foo.gz file is restored.  The data is appended uncompressed in
+   deflate stored blocks.  Return -1 if there was an error reading or writing
+   the foo.gz file. */
+local int log_append(struct log *log, unsigned char *data, size_t len)
+{
+    uint put;
+    off_t end;
+    unsigned char buf[8];
+
+    /* set the last block last-bit and length, in case recovering an
+       interrupted append, then position the file pointer to append to the
+       block */
+    if (log_last(log, 1))
+        return -1;
+
+    /* append, adding stored blocks and updating the offset of the last stored
+       block as needed, and update the total crc and length */
+    while (len) {
+        /* append as much as we can to the last block */
+        put = (MAX_STORE << 10) - log->stored;
+        if (put > len)
+            put = (uint)len;
+        if (put) {
+            if (write(log->fd, data, put) != put)
+                return -1;
+            BAIL(1);
+            log->tcrc = crc32(log->tcrc, data, put);
+            log->tlen += put;
+            log->stored += put;
+            data += put;
+            len -= put;
+        }
+
+        /* if we need to, add a new empty stored block */
+        if (len) {
+            /* mark current block as not last */
+            if (log_last(log, 0))
+                return -1;
+
+            /* point to new, empty stored block */
+            log->last += 4 + log->stored + 1;
+            log->stored = 0;
+        }
+
+        /* mark last block as last, update its length */
+        if (log_last(log, 1))
+            return -1;
+        BAIL(2);
+    }
+
+    /* write the new crc and length trailer, and truncate just in case (could
+       be recovering from partial append with a missing foo.add file) */
+    PUT4(buf, log->tcrc);
+    PUT4(buf + 4, log->tlen);
+    if (write(log->fd, buf, 8) != 8 ||
+        (end = lseek(log->fd, 0, SEEK_CUR)) < 0 || ftruncate(log->fd, end))
+        return -1;
+
+    /* write the extra field, marking the log file as done, delete .add file */
+    if (log_mark(log, NO_OP))
+        return -1;
+    strcpy(log->end, ".add");
+    unlink(log->path);          /* ignore error, since may not exist */
+    return 0;
+}
+
+/* Replace the foo.dict file with the foo.temp file.  Also delete the foo.add
+   file, since the compress operation may have been interrupted before that was
+   done.  Returns 1 if memory could not be allocated, or -1 if reading or
+   writing foo.gz fails, or if the rename fails for some reason other than
+   foo.temp not existing.  foo.temp not existing is a permitted error, since
+   the replace operation may have been interrupted after the rename is done,
+   but before foo.gz is marked as complete. */
+local int log_replace(struct log *log)
+{
+    int ret;
+    char *dest;
+
+    /* delete foo.add file */
+    strcpy(log->end, ".add");
+    unlink(log->path);         /* ignore error, since may not exist */
+    BAIL(3);
+
+    /* rename foo.name to foo.dict, replacing foo.dict if it exists */
+    strcpy(log->end, ".dict");
+    dest = malloc(strlen(log->path) + 1);
+    if (dest == NULL)
+        return -2;
+    strcpy(dest, log->path);
+    strcpy(log->end, ".temp");
+    ret = rename(log->path, dest);
+    free(dest);
+    if (ret && errno != ENOENT)
+        return -1;
+    BAIL(4);
+
+    /* mark the foo.gz file as done */
+    return log_mark(log, NO_OP);
+}
+
+/* Compress the len bytes at data and append the compressed data to the
+   foo.gz deflate data immediately after the previous compressed data.  This
+   overwrites the previous uncompressed data, which was stored in foo.add
+   and is the data provided in data[0..len-1].  If this operation is
+   interrupted, it picks up at the start of this routine, with the foo.add
+   file read in again.  If there is no data to compress (len == 0), then we
+   simply terminate the foo.gz file after the previously compressed data,
+   appending a final empty stored block and the gzip trailer.  Return -1 if
+   reading or writing the log.gz file failed, or -2 if there was a memory
+   allocation failure. */
+local int log_compress(struct log *log, unsigned char *data, size_t len)
+{
+    int fd;
+    uint got, max;
+    ssize_t dict;
+    off_t end;
+    z_stream strm;
+    unsigned char buf[DICT];
+
+    /* compress and append compressed data */
+    if (len) {
+        /* set up for deflate, allocating memory */
+        strm.zalloc = Z_NULL;
+        strm.zfree = Z_NULL;
+        strm.opaque = Z_NULL;
+        if (deflateInit2(&strm, Z_DEFAULT_COMPRESSION, Z_DEFLATED, -15, 8,
+                         Z_DEFAULT_STRATEGY) != Z_OK)
+            return -2;
+
+        /* read in dictionary (last 32K of data that was compressed) */
+        strcpy(log->end, ".dict");
+        fd = open(log->path, O_RDONLY, 0);
+        if (fd >= 0) {
+            dict = read(fd, buf, DICT);
+            close(fd);
+            if (dict < 0) {
+                deflateEnd(&strm);
+                return -1;
+            }
+            if (dict)
+                deflateSetDictionary(&strm, buf, (uint)dict);
+        }
+        log_touch(log);
+
+        /* prime deflate with last bits of previous block, position write
+           pointer to write those bits and overwrite what follows */
+        if (lseek(log->fd, log->first - (log->back > 8 ? 2 : 1),
+                SEEK_SET) < 0 ||
+            read(log->fd, buf, 1) != 1 || lseek(log->fd, -1, SEEK_CUR) < 0) {
+            deflateEnd(&strm);
+            return -1;
+        }
+        deflatePrime(&strm, (8 - log->back) & 7, *buf);
+
+        /* compress, finishing with a partial non-last empty static block */
+        strm.next_in = data;
+        max = (((uint)0 - 1) >> 1) + 1; /* in case int smaller than size_t */
+        do {
+            strm.avail_in = len > max ? max : (uint)len;
+            len -= strm.avail_in;
+            do {
+                strm.avail_out = DICT;
+                strm.next_out = buf;
+                deflate(&strm, len ? Z_NO_FLUSH : Z_PARTIAL_FLUSH);
+                got = DICT - strm.avail_out;
+                if (got && write(log->fd, buf, got) != got) {
+                    deflateEnd(&strm);
+                    return -1;
+                }
+                log_touch(log);
+            } while (strm.avail_out == 0);
+        } while (len);
+        deflateEnd(&strm);
+        BAIL(5);
+
+        /* find start of empty static block -- scanning backwards the first one
+           bit is the second bit of the block, if the last byte is zero, then
+           we know the byte before that has a one in the top bit, since an
+           empty static block is ten bits long */
+        if ((log->first = lseek(log->fd, -1, SEEK_CUR)) < 0 ||
+            read(log->fd, buf, 1) != 1)
+            return -1;
+        log->first++;
+        if (*buf) {
+            log->back = 1;
+            while ((*buf & ((uint)1 << (8 - log->back++))) == 0)
+                ;       /* guaranteed to terminate, since *buf != 0 */
+        }
+        else
+            log->back = 10;
+
+        /* update compressed crc and length */
+        log->ccrc = log->tcrc;
+        log->clen = log->tlen;
+    }
+    else {
+        /* no data to compress -- fix up existing gzip stream */
+        log->tcrc = log->ccrc;
+        log->tlen = log->clen;
+    }
+
+    /* complete and truncate gzip stream */
+    log->last = log->first;
+    log->stored = 0;
+    PUT4(buf, log->tcrc);
+    PUT4(buf + 4, log->tlen);
+    if (log_last(log, 1) || write(log->fd, buf, 8) != 8 ||
+        (end = lseek(log->fd, 0, SEEK_CUR)) < 0 || ftruncate(log->fd, end))
+        return -1;
+    BAIL(6);
+
+    /* mark as being in the replace operation */
+    if (log_mark(log, REPLACE_OP))
+        return -1;
+
+    /* execute the replace operation and mark the file as done */
+    return log_replace(log);
+}
+
+/* log a repair record to the .repairs file */
+local void log_log(struct log *log, int op, char *record)
+{
+    time_t now;
+    FILE *rec;
+
+    now = time(NULL);
+    strcpy(log->end, ".repairs");
+    rec = fopen(log->path, "a");
+    if (rec == NULL)
+        return;
+    fprintf(rec, "%.24s %s recovery: %s\n", ctime(&now), op == APPEND_OP ?
+            "append" : (op == COMPRESS_OP ? "compress" : "replace"), record);
+    fclose(rec);
+    return;
+}
+
+/* Recover the interrupted operation op.  First read foo.add for recovering an
+   append or compress operation.  Return -1 if there was an error reading or
+   writing foo.gz or reading an existing foo.add, or -2 if there was a memory
+   allocation failure. */
+local int log_recover(struct log *log, int op)
+{
+    int fd, ret = 0;
+    unsigned char *data = NULL;
+    size_t len = 0;
+    struct stat st;
+
+    /* log recovery */
+    log_log(log, op, "start");
+
+    /* load foo.add file if expected and present */
+    if (op == APPEND_OP || op == COMPRESS_OP) {
+        strcpy(log->end, ".add");
+        if (stat(log->path, &st) == 0 && st.st_size) {
+            len = (size_t)(st.st_size);
+            if ((off_t)len != st.st_size ||
+                    (data = malloc(st.st_size)) == NULL) {
+                log_log(log, op, "allocation failure");
+                return -2;
+            }
+            if ((fd = open(log->path, O_RDONLY, 0)) < 0) {
+                log_log(log, op, ".add file read failure");
+                return -1;
+            }
+            ret = (size_t)read(fd, data, len) != len;
+            close(fd);
+            if (ret) {
+                log_log(log, op, ".add file read failure");
+                return -1;
+            }
+            log_log(log, op, "loaded .add file");
+        }
+        else
+            log_log(log, op, "missing .add file!");
+    }
+
+    /* recover the interrupted operation */
+    switch (op) {
+    case APPEND_OP:
+        ret = log_append(log, data, len);
+        break;
+    case COMPRESS_OP:
+        ret = log_compress(log, data, len);
+        break;
+    case REPLACE_OP:
+        ret = log_replace(log);
+    }
+
+    /* log status */
+    log_log(log, op, ret ? "failure" : "complete");
+
+    /* clean up */
+    if (data != NULL)
+        free(data);
+    return ret;
+}
+
+/* Close the foo.gz file (if open) and release the lock. */
+local void log_close(struct log *log)
+{
+    if (log->fd >= 0)
+        close(log->fd);
+    log->fd = -1;
+    log_unlock(log);
+}
+
+/* Open foo.gz, verify the header, and load the extra field contents, after
+   first creating the foo.lock file to gain exclusive access to the foo.*
+   files.  If foo.gz does not exist or is empty, then write the initial header,
+   extra, and body content of an empty foo.gz log file.  If there is an error
+   creating the lock file due to access restrictions, or an error reading or
+   writing the foo.gz file, or if the foo.gz file is not a proper log file for
+   this object (e.g. not a gzip file or does not contain the expected extra
+   field), then return true.  If there is an error, the lock is released.
+   Otherwise, the lock is left in place. */
+local int log_open(struct log *log)
+{
+    int op;
+
+    /* release open file resource if left over -- can occur if lock lost
+       between gzlog_open() and gzlog_write() */
+    if (log->fd >= 0)
+        close(log->fd);
+    log->fd = -1;
+
+    /* negotiate exclusive access */
+    if (log_lock(log) < 0)
+        return -1;
+
+    /* open the log file, foo.gz */
+    strcpy(log->end, ".gz");
+    log->fd = open(log->path, O_RDWR | O_CREAT, 0644);
+    if (log->fd < 0) {
+        log_close(log);
+        return -1;
+    }
+
+    /* if new, initialize foo.gz with an empty log, delete old dictionary */
+    if (lseek(log->fd, 0, SEEK_END) == 0) {
+        if (write(log->fd, log_gzhead, HEAD) != HEAD ||
+            write(log->fd, log_gzext, EXTRA) != EXTRA ||
+            write(log->fd, log_gzbody, BODY) != BODY) {
+            log_close(log);
+            return -1;
+        }
+        strcpy(log->end, ".dict");
+        unlink(log->path);
+    }
+
+    /* verify log file and load extra field information */
+    if ((op = log_head(log)) < 0) {
+        log_close(log);
+        return -1;
+    }
+
+    /* check for interrupted process and if so, recover */
+    if (op != NO_OP && log_recover(log, op)) {
+        log_close(log);
+        return -1;
+    }
+
+    /* touch the lock file to prevent another process from grabbing it */
+    log_touch(log);
+    return 0;
+}
+
+/* See gzlog.h for the description of the external methods below */
+gzlog *gzlog_open(char *path)
+{
+    size_t n;
+    struct log *log;
+
+    /* check arguments */
+    if (path == NULL || *path == 0)
+        return NULL;
+
+    /* allocate and initialize log structure */
+    log = malloc(sizeof(struct log));
+    if (log == NULL)
+        return NULL;
+    strcpy(log->id, LOGID);
+    log->fd = -1;
+
+    /* save path and end of path for name construction */
+    n = strlen(path);
+    log->path = malloc(n + 9);              /* allow for ".repairs" */
+    if (log->path == NULL) {
+        free(log);
+        return NULL;
+    }
+    strcpy(log->path, path);
+    log->end = log->path + n;
+
+    /* gain exclusive access and verify log file -- may perform a
+       recovery operation if needed */
+    if (log_open(log)) {
+        free(log->path);
+        free(log);
+        return NULL;
+    }
+
+    /* return pointer to log structure */
+    return log;
+}
+
+/* gzlog_compress() return values:
+    0: all good
+   -1: file i/o error (usually access issue)
+   -2: memory allocation failure
+   -3: invalid log pointer argument */
+int gzlog_compress(gzlog *logd)
+{
+    int fd, ret;
+    uint block;
+    size_t len, next;
+    unsigned char *data, buf[5];
+    struct log *log = logd;
+
+    /* check arguments */
+    if (log == NULL || strcmp(log->id, LOGID))
+        return -3;
+
+    /* see if we lost the lock -- if so get it again and reload the extra
+       field information (it probably changed), recover last operation if
+       necessary */
+    if (log_check(log) && log_open(log))
+        return -1;
+
+    /* create space for uncompressed data */
+    len = ((size_t)(log->last - log->first) & ~(((size_t)1 << 10) - 1)) +
+          log->stored;
+    if ((data = malloc(len)) == NULL)
+        return -2;
+
+    /* do statement here is just a cheap trick for error handling */
+    do {
+        /* read in the uncompressed data */
+        if (lseek(log->fd, log->first - 1, SEEK_SET) < 0)
+            break;
+        next = 0;
+        while (next < len) {
+            if (read(log->fd, buf, 5) != 5)
+                break;
+            block = PULL2(buf + 1);
+            if (next + block > len ||
+                read(log->fd, (char *)data + next, block) != block)
+                break;
+            next += block;
+        }
+        if (lseek(log->fd, 0, SEEK_CUR) != log->last + 4 + log->stored)
+            break;
+        log_touch(log);
+
+        /* write the uncompressed data to the .add file */
+        strcpy(log->end, ".add");
+        fd = open(log->path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+        if (fd < 0)
+            break;
+        ret = (size_t)write(fd, data, len) != len;
+        if (ret | close(fd))
+            break;
+        log_touch(log);
+
+        /* write the dictionary for the next compress to the .temp file */
+        strcpy(log->end, ".temp");
+        fd = open(log->path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+        if (fd < 0)
+            break;
+        next = DICT > len ? len : DICT;
+        ret = (size_t)write(fd, (char *)data + len - next, next) != next;
+        if (ret | close(fd))
+            break;
+        log_touch(log);
+
+        /* roll back to compressed data, mark the compress in progress */
+        log->last = log->first;
+        log->stored = 0;
+        if (log_mark(log, COMPRESS_OP))
+            break;
+        BAIL(7);
+
+        /* compress and append the data (clears mark) */
+        ret = log_compress(log, data, len);
+        free(data);
+        return ret;
+    } while (0);
+
+    /* broke out of do above on i/o error */
+    free(data);
+    return -1;
+}
+
+/* gzlog_write() return values:
+    0: all good
+   -1: file i/o error (usually access issue)
+   -2: memory allocation failure
+   -3: invalid log pointer argument */
+int gzlog_write(gzlog *logd, void *data, size_t len)
+{
+    int fd, ret;
+    struct log *log = logd;
+
+    /* check arguments */
+    if (log == NULL || strcmp(log->id, LOGID))
+        return -3;
+    if (data == NULL || len <= 0)
+        return 0;
+
+    /* see if we lost the lock -- if so get it again and reload the extra
+       field information (it probably changed), recover last operation if
+       necessary */
+    if (log_check(log) && log_open(log))
+        return -1;
+
+    /* create and write .add file */
+    strcpy(log->end, ".add");
+    fd = open(log->path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+    if (fd < 0)
+        return -1;
+    ret = (size_t)write(fd, data, len) != len;
+    if (ret | close(fd))
+        return -1;
+    log_touch(log);
+
+    /* mark log file with append in progress */
+    if (log_mark(log, APPEND_OP))
+        return -1;
+    BAIL(8);
+
+    /* append data (clears mark) */
+    if (log_append(log, data, len))
+        return -1;
+
+    /* check to see if it's time to compress -- if not, then done */
+    if (((log->last - log->first) >> 10) + (log->stored >> 10) < TRIGGER)
+        return 0;
+
+    /* time to compress */
+    return gzlog_compress(log);
+}
+
+/* gzlog_close() return values:
+    0: ok
+   -3: invalid log pointer argument */
+int gzlog_close(gzlog *logd)
+{
+    struct log *log = logd;
+
+    /* check arguments */
+    if (log == NULL || strcmp(log->id, LOGID))
+        return -3;
+
+    /* close the log file and release the lock */
+    log_close(log);
+
+    /* free structure and return */
+    if (log->path != NULL)
+        free(log->path);
+    strcpy(log->id, "bad");
+    free(log);
+    return 0;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/examples/gzlog.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/examples/gzlog.h	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,91 @@
+/* gzlog.h
+  Copyright (C) 2004, 2008, 2012 Mark Adler, all rights reserved
+  version 2.2, 14 Aug 2012
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the author be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  Mark Adler    madler@alumni.caltech.edu
+ */
+
+/* Version History:
+   1.0  26 Nov 2004  First version
+   2.0  25 Apr 2008  Complete redesign for recovery of interrupted operations
+                     Interface changed slightly in that now path is a prefix
+                     Compression now occurs as needed during gzlog_write()
+                     gzlog_write() now always leaves the log file as valid gzip
+   2.1   8 Jul 2012  Fix argument checks in gzlog_compress() and gzlog_write()
+   2.2  14 Aug 2012  Clean up signed comparisons
+ */
+
+/*
+   The gzlog object allows writing short messages to a gzipped log file,
+   opening the log file locked for small bursts, and then closing it.  The log
+   object works by appending stored (uncompressed) data to the gzip file until
+   1 MB has been accumulated.  At that time, the stored data is compressed, and
+   replaces the uncompressed data in the file.  The log file is truncated to
+   its new size at that time.  After each write operation, the log file is a
+   valid gzip file that can decompressed to recover what was written.
+
+   The gzlog operations can be interupted at any point due to an application or
+   system crash, and the log file will be recovered the next time the log is
+   opened with gzlog_open().
+ */
+
+#ifndef GZLOG_H
+#define GZLOG_H
+
+/* gzlog object type */
+typedef void gzlog;
+
+/* Open a gzlog object, creating the log file if it does not exist.  Return
+   NULL on error.  Note that gzlog_open() could take a while to complete if it
+   has to wait to verify that a lock is stale (possibly for five minutes), or
+   if there is significant contention with other instantiations of this object
+   when locking the resource.  path is the prefix of the file names created by
+   this object.  If path is "foo", then the log file will be "foo.gz", and
+   other auxiliary files will be created and destroyed during the process:
+   "foo.dict" for a compression dictionary, "foo.temp" for a temporary (next)
+   dictionary, "foo.add" for data being added or compressed, "foo.lock" for the
+   lock file, and "foo.repairs" to log recovery operations performed due to
+   interrupted gzlog operations.  A gzlog_open() followed by a gzlog_close()
+   will recover a previously interrupted operation, if any. */
+gzlog *gzlog_open(char *path);
+
+/* Write to a gzlog object.  Return zero on success, -1 if there is a file i/o
+   error on any of the gzlog files (this should not happen if gzlog_open()
+   succeeded, unless the device has run out of space or leftover auxiliary
+   files have permissions or ownership that prevent their use), -2 if there is
+   a memory allocation failure, or -3 if the log argument is invalid (e.g. if
+   it was not created by gzlog_open()).  This function will write data to the
+   file uncompressed, until 1 MB has been accumulated, at which time that data
+   will be compressed.  The log file will be a valid gzip file upon successful
+   return. */
+int gzlog_write(gzlog *log, void *data, size_t len);
+
+/* Force compression of any uncompressed data in the log.  This should be used
+   sparingly, if at all.  The main application would be when a log file will
+   not be appended to again.  If this is used to compress frequently while
+   appending, it will both significantly increase the execution time and
+   reduce the compression ratio.  The return codes are the same as for
+   gzlog_write(). */
+int gzlog_compress(gzlog *log);
+
+/* Close a gzlog object.  Return zero on success, -3 if the log argument is
+   invalid.  The log object is freed, and so cannot be referenced again. */
+int gzlog_close(gzlog *log);
+
+#endif
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/examples/zlib_how.html
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/examples/zlib_how.html	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,545 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
+  "http://www.w3.org/TR/REC-html40/loose.dtd">
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
+<title>zlib Usage Example</title>
+<!--  Copyright (c) 2004, 2005 Mark Adler.  -->
+</head>
+<body bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#00A000">
+<h2 align="center"> zlib Usage Example </h2>
+We often get questions about how the <tt>deflate()</tt> and <tt>inflate()</tt> functions should be used.
+Users wonder when they should provide more input, when they should use more output,
+what to do with a <tt>Z_BUF_ERROR</tt>, how to make sure the process terminates properly, and
+so on.  So for those who have read <tt>zlib.h</tt> (a few times), and
+would like further edification, below is an annotated example in C of simple routines to compress and decompress
+from an input file to an output file using <tt>deflate()</tt> and <tt>inflate()</tt> respectively.  The
+annotations are interspersed between lines of the code.  So please read between the lines.
+We hope this helps explain some of the intricacies of <em>zlib</em>.
+<p>
+Without further adieu, here is the program <a href="zpipe.c"><tt>zpipe.c</tt></a>:
+<pre><b>
+/* zpipe.c: example of proper use of zlib's inflate() and deflate()
+   Not copyrighted -- provided to the public domain
+   Version 1.4  11 December 2005  Mark Adler */
+
+/* Version history:
+   1.0  30 Oct 2004  First version
+   1.1   8 Nov 2004  Add void casting for unused return values
+                     Use switch statement for inflate() return values
+   1.2   9 Nov 2004  Add assertions to document zlib guarantees
+   1.3   6 Apr 2005  Remove incorrect assertion in inf()
+   1.4  11 Dec 2005  Add hack to avoid MSDOS end-of-line conversions
+                     Avoid some compiler warnings for input and output buffers
+ */
+</b></pre><!-- -->
+We now include the header files for the required definitions.  From
+<tt>stdio.h</tt> we use <tt>fopen()</tt>, <tt>fread()</tt>, <tt>fwrite()</tt>,
+<tt>feof()</tt>, <tt>ferror()</tt>, and <tt>fclose()</tt> for file i/o, and
+<tt>fputs()</tt> for error messages.  From <tt>string.h</tt> we use
+<tt>strcmp()</tt> for command line argument processing.
+From <tt>assert.h</tt> we use the <tt>assert()</tt> macro.
+From <tt>zlib.h</tt>
+we use the basic compression functions <tt>deflateInit()</tt>,
+<tt>deflate()</tt>, and <tt>deflateEnd()</tt>, and the basic decompression
+functions <tt>inflateInit()</tt>, <tt>inflate()</tt>, and
+<tt>inflateEnd()</tt>.
+<pre><b>
+#include &lt;stdio.h&gt;
+#include &lt;string.h&gt;
+#include &lt;assert.h&gt;
+#include "zlib.h"
+</b></pre><!-- -->
+This is an ugly hack required to avoid corruption of the input and output data on
+Windows/MS-DOS systems.  Without this, those systems would assume that the input and output
+files are text, and try to convert the end-of-line characters from one standard to
+another.  That would corrupt binary data, and in particular would render the compressed data unusable.
+This sets the input and output to binary which suppresses the end-of-line conversions.
+<tt>SET_BINARY_MODE()</tt> will be used later on <tt>stdin</tt> and <tt>stdout</tt>, at the beginning of <tt>main()</tt>.
+<pre><b>
+#if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(__CYGWIN__)
+#  include &lt;fcntl.h&gt;
+#  include &lt;io.h&gt;
+#  define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY)
+#else
+#  define SET_BINARY_MODE(file)
+#endif
+</b></pre><!-- -->
+<tt>CHUNK</tt> is simply the buffer size for feeding data to and pulling data
+from the <em>zlib</em> routines.  Larger buffer sizes would be more efficient,
+especially for <tt>inflate()</tt>.  If the memory is available, buffers sizes
+on the order of 128K or 256K bytes should be used.
+<pre><b>
+#define CHUNK 16384
+</b></pre><!-- -->
+The <tt>def()</tt> routine compresses data from an input file to an output file.  The output data
+will be in the <em>zlib</em> format, which is different from the <em>gzip</em> or <em>zip</em>
+formats.  The <em>zlib</em> format has a very small header of only two bytes to identify it as
+a <em>zlib</em> stream and to provide decoding information, and a four-byte trailer with a fast
+check value to verify the integrity of the uncompressed data after decoding.
+<pre><b>
+/* Compress from file source to file dest until EOF on source.
+   def() returns Z_OK on success, Z_MEM_ERROR if memory could not be
+   allocated for processing, Z_STREAM_ERROR if an invalid compression
+   level is supplied, Z_VERSION_ERROR if the version of zlib.h and the
+   version of the library linked do not match, or Z_ERRNO if there is
+   an error reading or writing the files. */
+int def(FILE *source, FILE *dest, int level)
+{
+</b></pre>
+Here are the local variables for <tt>def()</tt>.  <tt>ret</tt> will be used for <em>zlib</em>
+return codes.  <tt>flush</tt> will keep track of the current flushing state for <tt>deflate()</tt>,
+which is either no flushing, or flush to completion after the end of the input file is reached.
+<tt>have</tt> is the amount of data returned from <tt>deflate()</tt>.  The <tt>strm</tt> structure
+is used to pass information to and from the <em>zlib</em> routines, and to maintain the
+<tt>deflate()</tt> state.  <tt>in</tt> and <tt>out</tt> are the input and output buffers for
+<tt>deflate()</tt>.
+<pre><b>
+    int ret, flush;
+    unsigned have;
+    z_stream strm;
+    unsigned char in[CHUNK];
+    unsigned char out[CHUNK];
+</b></pre><!-- -->
+The first thing we do is to initialize the <em>zlib</em> state for compression using
+<tt>deflateInit()</tt>.  This must be done before the first use of <tt>deflate()</tt>.
+The <tt>zalloc</tt>, <tt>zfree</tt>, and <tt>opaque</tt> fields in the <tt>strm</tt>
+structure must be initialized before calling <tt>deflateInit()</tt>.  Here they are
+set to the <em>zlib</em> constant <tt>Z_NULL</tt> to request that <em>zlib</em> use
+the default memory allocation routines.  An application may also choose to provide
+custom memory allocation routines here.  <tt>deflateInit()</tt> will allocate on the
+order of 256K bytes for the internal state.
+(See <a href="zlib_tech.html"><em>zlib Technical Details</em></a>.)
+<p>
+<tt>deflateInit()</tt> is called with a pointer to the structure to be initialized and
+the compression level, which is an integer in the range of -1 to 9.  Lower compression
+levels result in faster execution, but less compression.  Higher levels result in
+greater compression, but slower execution.  The <em>zlib</em> constant Z_DEFAULT_COMPRESSION,
+equal to -1,
+provides a good compromise between compression and speed and is equivalent to level 6.
+Level 0 actually does no compression at all, and in fact expands the data slightly to produce
+the <em>zlib</em> format (it is not a byte-for-byte copy of the input).
+More advanced applications of <em>zlib</em>
+may use <tt>deflateInit2()</tt> here instead.  Such an application may want to reduce how
+much memory will be used, at some price in compression.  Or it may need to request a
+<em>gzip</em> header and trailer instead of a <em>zlib</em> header and trailer, or raw
+encoding with no header or trailer at all.
+<p>
+We must check the return value of <tt>deflateInit()</tt> against the <em>zlib</em> constant
+<tt>Z_OK</tt> to make sure that it was able to
+allocate memory for the internal state, and that the provided arguments were valid.
+<tt>deflateInit()</tt> will also check that the version of <em>zlib</em> that the <tt>zlib.h</tt>
+file came from matches the version of <em>zlib</em> actually linked with the program.  This
+is especially important for environments in which <em>zlib</em> is a shared library.
+<p>
+Note that an application can initialize multiple, independent <em>zlib</em> streams, which can
+operate in parallel.  The state information maintained in the structure allows the <em>zlib</em>
+routines to be reentrant.
+<pre><b>
+    /* allocate deflate state */
+    strm.zalloc = Z_NULL;
+    strm.zfree = Z_NULL;
+    strm.opaque = Z_NULL;
+    ret = deflateInit(&amp;strm, level);
+    if (ret != Z_OK)
+        return ret;
+</b></pre><!-- -->
+With the pleasantries out of the way, now we can get down to business.  The outer <tt>do</tt>-loop
+reads all of the input file and exits at the bottom of the loop once end-of-file is reached.
+This loop contains the only call of <tt>deflate()</tt>.  So we must make sure that all of the
+input data has been processed and that all of the output data has been generated and consumed
+before we fall out of the loop at the bottom.
+<pre><b>
+    /* compress until end of file */
+    do {
+</b></pre>
+We start off by reading data from the input file.  The number of bytes read is put directly
+into <tt>avail_in</tt>, and a pointer to those bytes is put into <tt>next_in</tt>.  We also
+check to see if end-of-file on the input has been reached.  If we are at the end of file, then <tt>flush</tt> is set to the
+<em>zlib</em> constant <tt>Z_FINISH</tt>, which is later passed to <tt>deflate()</tt> to
+indicate that this is the last chunk of input data to compress.  We need to use <tt>feof()</tt>
+to check for end-of-file as opposed to seeing if fewer than <tt>CHUNK</tt> bytes have been read.  The
+reason is that if the input file length is an exact multiple of <tt>CHUNK</tt>, we will miss
+the fact that we got to the end-of-file, and not know to tell <tt>deflate()</tt> to finish
+up the compressed stream.  If we are not yet at the end of the input, then the <em>zlib</em>
+constant <tt>Z_NO_FLUSH</tt> will be passed to <tt>deflate</tt> to indicate that we are still
+in the middle of the uncompressed data.
+<p>
+If there is an error in reading from the input file, the process is aborted with
+<tt>deflateEnd()</tt> being called to free the allocated <em>zlib</em> state before returning
+the error.  We wouldn't want a memory leak, now would we?  <tt>deflateEnd()</tt> can be called
+at any time after the state has been initialized.  Once that's done, <tt>deflateInit()</tt> (or
+<tt>deflateInit2()</tt>) would have to be called to start a new compression process.  There is
+no point here in checking the <tt>deflateEnd()</tt> return code.  The deallocation can't fail.
+<pre><b>
+        strm.avail_in = fread(in, 1, CHUNK, source);
+        if (ferror(source)) {
+            (void)deflateEnd(&amp;strm);
+            return Z_ERRNO;
+        }
+        flush = feof(source) ? Z_FINISH : Z_NO_FLUSH;
+        strm.next_in = in;
+</b></pre><!-- -->
+The inner <tt>do</tt>-loop passes our chunk of input data to <tt>deflate()</tt>, and then
+keeps calling <tt>deflate()</tt> until it is done producing output.  Once there is no more
+new output, <tt>deflate()</tt> is guaranteed to have consumed all of the input, i.e.,
+<tt>avail_in</tt> will be zero.
+<pre><b>
+        /* run deflate() on input until output buffer not full, finish
+           compression if all of source has been read in */
+        do {
+</b></pre>
+Output space is provided to <tt>deflate()</tt> by setting <tt>avail_out</tt> to the number
+of available output bytes and <tt>next_out</tt> to a pointer to that space.
+<pre><b>
+            strm.avail_out = CHUNK;
+            strm.next_out = out;
+</b></pre>
+Now we call the compression engine itself, <tt>deflate()</tt>.  It takes as many of the
+<tt>avail_in</tt> bytes at <tt>next_in</tt> as it can process, and writes as many as
+<tt>avail_out</tt> bytes to <tt>next_out</tt>.  Those counters and pointers are then
+updated past the input data consumed and the output data written.  It is the amount of
+output space available that may limit how much input is consumed.
+Hence the inner loop to make sure that
+all of the input is consumed by providing more output space each time.  Since <tt>avail_in</tt>
+and <tt>next_in</tt> are updated by <tt>deflate()</tt>, we don't have to mess with those
+between <tt>deflate()</tt> calls until it's all used up.
+<p>
+The parameters to <tt>deflate()</tt> are a pointer to the <tt>strm</tt> structure containing
+the input and output information and the internal compression engine state, and a parameter
+indicating whether and how to flush data to the output.  Normally <tt>deflate</tt> will consume
+several K bytes of input data before producing any output (except for the header), in order
+to accumulate statistics on the data for optimum compression.  It will then put out a burst of
+compressed data, and proceed to consume more input before the next burst.  Eventually,
+<tt>deflate()</tt>
+must be told to terminate the stream, complete the compression with provided input data, and
+write out the trailer check value.  <tt>deflate()</tt> will continue to compress normally as long
+as the flush parameter is <tt>Z_NO_FLUSH</tt>.  Once the <tt>Z_FINISH</tt> parameter is provided,
+<tt>deflate()</tt> will begin to complete the compressed output stream.  However depending on how
+much output space is provided, <tt>deflate()</tt> may have to be called several times until it
+has provided the complete compressed stream, even after it has consumed all of the input.  The flush
+parameter must continue to be <tt>Z_FINISH</tt> for those subsequent calls.
+<p>
+There are other values of the flush parameter that are used in more advanced applications.  You can
+force <tt>deflate()</tt> to produce a burst of output that encodes all of the input data provided
+so far, even if it wouldn't have otherwise, for example to control data latency on a link with
+compressed data.  You can also ask that <tt>deflate()</tt> do that as well as erase any history up to
+that point so that what follows can be decompressed independently, for example for random access
+applications.  Both requests will degrade compression by an amount depending on how often such
+requests are made.
+<p>
+<tt>deflate()</tt> has a return value that can indicate errors, yet we do not check it here.  Why
+not?  Well, it turns out that <tt>deflate()</tt> can do no wrong here.  Let's go through
+<tt>deflate()</tt>'s return values and dispense with them one by one.  The possible values are
+<tt>Z_OK</tt>, <tt>Z_STREAM_END</tt>, <tt>Z_STREAM_ERROR</tt>, or <tt>Z_BUF_ERROR</tt>.  <tt>Z_OK</tt>
+is, well, ok.  <tt>Z_STREAM_END</tt> is also ok and will be returned for the last call of
+<tt>deflate()</tt>.  This is already guaranteed by calling <tt>deflate()</tt> with <tt>Z_FINISH</tt>
+until it has no more output.  <tt>Z_STREAM_ERROR</tt> is only possible if the stream is not
+initialized properly, but we did initialize it properly.  There is no harm in checking for
+<tt>Z_STREAM_ERROR</tt> here, for example to check for the possibility that some
+other part of the application inadvertently clobbered the memory containing the <em>zlib</em> state.
+<tt>Z_BUF_ERROR</tt> will be explained further below, but
+suffice it to say that this is simply an indication that <tt>deflate()</tt> could not consume
+more input or produce more output.  <tt>deflate()</tt> can be called again with more output space
+or more available input, which it will be in this code.
+<pre><b>
+            ret = deflate(&amp;strm, flush);    /* no bad return value */
+            assert(ret != Z_STREAM_ERROR);  /* state not clobbered */
+</b></pre>
+Now we compute how much output <tt>deflate()</tt> provided on the last call, which is the
+difference between how much space was provided before the call, and how much output space
+is still available after the call.  Then that data, if any, is written to the output file.
+We can then reuse the output buffer for the next call of <tt>deflate()</tt>.  Again if there
+is a file i/o error, we call <tt>deflateEnd()</tt> before returning to avoid a memory leak.
+<pre><b>
+            have = CHUNK - strm.avail_out;
+            if (fwrite(out, 1, have, dest) != have || ferror(dest)) {
+                (void)deflateEnd(&amp;strm);
+                return Z_ERRNO;
+            }
+</b></pre>
+The inner <tt>do</tt>-loop is repeated until the last <tt>deflate()</tt> call fails to fill the
+provided output buffer.  Then we know that <tt>deflate()</tt> has done as much as it can with
+the provided input, and that all of that input has been consumed.  We can then fall out of this
+loop and reuse the input buffer.
+<p>
+The way we tell that <tt>deflate()</tt> has no more output is by seeing that it did not fill
+the output buffer, leaving <tt>avail_out</tt> greater than zero.  However suppose that
+<tt>deflate()</tt> has no more output, but just so happened to exactly fill the output buffer!
+<tt>avail_out</tt> is zero, and we can't tell that <tt>deflate()</tt> has done all it can.
+As far as we know, <tt>deflate()</tt>
+has more output for us.  So we call it again.  But now <tt>deflate()</tt> produces no output
+at all, and <tt>avail_out</tt> remains unchanged as <tt>CHUNK</tt>.  That <tt>deflate()</tt> call
+wasn't able to do anything, either consume input or produce output, and so it returns
+<tt>Z_BUF_ERROR</tt>.  (See, I told you I'd cover this later.)  However this is not a problem at
+all.  Now we finally have the desired indication that <tt>deflate()</tt> is really done,
+and so we drop out of the inner loop to provide more input to <tt>deflate()</tt>.
+<p>
+With <tt>flush</tt> set to <tt>Z_FINISH</tt>, this final set of <tt>deflate()</tt> calls will
+complete the output stream.  Once that is done, subsequent calls of <tt>deflate()</tt> would return
+<tt>Z_STREAM_ERROR</tt> if the flush parameter is not <tt>Z_FINISH</tt>, and do no more processing
+until the state is reinitialized.
+<p>
+Some applications of <em>zlib</em> have two loops that call <tt>deflate()</tt>
+instead of the single inner loop we have here.  The first loop would call
+without flushing and feed all of the data to <tt>deflate()</tt>.  The second loop would call
+<tt>deflate()</tt> with no more
+data and the <tt>Z_FINISH</tt> parameter to complete the process.  As you can see from this
+example, that can be avoided by simply keeping track of the current flush state.
+<pre><b>
+        } while (strm.avail_out == 0);
+        assert(strm.avail_in == 0);     /* all input will be used */
+</b></pre><!-- -->
+Now we check to see if we have already processed all of the input file.  That information was
+saved in the <tt>flush</tt> variable, so we see if that was set to <tt>Z_FINISH</tt>.  If so,
+then we're done and we fall out of the outer loop.  We're guaranteed to get <tt>Z_STREAM_END</tt>
+from the last <tt>deflate()</tt> call, since we ran it until the last chunk of input was
+consumed and all of the output was generated.
+<pre><b>
+        /* done when last data in file processed */
+    } while (flush != Z_FINISH);
+    assert(ret == Z_STREAM_END);        /* stream will be complete */
+</b></pre><!-- -->
+The process is complete, but we still need to deallocate the state to avoid a memory leak
+(or rather more like a memory hemorrhage if you didn't do this).  Then
+finally we can return with a happy return value.
+<pre><b>
+    /* clean up and return */
+    (void)deflateEnd(&amp;strm);
+    return Z_OK;
+}
+</b></pre><!-- -->
+Now we do the same thing for decompression in the <tt>inf()</tt> routine. <tt>inf()</tt>
+decompresses what is hopefully a valid <em>zlib</em> stream from the input file and writes the
+uncompressed data to the output file.  Much of the discussion above for <tt>def()</tt>
+applies to <tt>inf()</tt> as well, so the discussion here will focus on the differences between
+the two.
+<pre><b>
+/* Decompress from file source to file dest until stream ends or EOF.
+   inf() returns Z_OK on success, Z_MEM_ERROR if memory could not be
+   allocated for processing, Z_DATA_ERROR if the deflate data is
+   invalid or incomplete, Z_VERSION_ERROR if the version of zlib.h and
+   the version of the library linked do not match, or Z_ERRNO if there
+   is an error reading or writing the files. */
+int inf(FILE *source, FILE *dest)
+{
+</b></pre>
+The local variables have the same functionality as they do for <tt>def()</tt>.  The
+only difference is that there is no <tt>flush</tt> variable, since <tt>inflate()</tt>
+can tell from the <em>zlib</em> stream itself when the stream is complete.
+<pre><b>
+    int ret;
+    unsigned have;
+    z_stream strm;
+    unsigned char in[CHUNK];
+    unsigned char out[CHUNK];
+</b></pre><!-- -->
+The initialization of the state is the same, except that there is no compression level,
+of course, and two more elements of the structure are initialized.  <tt>avail_in</tt>
+and <tt>next_in</tt> must be initialized before calling <tt>inflateInit()</tt>.  This
+is because the application has the option to provide the start of the zlib stream in
+order for <tt>inflateInit()</tt> to have access to information about the compression
+method to aid in memory allocation.  In the current implementation of <em>zlib</em>
+(up through versions 1.2.x), the method-dependent memory allocations are deferred to the first call of
+<tt>inflate()</tt> anyway.  However those fields must be initialized since later versions
+of <em>zlib</em> that provide more compression methods may take advantage of this interface.
+In any case, no decompression is performed by <tt>inflateInit()</tt>, so the
+<tt>avail_out</tt> and <tt>next_out</tt> fields do not need to be initialized before calling.
+<p>
+Here <tt>avail_in</tt> is set to zero and <tt>next_in</tt> is set to <tt>Z_NULL</tt> to
+indicate that no input data is being provided.
+<pre><b>
+    /* allocate inflate state */
+    strm.zalloc = Z_NULL;
+    strm.zfree = Z_NULL;
+    strm.opaque = Z_NULL;
+    strm.avail_in = 0;
+    strm.next_in = Z_NULL;
+    ret = inflateInit(&amp;strm);
+    if (ret != Z_OK)
+        return ret;
+</b></pre><!-- -->
+The outer <tt>do</tt>-loop decompresses input until <tt>inflate()</tt> indicates
+that it has reached the end of the compressed data and has produced all of the uncompressed
+output.  This is in contrast to <tt>def()</tt> which processes all of the input file.
+If end-of-file is reached before the compressed data self-terminates, then the compressed
+data is incomplete and an error is returned.
+<pre><b>
+    /* decompress until deflate stream ends or end of file */
+    do {
+</b></pre>
+We read input data and set the <tt>strm</tt> structure accordingly.  If we've reached the
+end of the input file, then we leave the outer loop and report an error, since the
+compressed data is incomplete.  Note that we may read more data than is eventually consumed
+by <tt>inflate()</tt>, if the input file continues past the <em>zlib</em> stream.
+For applications where <em>zlib</em> streams are embedded in other data, this routine would
+need to be modified to return the unused data, or at least indicate how much of the input
+data was not used, so the application would know where to pick up after the <em>zlib</em> stream.
+<pre><b>
+        strm.avail_in = fread(in, 1, CHUNK, source);
+        if (ferror(source)) {
+            (void)inflateEnd(&amp;strm);
+            return Z_ERRNO;
+        }
+        if (strm.avail_in == 0)
+            break;
+        strm.next_in = in;
+</b></pre><!-- -->
+The inner <tt>do</tt>-loop has the same function it did in <tt>def()</tt>, which is to
+keep calling <tt>inflate()</tt> until has generated all of the output it can with the
+provided input.
+<pre><b>
+        /* run inflate() on input until output buffer not full */
+        do {
+</b></pre>
+Just like in <tt>def()</tt>, the same output space is provided for each call of <tt>inflate()</tt>.
+<pre><b>
+            strm.avail_out = CHUNK;
+            strm.next_out = out;
+</b></pre>
+Now we run the decompression engine itself.  There is no need to adjust the flush parameter, since
+the <em>zlib</em> format is self-terminating. The main difference here is that there are
+return values that we need to pay attention to.  <tt>Z_DATA_ERROR</tt>
+indicates that <tt>inflate()</tt> detected an error in the <em>zlib</em> compressed data format,
+which means that either the data is not a <em>zlib</em> stream to begin with, or that the data was
+corrupted somewhere along the way since it was compressed.  The other error to be processed is
+<tt>Z_MEM_ERROR</tt>, which can occur since memory allocation is deferred until <tt>inflate()</tt>
+needs it, unlike <tt>deflate()</tt>, whose memory is allocated at the start by <tt>deflateInit()</tt>.
+<p>
+Advanced applications may use
+<tt>deflateSetDictionary()</tt> to prime <tt>deflate()</tt> with a set of likely data to improve the
+first 32K or so of compression.  This is noted in the <em>zlib</em> header, so <tt>inflate()</tt>
+requests that that dictionary be provided before it can start to decompress.  Without the dictionary,
+correct decompression is not possible.  For this routine, we have no idea what the dictionary is,
+so the <tt>Z_NEED_DICT</tt> indication is converted to a <tt>Z_DATA_ERROR</tt>.
+<p>
+<tt>inflate()</tt> can also return <tt>Z_STREAM_ERROR</tt>, which should not be possible here,
+but could be checked for as noted above for <tt>def()</tt>.  <tt>Z_BUF_ERROR</tt> does not need to be
+checked for here, for the same reasons noted for <tt>def()</tt>.  <tt>Z_STREAM_END</tt> will be
+checked for later.
+<pre><b>
+            ret = inflate(&amp;strm, Z_NO_FLUSH);
+            assert(ret != Z_STREAM_ERROR);  /* state not clobbered */
+            switch (ret) {
+            case Z_NEED_DICT:
+                ret = Z_DATA_ERROR;     /* and fall through */
+            case Z_DATA_ERROR:
+            case Z_MEM_ERROR:
+                (void)inflateEnd(&amp;strm);
+                return ret;
+            }
+</b></pre>
+The output of <tt>inflate()</tt> is handled identically to that of <tt>deflate()</tt>.
+<pre><b>
+            have = CHUNK - strm.avail_out;
+            if (fwrite(out, 1, have, dest) != have || ferror(dest)) {
+                (void)inflateEnd(&amp;strm);
+                return Z_ERRNO;
+            }
+</b></pre>
+The inner <tt>do</tt>-loop ends when <tt>inflate()</tt> has no more output as indicated
+by not filling the output buffer, just as for <tt>deflate()</tt>.  In this case, we cannot
+assert that <tt>strm.avail_in</tt> will be zero, since the deflate stream may end before the file
+does.
+<pre><b>
+        } while (strm.avail_out == 0);
+</b></pre><!-- -->
+The outer <tt>do</tt>-loop ends when <tt>inflate()</tt> reports that it has reached the
+end of the input <em>zlib</em> stream, has completed the decompression and integrity
+check, and has provided all of the output.  This is indicated by the <tt>inflate()</tt>
+return value <tt>Z_STREAM_END</tt>.  The inner loop is guaranteed to leave <tt>ret</tt>
+equal to <tt>Z_STREAM_END</tt> if the last chunk of the input file read contained the end
+of the <em>zlib</em> stream.  So if the return value is not <tt>Z_STREAM_END</tt>, the
+loop continues to read more input.
+<pre><b>
+        /* done when inflate() says it's done */
+    } while (ret != Z_STREAM_END);
+</b></pre><!-- -->
+At this point, decompression successfully completed, or we broke out of the loop due to no
+more data being available from the input file.  If the last <tt>inflate()</tt> return value
+is not <tt>Z_STREAM_END</tt>, then the <em>zlib</em> stream was incomplete and a data error
+is returned.  Otherwise, we return with a happy return value.  Of course, <tt>inflateEnd()</tt>
+is called first to avoid a memory leak.
+<pre><b>
+    /* clean up and return */
+    (void)inflateEnd(&amp;strm);
+    return ret == Z_STREAM_END ? Z_OK : Z_DATA_ERROR;
+}
+</b></pre><!-- -->
+That ends the routines that directly use <em>zlib</em>.  The following routines make this
+a command-line program by running data through the above routines from <tt>stdin</tt> to
+<tt>stdout</tt>, and handling any errors reported by <tt>def()</tt> or <tt>inf()</tt>.
+<p>
+<tt>zerr()</tt> is used to interpret the possible error codes from <tt>def()</tt>
+and <tt>inf()</tt>, as detailed in their comments above, and print out an error message.
+Note that these are only a subset of the possible return values from <tt>deflate()</tt>
+and <tt>inflate()</tt>.
+<pre><b>
+/* report a zlib or i/o error */
+void zerr(int ret)
+{
+    fputs("zpipe: ", stderr);
+    switch (ret) {
+    case Z_ERRNO:
+        if (ferror(stdin))
+            fputs("error reading stdin\n", stderr);
+        if (ferror(stdout))
+            fputs("error writing stdout\n", stderr);
+        break;
+    case Z_STREAM_ERROR:
+        fputs("invalid compression level\n", stderr);
+        break;
+    case Z_DATA_ERROR:
+        fputs("invalid or incomplete deflate data\n", stderr);
+        break;
+    case Z_MEM_ERROR:
+        fputs("out of memory\n", stderr);
+        break;
+    case Z_VERSION_ERROR:
+        fputs("zlib version mismatch!\n", stderr);
+    }
+}
+</b></pre><!-- -->
+Here is the <tt>main()</tt> routine used to test <tt>def()</tt> and <tt>inf()</tt>.  The
+<tt>zpipe</tt> command is simply a compression pipe from <tt>stdin</tt> to <tt>stdout</tt>, if
+no arguments are given, or it is a decompression pipe if <tt>zpipe -d</tt> is used.  If any other
+arguments are provided, no compression or decompression is performed.  Instead a usage
+message is displayed.  Examples are <tt>zpipe < foo.txt > foo.txt.z</tt> to compress, and
+<tt>zpipe -d < foo.txt.z > foo.txt</tt> to decompress.
+<pre><b>
+/* compress or decompress from stdin to stdout */
+int main(int argc, char **argv)
+{
+    int ret;
+
+    /* avoid end-of-line conversions */
+    SET_BINARY_MODE(stdin);
+    SET_BINARY_MODE(stdout);
+
+    /* do compression if no arguments */
+    if (argc == 1) {
+        ret = def(stdin, stdout, Z_DEFAULT_COMPRESSION);
+        if (ret != Z_OK)
+            zerr(ret);
+        return ret;
+    }
+
+    /* do decompression if -d specified */
+    else if (argc == 2 &amp;&amp; strcmp(argv[1], "-d") == 0) {
+        ret = inf(stdin, stdout);
+        if (ret != Z_OK)
+            zerr(ret);
+        return ret;
+    }
+
+    /* otherwise, report usage */
+    else {
+        fputs("zpipe usage: zpipe [-d] &lt; source &gt; dest\n", stderr);
+        return 1;
+    }
+}
+</b></pre>
+<hr>
+<i>Copyright (c) 2004, 2005 by Mark Adler<br>Last modified 11 December 2005</i>
+</body>
+</html>
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/examples/zpipe.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/examples/zpipe.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,205 @@
+/* zpipe.c: example of proper use of zlib's inflate() and deflate()
+   Not copyrighted -- provided to the public domain
+   Version 1.4  11 December 2005  Mark Adler */
+
+/* Version history:
+   1.0  30 Oct 2004  First version
+   1.1   8 Nov 2004  Add void casting for unused return values
+                     Use switch statement for inflate() return values
+   1.2   9 Nov 2004  Add assertions to document zlib guarantees
+   1.3   6 Apr 2005  Remove incorrect assertion in inf()
+   1.4  11 Dec 2005  Add hack to avoid MSDOS end-of-line conversions
+                     Avoid some compiler warnings for input and output buffers
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include "zlib.h"
+
+#if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(__CYGWIN__)
+#  include <fcntl.h>
+#  include <io.h>
+#  define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY)
+#else
+#  define SET_BINARY_MODE(file)
+#endif
+
+#define CHUNK 16384
+
+/* Compress from file source to file dest until EOF on source.
+   def() returns Z_OK on success, Z_MEM_ERROR if memory could not be
+   allocated for processing, Z_STREAM_ERROR if an invalid compression
+   level is supplied, Z_VERSION_ERROR if the version of zlib.h and the
+   version of the library linked do not match, or Z_ERRNO if there is
+   an error reading or writing the files. */
+int def(FILE *source, FILE *dest, int level)
+{
+    int ret, flush;
+    unsigned have;
+    z_stream strm;
+    unsigned char in[CHUNK];
+    unsigned char out[CHUNK];
+
+    /* allocate deflate state */
+    strm.zalloc = Z_NULL;
+    strm.zfree = Z_NULL;
+    strm.opaque = Z_NULL;
+    ret = deflateInit(&strm, level);
+    if (ret != Z_OK)
+        return ret;
+
+    /* compress until end of file */
+    do {
+        strm.avail_in = fread(in, 1, CHUNK, source);
+        if (ferror(source)) {
+            (void)deflateEnd(&strm);
+            return Z_ERRNO;
+        }
+        flush = feof(source) ? Z_FINISH : Z_NO_FLUSH;
+        strm.next_in = in;
+
+        /* run deflate() on input until output buffer not full, finish
+           compression if all of source has been read in */
+        do {
+            strm.avail_out = CHUNK;
+            strm.next_out = out;
+            ret = deflate(&strm, flush);    /* no bad return value */
+            assert(ret != Z_STREAM_ERROR);  /* state not clobbered */
+            have = CHUNK - strm.avail_out;
+            if (fwrite(out, 1, have, dest) != have || ferror(dest)) {
+                (void)deflateEnd(&strm);
+                return Z_ERRNO;
+            }
+        } while (strm.avail_out == 0);
+        assert(strm.avail_in == 0);     /* all input will be used */
+
+        /* done when last data in file processed */
+    } while (flush != Z_FINISH);
+    assert(ret == Z_STREAM_END);        /* stream will be complete */
+
+    /* clean up and return */
+    (void)deflateEnd(&strm);
+    return Z_OK;
+}
+
+/* Decompress from file source to file dest until stream ends or EOF.
+   inf() returns Z_OK on success, Z_MEM_ERROR if memory could not be
+   allocated for processing, Z_DATA_ERROR if the deflate data is
+   invalid or incomplete, Z_VERSION_ERROR if the version of zlib.h and
+   the version of the library linked do not match, or Z_ERRNO if there
+   is an error reading or writing the files. */
+int inf(FILE *source, FILE *dest)
+{
+    int ret;
+    unsigned have;
+    z_stream strm;
+    unsigned char in[CHUNK];
+    unsigned char out[CHUNK];
+
+    /* allocate inflate state */
+    strm.zalloc = Z_NULL;
+    strm.zfree = Z_NULL;
+    strm.opaque = Z_NULL;
+    strm.avail_in = 0;
+    strm.next_in = Z_NULL;
+    ret = inflateInit(&strm);
+    if (ret != Z_OK)
+        return ret;
+
+    /* decompress until deflate stream ends or end of file */
+    do {
+        strm.avail_in = fread(in, 1, CHUNK, source);
+        if (ferror(source)) {
+            (void)inflateEnd(&strm);
+            return Z_ERRNO;
+        }
+        if (strm.avail_in == 0)
+            break;
+        strm.next_in = in;
+
+        /* run inflate() on input until output buffer not full */
+        do {
+            strm.avail_out = CHUNK;
+            strm.next_out = out;
+            ret = inflate(&strm, Z_NO_FLUSH);
+            assert(ret != Z_STREAM_ERROR);  /* state not clobbered */
+            switch (ret) {
+            case Z_NEED_DICT:
+                ret = Z_DATA_ERROR;     /* and fall through */
+            case Z_DATA_ERROR:
+            case Z_MEM_ERROR:
+                (void)inflateEnd(&strm);
+                return ret;
+            }
+            have = CHUNK - strm.avail_out;
+            if (fwrite(out, 1, have, dest) != have || ferror(dest)) {
+                (void)inflateEnd(&strm);
+                return Z_ERRNO;
+            }
+        } while (strm.avail_out == 0);
+
+        /* done when inflate() says it's done */
+    } while (ret != Z_STREAM_END);
+
+    /* clean up and return */
+    (void)inflateEnd(&strm);
+    return ret == Z_STREAM_END ? Z_OK : Z_DATA_ERROR;
+}
+
+/* report a zlib or i/o error */
+void zerr(int ret)
+{
+    fputs("zpipe: ", stderr);
+    switch (ret) {
+    case Z_ERRNO:
+        if (ferror(stdin))
+            fputs("error reading stdin\n", stderr);
+        if (ferror(stdout))
+            fputs("error writing stdout\n", stderr);
+        break;
+    case Z_STREAM_ERROR:
+        fputs("invalid compression level\n", stderr);
+        break;
+    case Z_DATA_ERROR:
+        fputs("invalid or incomplete deflate data\n", stderr);
+        break;
+    case Z_MEM_ERROR:
+        fputs("out of memory\n", stderr);
+        break;
+    case Z_VERSION_ERROR:
+        fputs("zlib version mismatch!\n", stderr);
+    }
+}
+
+/* compress or decompress from stdin to stdout */
+int main(int argc, char **argv)
+{
+    int ret;
+
+    /* avoid end-of-line conversions */
+    SET_BINARY_MODE(stdin);
+    SET_BINARY_MODE(stdout);
+
+    /* do compression if no arguments */
+    if (argc == 1) {
+        ret = def(stdin, stdout, Z_DEFAULT_COMPRESSION);
+        if (ret != Z_OK)
+            zerr(ret);
+        return ret;
+    }
+
+    /* do decompression if -d specified */
+    else if (argc == 2 && strcmp(argv[1], "-d") == 0) {
+        ret = inf(stdin, stdout);
+        if (ret != Z_OK)
+            zerr(ret);
+        return ret;
+    }
+
+    /* otherwise, report usage */
+    else {
+        fputs("zpipe usage: zpipe [-d] < source > dest\n", stderr);
+        return 1;
+    }
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/examples/zran.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/examples/zran.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,409 @@
+/* zran.c -- example of zlib/gzip stream indexing and random access
+ * Copyright (C) 2005, 2012 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+   Version 1.1  29 Sep 2012  Mark Adler */
+
+/* Version History:
+ 1.0  29 May 2005  First version
+ 1.1  29 Sep 2012  Fix memory reallocation error
+ */
+
+/* Illustrate the use of Z_BLOCK, inflatePrime(), and inflateSetDictionary()
+   for random access of a compressed file.  A file containing a zlib or gzip
+   stream is provided on the command line.  The compressed stream is decoded in
+   its entirety, and an index built with access points about every SPAN bytes
+   in the uncompressed output.  The compressed file is left open, and can then
+   be read randomly, having to decompress on the average SPAN/2 uncompressed
+   bytes before getting to the desired block of data.
+
+   An access point can be created at the start of any deflate block, by saving
+   the starting file offset and bit of that block, and the 32K bytes of
+   uncompressed data that precede that block.  Also the uncompressed offset of
+   that block is saved to provide a referece for locating a desired starting
+   point in the uncompressed stream.  build_index() works by decompressing the
+   input zlib or gzip stream a block at a time, and at the end of each block
+   deciding if enough uncompressed data has gone by to justify the creation of
+   a new access point.  If so, that point is saved in a data structure that
+   grows as needed to accommodate the points.
+
+   To use the index, an offset in the uncompressed data is provided, for which
+   the latest access point at or preceding that offset is located in the index.
+   The input file is positioned to the specified location in the index, and if
+   necessary the first few bits of the compressed data is read from the file.
+   inflate is initialized with those bits and the 32K of uncompressed data, and
+   the decompression then proceeds until the desired offset in the file is
+   reached.  Then the decompression continues to read the desired uncompressed
+   data from the file.
+
+   Another approach would be to generate the index on demand.  In that case,
+   requests for random access reads from the compressed data would try to use
+   the index, but if a read far enough past the end of the index is required,
+   then further index entries would be generated and added.
+
+   There is some fair bit of overhead to starting inflation for the random
+   access, mainly copying the 32K byte dictionary.  So if small pieces of the
+   file are being accessed, it would make sense to implement a cache to hold
+   some lookahead and avoid many calls to extract() for small lengths.
+
+   Another way to build an index would be to use inflateCopy().  That would
+   not be constrained to have access points at block boundaries, but requires
+   more memory per access point, and also cannot be saved to file due to the
+   use of pointers in the state.  The approach here allows for storage of the
+   index in a file.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "zlib.h"
+
+#define local static
+
+#define SPAN 1048576L       /* desired distance between access points */
+#define WINSIZE 32768U      /* sliding window size */
+#define CHUNK 16384         /* file input buffer size */
+
+/* access point entry */
+struct point {
+    off_t out;          /* corresponding offset in uncompressed data */
+    off_t in;           /* offset in input file of first full byte */
+    int bits;           /* number of bits (1-7) from byte at in - 1, or 0 */
+    unsigned char window[WINSIZE];  /* preceding 32K of uncompressed data */
+};
+
+/* access point list */
+struct access {
+    int have;           /* number of list entries filled in */
+    int size;           /* number of list entries allocated */
+    struct point *list; /* allocated list */
+};
+
+/* Deallocate an index built by build_index() */
+local void free_index(struct access *index)
+{
+    if (index != NULL) {
+        free(index->list);
+        free(index);
+    }
+}
+
+/* Add an entry to the access point list.  If out of memory, deallocate the
+   existing list and return NULL. */
+local struct access *addpoint(struct access *index, int bits,
+    off_t in, off_t out, unsigned left, unsigned char *window)
+{
+    struct point *next;
+
+    /* if list is empty, create it (start with eight points) */
+    if (index == NULL) {
+        index = malloc(sizeof(struct access));
+        if (index == NULL) return NULL;
+        index->list = malloc(sizeof(struct point) << 3);
+        if (index->list == NULL) {
+            free(index);
+            return NULL;
+        }
+        index->size = 8;
+        index->have = 0;
+    }
+
+    /* if list is full, make it bigger */
+    else if (index->have == index->size) {
+        index->size <<= 1;
+        next = realloc(index->list, sizeof(struct point) * index->size);
+        if (next == NULL) {
+            free_index(index);
+            return NULL;
+        }
+        index->list = next;
+    }
+
+    /* fill in entry and increment how many we have */
+    next = index->list + index->have;
+    next->bits = bits;
+    next->in = in;
+    next->out = out;
+    if (left)
+        memcpy(next->window, window + WINSIZE - left, left);
+    if (left < WINSIZE)
+        memcpy(next->window + left, window, WINSIZE - left);
+    index->have++;
+
+    /* return list, possibly reallocated */
+    return index;
+}
+
+/* Make one entire pass through the compressed stream and build an index, with
+   access points about every span bytes of uncompressed output -- span is
+   chosen to balance the speed of random access against the memory requirements
+   of the list, about 32K bytes per access point.  Note that data after the end
+   of the first zlib or gzip stream in the file is ignored.  build_index()
+   returns the number of access points on success (>= 1), Z_MEM_ERROR for out
+   of memory, Z_DATA_ERROR for an error in the input file, or Z_ERRNO for a
+   file read error.  On success, *built points to the resulting index. */
+local int build_index(FILE *in, off_t span, struct access **built)
+{
+    int ret;
+    off_t totin, totout;        /* our own total counters to avoid 4GB limit */
+    off_t last;                 /* totout value of last access point */
+    struct access *index;       /* access points being generated */
+    z_stream strm;
+    unsigned char input[CHUNK];
+    unsigned char window[WINSIZE];
+
+    /* initialize inflate */
+    strm.zalloc = Z_NULL;
+    strm.zfree = Z_NULL;
+    strm.opaque = Z_NULL;
+    strm.avail_in = 0;
+    strm.next_in = Z_NULL;
+    ret = inflateInit2(&strm, 47);      /* automatic zlib or gzip decoding */
+    if (ret != Z_OK)
+        return ret;
+
+    /* inflate the input, maintain a sliding window, and build an index -- this
+       also validates the integrity of the compressed data using the check
+       information at the end of the gzip or zlib stream */
+    totin = totout = last = 0;
+    index = NULL;               /* will be allocated by first addpoint() */
+    strm.avail_out = 0;
+    do {
+        /* get some compressed data from input file */
+        strm.avail_in = fread(input, 1, CHUNK, in);
+        if (ferror(in)) {
+            ret = Z_ERRNO;
+            goto build_index_error;
+        }
+        if (strm.avail_in == 0) {
+            ret = Z_DATA_ERROR;
+            goto build_index_error;
+        }
+        strm.next_in = input;
+
+        /* process all of that, or until end of stream */
+        do {
+            /* reset sliding window if necessary */
+            if (strm.avail_out == 0) {
+                strm.avail_out = WINSIZE;
+                strm.next_out = window;
+            }
+
+            /* inflate until out of input, output, or at end of block --
+               update the total input and output counters */
+            totin += strm.avail_in;
+            totout += strm.avail_out;
+            ret = inflate(&strm, Z_BLOCK);      /* return at end of block */
+            totin -= strm.avail_in;
+            totout -= strm.avail_out;
+            if (ret == Z_NEED_DICT)
+                ret = Z_DATA_ERROR;
+            if (ret == Z_MEM_ERROR || ret == Z_DATA_ERROR)
+                goto build_index_error;
+            if (ret == Z_STREAM_END)
+                break;
+
+            /* if at end of block, consider adding an index entry (note that if
+               data_type indicates an end-of-block, then all of the
+               uncompressed data from that block has been delivered, and none
+               of the compressed data after that block has been consumed,
+               except for up to seven bits) -- the totout == 0 provides an
+               entry point after the zlib or gzip header, and assures that the
+               index always has at least one access point; we avoid creating an
+               access point after the last block by checking bit 6 of data_type
+             */
+            if ((strm.data_type & 128) && !(strm.data_type & 64) &&
+                (totout == 0 || totout - last > span)) {
+                index = addpoint(index, strm.data_type & 7, totin,
+                                 totout, strm.avail_out, window);
+                if (index == NULL) {
+                    ret = Z_MEM_ERROR;
+                    goto build_index_error;
+                }
+                last = totout;
+            }
+        } while (strm.avail_in != 0);
+    } while (ret != Z_STREAM_END);
+
+    /* clean up and return index (release unused entries in list) */
+    (void)inflateEnd(&strm);
+    index->list = realloc(index->list, sizeof(struct point) * index->have);
+    index->size = index->have;
+    *built = index;
+    return index->size;
+
+    /* return error */
+  build_index_error:
+    (void)inflateEnd(&strm);
+    if (index != NULL)
+        free_index(index);
+    return ret;
+}
+
+/* Use the index to read len bytes from offset into buf, return bytes read or
+   negative for error (Z_DATA_ERROR or Z_MEM_ERROR).  If data is requested past
+   the end of the uncompressed data, then extract() will return a value less
+   than len, indicating how much as actually read into buf.  This function
+   should not return a data error unless the file was modified since the index
+   was generated.  extract() may also return Z_ERRNO if there is an error on
+   reading or seeking the input file. */
+local int extract(FILE *in, struct access *index, off_t offset,
+                  unsigned char *buf, int len)
+{
+    int ret, skip;
+    z_stream strm;
+    struct point *here;
+    unsigned char input[CHUNK];
+    unsigned char discard[WINSIZE];
+
+    /* proceed only if something reasonable to do */
+    if (len < 0)
+        return 0;
+
+    /* find where in stream to start */
+    here = index->list;
+    ret = index->have;
+    while (--ret && here[1].out <= offset)
+        here++;
+
+    /* initialize file and inflate state to start there */
+    strm.zalloc = Z_NULL;
+    strm.zfree = Z_NULL;
+    strm.opaque = Z_NULL;
+    strm.avail_in = 0;
+    strm.next_in = Z_NULL;
+    ret = inflateInit2(&strm, -15);         /* raw inflate */
+    if (ret != Z_OK)
+        return ret;
+    ret = fseeko(in, here->in - (here->bits ? 1 : 0), SEEK_SET);
+    if (ret == -1)
+        goto extract_ret;
+    if (here->bits) {
+        ret = getc(in);
+        if (ret == -1) {
+            ret = ferror(in) ? Z_ERRNO : Z_DATA_ERROR;
+            goto extract_ret;
+        }
+        (void)inflatePrime(&strm, here->bits, ret >> (8 - here->bits));
+    }
+    (void)inflateSetDictionary(&strm, here->window, WINSIZE);
+
+    /* skip uncompressed bytes until offset reached, then satisfy request */
+    offset -= here->out;
+    strm.avail_in = 0;
+    skip = 1;                               /* while skipping to offset */
+    do {
+        /* define where to put uncompressed data, and how much */
+        if (offset == 0 && skip) {          /* at offset now */
+            strm.avail_out = len;
+            strm.next_out = buf;
+            skip = 0;                       /* only do this once */
+        }
+        if (offset > WINSIZE) {             /* skip WINSIZE bytes */
+            strm.avail_out = WINSIZE;
+            strm.next_out = discard;
+            offset -= WINSIZE;
+        }
+        else if (offset != 0) {             /* last skip */
+            strm.avail_out = (unsigned)offset;
+            strm.next_out = discard;
+            offset = 0;
+        }
+
+        /* uncompress until avail_out filled, or end of stream */
+        do {
+            if (strm.avail_in == 0) {
+                strm.avail_in = fread(input, 1, CHUNK, in);
+                if (ferror(in)) {
+                    ret = Z_ERRNO;
+                    goto extract_ret;
+                }
+                if (strm.avail_in == 0) {
+                    ret = Z_DATA_ERROR;
+                    goto extract_ret;
+                }
+                strm.next_in = input;
+            }
+            ret = inflate(&strm, Z_NO_FLUSH);       /* normal inflate */
+            if (ret == Z_NEED_DICT)
+                ret = Z_DATA_ERROR;
+            if (ret == Z_MEM_ERROR || ret == Z_DATA_ERROR)
+                goto extract_ret;
+            if (ret == Z_STREAM_END)
+                break;
+        } while (strm.avail_out != 0);
+
+        /* if reach end of stream, then don't keep trying to get more */
+        if (ret == Z_STREAM_END)
+            break;
+
+        /* do until offset reached and requested data read, or stream ends */
+    } while (skip);
+
+    /* compute number of uncompressed bytes read after offset */
+    ret = skip ? 0 : len - strm.avail_out;
+
+    /* clean up and return bytes read or error */
+  extract_ret:
+    (void)inflateEnd(&strm);
+    return ret;
+}
+
+/* Demonstrate the use of build_index() and extract() by processing the file
+   provided on the command line, and the extracting 16K from about 2/3rds of
+   the way through the uncompressed output, and writing that to stdout. */
+int main(int argc, char **argv)
+{
+    int len;
+    off_t offset;
+    FILE *in;
+    struct access *index = NULL;
+    unsigned char buf[CHUNK];
+
+    /* open input file */
+    if (argc != 2) {
+        fprintf(stderr, "usage: zran file.gz\n");
+        return 1;
+    }
+    in = fopen(argv[1], "rb");
+    if (in == NULL) {
+        fprintf(stderr, "zran: could not open %s for reading\n", argv[1]);
+        return 1;
+    }
+
+    /* build index */
+    len = build_index(in, SPAN, &index);
+    if (len < 0) {
+        fclose(in);
+        switch (len) {
+        case Z_MEM_ERROR:
+            fprintf(stderr, "zran: out of memory\n");
+            break;
+        case Z_DATA_ERROR:
+            fprintf(stderr, "zran: compressed data error in %s\n", argv[1]);
+            break;
+        case Z_ERRNO:
+            fprintf(stderr, "zran: read error on %s\n", argv[1]);
+            break;
+        default:
+            fprintf(stderr, "zran: error %d while building index\n", len);
+        }
+        return 1;
+    }
+    fprintf(stderr, "zran: built index with %d access points\n", len);
+
+    /* use index by reading some bytes from an arbitrary offset */
+    offset = (index->list[index->have - 1].out << 1) / 3;
+    len = extract(in, index, offset, buf, CHUNK);
+    if (len < 0)
+        fprintf(stderr, "zran: extraction failed: %s error\n",
+                len == Z_MEM_ERROR ? "out of memory" : "input corrupted");
+    else {
+        fwrite(buf, 1, len, stdout);
+        fprintf(stderr, "zran: extracted %d bytes at %llu\n", len, offset);
+    }
+
+    /* clean up and exit */
+    free_index(index);
+    fclose(in);
+    return 0;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/gzclose.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/gzclose.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,25 @@
+/* gzclose.c -- zlib gzclose() function
+ * Copyright (C) 2004, 2010 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "gzguts.h"
+
+/* gzclose() is in a separate file so that it is linked in only if it is used.
+   That way the other gzclose functions can be used instead to avoid linking in
+   unneeded compression or decompression routines. */
+int ZEXPORT gzclose(file)
+    gzFile file;
+{
+#ifndef NO_GZCOMPRESS
+    gz_statep state;
+
+    if (file == NULL)
+        return Z_STREAM_ERROR;
+    state = (gz_statep)file;
+
+    return state->mode == GZ_READ ? gzclose_r(file) : gzclose_w(file);
+#else
+    return gzclose_r(file);
+#endif
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/gzguts.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/gzguts.h	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,218 @@
+/* gzguts.h -- zlib internal header definitions for gz* operations
+ * Copyright (C) 2004, 2005, 2010, 2011, 2012, 2013, 2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#ifdef _LARGEFILE64_SOURCE
+#  ifndef _LARGEFILE_SOURCE
+#    define _LARGEFILE_SOURCE 1
+#  endif
+#  ifdef _FILE_OFFSET_BITS
+#    undef _FILE_OFFSET_BITS
+#  endif
+#endif
+
+#ifdef HAVE_HIDDEN
+#  define ZLIB_INTERNAL __attribute__((visibility ("hidden")))
+#else
+#  define ZLIB_INTERNAL
+#endif
+
+#include <stdio.h>
+#include "zlib.h"
+#ifdef STDC
+#  include <string.h>
+#  include <stdlib.h>
+#  include <limits.h>
+#endif
+
+#ifndef _POSIX_SOURCE
+#  define _POSIX_SOURCE
+#endif
+#include <fcntl.h>
+
+#ifdef _WIN32
+#  include <stddef.h>
+#endif
+
+#if defined(__TURBOC__) || defined(_MSC_VER) || defined(_WIN32)
+#  include <io.h>
+#endif
+
+#if defined(_WIN32) || defined(__CYGWIN__)
+#  define WIDECHAR
+#endif
+
+#ifdef WINAPI_FAMILY
+#  define open _open
+#  define read _read
+#  define write _write
+#  define close _close
+#endif
+
+#ifdef NO_DEFLATE       /* for compatibility with old definition */
+#  define NO_GZCOMPRESS
+#endif
+
+#if defined(STDC99) || (defined(__TURBOC__) && __TURBOC__ >= 0x550)
+#  ifndef HAVE_VSNPRINTF
+#    define HAVE_VSNPRINTF
+#  endif
+#endif
+
+#if defined(__CYGWIN__)
+#  ifndef HAVE_VSNPRINTF
+#    define HAVE_VSNPRINTF
+#  endif
+#endif
+
+#if defined(MSDOS) && defined(__BORLANDC__) && (BORLANDC > 0x410)
+#  ifndef HAVE_VSNPRINTF
+#    define HAVE_VSNPRINTF
+#  endif
+#endif
+
+#ifndef HAVE_VSNPRINTF
+#  ifdef MSDOS
+/* vsnprintf may exist on some MS-DOS compilers (DJGPP?),
+   but for now we just assume it doesn't. */
+#    define NO_vsnprintf
+#  endif
+#  ifdef __TURBOC__
+#    define NO_vsnprintf
+#  endif
+#  ifdef WIN32
+/* In Win32, vsnprintf is available as the "non-ANSI" _vsnprintf. */
+#    if !defined(vsnprintf) && !defined(NO_vsnprintf)
+#      if !defined(_MSC_VER) || ( defined(_MSC_VER) && _MSC_VER < 1500 )
+#         define vsnprintf _vsnprintf
+#      endif
+#    endif
+#  endif
+#  ifdef __SASC
+#    define NO_vsnprintf
+#  endif
+#  ifdef VMS
+#    define NO_vsnprintf
+#  endif
+#  ifdef __OS400__
+#    define NO_vsnprintf
+#  endif
+#  ifdef __MVS__
+#    define NO_vsnprintf
+#  endif
+#endif
+
+/* unlike snprintf (which is required in C99), _snprintf does not guarantee
+   null termination of the result -- however this is only used in gzlib.c where
+   the result is assured to fit in the space provided */
+#if defined(_MSC_VER) && _MSC_VER < 1900
+#  define snprintf _snprintf
+#endif
+
+#ifndef local
+#  define local static
+#endif
+/* since "static" is used to mean two completely different things in C, we
+   define "local" for the non-static meaning of "static", for readability
+   (compile with -Dlocal if your debugger can't find static symbols) */
+
+/* gz* functions always use library allocation functions */
+#ifndef STDC
+  extern voidp  malloc OF((uInt size));
+  extern void   free   OF((voidpf ptr));
+#endif
+
+/* get errno and strerror definition */
+#if defined UNDER_CE
+#  include <windows.h>
+#  define zstrerror() gz_strwinerror((DWORD)GetLastError())
+#else
+#  ifndef NO_STRERROR
+#    include <errno.h>
+#    define zstrerror() strerror(errno)
+#  else
+#    define zstrerror() "stdio error (consult errno)"
+#  endif
+#endif
+
+/* provide prototypes for these when building zlib without LFS */
+#if !defined(_LARGEFILE64_SOURCE) || _LFS64_LARGEFILE-0 == 0
+    ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
+    ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
+    ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
+    ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
+#endif
+
+/* default memLevel */
+#if MAX_MEM_LEVEL >= 8
+#  define DEF_MEM_LEVEL 8
+#else
+#  define DEF_MEM_LEVEL  MAX_MEM_LEVEL
+#endif
+
+/* default i/o buffer size -- double this for output when reading (this and
+   twice this must be able to fit in an unsigned type) */
+#define GZBUFSIZE 8192
+
+/* gzip modes, also provide a little integrity check on the passed structure */
+#define GZ_NONE 0
+#define GZ_READ 7247
+#define GZ_WRITE 31153
+#define GZ_APPEND 1     /* mode set to GZ_WRITE after the file is opened */
+
+/* values for gz_state how */
+#define LOOK 0      /* look for a gzip header */
+#define COPY 1      /* copy input directly */
+#define GZIP 2      /* decompress a gzip stream */
+
+/* internal gzip file state data structure */
+typedef struct {
+        /* exposed contents for gzgetc() macro */
+    struct gzFile_s x;      /* "x" for exposed */
+                            /* x.have: number of bytes available at x.next */
+                            /* x.next: next output data to deliver or write */
+                            /* x.pos: current position in uncompressed data */
+        /* used for both reading and writing */
+    int mode;               /* see gzip modes above */
+    int fd;                 /* file descriptor */
+    char *path;             /* path or fd for error messages */
+    unsigned size;          /* buffer size, zero if not allocated yet */
+    unsigned want;          /* requested buffer size, default is GZBUFSIZE */
+    unsigned char *in;      /* input buffer (double-sized when writing) */
+    unsigned char *out;     /* output buffer (double-sized when reading) */
+    int direct;             /* 0 if processing gzip, 1 if transparent */
+        /* just for reading */
+    int how;                /* 0: get header, 1: copy, 2: decompress */
+    z_off64_t start;        /* where the gzip data started, for rewinding */
+    int eof;                /* true if end of input file reached */
+    int past;               /* true if read requested past end */
+        /* just for writing */
+    int level;              /* compression level */
+    int strategy;           /* compression strategy */
+        /* seek request */
+    z_off64_t skip;         /* amount to skip (already rewound if backwards) */
+    int seek;               /* true if seek request pending */
+        /* error information */
+    int err;                /* error code */
+    char *msg;              /* error message */
+        /* zlib inflate or deflate stream */
+    z_stream strm;          /* stream structure in-place (not a pointer) */
+} gz_state;
+typedef gz_state FAR *gz_statep;
+
+/* shared functions */
+void ZLIB_INTERNAL gz_error OF((gz_statep, int, const char *));
+#if defined UNDER_CE
+char ZLIB_INTERNAL *gz_strwinerror OF((DWORD error));
+#endif
+
+/* GT_OFF(x), where x is an unsigned value, is true if x > maximum z_off64_t
+   value -- needed when comparing unsigned to z_off64_t, which is signed
+   (possible z_off64_t types off_t, off64_t, and long are all signed) */
+#ifdef INT_MAX
+#  define GT_OFF(x) (sizeof(int) == sizeof(z_off64_t) && (x) > INT_MAX)
+#else
+unsigned ZLIB_INTERNAL gz_intmax OF((void));
+#  define GT_OFF(x) (sizeof(int) == sizeof(z_off64_t) && (x) > gz_intmax())
+#endif
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/gzlib.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/gzlib.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,637 @@
+/* gzlib.c -- zlib functions common to reading and writing gzip files
+ * Copyright (C) 2004-2017 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "gzguts.h"
+
+#if defined(_WIN32) && !defined(__BORLANDC__) && !defined(__MINGW32__)
+#  define LSEEK _lseeki64
+#else
+#if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0
+#  define LSEEK lseek64
+#else
+#  define LSEEK lseek
+#endif
+#endif
+
+/* Local functions */
+local void gz_reset OF((gz_statep));
+local gzFile gz_open OF((const void *, int, const char *));
+
+#if defined UNDER_CE
+
+/* Map the Windows error number in ERROR to a locale-dependent error message
+   string and return a pointer to it.  Typically, the values for ERROR come
+   from GetLastError.
+
+   The string pointed to shall not be modified by the application, but may be
+   overwritten by a subsequent call to gz_strwinerror
+
+   The gz_strwinerror function does not change the current setting of
+   GetLastError. */
+char ZLIB_INTERNAL *gz_strwinerror (error)
+     DWORD error;
+{
+    static char buf[1024];
+
+    wchar_t *msgbuf;
+    DWORD lasterr = GetLastError();
+    DWORD chars = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM
+        | FORMAT_MESSAGE_ALLOCATE_BUFFER,
+        NULL,
+        error,
+        0, /* Default language */
+        (LPVOID)&msgbuf,
+        0,
+        NULL);
+    if (chars != 0) {
+        /* If there is an \r\n appended, zap it.  */
+        if (chars >= 2
+            && msgbuf[chars - 2] == '\r' && msgbuf[chars - 1] == '\n') {
+            chars -= 2;
+            msgbuf[chars] = 0;
+        }
+
+        if (chars > sizeof (buf) - 1) {
+            chars = sizeof (buf) - 1;
+            msgbuf[chars] = 0;
+        }
+
+        wcstombs(buf, msgbuf, chars + 1);
+        LocalFree(msgbuf);
+    }
+    else {
+        sprintf(buf, "unknown win32 error (%ld)", error);
+    }
+
+    SetLastError(lasterr);
+    return buf;
+}
+
+#endif /* UNDER_CE */
+
+/* Reset gzip file state */
+local void gz_reset(state)
+    gz_statep state;
+{
+    state->x.have = 0;              /* no output data available */
+    if (state->mode == GZ_READ) {   /* for reading ... */
+        state->eof = 0;             /* not at end of file */
+        state->past = 0;            /* have not read past end yet */
+        state->how = LOOK;          /* look for gzip header */
+    }
+    state->seek = 0;                /* no seek request pending */
+    gz_error(state, Z_OK, NULL);    /* clear error */
+    state->x.pos = 0;               /* no uncompressed data yet */
+    state->strm.avail_in = 0;       /* no input data yet */
+}
+
+/* Open a gzip file either by name or file descriptor. */
+local gzFile gz_open(path, fd, mode)
+    const void *path;
+    int fd;
+    const char *mode;
+{
+    gz_statep state;
+    z_size_t len;
+    int oflag;
+#ifdef O_CLOEXEC
+    int cloexec = 0;
+#endif
+#ifdef O_EXCL
+    int exclusive = 0;
+#endif
+
+    /* check input */
+    if (path == NULL)
+        return NULL;
+
+    /* allocate gzFile structure to return */
+    state = (gz_statep)malloc(sizeof(gz_state));
+    if (state == NULL)
+        return NULL;
+    state->size = 0;            /* no buffers allocated yet */
+    state->want = GZBUFSIZE;    /* requested buffer size */
+    state->msg = NULL;          /* no error message yet */
+
+    /* interpret mode */
+    state->mode = GZ_NONE;
+    state->level = Z_DEFAULT_COMPRESSION;
+    state->strategy = Z_DEFAULT_STRATEGY;
+    state->direct = 0;
+    while (*mode) {
+        if (*mode >= '0' && *mode <= '9')
+            state->level = *mode - '0';
+        else
+            switch (*mode) {
+            case 'r':
+                state->mode = GZ_READ;
+                break;
+#ifndef NO_GZCOMPRESS
+            case 'w':
+                state->mode = GZ_WRITE;
+                break;
+            case 'a':
+                state->mode = GZ_APPEND;
+                break;
+#endif
+            case '+':       /* can't read and write at the same time */
+                free(state);
+                return NULL;
+            case 'b':       /* ignore -- will request binary anyway */
+                break;
+#ifdef O_CLOEXEC
+            case 'e':
+                cloexec = 1;
+                break;
+#endif
+#ifdef O_EXCL
+            case 'x':
+                exclusive = 1;
+                break;
+#endif
+            case 'f':
+                state->strategy = Z_FILTERED;
+                break;
+            case 'h':
+                state->strategy = Z_HUFFMAN_ONLY;
+                break;
+            case 'R':
+                state->strategy = Z_RLE;
+                break;
+            case 'F':
+                state->strategy = Z_FIXED;
+                break;
+            case 'T':
+                state->direct = 1;
+                break;
+            default:        /* could consider as an error, but just ignore */
+                ;
+            }
+        mode++;
+    }
+
+    /* must provide an "r", "w", or "a" */
+    if (state->mode == GZ_NONE) {
+        free(state);
+        return NULL;
+    }
+
+    /* can't force transparent read */
+    if (state->mode == GZ_READ) {
+        if (state->direct) {
+            free(state);
+            return NULL;
+        }
+        state->direct = 1;      /* for empty file */
+    }
+
+    /* save the path name for error messages */
+#ifdef WIDECHAR
+    if (fd == -2) {
+        len = wcstombs(NULL, path, 0);
+        if (len == (z_size_t)-1)
+            len = 0;
+    }
+    else
+#endif
+        len = strlen((const char *)path);
+    state->path = (char *)malloc(len + 1);
+    if (state->path == NULL) {
+        free(state);
+        return NULL;
+    }
+#ifdef WIDECHAR
+    if (fd == -2)
+        if (len)
+            wcstombs(state->path, path, len + 1);
+        else
+            *(state->path) = 0;
+    else
+#endif
+#if !defined(NO_snprintf) && !defined(NO_vsnprintf)
+        (void)snprintf(state->path, len + 1, "%s", (const char *)path);
+#else
+        strcpy(state->path, path);
+#endif
+
+    /* compute the flags for open() */
+    oflag =
+#ifdef O_LARGEFILE
+        O_LARGEFILE |
+#endif
+#ifdef O_BINARY
+        O_BINARY |
+#endif
+#ifdef O_CLOEXEC
+        (cloexec ? O_CLOEXEC : 0) |
+#endif
+        (state->mode == GZ_READ ?
+         O_RDONLY :
+         (O_WRONLY | O_CREAT |
+#ifdef O_EXCL
+          (exclusive ? O_EXCL : 0) |
+#endif
+          (state->mode == GZ_WRITE ?
+           O_TRUNC :
+           O_APPEND)));
+
+    /* open the file with the appropriate flags (or just use fd) */
+    state->fd = fd > -1 ? fd : (
+#ifdef WIDECHAR
+        fd == -2 ? _wopen(path, oflag, 0666) :
+#endif
+        open((const char *)path, oflag, 0666));
+    if (state->fd == -1) {
+        free(state->path);
+        free(state);
+        return NULL;
+    }
+    if (state->mode == GZ_APPEND) {
+        LSEEK(state->fd, 0, SEEK_END);  /* so gzoffset() is correct */
+        state->mode = GZ_WRITE;         /* simplify later checks */
+    }
+
+    /* save the current position for rewinding (only if reading) */
+    if (state->mode == GZ_READ) {
+        state->start = LSEEK(state->fd, 0, SEEK_CUR);
+        if (state->start == -1) state->start = 0;
+    }
+
+    /* initialize stream */
+    gz_reset(state);
+
+    /* return stream */
+    return (gzFile)state;
+}
+
+/* -- see zlib.h -- */
+gzFile ZEXPORT gzopen(path, mode)
+    const char *path;
+    const char *mode;
+{
+    return gz_open(path, -1, mode);
+}
+
+/* -- see zlib.h -- */
+gzFile ZEXPORT gzopen64(path, mode)
+    const char *path;
+    const char *mode;
+{
+    return gz_open(path, -1, mode);
+}
+
+/* -- see zlib.h -- */
+gzFile ZEXPORT gzdopen(fd, mode)
+    int fd;
+    const char *mode;
+{
+    char *path;         /* identifier for error messages */
+    gzFile gz;
+
+    if (fd == -1 || (path = (char *)malloc(7 + 3 * sizeof(int))) == NULL)
+        return NULL;
+#if !defined(NO_snprintf) && !defined(NO_vsnprintf)
+    (void)snprintf(path, 7 + 3 * sizeof(int), "<fd:%d>", fd);
+#else
+    sprintf(path, "<fd:%d>", fd);   /* for debugging */
+#endif
+    gz = gz_open(path, fd, mode);
+    free(path);
+    return gz;
+}
+
+/* -- see zlib.h -- */
+#ifdef WIDECHAR
+gzFile ZEXPORT gzopen_w(path, mode)
+    const wchar_t *path;
+    const char *mode;
+{
+    return gz_open(path, -2, mode);
+}
+#endif
+
+/* -- see zlib.h -- */
+int ZEXPORT gzbuffer(file, size)
+    gzFile file;
+    unsigned size;
+{
+    gz_statep state;
+
+    /* get internal structure and check integrity */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
+        return -1;
+
+    /* make sure we haven't already allocated memory */
+    if (state->size != 0)
+        return -1;
+
+    /* check and set requested size */
+    if ((size << 1) < size)
+        return -1;              /* need to be able to double it */
+    if (size < 2)
+        size = 2;               /* need two bytes to check magic header */
+    state->want = size;
+    return 0;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzrewind(file)
+    gzFile file;
+{
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+
+    /* check that we're reading and that there's no error */
+    if (state->mode != GZ_READ ||
+            (state->err != Z_OK && state->err != Z_BUF_ERROR))
+        return -1;
+
+    /* back up and start over */
+    if (LSEEK(state->fd, state->start, SEEK_SET) == -1)
+        return -1;
+    gz_reset(state);
+    return 0;
+}
+
+/* -- see zlib.h -- */
+z_off64_t ZEXPORT gzseek64(file, offset, whence)
+    gzFile file;
+    z_off64_t offset;
+    int whence;
+{
+    unsigned n;
+    z_off64_t ret;
+    gz_statep state;
+
+    /* get internal structure and check integrity */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
+        return -1;
+
+    /* check that there's no error */
+    if (state->err != Z_OK && state->err != Z_BUF_ERROR)
+        return -1;
+
+    /* can only seek from start or relative to current position */
+    if (whence != SEEK_SET && whence != SEEK_CUR)
+        return -1;
+
+    /* normalize offset to a SEEK_CUR specification */
+    if (whence == SEEK_SET)
+        offset -= state->x.pos;
+    else if (state->seek)
+        offset += state->skip;
+    state->seek = 0;
+
+    /* if within raw area while reading, just go there */
+    if (state->mode == GZ_READ && state->how == COPY &&
+            state->x.pos + offset >= 0) {
+        ret = LSEEK(state->fd, offset - state->x.have, SEEK_CUR);
+        if (ret == -1)
+            return -1;
+        state->x.have = 0;
+        state->eof = 0;
+        state->past = 0;
+        state->seek = 0;
+        gz_error(state, Z_OK, NULL);
+        state->strm.avail_in = 0;
+        state->x.pos += offset;
+        return state->x.pos;
+    }
+
+    /* calculate skip amount, rewinding if needed for back seek when reading */
+    if (offset < 0) {
+        if (state->mode != GZ_READ)         /* writing -- can't go backwards */
+            return -1;
+        offset += state->x.pos;
+        if (offset < 0)                     /* before start of file! */
+            return -1;
+        if (gzrewind(file) == -1)           /* rewind, then skip to offset */
+            return -1;
+    }
+
+    /* if reading, skip what's in output buffer (one less gzgetc() check) */
+    if (state->mode == GZ_READ) {
+        n = GT_OFF(state->x.have) || (z_off64_t)state->x.have > offset ?
+            (unsigned)offset : state->x.have;
+        state->x.have -= n;
+        state->x.next += n;
+        state->x.pos += n;
+        offset -= n;
+    }
+
+    /* request skip (if not zero) */
+    if (offset) {
+        state->seek = 1;
+        state->skip = offset;
+    }
+    return state->x.pos + offset;
+}
+
+/* -- see zlib.h -- */
+z_off_t ZEXPORT gzseek(file, offset, whence)
+    gzFile file;
+    z_off_t offset;
+    int whence;
+{
+    z_off64_t ret;
+
+    ret = gzseek64(file, (z_off64_t)offset, whence);
+    return ret == (z_off_t)ret ? (z_off_t)ret : -1;
+}
+
+/* -- see zlib.h -- */
+z_off64_t ZEXPORT gztell64(file)
+    gzFile file;
+{
+    gz_statep state;
+
+    /* get internal structure and check integrity */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
+        return -1;
+
+    /* return position */
+    return state->x.pos + (state->seek ? state->skip : 0);
+}
+
+/* -- see zlib.h -- */
+z_off_t ZEXPORT gztell(file)
+    gzFile file;
+{
+    z_off64_t ret;
+
+    ret = gztell64(file);
+    return ret == (z_off_t)ret ? (z_off_t)ret : -1;
+}
+
+/* -- see zlib.h -- */
+z_off64_t ZEXPORT gzoffset64(file)
+    gzFile file;
+{
+    z_off64_t offset;
+    gz_statep state;
+
+    /* get internal structure and check integrity */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
+        return -1;
+
+    /* compute and return effective offset in file */
+    offset = LSEEK(state->fd, 0, SEEK_CUR);
+    if (offset == -1)
+        return -1;
+    if (state->mode == GZ_READ)             /* reading */
+        offset -= state->strm.avail_in;     /* don't count buffered input */
+    return offset;
+}
+
+/* -- see zlib.h -- */
+z_off_t ZEXPORT gzoffset(file)
+    gzFile file;
+{
+    z_off64_t ret;
+
+    ret = gzoffset64(file);
+    return ret == (z_off_t)ret ? (z_off_t)ret : -1;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzeof(file)
+    gzFile file;
+{
+    gz_statep state;
+
+    /* get internal structure and check integrity */
+    if (file == NULL)
+        return 0;
+    state = (gz_statep)file;
+    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
+        return 0;
+
+    /* return end-of-file state */
+    return state->mode == GZ_READ ? state->past : 0;
+}
+
+/* -- see zlib.h -- */
+const char * ZEXPORT gzerror(file, errnum)
+    gzFile file;
+    int *errnum;
+{
+    gz_statep state;
+
+    /* get internal structure and check integrity */
+    if (file == NULL)
+        return NULL;
+    state = (gz_statep)file;
+    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
+        return NULL;
+
+    /* return error information */
+    if (errnum != NULL)
+        *errnum = state->err;
+    return state->err == Z_MEM_ERROR ? "out of memory" :
+                                       (state->msg == NULL ? "" : state->msg);
+}
+
+/* -- see zlib.h -- */
+void ZEXPORT gzclearerr(file)
+    gzFile file;
+{
+    gz_statep state;
+
+    /* get internal structure and check integrity */
+    if (file == NULL)
+        return;
+    state = (gz_statep)file;
+    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
+        return;
+
+    /* clear error and end-of-file */
+    if (state->mode == GZ_READ) {
+        state->eof = 0;
+        state->past = 0;
+    }
+    gz_error(state, Z_OK, NULL);
+}
+
+/* Create an error message in allocated memory and set state->err and
+   state->msg accordingly.  Free any previous error message already there.  Do
+   not try to free or allocate space if the error is Z_MEM_ERROR (out of
+   memory).  Simply save the error message as a static string.  If there is an
+   allocation failure constructing the error message, then convert the error to
+   out of memory. */
+void ZLIB_INTERNAL gz_error(state, err, msg)
+    gz_statep state;
+    int err;
+    const char *msg;
+{
+    /* free previously allocated message and clear */
+    if (state->msg != NULL) {
+        if (state->err != Z_MEM_ERROR)
+            free(state->msg);
+        state->msg = NULL;
+    }
+
+    /* if fatal, set state->x.have to 0 so that the gzgetc() macro fails */
+    if (err != Z_OK && err != Z_BUF_ERROR)
+        state->x.have = 0;
+
+    /* set error code, and if no message, then done */
+    state->err = err;
+    if (msg == NULL)
+        return;
+
+    /* for an out of memory error, return literal string when requested */
+    if (err == Z_MEM_ERROR)
+        return;
+
+    /* construct error message with path */
+    if ((state->msg = (char *)malloc(strlen(state->path) + strlen(msg) + 3)) ==
+            NULL) {
+        state->err = Z_MEM_ERROR;
+        return;
+    }
+#if !defined(NO_snprintf) && !defined(NO_vsnprintf)
+    (void)snprintf(state->msg, strlen(state->path) + strlen(msg) + 3,
+                   "%s%s%s", state->path, ": ", msg);
+#else
+    strcpy(state->msg, state->path);
+    strcat(state->msg, ": ");
+    strcat(state->msg, msg);
+#endif
+}
+
+#ifndef INT_MAX
+/* portably return maximum value for an int (when limits.h presumed not
+   available) -- we need to do this to cover cases where 2's complement not
+   used, since C standard permits 1's complement and sign-bit representations,
+   otherwise we could just use ((unsigned)-1) >> 1 */
+unsigned ZLIB_INTERNAL gz_intmax()
+{
+    unsigned p, q;
+
+    p = 1;
+    do {
+        q = p;
+        p <<= 1;
+        p++;
+    } while (p > q);
+    return q >> 1;
+}
+#endif
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/gzread.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/gzread.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,654 @@
+/* gzread.c -- zlib functions for reading gzip files
+ * Copyright (C) 2004, 2005, 2010, 2011, 2012, 2013, 2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "gzguts.h"
+
+/* Local functions */
+local int gz_load OF((gz_statep, unsigned char *, unsigned, unsigned *));
+local int gz_avail OF((gz_statep));
+local int gz_look OF((gz_statep));
+local int gz_decomp OF((gz_statep));
+local int gz_fetch OF((gz_statep));
+local int gz_skip OF((gz_statep, z_off64_t));
+local z_size_t gz_read OF((gz_statep, voidp, z_size_t));
+
+/* Use read() to load a buffer -- return -1 on error, otherwise 0.  Read from
+   state->fd, and update state->eof, state->err, and state->msg as appropriate.
+   This function needs to loop on read(), since read() is not guaranteed to
+   read the number of bytes requested, depending on the type of descriptor. */
+local int gz_load(state, buf, len, have)
+    gz_statep state;
+    unsigned char *buf;
+    unsigned len;
+    unsigned *have;
+{
+    int ret;
+    unsigned get, max = ((unsigned)-1 >> 2) + 1;
+
+    *have = 0;
+    do {
+        get = len - *have;
+        if (get > max)
+            get = max;
+        ret = read(state->fd, buf + *have, get);
+        if (ret <= 0)
+            break;
+        *have += (unsigned)ret;
+    } while (*have < len);
+    if (ret < 0) {
+        gz_error(state, Z_ERRNO, zstrerror());
+        return -1;
+    }
+    if (ret == 0)
+        state->eof = 1;
+    return 0;
+}
+
+/* Load up input buffer and set eof flag if last data loaded -- return -1 on
+   error, 0 otherwise.  Note that the eof flag is set when the end of the input
+   file is reached, even though there may be unused data in the buffer.  Once
+   that data has been used, no more attempts will be made to read the file.
+   If strm->avail_in != 0, then the current data is moved to the beginning of
+   the input buffer, and then the remainder of the buffer is loaded with the
+   available data from the input file. */
+local int gz_avail(state)
+    gz_statep state;
+{
+    unsigned got;
+    z_streamp strm = &(state->strm);
+
+    if (state->err != Z_OK && state->err != Z_BUF_ERROR)
+        return -1;
+    if (state->eof == 0) {
+        if (strm->avail_in) {       /* copy what's there to the start */
+            unsigned char *p = state->in;
+            unsigned const char *q = strm->next_in;
+            unsigned n = strm->avail_in;
+            do {
+                *p++ = *q++;
+            } while (--n);
+        }
+        if (gz_load(state, state->in + strm->avail_in,
+                    state->size - strm->avail_in, &got) == -1)
+            return -1;
+        strm->avail_in += got;
+        strm->next_in = state->in;
+    }
+    return 0;
+}
+
+/* Look for gzip header, set up for inflate or copy.  state->x.have must be 0.
+   If this is the first time in, allocate required memory.  state->how will be
+   left unchanged if there is no more input data available, will be set to COPY
+   if there is no gzip header and direct copying will be performed, or it will
+   be set to GZIP for decompression.  If direct copying, then leftover input
+   data from the input buffer will be copied to the output buffer.  In that
+   case, all further file reads will be directly to either the output buffer or
+   a user buffer.  If decompressing, the inflate state will be initialized.
+   gz_look() will return 0 on success or -1 on failure. */
+local int gz_look(state)
+    gz_statep state;
+{
+    z_streamp strm = &(state->strm);
+
+    /* allocate read buffers and inflate memory */
+    if (state->size == 0) {
+        /* allocate buffers */
+        state->in = (unsigned char *)malloc(state->want);
+        state->out = (unsigned char *)malloc(state->want << 1);
+        if (state->in == NULL || state->out == NULL) {
+            free(state->out);
+            free(state->in);
+            gz_error(state, Z_MEM_ERROR, "out of memory");
+            return -1;
+        }
+        state->size = state->want;
+
+        /* allocate inflate memory */
+        state->strm.zalloc = Z_NULL;
+        state->strm.zfree = Z_NULL;
+        state->strm.opaque = Z_NULL;
+        state->strm.avail_in = 0;
+        state->strm.next_in = Z_NULL;
+        if (inflateInit2(&(state->strm), 15 + 16) != Z_OK) {    /* gunzip */
+            free(state->out);
+            free(state->in);
+            state->size = 0;
+            gz_error(state, Z_MEM_ERROR, "out of memory");
+            return -1;
+        }
+    }
+
+    /* get at least the magic bytes in the input buffer */
+    if (strm->avail_in < 2) {
+        if (gz_avail(state) == -1)
+            return -1;
+        if (strm->avail_in == 0)
+            return 0;
+    }
+
+    /* look for gzip magic bytes -- if there, do gzip decoding (note: there is
+       a logical dilemma here when considering the case of a partially written
+       gzip file, to wit, if a single 31 byte is written, then we cannot tell
+       whether this is a single-byte file, or just a partially written gzip
+       file -- for here we assume that if a gzip file is being written, then
+       the header will be written in a single operation, so that reading a
+       single byte is sufficient indication that it is not a gzip file) */
+    if (strm->avail_in > 1 &&
+            strm->next_in[0] == 31 && strm->next_in[1] == 139) {
+        inflateReset(strm);
+        state->how = GZIP;
+        state->direct = 0;
+        return 0;
+    }
+
+    /* no gzip header -- if we were decoding gzip before, then this is trailing
+       garbage.  Ignore the trailing garbage and finish. */
+    if (state->direct == 0) {
+        strm->avail_in = 0;
+        state->eof = 1;
+        state->x.have = 0;
+        return 0;
+    }
+
+    /* doing raw i/o, copy any leftover input to output -- this assumes that
+       the output buffer is larger than the input buffer, which also assures
+       space for gzungetc() */
+    state->x.next = state->out;
+    if (strm->avail_in) {
+        memcpy(state->x.next, strm->next_in, strm->avail_in);
+        state->x.have = strm->avail_in;
+        strm->avail_in = 0;
+    }
+    state->how = COPY;
+    state->direct = 1;
+    return 0;
+}
+
+/* Decompress from input to the provided next_out and avail_out in the state.
+   On return, state->x.have and state->x.next point to the just decompressed
+   data.  If the gzip stream completes, state->how is reset to LOOK to look for
+   the next gzip stream or raw data, once state->x.have is depleted.  Returns 0
+   on success, -1 on failure. */
+local int gz_decomp(state)
+    gz_statep state;
+{
+    int ret = Z_OK;
+    unsigned had;
+    z_streamp strm = &(state->strm);
+
+    /* fill output buffer up to end of deflate stream */
+    had = strm->avail_out;
+    do {
+        /* get more input for inflate() */
+        if (strm->avail_in == 0 && gz_avail(state) == -1)
+            return -1;
+        if (strm->avail_in == 0) {
+            gz_error(state, Z_BUF_ERROR, "unexpected end of file");
+            break;
+        }
+
+        /* decompress and handle errors */
+        ret = inflate(strm, Z_NO_FLUSH);
+        if (ret == Z_STREAM_ERROR || ret == Z_NEED_DICT) {
+            gz_error(state, Z_STREAM_ERROR,
+                     "internal error: inflate stream corrupt");
+            return -1;
+        }
+        if (ret == Z_MEM_ERROR) {
+            gz_error(state, Z_MEM_ERROR, "out of memory");
+            return -1;
+        }
+        if (ret == Z_DATA_ERROR) {              /* deflate stream invalid */
+            gz_error(state, Z_DATA_ERROR,
+                     strm->msg == NULL ? "compressed data error" : strm->msg);
+            return -1;
+        }
+    } while (strm->avail_out && ret != Z_STREAM_END);
+
+    /* update available output */
+    state->x.have = had - strm->avail_out;
+    state->x.next = strm->next_out - state->x.have;
+
+    /* if the gzip stream completed successfully, look for another */
+    if (ret == Z_STREAM_END)
+        state->how = LOOK;
+
+    /* good decompression */
+    return 0;
+}
+
+/* Fetch data and put it in the output buffer.  Assumes state->x.have is 0.
+   Data is either copied from the input file or decompressed from the input
+   file depending on state->how.  If state->how is LOOK, then a gzip header is
+   looked for to determine whether to copy or decompress.  Returns -1 on error,
+   otherwise 0.  gz_fetch() will leave state->how as COPY or GZIP unless the
+   end of the input file has been reached and all data has been processed.  */
+local int gz_fetch(state)
+    gz_statep state;
+{
+    z_streamp strm = &(state->strm);
+
+    do {
+        switch(state->how) {
+        case LOOK:      /* -> LOOK, COPY (only if never GZIP), or GZIP */
+            if (gz_look(state) == -1)
+                return -1;
+            if (state->how == LOOK)
+                return 0;
+            break;
+        case COPY:      /* -> COPY */
+            if (gz_load(state, state->out, state->size << 1, &(state->x.have))
+                    == -1)
+                return -1;
+            state->x.next = state->out;
+            return 0;
+        case GZIP:      /* -> GZIP or LOOK (if end of gzip stream) */
+            strm->avail_out = state->size << 1;
+            strm->next_out = state->out;
+            if (gz_decomp(state) == -1)
+                return -1;
+        }
+    } while (state->x.have == 0 && (!state->eof || strm->avail_in));
+    return 0;
+}
+
+/* Skip len uncompressed bytes of output.  Return -1 on error, 0 on success. */
+local int gz_skip(state, len)
+    gz_statep state;
+    z_off64_t len;
+{
+    unsigned n;
+
+    /* skip over len bytes or reach end-of-file, whichever comes first */
+    while (len)
+        /* skip over whatever is in output buffer */
+        if (state->x.have) {
+            n = GT_OFF(state->x.have) || (z_off64_t)state->x.have > len ?
+                (unsigned)len : state->x.have;
+            state->x.have -= n;
+            state->x.next += n;
+            state->x.pos += n;
+            len -= n;
+        }
+
+        /* output buffer empty -- return if we're at the end of the input */
+        else if (state->eof && state->strm.avail_in == 0)
+            break;
+
+        /* need more data to skip -- load up output buffer */
+        else {
+            /* get more output, looking for header if required */
+            if (gz_fetch(state) == -1)
+                return -1;
+        }
+    return 0;
+}
+
+/* Read len bytes into buf from file, or less than len up to the end of the
+   input.  Return the number of bytes read.  If zero is returned, either the
+   end of file was reached, or there was an error.  state->err must be
+   consulted in that case to determine which. */
+local z_size_t gz_read(state, buf, len)
+    gz_statep state;
+    voidp buf;
+    z_size_t len;
+{
+    z_size_t got;
+    unsigned n;
+
+    /* if len is zero, avoid unnecessary operations */
+    if (len == 0)
+        return 0;
+
+    /* process a skip request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_skip(state, state->skip) == -1)
+            return 0;
+    }
+
+    /* get len bytes to buf, or less than len if at the end */
+    got = 0;
+    do {
+        /* set n to the maximum amount of len that fits in an unsigned int */
+        n = -1;
+        if (n > len)
+            n = len;
+
+        /* first just try copying data from the output buffer */
+        if (state->x.have) {
+            if (state->x.have < n)
+                n = state->x.have;
+            memcpy(buf, state->x.next, n);
+            state->x.next += n;
+            state->x.have -= n;
+        }
+
+        /* output buffer empty -- return if we're at the end of the input */
+        else if (state->eof && state->strm.avail_in == 0) {
+            state->past = 1;        /* tried to read past end */
+            break;
+        }
+
+        /* need output data -- for small len or new stream load up our output
+           buffer */
+        else if (state->how == LOOK || n < (state->size << 1)) {
+            /* get more output, looking for header if required */
+            if (gz_fetch(state) == -1)
+                return 0;
+            continue;       /* no progress yet -- go back to copy above */
+            /* the copy above assures that we will leave with space in the
+               output buffer, allowing at least one gzungetc() to succeed */
+        }
+
+        /* large len -- read directly into user buffer */
+        else if (state->how == COPY) {      /* read directly */
+            if (gz_load(state, (unsigned char *)buf, n, &n) == -1)
+                return 0;
+        }
+
+        /* large len -- decompress directly into user buffer */
+        else {  /* state->how == GZIP */
+            state->strm.avail_out = n;
+            state->strm.next_out = (unsigned char *)buf;
+            if (gz_decomp(state) == -1)
+                return 0;
+            n = state->x.have;
+            state->x.have = 0;
+        }
+
+        /* update progress */
+        len -= n;
+        buf = (char *)buf + n;
+        got += n;
+        state->x.pos += n;
+    } while (len);
+
+    /* return number of bytes read into user buffer */
+    return got;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzread(file, buf, len)
+    gzFile file;
+    voidp buf;
+    unsigned len;
+{
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+
+    /* check that we're reading and that there's no (serious) error */
+    if (state->mode != GZ_READ ||
+            (state->err != Z_OK && state->err != Z_BUF_ERROR))
+        return -1;
+
+    /* since an int is returned, make sure len fits in one, otherwise return
+       with an error (this avoids a flaw in the interface) */
+    if ((int)len < 0) {
+        gz_error(state, Z_STREAM_ERROR, "request does not fit in an int");
+        return -1;
+    }
+
+    /* read len or fewer bytes to buf */
+    len = gz_read(state, buf, len);
+
+    /* check for an error */
+    if (len == 0 && state->err != Z_OK && state->err != Z_BUF_ERROR)
+        return -1;
+
+    /* return the number of bytes read (this is assured to fit in an int) */
+    return (int)len;
+}
+
+/* -- see zlib.h -- */
+z_size_t ZEXPORT gzfread(buf, size, nitems, file)
+    voidp buf;
+    z_size_t size;
+    z_size_t nitems;
+    gzFile file;
+{
+    z_size_t len;
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return 0;
+    state = (gz_statep)file;
+
+    /* check that we're reading and that there's no (serious) error */
+    if (state->mode != GZ_READ ||
+            (state->err != Z_OK && state->err != Z_BUF_ERROR))
+        return 0;
+
+    /* compute bytes to read -- error on overflow */
+    len = nitems * size;
+    if (size && len / size != nitems) {
+        gz_error(state, Z_STREAM_ERROR, "request does not fit in a size_t");
+        return 0;
+    }
+
+    /* read len or fewer bytes to buf, return the number of full items read */
+    return len ? gz_read(state, buf, len) / size : 0;
+}
+
+/* -- see zlib.h -- */
+#ifdef Z_PREFIX_SET
+#  undef z_gzgetc
+#else
+#  undef gzgetc
+#endif
+int ZEXPORT gzgetc(file)
+    gzFile file;
+{
+    int ret;
+    unsigned char buf[1];
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+
+    /* check that we're reading and that there's no (serious) error */
+    if (state->mode != GZ_READ ||
+        (state->err != Z_OK && state->err != Z_BUF_ERROR))
+        return -1;
+
+    /* try output buffer (no need to check for skip request) */
+    if (state->x.have) {
+        state->x.have--;
+        state->x.pos++;
+        return *(state->x.next)++;
+    }
+
+    /* nothing there -- try gz_read() */
+    ret = gz_read(state, buf, 1);
+    return ret < 1 ? -1 : buf[0];
+}
+
+int ZEXPORT gzgetc_(file)
+gzFile file;
+{
+    return gzgetc(file);
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzungetc(c, file)
+    int c;
+    gzFile file;
+{
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+
+    /* check that we're reading and that there's no (serious) error */
+    if (state->mode != GZ_READ ||
+        (state->err != Z_OK && state->err != Z_BUF_ERROR))
+        return -1;
+
+    /* process a skip request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_skip(state, state->skip) == -1)
+            return -1;
+    }
+
+    /* can't push EOF */
+    if (c < 0)
+        return -1;
+
+    /* if output buffer empty, put byte at end (allows more pushing) */
+    if (state->x.have == 0) {
+        state->x.have = 1;
+        state->x.next = state->out + (state->size << 1) - 1;
+        state->x.next[0] = (unsigned char)c;
+        state->x.pos--;
+        state->past = 0;
+        return c;
+    }
+
+    /* if no room, give up (must have already done a gzungetc()) */
+    if (state->x.have == (state->size << 1)) {
+        gz_error(state, Z_DATA_ERROR, "out of room to push characters");
+        return -1;
+    }
+
+    /* slide output data if needed and insert byte before existing data */
+    if (state->x.next == state->out) {
+        unsigned char *src = state->out + state->x.have;
+        unsigned char *dest = state->out + (state->size << 1);
+        while (src > state->out)
+            *--dest = *--src;
+        state->x.next = dest;
+    }
+    state->x.have++;
+    state->x.next--;
+    state->x.next[0] = (unsigned char)c;
+    state->x.pos--;
+    state->past = 0;
+    return c;
+}
+
+/* -- see zlib.h -- */
+char * ZEXPORT gzgets(file, buf, len)
+    gzFile file;
+    char *buf;
+    int len;
+{
+    unsigned left, n;
+    char *str;
+    unsigned char *eol;
+    gz_statep state;
+
+    /* check parameters and get internal structure */
+    if (file == NULL || buf == NULL || len < 1)
+        return NULL;
+    state = (gz_statep)file;
+
+    /* check that we're reading and that there's no (serious) error */
+    if (state->mode != GZ_READ ||
+        (state->err != Z_OK && state->err != Z_BUF_ERROR))
+        return NULL;
+
+    /* process a skip request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_skip(state, state->skip) == -1)
+            return NULL;
+    }
+
+    /* copy output bytes up to new line or len - 1, whichever comes first --
+       append a terminating zero to the string (we don't check for a zero in
+       the contents, let the user worry about that) */
+    str = buf;
+    left = (unsigned)len - 1;
+    if (left) do {
+        /* assure that something is in the output buffer */
+        if (state->x.have == 0 && gz_fetch(state) == -1)
+            return NULL;                /* error */
+        if (state->x.have == 0) {       /* end of file */
+            state->past = 1;            /* read past end */
+            break;                      /* return what we have */
+        }
+
+        /* look for end-of-line in current output buffer */
+        n = state->x.have > left ? left : state->x.have;
+        eol = (unsigned char *)memchr(state->x.next, '\n', n);
+        if (eol != NULL)
+            n = (unsigned)(eol - state->x.next) + 1;
+
+        /* copy through end-of-line, or remainder if not found */
+        memcpy(buf, state->x.next, n);
+        state->x.have -= n;
+        state->x.next += n;
+        state->x.pos += n;
+        left -= n;
+        buf += n;
+    } while (left && eol == NULL);
+
+    /* return terminated string, or if nothing, end of file */
+    if (buf == str)
+        return NULL;
+    buf[0] = 0;
+    return str;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzdirect(file)
+    gzFile file;
+{
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return 0;
+    state = (gz_statep)file;
+
+    /* if the state is not known, but we can find out, then do so (this is
+       mainly for right after a gzopen() or gzdopen()) */
+    if (state->mode == GZ_READ && state->how == LOOK && state->x.have == 0)
+        (void)gz_look(state);
+
+    /* return 1 if transparent, 0 if processing a gzip stream */
+    return state->direct;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzclose_r(file)
+    gzFile file;
+{
+    int ret, err;
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return Z_STREAM_ERROR;
+    state = (gz_statep)file;
+
+    /* check that we're reading */
+    if (state->mode != GZ_READ)
+        return Z_STREAM_ERROR;
+
+    /* free memory and close file */
+    if (state->size) {
+        inflateEnd(&(state->strm));
+        free(state->out);
+        free(state->in);
+    }
+    err = state->err == Z_BUF_ERROR ? Z_BUF_ERROR : Z_OK;
+    gz_error(state, Z_OK, NULL);
+    free(state->path);
+    ret = close(state->fd);
+    free(state);
+    return ret ? Z_ERRNO : err;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/gzwrite.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/gzwrite.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,665 @@
+/* gzwrite.c -- zlib functions for writing gzip files
+ * Copyright (C) 2004-2017 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "gzguts.h"
+
+/* Local functions */
+local int gz_init OF((gz_statep));
+local int gz_comp OF((gz_statep, int));
+local int gz_zero OF((gz_statep, z_off64_t));
+local z_size_t gz_write OF((gz_statep, voidpc, z_size_t));
+
+/* Initialize state for writing a gzip file.  Mark initialization by setting
+   state->size to non-zero.  Return -1 on a memory allocation failure, or 0 on
+   success. */
+local int gz_init(state)
+    gz_statep state;
+{
+    int ret;
+    z_streamp strm = &(state->strm);
+
+    /* allocate input buffer (double size for gzprintf) */
+    state->in = (unsigned char *)malloc(state->want << 1);
+    if (state->in == NULL) {
+        gz_error(state, Z_MEM_ERROR, "out of memory");
+        return -1;
+    }
+
+    /* only need output buffer and deflate state if compressing */
+    if (!state->direct) {
+        /* allocate output buffer */
+        state->out = (unsigned char *)malloc(state->want);
+        if (state->out == NULL) {
+            free(state->in);
+            gz_error(state, Z_MEM_ERROR, "out of memory");
+            return -1;
+        }
+
+        /* allocate deflate memory, set up for gzip compression */
+        strm->zalloc = Z_NULL;
+        strm->zfree = Z_NULL;
+        strm->opaque = Z_NULL;
+        ret = deflateInit2(strm, state->level, Z_DEFLATED,
+                           MAX_WBITS + 16, DEF_MEM_LEVEL, state->strategy);
+        if (ret != Z_OK) {
+            free(state->out);
+            free(state->in);
+            gz_error(state, Z_MEM_ERROR, "out of memory");
+            return -1;
+        }
+        strm->next_in = NULL;
+    }
+
+    /* mark state as initialized */
+    state->size = state->want;
+
+    /* initialize write buffer if compressing */
+    if (!state->direct) {
+        strm->avail_out = state->size;
+        strm->next_out = state->out;
+        state->x.next = strm->next_out;
+    }
+    return 0;
+}
+
+/* Compress whatever is at avail_in and next_in and write to the output file.
+   Return -1 if there is an error writing to the output file or if gz_init()
+   fails to allocate memory, otherwise 0.  flush is assumed to be a valid
+   deflate() flush value.  If flush is Z_FINISH, then the deflate() state is
+   reset to start a new gzip stream.  If gz->direct is true, then simply write
+   to the output file without compressing, and ignore flush. */
+local int gz_comp(state, flush)
+    gz_statep state;
+    int flush;
+{
+    int ret, writ;
+    unsigned have, put, max = ((unsigned)-1 >> 2) + 1;
+    z_streamp strm = &(state->strm);
+
+    /* allocate memory if this is the first time through */
+    if (state->size == 0 && gz_init(state) == -1)
+        return -1;
+
+    /* write directly if requested */
+    if (state->direct) {
+        while (strm->avail_in) {
+            put = strm->avail_in > max ? max : strm->avail_in;
+            writ = write(state->fd, strm->next_in, put);
+            if (writ < 0) {
+                gz_error(state, Z_ERRNO, zstrerror());
+                return -1;
+            }
+            strm->avail_in -= (unsigned)writ;
+            strm->next_in += writ;
+        }
+        return 0;
+    }
+
+    /* run deflate() on provided input until it produces no more output */
+    ret = Z_OK;
+    do {
+        /* write out current buffer contents if full, or if flushing, but if
+           doing Z_FINISH then don't write until we get to Z_STREAM_END */
+        if (strm->avail_out == 0 || (flush != Z_NO_FLUSH &&
+            (flush != Z_FINISH || ret == Z_STREAM_END))) {
+            while (strm->next_out > state->x.next) {
+                put = strm->next_out - state->x.next > (int)max ? max :
+                      (unsigned)(strm->next_out - state->x.next);
+                writ = write(state->fd, state->x.next, put);
+                if (writ < 0) {
+                    gz_error(state, Z_ERRNO, zstrerror());
+                    return -1;
+                }
+                state->x.next += writ;
+            }
+            if (strm->avail_out == 0) {
+                strm->avail_out = state->size;
+                strm->next_out = state->out;
+                state->x.next = state->out;
+            }
+        }
+
+        /* compress */
+        have = strm->avail_out;
+        ret = deflate(strm, flush);
+        if (ret == Z_STREAM_ERROR) {
+            gz_error(state, Z_STREAM_ERROR,
+                      "internal error: deflate stream corrupt");
+            return -1;
+        }
+        have -= strm->avail_out;
+    } while (have);
+
+    /* if that completed a deflate stream, allow another to start */
+    if (flush == Z_FINISH)
+        deflateReset(strm);
+
+    /* all done, no errors */
+    return 0;
+}
+
+/* Compress len zeros to output.  Return -1 on a write error or memory
+   allocation failure by gz_comp(), or 0 on success. */
+local int gz_zero(state, len)
+    gz_statep state;
+    z_off64_t len;
+{
+    int first;
+    unsigned n;
+    z_streamp strm = &(state->strm);
+
+    /* consume whatever's left in the input buffer */
+    if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
+        return -1;
+
+    /* compress len zeros (len guaranteed > 0) */
+    first = 1;
+    while (len) {
+        n = GT_OFF(state->size) || (z_off64_t)state->size > len ?
+            (unsigned)len : state->size;
+        if (first) {
+            memset(state->in, 0, n);
+            first = 0;
+        }
+        strm->avail_in = n;
+        strm->next_in = state->in;
+        state->x.pos += n;
+        if (gz_comp(state, Z_NO_FLUSH) == -1)
+            return -1;
+        len -= n;
+    }
+    return 0;
+}
+
+/* Write len bytes from buf to file.  Return the number of bytes written.  If
+   the returned value is less than len, then there was an error. */
+local z_size_t gz_write(state, buf, len)
+    gz_statep state;
+    voidpc buf;
+    z_size_t len;
+{
+    z_size_t put = len;
+
+    /* if len is zero, avoid unnecessary operations */
+    if (len == 0)
+        return 0;
+
+    /* allocate memory if this is the first time through */
+    if (state->size == 0 && gz_init(state) == -1)
+        return 0;
+
+    /* check for seek request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_zero(state, state->skip) == -1)
+            return 0;
+    }
+
+    /* for small len, copy to input buffer, otherwise compress directly */
+    if (len < state->size) {
+        /* copy to input buffer, compress when full */
+        do {
+            unsigned have, copy;
+
+            if (state->strm.avail_in == 0)
+                state->strm.next_in = state->in;
+            have = (unsigned)((state->strm.next_in + state->strm.avail_in) -
+                              state->in);
+            copy = state->size - have;
+            if (copy > len)
+                copy = len;
+            memcpy(state->in + have, buf, copy);
+            state->strm.avail_in += copy;
+            state->x.pos += copy;
+            buf = (const char *)buf + copy;
+            len -= copy;
+            if (len && gz_comp(state, Z_NO_FLUSH) == -1)
+                return 0;
+        } while (len);
+    }
+    else {
+        /* consume whatever's left in the input buffer */
+        if (state->strm.avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
+            return 0;
+
+        /* directly compress user buffer to file */
+        state->strm.next_in = (z_const Bytef *)buf;
+        do {
+            unsigned n = (unsigned)-1;
+            if (n > len)
+                n = len;
+            state->strm.avail_in = n;
+            state->x.pos += n;
+            if (gz_comp(state, Z_NO_FLUSH) == -1)
+                return 0;
+            len -= n;
+        } while (len);
+    }
+
+    /* input was all buffered or compressed */
+    return put;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzwrite(file, buf, len)
+    gzFile file;
+    voidpc buf;
+    unsigned len;
+{
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return 0;
+    state = (gz_statep)file;
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return 0;
+
+    /* since an int is returned, make sure len fits in one, otherwise return
+       with an error (this avoids a flaw in the interface) */
+    if ((int)len < 0) {
+        gz_error(state, Z_DATA_ERROR, "requested length does not fit in int");
+        return 0;
+    }
+
+    /* write len bytes from buf (the return value will fit in an int) */
+    return (int)gz_write(state, buf, len);
+}
+
+/* -- see zlib.h -- */
+z_size_t ZEXPORT gzfwrite(buf, size, nitems, file)
+    voidpc buf;
+    z_size_t size;
+    z_size_t nitems;
+    gzFile file;
+{
+    z_size_t len;
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return 0;
+    state = (gz_statep)file;
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return 0;
+
+    /* compute bytes to read -- error on overflow */
+    len = nitems * size;
+    if (size && len / size != nitems) {
+        gz_error(state, Z_STREAM_ERROR, "request does not fit in a size_t");
+        return 0;
+    }
+
+    /* write len bytes to buf, return the number of full items written */
+    return len ? gz_write(state, buf, len) / size : 0;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzputc(file, c)
+    gzFile file;
+    int c;
+{
+    unsigned have;
+    unsigned char buf[1];
+    gz_statep state;
+    z_streamp strm;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+    strm = &(state->strm);
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return -1;
+
+    /* check for seek request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_zero(state, state->skip) == -1)
+            return -1;
+    }
+
+    /* try writing to input buffer for speed (state->size == 0 if buffer not
+       initialized) */
+    if (state->size) {
+        if (strm->avail_in == 0)
+            strm->next_in = state->in;
+        have = (unsigned)((strm->next_in + strm->avail_in) - state->in);
+        if (have < state->size) {
+            state->in[have] = (unsigned char)c;
+            strm->avail_in++;
+            state->x.pos++;
+            return c & 0xff;
+        }
+    }
+
+    /* no room in buffer or not initialized, use gz_write() */
+    buf[0] = (unsigned char)c;
+    if (gz_write(state, buf, 1) != 1)
+        return -1;
+    return c & 0xff;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzputs(file, str)
+    gzFile file;
+    const char *str;
+{
+    int ret;
+    z_size_t len;
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return -1;
+    state = (gz_statep)file;
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return -1;
+
+    /* write string */
+    len = strlen(str);
+    ret = gz_write(state, str, len);
+    return ret == 0 && len != 0 ? -1 : ret;
+}
+
+#if defined(STDC) || defined(Z_HAVE_STDARG_H)
+#include <stdarg.h>
+
+/* -- see zlib.h -- */
+int ZEXPORTVA gzvprintf(gzFile file, const char *format, va_list va)
+{
+    int len;
+    unsigned left;
+    char *next;
+    gz_statep state;
+    z_streamp strm;
+
+    /* get internal structure */
+    if (file == NULL)
+        return Z_STREAM_ERROR;
+    state = (gz_statep)file;
+    strm = &(state->strm);
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return Z_STREAM_ERROR;
+
+    /* make sure we have some buffer space */
+    if (state->size == 0 && gz_init(state) == -1)
+        return state->err;
+
+    /* check for seek request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_zero(state, state->skip) == -1)
+            return state->err;
+    }
+
+    /* do the printf() into the input buffer, put length in len -- the input
+       buffer is double-sized just for this function, so there is guaranteed to
+       be state->size bytes available after the current contents */
+    if (strm->avail_in == 0)
+        strm->next_in = state->in;
+    next = (char *)(state->in + (strm->next_in - state->in) + strm->avail_in);
+    next[state->size - 1] = 0;
+#ifdef NO_vsnprintf
+#  ifdef HAS_vsprintf_void
+    (void)vsprintf(next, format, va);
+    for (len = 0; len < state->size; len++)
+        if (next[len] == 0) break;
+#  else
+    len = vsprintf(next, format, va);
+#  endif
+#else
+#  ifdef HAS_vsnprintf_void
+    (void)vsnprintf(next, state->size, format, va);
+    len = strlen(next);
+#  else
+    len = vsnprintf(next, state->size, format, va);
+#  endif
+#endif
+
+    /* check that printf() results fit in buffer */
+    if (len == 0 || (unsigned)len >= state->size || next[state->size - 1] != 0)
+        return 0;
+
+    /* update buffer and position, compress first half if past that */
+    strm->avail_in += (unsigned)len;
+    state->x.pos += len;
+    if (strm->avail_in >= state->size) {
+        left = strm->avail_in - state->size;
+        strm->avail_in = state->size;
+        if (gz_comp(state, Z_NO_FLUSH) == -1)
+            return state->err;
+        memcpy(state->in, state->in + state->size, left);
+        strm->next_in = state->in;
+        strm->avail_in = left;
+    }
+    return len;
+}
+
+int ZEXPORTVA gzprintf(gzFile file, const char *format, ...)
+{
+    va_list va;
+    int ret;
+
+    va_start(va, format);
+    ret = gzvprintf(file, format, va);
+    va_end(va);
+    return ret;
+}
+
+#else /* !STDC && !Z_HAVE_STDARG_H */
+
+/* -- see zlib.h -- */
+int ZEXPORTVA gzprintf (file, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
+                       a11, a12, a13, a14, a15, a16, a17, a18, a19, a20)
+    gzFile file;
+    const char *format;
+    int a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
+        a11, a12, a13, a14, a15, a16, a17, a18, a19, a20;
+{
+    unsigned len, left;
+    char *next;
+    gz_statep state;
+    z_streamp strm;
+
+    /* get internal structure */
+    if (file == NULL)
+        return Z_STREAM_ERROR;
+    state = (gz_statep)file;
+    strm = &(state->strm);
+
+    /* check that can really pass pointer in ints */
+    if (sizeof(int) != sizeof(void *))
+        return Z_STREAM_ERROR;
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return Z_STREAM_ERROR;
+
+    /* make sure we have some buffer space */
+    if (state->size == 0 && gz_init(state) == -1)
+        return state->error;
+
+    /* check for seek request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_zero(state, state->skip) == -1)
+            return state->error;
+    }
+
+    /* do the printf() into the input buffer, put length in len -- the input
+       buffer is double-sized just for this function, so there is guaranteed to
+       be state->size bytes available after the current contents */
+    if (strm->avail_in == 0)
+        strm->next_in = state->in;
+    next = (char *)(strm->next_in + strm->avail_in);
+    next[state->size - 1] = 0;
+#ifdef NO_snprintf
+#  ifdef HAS_sprintf_void
+    sprintf(next, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12,
+            a13, a14, a15, a16, a17, a18, a19, a20);
+    for (len = 0; len < size; len++)
+        if (next[len] == 0)
+            break;
+#  else
+    len = sprintf(next, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11,
+                  a12, a13, a14, a15, a16, a17, a18, a19, a20);
+#  endif
+#else
+#  ifdef HAS_snprintf_void
+    snprintf(next, state->size, format, a1, a2, a3, a4, a5, a6, a7, a8, a9,
+             a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
+    len = strlen(next);
+#  else
+    len = snprintf(next, state->size, format, a1, a2, a3, a4, a5, a6, a7, a8,
+                   a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
+#  endif
+#endif
+
+    /* check that printf() results fit in buffer */
+    if (len == 0 || len >= state->size || next[state->size - 1] != 0)
+        return 0;
+
+    /* update buffer and position, compress first half if past that */
+    strm->avail_in += len;
+    state->x.pos += len;
+    if (strm->avail_in >= state->size) {
+        left = strm->avail_in - state->size;
+        strm->avail_in = state->size;
+        if (gz_comp(state, Z_NO_FLUSH) == -1)
+            return state->err;
+        memcpy(state->in, state->in + state->size, left);
+        strm->next_in = state->in;
+        strm->avail_in = left;
+    }
+    return (int)len;
+}
+
+#endif
+
+/* -- see zlib.h -- */
+int ZEXPORT gzflush(file, flush)
+    gzFile file;
+    int flush;
+{
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return Z_STREAM_ERROR;
+    state = (gz_statep)file;
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return Z_STREAM_ERROR;
+
+    /* check flush parameter */
+    if (flush < 0 || flush > Z_FINISH)
+        return Z_STREAM_ERROR;
+
+    /* check for seek request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_zero(state, state->skip) == -1)
+            return state->err;
+    }
+
+    /* compress remaining data with requested flush */
+    (void)gz_comp(state, flush);
+    return state->err;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzsetparams(file, level, strategy)
+    gzFile file;
+    int level;
+    int strategy;
+{
+    gz_statep state;
+    z_streamp strm;
+
+    /* get internal structure */
+    if (file == NULL)
+        return Z_STREAM_ERROR;
+    state = (gz_statep)file;
+    strm = &(state->strm);
+
+    /* check that we're writing and that there's no error */
+    if (state->mode != GZ_WRITE || state->err != Z_OK)
+        return Z_STREAM_ERROR;
+
+    /* if no change is requested, then do nothing */
+    if (level == state->level && strategy == state->strategy)
+        return Z_OK;
+
+    /* check for seek request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_zero(state, state->skip) == -1)
+            return state->err;
+    }
+
+    /* change compression parameters for subsequent input */
+    if (state->size) {
+        /* flush previous input with previous parameters before changing */
+        if (strm->avail_in && gz_comp(state, Z_BLOCK) == -1)
+            return state->err;
+        deflateParams(strm, level, strategy);
+    }
+    state->level = level;
+    state->strategy = strategy;
+    return Z_OK;
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzclose_w(file)
+    gzFile file;
+{
+    int ret = Z_OK;
+    gz_statep state;
+
+    /* get internal structure */
+    if (file == NULL)
+        return Z_STREAM_ERROR;
+    state = (gz_statep)file;
+
+    /* check that we're writing */
+    if (state->mode != GZ_WRITE)
+        return Z_STREAM_ERROR;
+
+    /* check for seek request */
+    if (state->seek) {
+        state->seek = 0;
+        if (gz_zero(state, state->skip) == -1)
+            ret = state->err;
+    }
+
+    /* flush, free memory, and close file */
+    if (gz_comp(state, Z_FINISH) == -1)
+        ret = state->err;
+    if (state->size) {
+        if (!state->direct) {
+            (void)deflateEnd(&(state->strm));
+            free(state->out);
+        }
+        free(state->in);
+    }
+    gz_error(state, Z_OK, NULL);
+    free(state->path);
+    if (close(state->fd) == -1)
+        ret = Z_ERRNO;
+    free(state);
+    return ret;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/infback.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/infback.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,640 @@
+/* infback.c -- inflate using a call-back interface
+ * Copyright (C) 1995-2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/*
+   This code is largely copied from inflate.c.  Normally either infback.o or
+   inflate.o would be linked into an application--not both.  The interface
+   with inffast.c is retained so that optimized assembler-coded versions of
+   inflate_fast() can be used with either inflate.c or infback.c.
+ */
+
+#include "zutil.h"
+#include "inftrees.h"
+#include "inflate.h"
+#include "inffast.h"
+
+/* function prototypes */
+local void fixedtables OF((struct inflate_state FAR *state));
+
+/*
+   strm provides memory allocation functions in zalloc and zfree, or
+   Z_NULL to use the library memory allocation functions.
+
+   windowBits is in the range 8..15, and window is a user-supplied
+   window and output buffer that is 2**windowBits bytes.
+ */
+int ZEXPORT inflateBackInit_(strm, windowBits, window, version, stream_size)
+z_streamp strm;
+int windowBits;
+unsigned char FAR *window;
+const char *version;
+int stream_size;
+{
+    struct inflate_state FAR *state;
+
+    if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
+        stream_size != (int)(sizeof(z_stream)))
+        return Z_VERSION_ERROR;
+    if (strm == Z_NULL || window == Z_NULL ||
+        windowBits < 8 || windowBits > 15)
+        return Z_STREAM_ERROR;
+    strm->msg = Z_NULL;                 /* in case we return an error */
+    if (strm->zalloc == (alloc_func)0) {
+#ifdef Z_SOLO
+        return Z_STREAM_ERROR;
+#else
+        strm->zalloc = zcalloc;
+        strm->opaque = (voidpf)0;
+#endif
+    }
+    if (strm->zfree == (free_func)0)
+#ifdef Z_SOLO
+        return Z_STREAM_ERROR;
+#else
+    strm->zfree = zcfree;
+#endif
+    state = (struct inflate_state FAR *)ZALLOC(strm, 1,
+                                               sizeof(struct inflate_state));
+    if (state == Z_NULL) return Z_MEM_ERROR;
+    Tracev((stderr, "inflate: allocated\n"));
+    strm->state = (struct internal_state FAR *)state;
+    state->dmax = 32768U;
+    state->wbits = (uInt)windowBits;
+    state->wsize = 1U << windowBits;
+    state->window = window;
+    state->wnext = 0;
+    state->whave = 0;
+    return Z_OK;
+}
+
+/*
+   Return state with length and distance decoding tables and index sizes set to
+   fixed code decoding.  Normally this returns fixed tables from inffixed.h.
+   If BUILDFIXED is defined, then instead this routine builds the tables the
+   first time it's called, and returns those tables the first time and
+   thereafter.  This reduces the size of the code by about 2K bytes, in
+   exchange for a little execution time.  However, BUILDFIXED should not be
+   used for threaded applications, since the rewriting of the tables and virgin
+   may not be thread-safe.
+ */
+local void fixedtables(state)
+struct inflate_state FAR *state;
+{
+#ifdef BUILDFIXED
+    static int virgin = 1;
+    static code *lenfix, *distfix;
+    static code fixed[544];
+
+    /* build fixed huffman tables if first call (may not be thread safe) */
+    if (virgin) {
+        unsigned sym, bits;
+        static code *next;
+
+        /* literal/length table */
+        sym = 0;
+        while (sym < 144) state->lens[sym++] = 8;
+        while (sym < 256) state->lens[sym++] = 9;
+        while (sym < 280) state->lens[sym++] = 7;
+        while (sym < 288) state->lens[sym++] = 8;
+        next = fixed;
+        lenfix = next;
+        bits = 9;
+        inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
+
+        /* distance table */
+        sym = 0;
+        while (sym < 32) state->lens[sym++] = 5;
+        distfix = next;
+        bits = 5;
+        inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
+
+        /* do this just once */
+        virgin = 0;
+    }
+#else /* !BUILDFIXED */
+#   include "inffixed.h"
+#endif /* BUILDFIXED */
+    state->lencode = lenfix;
+    state->lenbits = 9;
+    state->distcode = distfix;
+    state->distbits = 5;
+}
+
+/* Macros for inflateBack(): */
+
+/* Load returned state from inflate_fast() */
+#define LOAD() \
+    do { \
+        put = strm->next_out; \
+        left = strm->avail_out; \
+        next = strm->next_in; \
+        have = strm->avail_in; \
+        hold = state->hold; \
+        bits = state->bits; \
+    } while (0)
+
+/* Set state from registers for inflate_fast() */
+#define RESTORE() \
+    do { \
+        strm->next_out = put; \
+        strm->avail_out = left; \
+        strm->next_in = next; \
+        strm->avail_in = have; \
+        state->hold = hold; \
+        state->bits = bits; \
+    } while (0)
+
+/* Clear the input bit accumulator */
+#define INITBITS() \
+    do { \
+        hold = 0; \
+        bits = 0; \
+    } while (0)
+
+/* Assure that some input is available.  If input is requested, but denied,
+   then return a Z_BUF_ERROR from inflateBack(). */
+#define PULL() \
+    do { \
+        if (have == 0) { \
+            have = in(in_desc, &next); \
+            if (have == 0) { \
+                next = Z_NULL; \
+                ret = Z_BUF_ERROR; \
+                goto inf_leave; \
+            } \
+        } \
+    } while (0)
+
+/* Get a byte of input into the bit accumulator, or return from inflateBack()
+   with an error if there is no input available. */
+#define PULLBYTE() \
+    do { \
+        PULL(); \
+        have--; \
+        hold += (unsigned long)(*next++) << bits; \
+        bits += 8; \
+    } while (0)
+
+/* Assure that there are at least n bits in the bit accumulator.  If there is
+   not enough available input to do that, then return from inflateBack() with
+   an error. */
+#define NEEDBITS(n) \
+    do { \
+        while (bits < (unsigned)(n)) \
+            PULLBYTE(); \
+    } while (0)
+
+/* Return the low n bits of the bit accumulator (n < 16) */
+#define BITS(n) \
+    ((unsigned)hold & ((1U << (n)) - 1))
+
+/* Remove n bits from the bit accumulator */
+#define DROPBITS(n) \
+    do { \
+        hold >>= (n); \
+        bits -= (unsigned)(n); \
+    } while (0)
+
+/* Remove zero to seven bits as needed to go to a byte boundary */
+#define BYTEBITS() \
+    do { \
+        hold >>= bits & 7; \
+        bits -= bits & 7; \
+    } while (0)
+
+/* Assure that some output space is available, by writing out the window
+   if it's full.  If the write fails, return from inflateBack() with a
+   Z_BUF_ERROR. */
+#define ROOM() \
+    do { \
+        if (left == 0) { \
+            put = state->window; \
+            left = state->wsize; \
+            state->whave = left; \
+            if (out(out_desc, put, left)) { \
+                ret = Z_BUF_ERROR; \
+                goto inf_leave; \
+            } \
+        } \
+    } while (0)
+
+/*
+   strm provides the memory allocation functions and window buffer on input,
+   and provides information on the unused input on return.  For Z_DATA_ERROR
+   returns, strm will also provide an error message.
+
+   in() and out() are the call-back input and output functions.  When
+   inflateBack() needs more input, it calls in().  When inflateBack() has
+   filled the window with output, or when it completes with data in the
+   window, it calls out() to write out the data.  The application must not
+   change the provided input until in() is called again or inflateBack()
+   returns.  The application must not change the window/output buffer until
+   inflateBack() returns.
+
+   in() and out() are called with a descriptor parameter provided in the
+   inflateBack() call.  This parameter can be a structure that provides the
+   information required to do the read or write, as well as accumulated
+   information on the input and output such as totals and check values.
+
+   in() should return zero on failure.  out() should return non-zero on
+   failure.  If either in() or out() fails, than inflateBack() returns a
+   Z_BUF_ERROR.  strm->next_in can be checked for Z_NULL to see whether it
+   was in() or out() that caused in the error.  Otherwise,  inflateBack()
+   returns Z_STREAM_END on success, Z_DATA_ERROR for an deflate format
+   error, or Z_MEM_ERROR if it could not allocate memory for the state.
+   inflateBack() can also return Z_STREAM_ERROR if the input parameters
+   are not correct, i.e. strm is Z_NULL or the state was not initialized.
+ */
+int ZEXPORT inflateBack(strm, in, in_desc, out, out_desc)
+z_streamp strm;
+in_func in;
+void FAR *in_desc;
+out_func out;
+void FAR *out_desc;
+{
+    struct inflate_state FAR *state;
+    z_const unsigned char FAR *next;    /* next input */
+    unsigned char FAR *put;     /* next output */
+    unsigned have, left;        /* available input and output */
+    unsigned long hold;         /* bit buffer */
+    unsigned bits;              /* bits in bit buffer */
+    unsigned copy;              /* number of stored or match bytes to copy */
+    unsigned char FAR *from;    /* where to copy match bytes from */
+    code here;                  /* current decoding table entry */
+    code last;                  /* parent table entry */
+    unsigned len;               /* length to copy for repeats, bits to drop */
+    int ret;                    /* return code */
+    static const unsigned short order[19] = /* permutation of code lengths */
+        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+
+    /* Check that the strm exists and that the state was initialized */
+    if (strm == Z_NULL || strm->state == Z_NULL)
+        return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+
+    /* Reset the state */
+    strm->msg = Z_NULL;
+    state->mode = TYPE;
+    state->last = 0;
+    state->whave = 0;
+    next = strm->next_in;
+    have = next != Z_NULL ? strm->avail_in : 0;
+    hold = 0;
+    bits = 0;
+    put = state->window;
+    left = state->wsize;
+
+    /* Inflate until end of block marked as last */
+    for (;;)
+        switch (state->mode) {
+        case TYPE:
+            /* determine and dispatch block type */
+            if (state->last) {
+                BYTEBITS();
+                state->mode = DONE;
+                break;
+            }
+            NEEDBITS(3);
+            state->last = BITS(1);
+            DROPBITS(1);
+            switch (BITS(2)) {
+            case 0:                             /* stored block */
+                Tracev((stderr, "inflate:     stored block%s\n",
+                        state->last ? " (last)" : ""));
+                state->mode = STORED;
+                break;
+            case 1:                             /* fixed block */
+                fixedtables(state);
+                Tracev((stderr, "inflate:     fixed codes block%s\n",
+                        state->last ? " (last)" : ""));
+                state->mode = LEN;              /* decode codes */
+                break;
+            case 2:                             /* dynamic block */
+                Tracev((stderr, "inflate:     dynamic codes block%s\n",
+                        state->last ? " (last)" : ""));
+                state->mode = TABLE;
+                break;
+            case 3:
+                strm->msg = (char *)"invalid block type";
+                state->mode = BAD;
+            }
+            DROPBITS(2);
+            break;
+
+        case STORED:
+            /* get and verify stored block length */
+            BYTEBITS();                         /* go to byte boundary */
+            NEEDBITS(32);
+            if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
+                strm->msg = (char *)"invalid stored block lengths";
+                state->mode = BAD;
+                break;
+            }
+            state->length = (unsigned)hold & 0xffff;
+            Tracev((stderr, "inflate:       stored length %u\n",
+                    state->length));
+            INITBITS();
+
+            /* copy stored block from input to output */
+            while (state->length != 0) {
+                copy = state->length;
+                PULL();
+                ROOM();
+                if (copy > have) copy = have;
+                if (copy > left) copy = left;
+                zmemcpy(put, next, copy);
+                have -= copy;
+                next += copy;
+                left -= copy;
+                put += copy;
+                state->length -= copy;
+            }
+            Tracev((stderr, "inflate:       stored end\n"));
+            state->mode = TYPE;
+            break;
+
+        case TABLE:
+            /* get dynamic table entries descriptor */
+            NEEDBITS(14);
+            state->nlen = BITS(5) + 257;
+            DROPBITS(5);
+            state->ndist = BITS(5) + 1;
+            DROPBITS(5);
+            state->ncode = BITS(4) + 4;
+            DROPBITS(4);
+#ifndef PKZIP_BUG_WORKAROUND
+            if (state->nlen > 286 || state->ndist > 30) {
+                strm->msg = (char *)"too many length or distance symbols";
+                state->mode = BAD;
+                break;
+            }
+#endif
+            Tracev((stderr, "inflate:       table sizes ok\n"));
+
+            /* get code length code lengths (not a typo) */
+            state->have = 0;
+            while (state->have < state->ncode) {
+                NEEDBITS(3);
+                state->lens[order[state->have++]] = (unsigned short)BITS(3);
+                DROPBITS(3);
+            }
+            while (state->have < 19)
+                state->lens[order[state->have++]] = 0;
+            state->next = state->codes;
+            state->lencode = (code const FAR *)(state->next);
+            state->lenbits = 7;
+            ret = inflate_table(CODES, state->lens, 19, &(state->next),
+                                &(state->lenbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid code lengths set";
+                state->mode = BAD;
+                break;
+            }
+            Tracev((stderr, "inflate:       code lengths ok\n"));
+
+            /* get length and distance code code lengths */
+            state->have = 0;
+            while (state->have < state->nlen + state->ndist) {
+                for (;;) {
+                    here = state->lencode[BITS(state->lenbits)];
+                    if ((unsigned)(here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                if (here.val < 16) {
+                    DROPBITS(here.bits);
+                    state->lens[state->have++] = here.val;
+                }
+                else {
+                    if (here.val == 16) {
+                        NEEDBITS(here.bits + 2);
+                        DROPBITS(here.bits);
+                        if (state->have == 0) {
+                            strm->msg = (char *)"invalid bit length repeat";
+                            state->mode = BAD;
+                            break;
+                        }
+                        len = (unsigned)(state->lens[state->have - 1]);
+                        copy = 3 + BITS(2);
+                        DROPBITS(2);
+                    }
+                    else if (here.val == 17) {
+                        NEEDBITS(here.bits + 3);
+                        DROPBITS(here.bits);
+                        len = 0;
+                        copy = 3 + BITS(3);
+                        DROPBITS(3);
+                    }
+                    else {
+                        NEEDBITS(here.bits + 7);
+                        DROPBITS(here.bits);
+                        len = 0;
+                        copy = 11 + BITS(7);
+                        DROPBITS(7);
+                    }
+                    if (state->have + copy > state->nlen + state->ndist) {
+                        strm->msg = (char *)"invalid bit length repeat";
+                        state->mode = BAD;
+                        break;
+                    }
+                    while (copy--)
+                        state->lens[state->have++] = (unsigned short)len;
+                }
+            }
+
+            /* handle error breaks in while */
+            if (state->mode == BAD) break;
+
+            /* check for end-of-block code (better have one) */
+            if (state->lens[256] == 0) {
+                strm->msg = (char *)"invalid code -- missing end-of-block";
+                state->mode = BAD;
+                break;
+            }
+
+            /* build code tables -- note: do not change the lenbits or distbits
+               values here (9 and 6) without reading the comments in inftrees.h
+               concerning the ENOUGH constants, which depend on those values */
+            state->next = state->codes;
+            state->lencode = (code const FAR *)(state->next);
+            state->lenbits = 9;
+            ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
+                                &(state->lenbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid literal/lengths set";
+                state->mode = BAD;
+                break;
+            }
+            state->distcode = (code const FAR *)(state->next);
+            state->distbits = 6;
+            ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
+                            &(state->next), &(state->distbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid distances set";
+                state->mode = BAD;
+                break;
+            }
+            Tracev((stderr, "inflate:       codes ok\n"));
+            state->mode = LEN;
+
+        case LEN:
+            /* use inflate_fast() if we have enough input and output */
+            if (have >= 6 && left >= 258) {
+                RESTORE();
+                if (state->whave < state->wsize)
+                    state->whave = state->wsize - left;
+                inflate_fast(strm, state->wsize);
+                LOAD();
+                break;
+            }
+
+            /* get a literal, length, or end-of-block code */
+            for (;;) {
+                here = state->lencode[BITS(state->lenbits)];
+                if ((unsigned)(here.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if (here.op && (here.op & 0xf0) == 0) {
+                last = here;
+                for (;;) {
+                    here = state->lencode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+            }
+            DROPBITS(here.bits);
+            state->length = (unsigned)here.val;
+
+            /* process literal */
+            if (here.op == 0) {
+                Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
+                        "inflate:         literal '%c'\n" :
+                        "inflate:         literal 0x%02x\n", here.val));
+                ROOM();
+                *put++ = (unsigned char)(state->length);
+                left--;
+                state->mode = LEN;
+                break;
+            }
+
+            /* process end of block */
+            if (here.op & 32) {
+                Tracevv((stderr, "inflate:         end of block\n"));
+                state->mode = TYPE;
+                break;
+            }
+
+            /* invalid code */
+            if (here.op & 64) {
+                strm->msg = (char *)"invalid literal/length code";
+                state->mode = BAD;
+                break;
+            }
+
+            /* length code -- get extra bits, if any */
+            state->extra = (unsigned)(here.op) & 15;
+            if (state->extra != 0) {
+                NEEDBITS(state->extra);
+                state->length += BITS(state->extra);
+                DROPBITS(state->extra);
+            }
+            Tracevv((stderr, "inflate:         length %u\n", state->length));
+
+            /* get distance code */
+            for (;;) {
+                here = state->distcode[BITS(state->distbits)];
+                if ((unsigned)(here.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if ((here.op & 0xf0) == 0) {
+                last = here;
+                for (;;) {
+                    here = state->distcode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+            }
+            DROPBITS(here.bits);
+            if (here.op & 64) {
+                strm->msg = (char *)"invalid distance code";
+                state->mode = BAD;
+                break;
+            }
+            state->offset = (unsigned)here.val;
+
+            /* get distance extra bits, if any */
+            state->extra = (unsigned)(here.op) & 15;
+            if (state->extra != 0) {
+                NEEDBITS(state->extra);
+                state->offset += BITS(state->extra);
+                DROPBITS(state->extra);
+            }
+            if (state->offset > state->wsize - (state->whave < state->wsize ?
+                                                left : 0)) {
+                strm->msg = (char *)"invalid distance too far back";
+                state->mode = BAD;
+                break;
+            }
+            Tracevv((stderr, "inflate:         distance %u\n", state->offset));
+
+            /* copy match from window to output */
+            do {
+                ROOM();
+                copy = state->wsize - state->offset;
+                if (copy < left) {
+                    from = put + copy;
+                    copy = left - copy;
+                }
+                else {
+                    from = put - state->offset;
+                    copy = left;
+                }
+                if (copy > state->length) copy = state->length;
+                state->length -= copy;
+                left -= copy;
+                do {
+                    *put++ = *from++;
+                } while (--copy);
+            } while (state->length != 0);
+            break;
+
+        case DONE:
+            /* inflate stream terminated properly -- write leftover output */
+            ret = Z_STREAM_END;
+            if (left < state->wsize) {
+                if (out(out_desc, state->window, state->wsize - left))
+                    ret = Z_BUF_ERROR;
+            }
+            goto inf_leave;
+
+        case BAD:
+            ret = Z_DATA_ERROR;
+            goto inf_leave;
+
+        default:                /* can't happen, but makes compilers happy */
+            ret = Z_STREAM_ERROR;
+            goto inf_leave;
+        }
+
+    /* Return unused input */
+  inf_leave:
+    strm->next_in = next;
+    strm->avail_in = have;
+    return ret;
+}
+
+int ZEXPORT inflateBackEnd(strm)
+z_streamp strm;
+{
+    if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
+        return Z_STREAM_ERROR;
+    ZFREE(strm, strm->state);
+    strm->state = Z_NULL;
+    Tracev((stderr, "inflate: end\n"));
+    return Z_OK;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/inffast.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/inffast.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,323 @@
+/* inffast.c -- fast decoding
+ * Copyright (C) 1995-2017 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "zutil.h"
+#include "inftrees.h"
+#include "inflate.h"
+#include "inffast.h"
+
+#ifdef ASMINF
+#  pragma message("Assembler code may have bugs -- use at your own risk")
+#else
+
+/*
+   Decode literal, length, and distance codes and write out the resulting
+   literal and match bytes until either not enough input or output is
+   available, an end-of-block is encountered, or a data error is encountered.
+   When large enough input and output buffers are supplied to inflate(), for
+   example, a 16K input buffer and a 64K output buffer, more than 95% of the
+   inflate execution time is spent in this routine.
+
+   Entry assumptions:
+
+        state->mode == LEN
+        strm->avail_in >= 6
+        strm->avail_out >= 258
+        start >= strm->avail_out
+        state->bits < 8
+
+   On return, state->mode is one of:
+
+        LEN -- ran out of enough output space or enough available input
+        TYPE -- reached end of block code, inflate() to interpret next block
+        BAD -- error in block data
+
+   Notes:
+
+    - The maximum input bits used by a length/distance pair is 15 bits for the
+      length code, 5 bits for the length extra, 15 bits for the distance code,
+      and 13 bits for the distance extra.  This totals 48 bits, or six bytes.
+      Therefore if strm->avail_in >= 6, then there is enough input to avoid
+      checking for available input while decoding.
+
+    - The maximum bytes that a single length/distance pair can output is 258
+      bytes, which is the maximum length that can be coded.  inflate_fast()
+      requires strm->avail_out >= 258 for each loop to avoid checking for
+      output space.
+ */
+void ZLIB_INTERNAL inflate_fast(strm, start)
+z_streamp strm;
+unsigned start;         /* inflate()'s starting value for strm->avail_out */
+{
+    struct inflate_state FAR *state;
+    z_const unsigned char FAR *in;      /* local strm->next_in */
+    z_const unsigned char FAR *last;    /* have enough input while in < last */
+    unsigned char FAR *out;     /* local strm->next_out */
+    unsigned char FAR *beg;     /* inflate()'s initial strm->next_out */
+    unsigned char FAR *end;     /* while out < end, enough space available */
+#ifdef INFLATE_STRICT
+    unsigned dmax;              /* maximum distance from zlib header */
+#endif
+    unsigned wsize;             /* window size or zero if not using window */
+    unsigned whave;             /* valid bytes in the window */
+    unsigned wnext;             /* window write index */
+    unsigned char FAR *window;  /* allocated sliding window, if wsize != 0 */
+    unsigned long hold;         /* local strm->hold */
+    unsigned bits;              /* local strm->bits */
+    code const FAR *lcode;      /* local strm->lencode */
+    code const FAR *dcode;      /* local strm->distcode */
+    unsigned lmask;             /* mask for first level of length codes */
+    unsigned dmask;             /* mask for first level of distance codes */
+    code here;                  /* retrieved table entry */
+    unsigned op;                /* code bits, operation, extra bits, or */
+                                /*  window position, window bytes to copy */
+    unsigned len;               /* match length, unused bytes */
+    unsigned dist;              /* match distance */
+    unsigned char FAR *from;    /* where to copy match from */
+
+    /* copy state to local variables */
+    state = (struct inflate_state FAR *)strm->state;
+    in = strm->next_in;
+    last = in + (strm->avail_in - 5);
+    out = strm->next_out;
+    beg = out - (start - strm->avail_out);
+    end = out + (strm->avail_out - 257);
+#ifdef INFLATE_STRICT
+    dmax = state->dmax;
+#endif
+    wsize = state->wsize;
+    whave = state->whave;
+    wnext = state->wnext;
+    window = state->window;
+    hold = state->hold;
+    bits = state->bits;
+    lcode = state->lencode;
+    dcode = state->distcode;
+    lmask = (1U << state->lenbits) - 1;
+    dmask = (1U << state->distbits) - 1;
+
+    /* decode literals and length/distances until end-of-block or not enough
+       input data or output space */
+    do {
+        if (bits < 15) {
+            hold += (unsigned long)(*in++) << bits;
+            bits += 8;
+            hold += (unsigned long)(*in++) << bits;
+            bits += 8;
+        }
+        here = lcode[hold & lmask];
+      dolen:
+        op = (unsigned)(here.bits);
+        hold >>= op;
+        bits -= op;
+        op = (unsigned)(here.op);
+        if (op == 0) {                          /* literal */
+            Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
+                    "inflate:         literal '%c'\n" :
+                    "inflate:         literal 0x%02x\n", here.val));
+            *out++ = (unsigned char)(here.val);
+        }
+        else if (op & 16) {                     /* length base */
+            len = (unsigned)(here.val);
+            op &= 15;                           /* number of extra bits */
+            if (op) {
+                if (bits < op) {
+                    hold += (unsigned long)(*in++) << bits;
+                    bits += 8;
+                }
+                len += (unsigned)hold & ((1U << op) - 1);
+                hold >>= op;
+                bits -= op;
+            }
+            Tracevv((stderr, "inflate:         length %u\n", len));
+            if (bits < 15) {
+                hold += (unsigned long)(*in++) << bits;
+                bits += 8;
+                hold += (unsigned long)(*in++) << bits;
+                bits += 8;
+            }
+            here = dcode[hold & dmask];
+          dodist:
+            op = (unsigned)(here.bits);
+            hold >>= op;
+            bits -= op;
+            op = (unsigned)(here.op);
+            if (op & 16) {                      /* distance base */
+                dist = (unsigned)(here.val);
+                op &= 15;                       /* number of extra bits */
+                if (bits < op) {
+                    hold += (unsigned long)(*in++) << bits;
+                    bits += 8;
+                    if (bits < op) {
+                        hold += (unsigned long)(*in++) << bits;
+                        bits += 8;
+                    }
+                }
+                dist += (unsigned)hold & ((1U << op) - 1);
+#ifdef INFLATE_STRICT
+                if (dist > dmax) {
+                    strm->msg = (char *)"invalid distance too far back";
+                    state->mode = BAD;
+                    break;
+                }
+#endif
+                hold >>= op;
+                bits -= op;
+                Tracevv((stderr, "inflate:         distance %u\n", dist));
+                op = (unsigned)(out - beg);     /* max distance in output */
+                if (dist > op) {                /* see if copy from window */
+                    op = dist - op;             /* distance back in window */
+                    if (op > whave) {
+                        if (state->sane) {
+                            strm->msg =
+                                (char *)"invalid distance too far back";
+                            state->mode = BAD;
+                            break;
+                        }
+#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
+                        if (len <= op - whave) {
+                            do {
+                                *out++ = 0;
+                            } while (--len);
+                            continue;
+                        }
+                        len -= op - whave;
+                        do {
+                            *out++ = 0;
+                        } while (--op > whave);
+                        if (op == 0) {
+                            from = out - dist;
+                            do {
+                                *out++ = *from++;
+                            } while (--len);
+                            continue;
+                        }
+#endif
+                    }
+                    from = window;
+                    if (wnext == 0) {           /* very common case */
+                        from += wsize - op;
+                        if (op < len) {         /* some from window */
+                            len -= op;
+                            do {
+                                *out++ = *from++;
+                            } while (--op);
+                            from = out - dist;  /* rest from output */
+                        }
+                    }
+                    else if (wnext < op) {      /* wrap around window */
+                        from += wsize + wnext - op;
+                        op -= wnext;
+                        if (op < len) {         /* some from end of window */
+                            len -= op;
+                            do {
+                                *out++ = *from++;
+                            } while (--op);
+                            from = window;
+                            if (wnext < len) {  /* some from start of window */
+                                op = wnext;
+                                len -= op;
+                                do {
+                                    *out++ = *from++;
+                                } while (--op);
+                                from = out - dist;      /* rest from output */
+                            }
+                        }
+                    }
+                    else {                      /* contiguous in window */
+                        from += wnext - op;
+                        if (op < len) {         /* some from window */
+                            len -= op;
+                            do {
+                                *out++ = *from++;
+                            } while (--op);
+                            from = out - dist;  /* rest from output */
+                        }
+                    }
+                    while (len > 2) {
+                        *out++ = *from++;
+                        *out++ = *from++;
+                        *out++ = *from++;
+                        len -= 3;
+                    }
+                    if (len) {
+                        *out++ = *from++;
+                        if (len > 1)
+                            *out++ = *from++;
+                    }
+                }
+                else {
+                    from = out - dist;          /* copy direct from output */
+                    do {                        /* minimum length is three */
+                        *out++ = *from++;
+                        *out++ = *from++;
+                        *out++ = *from++;
+                        len -= 3;
+                    } while (len > 2);
+                    if (len) {
+                        *out++ = *from++;
+                        if (len > 1)
+                            *out++ = *from++;
+                    }
+                }
+            }
+            else if ((op & 64) == 0) {          /* 2nd level distance code */
+                here = dcode[here.val + (hold & ((1U << op) - 1))];
+                goto dodist;
+            }
+            else {
+                strm->msg = (char *)"invalid distance code";
+                state->mode = BAD;
+                break;
+            }
+        }
+        else if ((op & 64) == 0) {              /* 2nd level length code */
+            here = lcode[here.val + (hold & ((1U << op) - 1))];
+            goto dolen;
+        }
+        else if (op & 32) {                     /* end-of-block */
+            Tracevv((stderr, "inflate:         end of block\n"));
+            state->mode = TYPE;
+            break;
+        }
+        else {
+            strm->msg = (char *)"invalid literal/length code";
+            state->mode = BAD;
+            break;
+        }
+    } while (in < last && out < end);
+
+    /* return unused bytes (on entry, bits < 8, so in won't go too far back) */
+    len = bits >> 3;
+    in -= len;
+    bits -= len << 3;
+    hold &= (1U << bits) - 1;
+
+    /* update state and return */
+    strm->next_in = in;
+    strm->next_out = out;
+    strm->avail_in = (unsigned)(in < last ? 5 + (last - in) : 5 - (in - last));
+    strm->avail_out = (unsigned)(out < end ?
+                                 257 + (end - out) : 257 - (out - end));
+    state->hold = hold;
+    state->bits = bits;
+    return;
+}
+
+/*
+   inflate_fast() speedups that turned out slower (on a PowerPC G3 750CXe):
+   - Using bit fields for code structure
+   - Different op definition to avoid & for extra bits (do & for table bits)
+   - Three separate decoding do-loops for direct, window, and wnext == 0
+   - Special case for distance > 1 copies to do overlapped load and store copy
+   - Explicit branch predictions (based on measured branch probabilities)
+   - Deferring match copy and interspersed it with decoding subsequent codes
+   - Swapping literal/length else
+   - Swapping window/direct else
+   - Larger unrolled copy loops (three is about right)
+   - Moving len -= 3 statement into middle of loop
+ */
+
+#endif /* !ASMINF */
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/inffast.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/inffast.h	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,11 @@
+/* inffast.h -- header to use inffast.c
+ * Copyright (C) 1995-2003, 2010 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+void ZLIB_INTERNAL inflate_fast OF((z_streamp strm, unsigned start));
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/inffixed.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/inffixed.h	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,94 @@
+    /* inffixed.h -- table for decoding fixed codes
+     * Generated automatically by makefixed().
+     */
+
+    /* WARNING: this file should *not* be used by applications.
+       It is part of the implementation of this library and is
+       subject to change. Applications should only use zlib.h.
+     */
+
+    static const code lenfix[512] = {
+        {96,7,0},{0,8,80},{0,8,16},{20,8,115},{18,7,31},{0,8,112},{0,8,48},
+        {0,9,192},{16,7,10},{0,8,96},{0,8,32},{0,9,160},{0,8,0},{0,8,128},
+        {0,8,64},{0,9,224},{16,7,6},{0,8,88},{0,8,24},{0,9,144},{19,7,59},
+        {0,8,120},{0,8,56},{0,9,208},{17,7,17},{0,8,104},{0,8,40},{0,9,176},
+        {0,8,8},{0,8,136},{0,8,72},{0,9,240},{16,7,4},{0,8,84},{0,8,20},
+        {21,8,227},{19,7,43},{0,8,116},{0,8,52},{0,9,200},{17,7,13},{0,8,100},
+        {0,8,36},{0,9,168},{0,8,4},{0,8,132},{0,8,68},{0,9,232},{16,7,8},
+        {0,8,92},{0,8,28},{0,9,152},{20,7,83},{0,8,124},{0,8,60},{0,9,216},
+        {18,7,23},{0,8,108},{0,8,44},{0,9,184},{0,8,12},{0,8,140},{0,8,76},
+        {0,9,248},{16,7,3},{0,8,82},{0,8,18},{21,8,163},{19,7,35},{0,8,114},
+        {0,8,50},{0,9,196},{17,7,11},{0,8,98},{0,8,34},{0,9,164},{0,8,2},
+        {0,8,130},{0,8,66},{0,9,228},{16,7,7},{0,8,90},{0,8,26},{0,9,148},
+        {20,7,67},{0,8,122},{0,8,58},{0,9,212},{18,7,19},{0,8,106},{0,8,42},
+        {0,9,180},{0,8,10},{0,8,138},{0,8,74},{0,9,244},{16,7,5},{0,8,86},
+        {0,8,22},{64,8,0},{19,7,51},{0,8,118},{0,8,54},{0,9,204},{17,7,15},
+        {0,8,102},{0,8,38},{0,9,172},{0,8,6},{0,8,134},{0,8,70},{0,9,236},
+        {16,7,9},{0,8,94},{0,8,30},{0,9,156},{20,7,99},{0,8,126},{0,8,62},
+        {0,9,220},{18,7,27},{0,8,110},{0,8,46},{0,9,188},{0,8,14},{0,8,142},
+        {0,8,78},{0,9,252},{96,7,0},{0,8,81},{0,8,17},{21,8,131},{18,7,31},
+        {0,8,113},{0,8,49},{0,9,194},{16,7,10},{0,8,97},{0,8,33},{0,9,162},
+        {0,8,1},{0,8,129},{0,8,65},{0,9,226},{16,7,6},{0,8,89},{0,8,25},
+        {0,9,146},{19,7,59},{0,8,121},{0,8,57},{0,9,210},{17,7,17},{0,8,105},
+        {0,8,41},{0,9,178},{0,8,9},{0,8,137},{0,8,73},{0,9,242},{16,7,4},
+        {0,8,85},{0,8,21},{16,8,258},{19,7,43},{0,8,117},{0,8,53},{0,9,202},
+        {17,7,13},{0,8,101},{0,8,37},{0,9,170},{0,8,5},{0,8,133},{0,8,69},
+        {0,9,234},{16,7,8},{0,8,93},{0,8,29},{0,9,154},{20,7,83},{0,8,125},
+        {0,8,61},{0,9,218},{18,7,23},{0,8,109},{0,8,45},{0,9,186},{0,8,13},
+        {0,8,141},{0,8,77},{0,9,250},{16,7,3},{0,8,83},{0,8,19},{21,8,195},
+        {19,7,35},{0,8,115},{0,8,51},{0,9,198},{17,7,11},{0,8,99},{0,8,35},
+        {0,9,166},{0,8,3},{0,8,131},{0,8,67},{0,9,230},{16,7,7},{0,8,91},
+        {0,8,27},{0,9,150},{20,7,67},{0,8,123},{0,8,59},{0,9,214},{18,7,19},
+        {0,8,107},{0,8,43},{0,9,182},{0,8,11},{0,8,139},{0,8,75},{0,9,246},
+        {16,7,5},{0,8,87},{0,8,23},{64,8,0},{19,7,51},{0,8,119},{0,8,55},
+        {0,9,206},{17,7,15},{0,8,103},{0,8,39},{0,9,174},{0,8,7},{0,8,135},
+        {0,8,71},{0,9,238},{16,7,9},{0,8,95},{0,8,31},{0,9,158},{20,7,99},
+        {0,8,127},{0,8,63},{0,9,222},{18,7,27},{0,8,111},{0,8,47},{0,9,190},
+        {0,8,15},{0,8,143},{0,8,79},{0,9,254},{96,7,0},{0,8,80},{0,8,16},
+        {20,8,115},{18,7,31},{0,8,112},{0,8,48},{0,9,193},{16,7,10},{0,8,96},
+        {0,8,32},{0,9,161},{0,8,0},{0,8,128},{0,8,64},{0,9,225},{16,7,6},
+        {0,8,88},{0,8,24},{0,9,145},{19,7,59},{0,8,120},{0,8,56},{0,9,209},
+        {17,7,17},{0,8,104},{0,8,40},{0,9,177},{0,8,8},{0,8,136},{0,8,72},
+        {0,9,241},{16,7,4},{0,8,84},{0,8,20},{21,8,227},{19,7,43},{0,8,116},
+        {0,8,52},{0,9,201},{17,7,13},{0,8,100},{0,8,36},{0,9,169},{0,8,4},
+        {0,8,132},{0,8,68},{0,9,233},{16,7,8},{0,8,92},{0,8,28},{0,9,153},
+        {20,7,83},{0,8,124},{0,8,60},{0,9,217},{18,7,23},{0,8,108},{0,8,44},
+        {0,9,185},{0,8,12},{0,8,140},{0,8,76},{0,9,249},{16,7,3},{0,8,82},
+        {0,8,18},{21,8,163},{19,7,35},{0,8,114},{0,8,50},{0,9,197},{17,7,11},
+        {0,8,98},{0,8,34},{0,9,165},{0,8,2},{0,8,130},{0,8,66},{0,9,229},
+        {16,7,7},{0,8,90},{0,8,26},{0,9,149},{20,7,67},{0,8,122},{0,8,58},
+        {0,9,213},{18,7,19},{0,8,106},{0,8,42},{0,9,181},{0,8,10},{0,8,138},
+        {0,8,74},{0,9,245},{16,7,5},{0,8,86},{0,8,22},{64,8,0},{19,7,51},
+        {0,8,118},{0,8,54},{0,9,205},{17,7,15},{0,8,102},{0,8,38},{0,9,173},
+        {0,8,6},{0,8,134},{0,8,70},{0,9,237},{16,7,9},{0,8,94},{0,8,30},
+        {0,9,157},{20,7,99},{0,8,126},{0,8,62},{0,9,221},{18,7,27},{0,8,110},
+        {0,8,46},{0,9,189},{0,8,14},{0,8,142},{0,8,78},{0,9,253},{96,7,0},
+        {0,8,81},{0,8,17},{21,8,131},{18,7,31},{0,8,113},{0,8,49},{0,9,195},
+        {16,7,10},{0,8,97},{0,8,33},{0,9,163},{0,8,1},{0,8,129},{0,8,65},
+        {0,9,227},{16,7,6},{0,8,89},{0,8,25},{0,9,147},{19,7,59},{0,8,121},
+        {0,8,57},{0,9,211},{17,7,17},{0,8,105},{0,8,41},{0,9,179},{0,8,9},
+        {0,8,137},{0,8,73},{0,9,243},{16,7,4},{0,8,85},{0,8,21},{16,8,258},
+        {19,7,43},{0,8,117},{0,8,53},{0,9,203},{17,7,13},{0,8,101},{0,8,37},
+        {0,9,171},{0,8,5},{0,8,133},{0,8,69},{0,9,235},{16,7,8},{0,8,93},
+        {0,8,29},{0,9,155},{20,7,83},{0,8,125},{0,8,61},{0,9,219},{18,7,23},
+        {0,8,109},{0,8,45},{0,9,187},{0,8,13},{0,8,141},{0,8,77},{0,9,251},
+        {16,7,3},{0,8,83},{0,8,19},{21,8,195},{19,7,35},{0,8,115},{0,8,51},
+        {0,9,199},{17,7,11},{0,8,99},{0,8,35},{0,9,167},{0,8,3},{0,8,131},
+        {0,8,67},{0,9,231},{16,7,7},{0,8,91},{0,8,27},{0,9,151},{20,7,67},
+        {0,8,123},{0,8,59},{0,9,215},{18,7,19},{0,8,107},{0,8,43},{0,9,183},
+        {0,8,11},{0,8,139},{0,8,75},{0,9,247},{16,7,5},{0,8,87},{0,8,23},
+        {64,8,0},{19,7,51},{0,8,119},{0,8,55},{0,9,207},{17,7,15},{0,8,103},
+        {0,8,39},{0,9,175},{0,8,7},{0,8,135},{0,8,71},{0,9,239},{16,7,9},
+        {0,8,95},{0,8,31},{0,9,159},{20,7,99},{0,8,127},{0,8,63},{0,9,223},
+        {18,7,27},{0,8,111},{0,8,47},{0,9,191},{0,8,15},{0,8,143},{0,8,79},
+        {0,9,255}
+    };
+
+    static const code distfix[32] = {
+        {16,5,1},{23,5,257},{19,5,17},{27,5,4097},{17,5,5},{25,5,1025},
+        {21,5,65},{29,5,16385},{16,5,3},{24,5,513},{20,5,33},{28,5,8193},
+        {18,5,9},{26,5,2049},{22,5,129},{64,5,0},{16,5,2},{23,5,385},
+        {19,5,25},{27,5,6145},{17,5,7},{25,5,1537},{21,5,97},{29,5,24577},
+        {16,5,4},{24,5,769},{20,5,49},{28,5,12289},{18,5,13},{26,5,3073},
+        {22,5,193},{64,5,0}
+    };
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/inflate.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/inflate.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,1561 @@
+/* inflate.c -- zlib decompression
+ * Copyright (C) 1995-2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/*
+ * Change history:
+ *
+ * 1.2.beta0    24 Nov 2002
+ * - First version -- complete rewrite of inflate to simplify code, avoid
+ *   creation of window when not needed, minimize use of window when it is
+ *   needed, make inffast.c even faster, implement gzip decoding, and to
+ *   improve code readability and style over the previous zlib inflate code
+ *
+ * 1.2.beta1    25 Nov 2002
+ * - Use pointers for available input and output checking in inffast.c
+ * - Remove input and output counters in inffast.c
+ * - Change inffast.c entry and loop from avail_in >= 7 to >= 6
+ * - Remove unnecessary second byte pull from length extra in inffast.c
+ * - Unroll direct copy to three copies per loop in inffast.c
+ *
+ * 1.2.beta2    4 Dec 2002
+ * - Change external routine names to reduce potential conflicts
+ * - Correct filename to inffixed.h for fixed tables in inflate.c
+ * - Make hbuf[] unsigned char to match parameter type in inflate.c
+ * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset)
+ *   to avoid negation problem on Alphas (64 bit) in inflate.c
+ *
+ * 1.2.beta3    22 Dec 2002
+ * - Add comments on state->bits assertion in inffast.c
+ * - Add comments on op field in inftrees.h
+ * - Fix bug in reuse of allocated window after inflateReset()
+ * - Remove bit fields--back to byte structure for speed
+ * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths
+ * - Change post-increments to pre-increments in inflate_fast(), PPC biased?
+ * - Add compile time option, POSTINC, to use post-increments instead (Intel?)
+ * - Make MATCH copy in inflate() much faster for when inflate_fast() not used
+ * - Use local copies of stream next and avail values, as well as local bit
+ *   buffer and bit count in inflate()--for speed when inflate_fast() not used
+ *
+ * 1.2.beta4    1 Jan 2003
+ * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings
+ * - Move a comment on output buffer sizes from inffast.c to inflate.c
+ * - Add comments in inffast.c to introduce the inflate_fast() routine
+ * - Rearrange window copies in inflate_fast() for speed and simplification
+ * - Unroll last copy for window match in inflate_fast()
+ * - Use local copies of window variables in inflate_fast() for speed
+ * - Pull out common wnext == 0 case for speed in inflate_fast()
+ * - Make op and len in inflate_fast() unsigned for consistency
+ * - Add FAR to lcode and dcode declarations in inflate_fast()
+ * - Simplified bad distance check in inflate_fast()
+ * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new
+ *   source file infback.c to provide a call-back interface to inflate for
+ *   programs like gzip and unzip -- uses window as output buffer to avoid
+ *   window copying
+ *
+ * 1.2.beta5    1 Jan 2003
+ * - Improved inflateBack() interface to allow the caller to provide initial
+ *   input in strm.
+ * - Fixed stored blocks bug in inflateBack()
+ *
+ * 1.2.beta6    4 Jan 2003
+ * - Added comments in inffast.c on effectiveness of POSTINC
+ * - Typecasting all around to reduce compiler warnings
+ * - Changed loops from while (1) or do {} while (1) to for (;;), again to
+ *   make compilers happy
+ * - Changed type of window in inflateBackInit() to unsigned char *
+ *
+ * 1.2.beta7    27 Jan 2003
+ * - Changed many types to unsigned or unsigned short to avoid warnings
+ * - Added inflateCopy() function
+ *
+ * 1.2.0        9 Mar 2003
+ * - Changed inflateBack() interface to provide separate opaque descriptors
+ *   for the in() and out() functions
+ * - Changed inflateBack() argument and in_func typedef to swap the length
+ *   and buffer address return values for the input function
+ * - Check next_in and next_out for Z_NULL on entry to inflate()
+ *
+ * The history for versions after 1.2.0 are in ChangeLog in zlib distribution.
+ */
+
+#include "zutil.h"
+#include "inftrees.h"
+#include "inflate.h"
+#include "inffast.h"
+
+#ifdef MAKEFIXED
+#  ifndef BUILDFIXED
+#    define BUILDFIXED
+#  endif
+#endif
+
+/* function prototypes */
+local int inflateStateCheck OF((z_streamp strm));
+local void fixedtables OF((struct inflate_state FAR *state));
+local int updatewindow OF((z_streamp strm, const unsigned char FAR *end,
+                           unsigned copy));
+#ifdef BUILDFIXED
+   void makefixed OF((void));
+#endif
+local unsigned syncsearch OF((unsigned FAR *have, const unsigned char FAR *buf,
+                              unsigned len));
+
+local int inflateStateCheck(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+    if (strm == Z_NULL ||
+        strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
+        return 1;
+    state = (struct inflate_state FAR *)strm->state;
+    if (state == Z_NULL || state->strm != strm ||
+        state->mode < HEAD || state->mode > SYNC)
+        return 1;
+    return 0;
+}
+
+int ZEXPORT inflateResetKeep(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    strm->total_in = strm->total_out = state->total = 0;
+    strm->msg = Z_NULL;
+    if (state->wrap)        /* to support ill-conceived Java test suite */
+        strm->adler = state->wrap & 1;
+    state->mode = HEAD;
+    state->last = 0;
+    state->havedict = 0;
+    state->dmax = 32768U;
+    state->head = Z_NULL;
+    state->hold = 0;
+    state->bits = 0;
+    state->lencode = state->distcode = state->next = state->codes;
+    state->sane = 1;
+    state->back = -1;
+    Tracev((stderr, "inflate: reset\n"));
+    return Z_OK;
+}
+
+int ZEXPORT inflateReset(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    state->wsize = 0;
+    state->whave = 0;
+    state->wnext = 0;
+    return inflateResetKeep(strm);
+}
+
+int ZEXPORT inflateReset2(strm, windowBits)
+z_streamp strm;
+int windowBits;
+{
+    int wrap;
+    struct inflate_state FAR *state;
+
+    /* get the state */
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+
+    /* extract wrap request from windowBits parameter */
+    if (windowBits < 0) {
+        wrap = 0;
+        windowBits = -windowBits;
+    }
+    else {
+        wrap = (windowBits >> 4) + 5;
+#ifdef GUNZIP
+        if (windowBits < 48)
+            windowBits &= 15;
+#endif
+    }
+
+    /* set number of window bits, free window if different */
+    if (windowBits && (windowBits < 8 || windowBits > 15))
+        return Z_STREAM_ERROR;
+    if (state->window != Z_NULL && state->wbits != (unsigned)windowBits) {
+        ZFREE(strm, state->window);
+        state->window = Z_NULL;
+    }
+
+    /* update state and reset the rest of it */
+    state->wrap = wrap;
+    state->wbits = (unsigned)windowBits;
+    return inflateReset(strm);
+}
+
+int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size)
+z_streamp strm;
+int windowBits;
+const char *version;
+int stream_size;
+{
+    int ret;
+    struct inflate_state FAR *state;
+
+    if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
+        stream_size != (int)(sizeof(z_stream)))
+        return Z_VERSION_ERROR;
+    if (strm == Z_NULL) return Z_STREAM_ERROR;
+    strm->msg = Z_NULL;                 /* in case we return an error */
+    if (strm->zalloc == (alloc_func)0) {
+#ifdef Z_SOLO
+        return Z_STREAM_ERROR;
+#else
+        strm->zalloc = zcalloc;
+        strm->opaque = (voidpf)0;
+#endif
+    }
+    if (strm->zfree == (free_func)0)
+#ifdef Z_SOLO
+        return Z_STREAM_ERROR;
+#else
+        strm->zfree = zcfree;
+#endif
+    state = (struct inflate_state FAR *)
+            ZALLOC(strm, 1, sizeof(struct inflate_state));
+    if (state == Z_NULL) return Z_MEM_ERROR;
+    Tracev((stderr, "inflate: allocated\n"));
+    strm->state = (struct internal_state FAR *)state;
+    state->strm = strm;
+    state->window = Z_NULL;
+    state->mode = HEAD;     /* to pass state test in inflateReset2() */
+    ret = inflateReset2(strm, windowBits);
+    if (ret != Z_OK) {
+        ZFREE(strm, state);
+        strm->state = Z_NULL;
+    }
+    return ret;
+}
+
+int ZEXPORT inflateInit_(strm, version, stream_size)
+z_streamp strm;
+const char *version;
+int stream_size;
+{
+    return inflateInit2_(strm, DEF_WBITS, version, stream_size);
+}
+
+int ZEXPORT inflatePrime(strm, bits, value)
+z_streamp strm;
+int bits;
+int value;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    if (bits < 0) {
+        state->hold = 0;
+        state->bits = 0;
+        return Z_OK;
+    }
+    if (bits > 16 || state->bits + (uInt)bits > 32) return Z_STREAM_ERROR;
+    value &= (1L << bits) - 1;
+    state->hold += (unsigned)value << state->bits;
+    state->bits += (uInt)bits;
+    return Z_OK;
+}
+
+/*
+   Return state with length and distance decoding tables and index sizes set to
+   fixed code decoding.  Normally this returns fixed tables from inffixed.h.
+   If BUILDFIXED is defined, then instead this routine builds the tables the
+   first time it's called, and returns those tables the first time and
+   thereafter.  This reduces the size of the code by about 2K bytes, in
+   exchange for a little execution time.  However, BUILDFIXED should not be
+   used for threaded applications, since the rewriting of the tables and virgin
+   may not be thread-safe.
+ */
+local void fixedtables(state)
+struct inflate_state FAR *state;
+{
+#ifdef BUILDFIXED
+    static int virgin = 1;
+    static code *lenfix, *distfix;
+    static code fixed[544];
+
+    /* build fixed huffman tables if first call (may not be thread safe) */
+    if (virgin) {
+        unsigned sym, bits;
+        static code *next;
+
+        /* literal/length table */
+        sym = 0;
+        while (sym < 144) state->lens[sym++] = 8;
+        while (sym < 256) state->lens[sym++] = 9;
+        while (sym < 280) state->lens[sym++] = 7;
+        while (sym < 288) state->lens[sym++] = 8;
+        next = fixed;
+        lenfix = next;
+        bits = 9;
+        inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
+
+        /* distance table */
+        sym = 0;
+        while (sym < 32) state->lens[sym++] = 5;
+        distfix = next;
+        bits = 5;
+        inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
+
+        /* do this just once */
+        virgin = 0;
+    }
+#else /* !BUILDFIXED */
+#   include "inffixed.h"
+#endif /* BUILDFIXED */
+    state->lencode = lenfix;
+    state->lenbits = 9;
+    state->distcode = distfix;
+    state->distbits = 5;
+}
+
+#ifdef MAKEFIXED
+#include <stdio.h>
+
+/*
+   Write out the inffixed.h that is #include'd above.  Defining MAKEFIXED also
+   defines BUILDFIXED, so the tables are built on the fly.  makefixed() writes
+   those tables to stdout, which would be piped to inffixed.h.  A small program
+   can simply call makefixed to do this:
+
+    void makefixed(void);
+
+    int main(void)
+    {
+        makefixed();
+        return 0;
+    }
+
+   Then that can be linked with zlib built with MAKEFIXED defined and run:
+
+    a.out > inffixed.h
+ */
+void makefixed()
+{
+    unsigned low, size;
+    struct inflate_state state;
+
+    fixedtables(&state);
+    puts("    /* inffixed.h -- table for decoding fixed codes");
+    puts("     * Generated automatically by makefixed().");
+    puts("     */");
+    puts("");
+    puts("    /* WARNING: this file should *not* be used by applications.");
+    puts("       It is part of the implementation of this library and is");
+    puts("       subject to change. Applications should only use zlib.h.");
+    puts("     */");
+    puts("");
+    size = 1U << 9;
+    printf("    static const code lenfix[%u] = {", size);
+    low = 0;
+    for (;;) {
+        if ((low % 7) == 0) printf("\n        ");
+        printf("{%u,%u,%d}", (low & 127) == 99 ? 64 : state.lencode[low].op,
+               state.lencode[low].bits, state.lencode[low].val);
+        if (++low == size) break;
+        putchar(',');
+    }
+    puts("\n    };");
+    size = 1U << 5;
+    printf("\n    static const code distfix[%u] = {", size);
+    low = 0;
+    for (;;) {
+        if ((low % 6) == 0) printf("\n        ");
+        printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits,
+               state.distcode[low].val);
+        if (++low == size) break;
+        putchar(',');
+    }
+    puts("\n    };");
+}
+#endif /* MAKEFIXED */
+
+/*
+   Update the window with the last wsize (normally 32K) bytes written before
+   returning.  If window does not exist yet, create it.  This is only called
+   when a window is already in use, or when output has been written during this
+   inflate call, but the end of the deflate stream has not been reached yet.
+   It is also called to create a window for dictionary data when a dictionary
+   is loaded.
+
+   Providing output buffers larger than 32K to inflate() should provide a speed
+   advantage, since only the last 32K of output is copied to the sliding window
+   upon return from inflate(), and since all distances after the first 32K of
+   output will fall in the output data, making match copies simpler and faster.
+   The advantage may be dependent on the size of the processor's data caches.
+ */
+local int updatewindow(strm, end, copy)
+z_streamp strm;
+const Bytef *end;
+unsigned copy;
+{
+    struct inflate_state FAR *state;
+    unsigned dist;
+
+    state = (struct inflate_state FAR *)strm->state;
+
+    /* if it hasn't been done already, allocate space for the window */
+    if (state->window == Z_NULL) {
+        state->window = (unsigned char FAR *)
+                        ZALLOC(strm, 1U << state->wbits,
+                               sizeof(unsigned char));
+        if (state->window == Z_NULL) return 1;
+    }
+
+    /* if window not in use yet, initialize */
+    if (state->wsize == 0) {
+        state->wsize = 1U << state->wbits;
+        state->wnext = 0;
+        state->whave = 0;
+    }
+
+    /* copy state->wsize or less output bytes into the circular window */
+    if (copy >= state->wsize) {
+        zmemcpy(state->window, end - state->wsize, state->wsize);
+        state->wnext = 0;
+        state->whave = state->wsize;
+    }
+    else {
+        dist = state->wsize - state->wnext;
+        if (dist > copy) dist = copy;
+        zmemcpy(state->window + state->wnext, end - copy, dist);
+        copy -= dist;
+        if (copy) {
+            zmemcpy(state->window, end - copy, copy);
+            state->wnext = copy;
+            state->whave = state->wsize;
+        }
+        else {
+            state->wnext += dist;
+            if (state->wnext == state->wsize) state->wnext = 0;
+            if (state->whave < state->wsize) state->whave += dist;
+        }
+    }
+    return 0;
+}
+
+/* Macros for inflate(): */
+
+/* check function to use adler32() for zlib or crc32() for gzip */
+#ifdef GUNZIP
+#  define UPDATE(check, buf, len) \
+    (state->flags ? crc32(check, buf, len) : adler32(check, buf, len))
+#else
+#  define UPDATE(check, buf, len) adler32(check, buf, len)
+#endif
+
+/* check macros for header crc */
+#ifdef GUNZIP
+#  define CRC2(check, word) \
+    do { \
+        hbuf[0] = (unsigned char)(word); \
+        hbuf[1] = (unsigned char)((word) >> 8); \
+        check = crc32(check, hbuf, 2); \
+    } while (0)
+
+#  define CRC4(check, word) \
+    do { \
+        hbuf[0] = (unsigned char)(word); \
+        hbuf[1] = (unsigned char)((word) >> 8); \
+        hbuf[2] = (unsigned char)((word) >> 16); \
+        hbuf[3] = (unsigned char)((word) >> 24); \
+        check = crc32(check, hbuf, 4); \
+    } while (0)
+#endif
+
+/* Load registers with state in inflate() for speed */
+#define LOAD() \
+    do { \
+        put = strm->next_out; \
+        left = strm->avail_out; \
+        next = strm->next_in; \
+        have = strm->avail_in; \
+        hold = state->hold; \
+        bits = state->bits; \
+    } while (0)
+
+/* Restore state from registers in inflate() */
+#define RESTORE() \
+    do { \
+        strm->next_out = put; \
+        strm->avail_out = left; \
+        strm->next_in = next; \
+        strm->avail_in = have; \
+        state->hold = hold; \
+        state->bits = bits; \
+    } while (0)
+
+/* Clear the input bit accumulator */
+#define INITBITS() \
+    do { \
+        hold = 0; \
+        bits = 0; \
+    } while (0)
+
+/* Get a byte of input into the bit accumulator, or return from inflate()
+   if there is no input available. */
+#define PULLBYTE() \
+    do { \
+        if (have == 0) goto inf_leave; \
+        have--; \
+        hold += (unsigned long)(*next++) << bits; \
+        bits += 8; \
+    } while (0)
+
+/* Assure that there are at least n bits in the bit accumulator.  If there is
+   not enough available input to do that, then return from inflate(). */
+#define NEEDBITS(n) \
+    do { \
+        while (bits < (unsigned)(n)) \
+            PULLBYTE(); \
+    } while (0)
+
+/* Return the low n bits of the bit accumulator (n < 16) */
+#define BITS(n) \
+    ((unsigned)hold & ((1U << (n)) - 1))
+
+/* Remove n bits from the bit accumulator */
+#define DROPBITS(n) \
+    do { \
+        hold >>= (n); \
+        bits -= (unsigned)(n); \
+    } while (0)
+
+/* Remove zero to seven bits as needed to go to a byte boundary */
+#define BYTEBITS() \
+    do { \
+        hold >>= bits & 7; \
+        bits -= bits & 7; \
+    } while (0)
+
+/*
+   inflate() uses a state machine to process as much input data and generate as
+   much output data as possible before returning.  The state machine is
+   structured roughly as follows:
+
+    for (;;) switch (state) {
+    ...
+    case STATEn:
+        if (not enough input data or output space to make progress)
+            return;
+        ... make progress ...
+        state = STATEm;
+        break;
+    ...
+    }
+
+   so when inflate() is called again, the same case is attempted again, and
+   if the appropriate resources are provided, the machine proceeds to the
+   next state.  The NEEDBITS() macro is usually the way the state evaluates
+   whether it can proceed or should return.  NEEDBITS() does the return if
+   the requested bits are not available.  The typical use of the BITS macros
+   is:
+
+        NEEDBITS(n);
+        ... do something with BITS(n) ...
+        DROPBITS(n);
+
+   where NEEDBITS(n) either returns from inflate() if there isn't enough
+   input left to load n bits into the accumulator, or it continues.  BITS(n)
+   gives the low n bits in the accumulator.  When done, DROPBITS(n) drops
+   the low n bits off the accumulator.  INITBITS() clears the accumulator
+   and sets the number of available bits to zero.  BYTEBITS() discards just
+   enough bits to put the accumulator on a byte boundary.  After BYTEBITS()
+   and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
+
+   NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
+   if there is no input available.  The decoding of variable length codes uses
+   PULLBYTE() directly in order to pull just enough bytes to decode the next
+   code, and no more.
+
+   Some states loop until they get enough input, making sure that enough
+   state information is maintained to continue the loop where it left off
+   if NEEDBITS() returns in the loop.  For example, want, need, and keep
+   would all have to actually be part of the saved state in case NEEDBITS()
+   returns:
+
+    case STATEw:
+        while (want < need) {
+            NEEDBITS(n);
+            keep[want++] = BITS(n);
+            DROPBITS(n);
+        }
+        state = STATEx;
+    case STATEx:
+
+   As shown above, if the next state is also the next case, then the break
+   is omitted.
+
+   A state may also return if there is not enough output space available to
+   complete that state.  Those states are copying stored data, writing a
+   literal byte, and copying a matching string.
+
+   When returning, a "goto inf_leave" is used to update the total counters,
+   update the check value, and determine whether any progress has been made
+   during that inflate() call in order to return the proper return code.
+   Progress is defined as a change in either strm->avail_in or strm->avail_out.
+   When there is a window, goto inf_leave will update the window with the last
+   output written.  If a goto inf_leave occurs in the middle of decompression
+   and there is no window currently, goto inf_leave will create one and copy
+   output to the window for the next call of inflate().
+
+   In this implementation, the flush parameter of inflate() only affects the
+   return code (per zlib.h).  inflate() always writes as much as possible to
+   strm->next_out, given the space available and the provided input--the effect
+   documented in zlib.h of Z_SYNC_FLUSH.  Furthermore, inflate() always defers
+   the allocation of and copying into a sliding window until necessary, which
+   provides the effect documented in zlib.h for Z_FINISH when the entire input
+   stream available.  So the only thing the flush parameter actually does is:
+   when flush is set to Z_FINISH, inflate() cannot return Z_OK.  Instead it
+   will return Z_BUF_ERROR if it has not reached the end of the stream.
+ */
+
+int ZEXPORT inflate(strm, flush)
+z_streamp strm;
+int flush;
+{
+    struct inflate_state FAR *state;
+    z_const unsigned char FAR *next;    /* next input */
+    unsigned char FAR *put;     /* next output */
+    unsigned have, left;        /* available input and output */
+    unsigned long hold;         /* bit buffer */
+    unsigned bits;              /* bits in bit buffer */
+    unsigned in, out;           /* save starting available input and output */
+    unsigned copy;              /* number of stored or match bytes to copy */
+    unsigned char FAR *from;    /* where to copy match bytes from */
+    code here;                  /* current decoding table entry */
+    code last;                  /* parent table entry */
+    unsigned len;               /* length to copy for repeats, bits to drop */
+    int ret;                    /* return code */
+#ifdef GUNZIP
+    unsigned char hbuf[4];      /* buffer for gzip header crc calculation */
+#endif
+    static const unsigned short order[19] = /* permutation of code lengths */
+        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+
+    if (inflateStateCheck(strm) || strm->next_out == Z_NULL ||
+        (strm->next_in == Z_NULL && strm->avail_in != 0))
+        return Z_STREAM_ERROR;
+
+    state = (struct inflate_state FAR *)strm->state;
+    if (state->mode == TYPE) state->mode = TYPEDO;      /* skip check */
+    LOAD();
+    in = have;
+    out = left;
+    ret = Z_OK;
+    for (;;)
+        switch (state->mode) {
+        case HEAD:
+            if (state->wrap == 0) {
+                state->mode = TYPEDO;
+                break;
+            }
+            NEEDBITS(16);
+#ifdef GUNZIP
+            if ((state->wrap & 2) && hold == 0x8b1f) {  /* gzip header */
+                if (state->wbits == 0)
+                    state->wbits = 15;
+                state->check = crc32(0L, Z_NULL, 0);
+                CRC2(state->check, hold);
+                INITBITS();
+                state->mode = FLAGS;
+                break;
+            }
+            state->flags = 0;           /* expect zlib header */
+            if (state->head != Z_NULL)
+                state->head->done = -1;
+            if (!(state->wrap & 1) ||   /* check if zlib header allowed */
+#else
+            if (
+#endif
+                ((BITS(8) << 8) + (hold >> 8)) % 31) {
+                strm->msg = (char *)"incorrect header check";
+                state->mode = BAD;
+                break;
+            }
+            if (BITS(4) != Z_DEFLATED) {
+                strm->msg = (char *)"unknown compression method";
+                state->mode = BAD;
+                break;
+            }
+            DROPBITS(4);
+            len = BITS(4) + 8;
+            if (state->wbits == 0)
+                state->wbits = len;
+            if (len > 15 || len > state->wbits) {
+                strm->msg = (char *)"invalid window size";
+                state->mode = BAD;
+                break;
+            }
+            state->dmax = 1U << len;
+            Tracev((stderr, "inflate:   zlib header ok\n"));
+            strm->adler = state->check = adler32(0L, Z_NULL, 0);
+            state->mode = hold & 0x200 ? DICTID : TYPE;
+            INITBITS();
+            break;
+#ifdef GUNZIP
+        case FLAGS:
+            NEEDBITS(16);
+            state->flags = (int)(hold);
+            if ((state->flags & 0xff) != Z_DEFLATED) {
+                strm->msg = (char *)"unknown compression method";
+                state->mode = BAD;
+                break;
+            }
+            if (state->flags & 0xe000) {
+                strm->msg = (char *)"unknown header flags set";
+                state->mode = BAD;
+                break;
+            }
+            if (state->head != Z_NULL)
+                state->head->text = (int)((hold >> 8) & 1);
+            if ((state->flags & 0x0200) && (state->wrap & 4))
+                CRC2(state->check, hold);
+            INITBITS();
+            state->mode = TIME;
+        case TIME:
+            NEEDBITS(32);
+            if (state->head != Z_NULL)
+                state->head->time = hold;
+            if ((state->flags & 0x0200) && (state->wrap & 4))
+                CRC4(state->check, hold);
+            INITBITS();
+            state->mode = OS;
+        case OS:
+            NEEDBITS(16);
+            if (state->head != Z_NULL) {
+                state->head->xflags = (int)(hold & 0xff);
+                state->head->os = (int)(hold >> 8);
+            }
+            if ((state->flags & 0x0200) && (state->wrap & 4))
+                CRC2(state->check, hold);
+            INITBITS();
+            state->mode = EXLEN;
+        case EXLEN:
+            if (state->flags & 0x0400) {
+                NEEDBITS(16);
+                state->length = (unsigned)(hold);
+                if (state->head != Z_NULL)
+                    state->head->extra_len = (unsigned)hold;
+                if ((state->flags & 0x0200) && (state->wrap & 4))
+                    CRC2(state->check, hold);
+                INITBITS();
+            }
+            else if (state->head != Z_NULL)
+                state->head->extra = Z_NULL;
+            state->mode = EXTRA;
+        case EXTRA:
+            if (state->flags & 0x0400) {
+                copy = state->length;
+                if (copy > have) copy = have;
+                if (copy) {
+                    if (state->head != Z_NULL &&
+                        state->head->extra != Z_NULL) {
+                        len = state->head->extra_len - state->length;
+                        zmemcpy(state->head->extra + len, next,
+                                len + copy > state->head->extra_max ?
+                                state->head->extra_max - len : copy);
+                    }
+                    if ((state->flags & 0x0200) && (state->wrap & 4))
+                        state->check = crc32(state->check, next, copy);
+                    have -= copy;
+                    next += copy;
+                    state->length -= copy;
+                }
+                if (state->length) goto inf_leave;
+            }
+            state->length = 0;
+            state->mode = NAME;
+        case NAME:
+            if (state->flags & 0x0800) {
+                if (have == 0) goto inf_leave;
+                copy = 0;
+                do {
+                    len = (unsigned)(next[copy++]);
+                    if (state->head != Z_NULL &&
+                            state->head->name != Z_NULL &&
+                            state->length < state->head->name_max)
+                        state->head->name[state->length++] = (Bytef)len;
+                } while (len && copy < have);
+                if ((state->flags & 0x0200) && (state->wrap & 4))
+                    state->check = crc32(state->check, next, copy);
+                have -= copy;
+                next += copy;
+                if (len) goto inf_leave;
+            }
+            else if (state->head != Z_NULL)
+                state->head->name = Z_NULL;
+            state->length = 0;
+            state->mode = COMMENT;
+        case COMMENT:
+            if (state->flags & 0x1000) {
+                if (have == 0) goto inf_leave;
+                copy = 0;
+                do {
+                    len = (unsigned)(next[copy++]);
+                    if (state->head != Z_NULL &&
+                            state->head->comment != Z_NULL &&
+                            state->length < state->head->comm_max)
+                        state->head->comment[state->length++] = (Bytef)len;
+                } while (len && copy < have);
+                if ((state->flags & 0x0200) && (state->wrap & 4))
+                    state->check = crc32(state->check, next, copy);
+                have -= copy;
+                next += copy;
+                if (len) goto inf_leave;
+            }
+            else if (state->head != Z_NULL)
+                state->head->comment = Z_NULL;
+            state->mode = HCRC;
+        case HCRC:
+            if (state->flags & 0x0200) {
+                NEEDBITS(16);
+                if ((state->wrap & 4) && hold != (state->check & 0xffff)) {
+                    strm->msg = (char *)"header crc mismatch";
+                    state->mode = BAD;
+                    break;
+                }
+                INITBITS();
+            }
+            if (state->head != Z_NULL) {
+                state->head->hcrc = (int)((state->flags >> 9) & 1);
+                state->head->done = 1;
+            }
+            strm->adler = state->check = crc32(0L, Z_NULL, 0);
+            state->mode = TYPE;
+            break;
+#endif
+        case DICTID:
+            NEEDBITS(32);
+            strm->adler = state->check = ZSWAP32(hold);
+            INITBITS();
+            state->mode = DICT;
+        case DICT:
+            if (state->havedict == 0) {
+                RESTORE();
+                return Z_NEED_DICT;
+            }
+            strm->adler = state->check = adler32(0L, Z_NULL, 0);
+            state->mode = TYPE;
+        case TYPE:
+            if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave;
+        case TYPEDO:
+            if (state->last) {
+                BYTEBITS();
+                state->mode = CHECK;
+                break;
+            }
+            NEEDBITS(3);
+            state->last = BITS(1);
+            DROPBITS(1);
+            switch (BITS(2)) {
+            case 0:                             /* stored block */
+                Tracev((stderr, "inflate:     stored block%s\n",
+                        state->last ? " (last)" : ""));
+                state->mode = STORED;
+                break;
+            case 1:                             /* fixed block */
+                fixedtables(state);
+                Tracev((stderr, "inflate:     fixed codes block%s\n",
+                        state->last ? " (last)" : ""));
+                state->mode = LEN_;             /* decode codes */
+                if (flush == Z_TREES) {
+                    DROPBITS(2);
+                    goto inf_leave;
+                }
+                break;
+            case 2:                             /* dynamic block */
+                Tracev((stderr, "inflate:     dynamic codes block%s\n",
+                        state->last ? " (last)" : ""));
+                state->mode = TABLE;
+                break;
+            case 3:
+                strm->msg = (char *)"invalid block type";
+                state->mode = BAD;
+            }
+            DROPBITS(2);
+            break;
+        case STORED:
+            BYTEBITS();                         /* go to byte boundary */
+            NEEDBITS(32);
+            if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
+                strm->msg = (char *)"invalid stored block lengths";
+                state->mode = BAD;
+                break;
+            }
+            state->length = (unsigned)hold & 0xffff;
+            Tracev((stderr, "inflate:       stored length %u\n",
+                    state->length));
+            INITBITS();
+            state->mode = COPY_;
+            if (flush == Z_TREES) goto inf_leave;
+        case COPY_:
+            state->mode = COPY;
+        case COPY:
+            copy = state->length;
+            if (copy) {
+                if (copy > have) copy = have;
+                if (copy > left) copy = left;
+                if (copy == 0) goto inf_leave;
+                zmemcpy(put, next, copy);
+                have -= copy;
+                next += copy;
+                left -= copy;
+                put += copy;
+                state->length -= copy;
+                break;
+            }
+            Tracev((stderr, "inflate:       stored end\n"));
+            state->mode = TYPE;
+            break;
+        case TABLE:
+            NEEDBITS(14);
+            state->nlen = BITS(5) + 257;
+            DROPBITS(5);
+            state->ndist = BITS(5) + 1;
+            DROPBITS(5);
+            state->ncode = BITS(4) + 4;
+            DROPBITS(4);
+#ifndef PKZIP_BUG_WORKAROUND
+            if (state->nlen > 286 || state->ndist > 30) {
+                strm->msg = (char *)"too many length or distance symbols";
+                state->mode = BAD;
+                break;
+            }
+#endif
+            Tracev((stderr, "inflate:       table sizes ok\n"));
+            state->have = 0;
+            state->mode = LENLENS;
+        case LENLENS:
+            while (state->have < state->ncode) {
+                NEEDBITS(3);
+                state->lens[order[state->have++]] = (unsigned short)BITS(3);
+                DROPBITS(3);
+            }
+            while (state->have < 19)
+                state->lens[order[state->have++]] = 0;
+            state->next = state->codes;
+            state->lencode = (const code FAR *)(state->next);
+            state->lenbits = 7;
+            ret = inflate_table(CODES, state->lens, 19, &(state->next),
+                                &(state->lenbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid code lengths set";
+                state->mode = BAD;
+                break;
+            }
+            Tracev((stderr, "inflate:       code lengths ok\n"));
+            state->have = 0;
+            state->mode = CODELENS;
+        case CODELENS:
+            while (state->have < state->nlen + state->ndist) {
+                for (;;) {
+                    here = state->lencode[BITS(state->lenbits)];
+                    if ((unsigned)(here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                if (here.val < 16) {
+                    DROPBITS(here.bits);
+                    state->lens[state->have++] = here.val;
+                }
+                else {
+                    if (here.val == 16) {
+                        NEEDBITS(here.bits + 2);
+                        DROPBITS(here.bits);
+                        if (state->have == 0) {
+                            strm->msg = (char *)"invalid bit length repeat";
+                            state->mode = BAD;
+                            break;
+                        }
+                        len = state->lens[state->have - 1];
+                        copy = 3 + BITS(2);
+                        DROPBITS(2);
+                    }
+                    else if (here.val == 17) {
+                        NEEDBITS(here.bits + 3);
+                        DROPBITS(here.bits);
+                        len = 0;
+                        copy = 3 + BITS(3);
+                        DROPBITS(3);
+                    }
+                    else {
+                        NEEDBITS(here.bits + 7);
+                        DROPBITS(here.bits);
+                        len = 0;
+                        copy = 11 + BITS(7);
+                        DROPBITS(7);
+                    }
+                    if (state->have + copy > state->nlen + state->ndist) {
+                        strm->msg = (char *)"invalid bit length repeat";
+                        state->mode = BAD;
+                        break;
+                    }
+                    while (copy--)
+                        state->lens[state->have++] = (unsigned short)len;
+                }
+            }
+
+            /* handle error breaks in while */
+            if (state->mode == BAD) break;
+
+            /* check for end-of-block code (better have one) */
+            if (state->lens[256] == 0) {
+                strm->msg = (char *)"invalid code -- missing end-of-block";
+                state->mode = BAD;
+                break;
+            }
+
+            /* build code tables -- note: do not change the lenbits or distbits
+               values here (9 and 6) without reading the comments in inftrees.h
+               concerning the ENOUGH constants, which depend on those values */
+            state->next = state->codes;
+            state->lencode = (const code FAR *)(state->next);
+            state->lenbits = 9;
+            ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
+                                &(state->lenbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid literal/lengths set";
+                state->mode = BAD;
+                break;
+            }
+            state->distcode = (const code FAR *)(state->next);
+            state->distbits = 6;
+            ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
+                            &(state->next), &(state->distbits), state->work);
+            if (ret) {
+                strm->msg = (char *)"invalid distances set";
+                state->mode = BAD;
+                break;
+            }
+            Tracev((stderr, "inflate:       codes ok\n"));
+            state->mode = LEN_;
+            if (flush == Z_TREES) goto inf_leave;
+        case LEN_:
+            state->mode = LEN;
+        case LEN:
+            if (have >= 6 && left >= 258) {
+                RESTORE();
+                inflate_fast(strm, out);
+                LOAD();
+                if (state->mode == TYPE)
+                    state->back = -1;
+                break;
+            }
+            state->back = 0;
+            for (;;) {
+                here = state->lencode[BITS(state->lenbits)];
+                if ((unsigned)(here.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if (here.op && (here.op & 0xf0) == 0) {
+                last = here;
+                for (;;) {
+                    here = state->lencode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+                state->back += last.bits;
+            }
+            DROPBITS(here.bits);
+            state->back += here.bits;
+            state->length = (unsigned)here.val;
+            if ((int)(here.op) == 0) {
+                Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
+                        "inflate:         literal '%c'\n" :
+                        "inflate:         literal 0x%02x\n", here.val));
+                state->mode = LIT;
+                break;
+            }
+            if (here.op & 32) {
+                Tracevv((stderr, "inflate:         end of block\n"));
+                state->back = -1;
+                state->mode = TYPE;
+                break;
+            }
+            if (here.op & 64) {
+                strm->msg = (char *)"invalid literal/length code";
+                state->mode = BAD;
+                break;
+            }
+            state->extra = (unsigned)(here.op) & 15;
+            state->mode = LENEXT;
+        case LENEXT:
+            if (state->extra) {
+                NEEDBITS(state->extra);
+                state->length += BITS(state->extra);
+                DROPBITS(state->extra);
+                state->back += state->extra;
+            }
+            Tracevv((stderr, "inflate:         length %u\n", state->length));
+            state->was = state->length;
+            state->mode = DIST;
+        case DIST:
+            for (;;) {
+                here = state->distcode[BITS(state->distbits)];
+                if ((unsigned)(here.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if ((here.op & 0xf0) == 0) {
+                last = here;
+                for (;;) {
+                    here = state->distcode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + here.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+                state->back += last.bits;
+            }
+            DROPBITS(here.bits);
+            state->back += here.bits;
+            if (here.op & 64) {
+                strm->msg = (char *)"invalid distance code";
+                state->mode = BAD;
+                break;
+            }
+            state->offset = (unsigned)here.val;
+            state->extra = (unsigned)(here.op) & 15;
+            state->mode = DISTEXT;
+        case DISTEXT:
+            if (state->extra) {
+                NEEDBITS(state->extra);
+                state->offset += BITS(state->extra);
+                DROPBITS(state->extra);
+                state->back += state->extra;
+            }
+#ifdef INFLATE_STRICT
+            if (state->offset > state->dmax) {
+                strm->msg = (char *)"invalid distance too far back";
+                state->mode = BAD;
+                break;
+            }
+#endif
+            Tracevv((stderr, "inflate:         distance %u\n", state->offset));
+            state->mode = MATCH;
+        case MATCH:
+            if (left == 0) goto inf_leave;
+            copy = out - left;
+            if (state->offset > copy) {         /* copy from window */
+                copy = state->offset - copy;
+                if (copy > state->whave) {
+                    if (state->sane) {
+                        strm->msg = (char *)"invalid distance too far back";
+                        state->mode = BAD;
+                        break;
+                    }
+#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
+                    Trace((stderr, "inflate.c too far\n"));
+                    copy -= state->whave;
+                    if (copy > state->length) copy = state->length;
+                    if (copy > left) copy = left;
+                    left -= copy;
+                    state->length -= copy;
+                    do {
+                        *put++ = 0;
+                    } while (--copy);
+                    if (state->length == 0) state->mode = LEN;
+                    break;
+#endif
+                }
+                if (copy > state->wnext) {
+                    copy -= state->wnext;
+                    from = state->window + (state->wsize - copy);
+                }
+                else
+                    from = state->window + (state->wnext - copy);
+                if (copy > state->length) copy = state->length;
+            }
+            else {                              /* copy from output */
+                from = put - state->offset;
+                copy = state->length;
+            }
+            if (copy > left) copy = left;
+            left -= copy;
+            state->length -= copy;
+            do {
+                *put++ = *from++;
+            } while (--copy);
+            if (state->length == 0) state->mode = LEN;
+            break;
+        case LIT:
+            if (left == 0) goto inf_leave;
+            *put++ = (unsigned char)(state->length);
+            left--;
+            state->mode = LEN;
+            break;
+        case CHECK:
+            if (state->wrap) {
+                NEEDBITS(32);
+                out -= left;
+                strm->total_out += out;
+                state->total += out;
+                if ((state->wrap & 4) && out)
+                    strm->adler = state->check =
+                        UPDATE(state->check, put - out, out);
+                out = left;
+                if ((state->wrap & 4) && (
+#ifdef GUNZIP
+                     state->flags ? hold :
+#endif
+                     ZSWAP32(hold)) != state->check) {
+                    strm->msg = (char *)"incorrect data check";
+                    state->mode = BAD;
+                    break;
+                }
+                INITBITS();
+                Tracev((stderr, "inflate:   check matches trailer\n"));
+            }
+#ifdef GUNZIP
+            state->mode = LENGTH;
+        case LENGTH:
+            if (state->wrap && state->flags) {
+                NEEDBITS(32);
+                if (hold != (state->total & 0xffffffffUL)) {
+                    strm->msg = (char *)"incorrect length check";
+                    state->mode = BAD;
+                    break;
+                }
+                INITBITS();
+                Tracev((stderr, "inflate:   length matches trailer\n"));
+            }
+#endif
+            state->mode = DONE;
+        case DONE:
+            ret = Z_STREAM_END;
+            goto inf_leave;
+        case BAD:
+            ret = Z_DATA_ERROR;
+            goto inf_leave;
+        case MEM:
+            return Z_MEM_ERROR;
+        case SYNC:
+        default:
+            return Z_STREAM_ERROR;
+        }
+
+    /*
+       Return from inflate(), updating the total counts and the check value.
+       If there was no progress during the inflate() call, return a buffer
+       error.  Call updatewindow() to create and/or update the window state.
+       Note: a memory error from inflate() is non-recoverable.
+     */
+  inf_leave:
+    RESTORE();
+    if (state->wsize || (out != strm->avail_out && state->mode < BAD &&
+            (state->mode < CHECK || flush != Z_FINISH)))
+        if (updatewindow(strm, strm->next_out, out - strm->avail_out)) {
+            state->mode = MEM;
+            return Z_MEM_ERROR;
+        }
+    in -= strm->avail_in;
+    out -= strm->avail_out;
+    strm->total_in += in;
+    strm->total_out += out;
+    state->total += out;
+    if ((state->wrap & 4) && out)
+        strm->adler = state->check =
+            UPDATE(state->check, strm->next_out - out, out);
+    strm->data_type = (int)state->bits + (state->last ? 64 : 0) +
+                      (state->mode == TYPE ? 128 : 0) +
+                      (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
+    if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
+        ret = Z_BUF_ERROR;
+    return ret;
+}
+
+int ZEXPORT inflateEnd(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+    if (inflateStateCheck(strm))
+        return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    if (state->window != Z_NULL) ZFREE(strm, state->window);
+    ZFREE(strm, strm->state);
+    strm->state = Z_NULL;
+    Tracev((stderr, "inflate: end\n"));
+    return Z_OK;
+}
+
+int ZEXPORT inflateGetDictionary(strm, dictionary, dictLength)
+z_streamp strm;
+Bytef *dictionary;
+uInt *dictLength;
+{
+    struct inflate_state FAR *state;
+
+    /* check state */
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+
+    /* copy dictionary */
+    if (state->whave && dictionary != Z_NULL) {
+        zmemcpy(dictionary, state->window + state->wnext,
+                state->whave - state->wnext);
+        zmemcpy(dictionary + state->whave - state->wnext,
+                state->window, state->wnext);
+    }
+    if (dictLength != Z_NULL)
+        *dictLength = state->whave;
+    return Z_OK;
+}
+
+int ZEXPORT inflateSetDictionary(strm, dictionary, dictLength)
+z_streamp strm;
+const Bytef *dictionary;
+uInt dictLength;
+{
+    struct inflate_state FAR *state;
+    unsigned long dictid;
+    int ret;
+
+    /* check state */
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    if (state->wrap != 0 && state->mode != DICT)
+        return Z_STREAM_ERROR;
+
+    /* check for correct dictionary identifier */
+    if (state->mode == DICT) {
+        dictid = adler32(0L, Z_NULL, 0);
+        dictid = adler32(dictid, dictionary, dictLength);
+        if (dictid != state->check)
+            return Z_DATA_ERROR;
+    }
+
+    /* copy dictionary to window using updatewindow(), which will amend the
+       existing dictionary if appropriate */
+    ret = updatewindow(strm, dictionary + dictLength, dictLength);
+    if (ret) {
+        state->mode = MEM;
+        return Z_MEM_ERROR;
+    }
+    state->havedict = 1;
+    Tracev((stderr, "inflate:   dictionary set\n"));
+    return Z_OK;
+}
+
+int ZEXPORT inflateGetHeader(strm, head)
+z_streamp strm;
+gz_headerp head;
+{
+    struct inflate_state FAR *state;
+
+    /* check state */
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    if ((state->wrap & 2) == 0) return Z_STREAM_ERROR;
+
+    /* save header structure */
+    state->head = head;
+    head->done = 0;
+    return Z_OK;
+}
+
+/*
+   Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff.  Return when found
+   or when out of input.  When called, *have is the number of pattern bytes
+   found in order so far, in 0..3.  On return *have is updated to the new
+   state.  If on return *have equals four, then the pattern was found and the
+   return value is how many bytes were read including the last byte of the
+   pattern.  If *have is less than four, then the pattern has not been found
+   yet and the return value is len.  In the latter case, syncsearch() can be
+   called again with more data and the *have state.  *have is initialized to
+   zero for the first call.
+ */
+local unsigned syncsearch(have, buf, len)
+unsigned FAR *have;
+const unsigned char FAR *buf;
+unsigned len;
+{
+    unsigned got;
+    unsigned next;
+
+    got = *have;
+    next = 0;
+    while (next < len && got < 4) {
+        if ((int)(buf[next]) == (got < 2 ? 0 : 0xff))
+            got++;
+        else if (buf[next])
+            got = 0;
+        else
+            got = 4 - got;
+        next++;
+    }
+    *have = got;
+    return next;
+}
+
+int ZEXPORT inflateSync(strm)
+z_streamp strm;
+{
+    unsigned len;               /* number of bytes to look at or looked at */
+    unsigned long in, out;      /* temporary to save total_in and total_out */
+    unsigned char buf[4];       /* to restore bit buffer to byte string */
+    struct inflate_state FAR *state;
+
+    /* check parameters */
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;
+
+    /* if first time, start search in bit buffer */
+    if (state->mode != SYNC) {
+        state->mode = SYNC;
+        state->hold <<= state->bits & 7;
+        state->bits -= state->bits & 7;
+        len = 0;
+        while (state->bits >= 8) {
+            buf[len++] = (unsigned char)(state->hold);
+            state->hold >>= 8;
+            state->bits -= 8;
+        }
+        state->have = 0;
+        syncsearch(&(state->have), buf, len);
+    }
+
+    /* search available input */
+    len = syncsearch(&(state->have), strm->next_in, strm->avail_in);
+    strm->avail_in -= len;
+    strm->next_in += len;
+    strm->total_in += len;
+
+    /* return no joy or set up to restart inflate() on a new block */
+    if (state->have != 4) return Z_DATA_ERROR;
+    in = strm->total_in;  out = strm->total_out;
+    inflateReset(strm);
+    strm->total_in = in;  strm->total_out = out;
+    state->mode = TYPE;
+    return Z_OK;
+}
+
+/*
+   Returns true if inflate is currently at the end of a block generated by
+   Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
+   implementation to provide an additional safety check. PPP uses
+   Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored
+   block. When decompressing, PPP checks that at the end of input packet,
+   inflate is waiting for these length bytes.
+ */
+int ZEXPORT inflateSyncPoint(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    return state->mode == STORED && state->bits == 0;
+}
+
+int ZEXPORT inflateCopy(dest, source)
+z_streamp dest;
+z_streamp source;
+{
+    struct inflate_state FAR *state;
+    struct inflate_state FAR *copy;
+    unsigned char FAR *window;
+    unsigned wsize;
+
+    /* check input */
+    if (inflateStateCheck(source) || dest == Z_NULL)
+        return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)source->state;
+
+    /* allocate space */
+    copy = (struct inflate_state FAR *)
+           ZALLOC(source, 1, sizeof(struct inflate_state));
+    if (copy == Z_NULL) return Z_MEM_ERROR;
+    window = Z_NULL;
+    if (state->window != Z_NULL) {
+        window = (unsigned char FAR *)
+                 ZALLOC(source, 1U << state->wbits, sizeof(unsigned char));
+        if (window == Z_NULL) {
+            ZFREE(source, copy);
+            return Z_MEM_ERROR;
+        }
+    }
+
+    /* copy state */
+    zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream));
+    zmemcpy((voidpf)copy, (voidpf)state, sizeof(struct inflate_state));
+    copy->strm = dest;
+    if (state->lencode >= state->codes &&
+        state->lencode <= state->codes + ENOUGH - 1) {
+        copy->lencode = copy->codes + (state->lencode - state->codes);
+        copy->distcode = copy->codes + (state->distcode - state->codes);
+    }
+    copy->next = copy->codes + (state->next - state->codes);
+    if (window != Z_NULL) {
+        wsize = 1U << state->wbits;
+        zmemcpy(window, state->window, wsize);
+    }
+    copy->window = window;
+    dest->state = (struct internal_state FAR *)copy;
+    return Z_OK;
+}
+
+int ZEXPORT inflateUndermine(strm, subvert)
+z_streamp strm;
+int subvert;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
+    state->sane = !subvert;
+    return Z_OK;
+#else
+    (void)subvert;
+    state->sane = 1;
+    return Z_DATA_ERROR;
+#endif
+}
+
+int ZEXPORT inflateValidate(strm, check)
+z_streamp strm;
+int check;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+    state = (struct inflate_state FAR *)strm->state;
+    if (check)
+        state->wrap |= 4;
+    else
+        state->wrap &= ~4;
+    return Z_OK;
+}
+
+long ZEXPORT inflateMark(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+
+    if (inflateStateCheck(strm))
+        return -(1L << 16);
+    state = (struct inflate_state FAR *)strm->state;
+    return (long)(((unsigned long)((long)state->back)) << 16) +
+        (state->mode == COPY ? state->length :
+            (state->mode == MATCH ? state->was - state->length : 0));
+}
+
+unsigned long ZEXPORT inflateCodesUsed(strm)
+z_streamp strm;
+{
+    struct inflate_state FAR *state;
+    if (inflateStateCheck(strm)) return (unsigned long)-1;
+    state = (struct inflate_state FAR *)strm->state;
+    return (unsigned long)(state->next - state->codes);
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/inflate.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/inflate.h	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,125 @@
+/* inflate.h -- internal inflate state definition
+ * Copyright (C) 1995-2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+/* define NO_GZIP when compiling if you want to disable gzip header and
+   trailer decoding by inflate().  NO_GZIP would be used to avoid linking in
+   the crc code when it is not needed.  For shared libraries, gzip decoding
+   should be left enabled. */
+#ifndef NO_GZIP
+#  define GUNZIP
+#endif
+
+/* Possible inflate modes between inflate() calls */
+typedef enum {
+    HEAD = 16180,   /* i: waiting for magic header */
+    FLAGS,      /* i: waiting for method and flags (gzip) */
+    TIME,       /* i: waiting for modification time (gzip) */
+    OS,         /* i: waiting for extra flags and operating system (gzip) */
+    EXLEN,      /* i: waiting for extra length (gzip) */
+    EXTRA,      /* i: waiting for extra bytes (gzip) */
+    NAME,       /* i: waiting for end of file name (gzip) */
+    COMMENT,    /* i: waiting for end of comment (gzip) */
+    HCRC,       /* i: waiting for header crc (gzip) */
+    DICTID,     /* i: waiting for dictionary check value */
+    DICT,       /* waiting for inflateSetDictionary() call */
+        TYPE,       /* i: waiting for type bits, including last-flag bit */
+        TYPEDO,     /* i: same, but skip check to exit inflate on new block */
+        STORED,     /* i: waiting for stored size (length and complement) */
+        COPY_,      /* i/o: same as COPY below, but only first time in */
+        COPY,       /* i/o: waiting for input or output to copy stored block */
+        TABLE,      /* i: waiting for dynamic block table lengths */
+        LENLENS,    /* i: waiting for code length code lengths */
+        CODELENS,   /* i: waiting for length/lit and distance code lengths */
+            LEN_,       /* i: same as LEN below, but only first time in */
+            LEN,        /* i: waiting for length/lit/eob code */
+            LENEXT,     /* i: waiting for length extra bits */
+            DIST,       /* i: waiting for distance code */
+            DISTEXT,    /* i: waiting for distance extra bits */
+            MATCH,      /* o: waiting for output space to copy string */
+            LIT,        /* o: waiting for output space to write literal */
+    CHECK,      /* i: waiting for 32-bit check value */
+    LENGTH,     /* i: waiting for 32-bit length (gzip) */
+    DONE,       /* finished check, done -- remain here until reset */
+    BAD,        /* got a data error -- remain here until reset */
+    MEM,        /* got an inflate() memory error -- remain here until reset */
+    SYNC        /* looking for synchronization bytes to restart inflate() */
+} inflate_mode;
+
+/*
+    State transitions between above modes -
+
+    (most modes can go to BAD or MEM on error -- not shown for clarity)
+
+    Process header:
+        HEAD -> (gzip) or (zlib) or (raw)
+        (gzip) -> FLAGS -> TIME -> OS -> EXLEN -> EXTRA -> NAME -> COMMENT ->
+                  HCRC -> TYPE
+        (zlib) -> DICTID or TYPE
+        DICTID -> DICT -> TYPE
+        (raw) -> TYPEDO
+    Read deflate blocks:
+            TYPE -> TYPEDO -> STORED or TABLE or LEN_ or CHECK
+            STORED -> COPY_ -> COPY -> TYPE
+            TABLE -> LENLENS -> CODELENS -> LEN_
+            LEN_ -> LEN
+    Read deflate codes in fixed or dynamic block:
+                LEN -> LENEXT or LIT or TYPE
+                LENEXT -> DIST -> DISTEXT -> MATCH -> LEN
+                LIT -> LEN
+    Process trailer:
+        CHECK -> LENGTH -> DONE
+ */
+
+/* State maintained between inflate() calls -- approximately 7K bytes, not
+   including the allocated sliding window, which is up to 32K bytes. */
+struct inflate_state {
+    z_streamp strm;             /* pointer back to this zlib stream */
+    inflate_mode mode;          /* current inflate mode */
+    int last;                   /* true if processing last block */
+    int wrap;                   /* bit 0 true for zlib, bit 1 true for gzip,
+                                   bit 2 true to validate check value */
+    int havedict;               /* true if dictionary provided */
+    int flags;                  /* gzip header method and flags (0 if zlib) */
+    unsigned dmax;              /* zlib header max distance (INFLATE_STRICT) */
+    unsigned long check;        /* protected copy of check value */
+    unsigned long total;        /* protected copy of output count */
+    gz_headerp head;            /* where to save gzip header information */
+        /* sliding window */
+    unsigned wbits;             /* log base 2 of requested window size */
+    unsigned wsize;             /* window size or zero if not using window */
+    unsigned whave;             /* valid bytes in the window */
+    unsigned wnext;             /* window write index */
+    unsigned char FAR *window;  /* allocated sliding window, if needed */
+        /* bit accumulator */
+    unsigned long hold;         /* input bit accumulator */
+    unsigned bits;              /* number of bits in "in" */
+        /* for string and stored block copying */
+    unsigned length;            /* literal or length of data to copy */
+    unsigned offset;            /* distance back to copy string from */
+        /* for table and code decoding */
+    unsigned extra;             /* extra bits needed */
+        /* fixed and dynamic code tables */
+    code const FAR *lencode;    /* starting table for length/literal codes */
+    code const FAR *distcode;   /* starting table for distance codes */
+    unsigned lenbits;           /* index bits for lencode */
+    unsigned distbits;          /* index bits for distcode */
+        /* dynamic table building */
+    unsigned ncode;             /* number of code length code lengths */
+    unsigned nlen;              /* number of length code lengths */
+    unsigned ndist;             /* number of distance code lengths */
+    unsigned have;              /* number of code lengths in lens[] */
+    code FAR *next;             /* next available space in codes[] */
+    unsigned short lens[320];   /* temporary storage for code lengths */
+    unsigned short work[288];   /* work area for code table building */
+    code codes[ENOUGH];         /* space for code tables */
+    int sane;                   /* if false, allow invalid distance too far */
+    int back;                   /* bits back of last unprocessed length/lit */
+    unsigned was;               /* initial length of match */
+};
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/inftrees.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/inftrees.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,304 @@
+/* inftrees.c -- generate Huffman trees for efficient decoding
+ * Copyright (C) 1995-2017 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "zutil.h"
+#include "inftrees.h"
+
+#define MAXBITS 15
+
+const char inflate_copyright[] =
+   " inflate 1.2.11 Copyright 1995-2017 Mark Adler ";
+/*
+  If you use the zlib library in a product, an acknowledgment is welcome
+  in the documentation of your product. If for some reason you cannot
+  include such an acknowledgment, I would appreciate that you keep this
+  copyright string in the executable of your product.
+ */
+
+/*
+   Build a set of tables to decode the provided canonical Huffman code.
+   The code lengths are lens[0..codes-1].  The result starts at *table,
+   whose indices are 0..2^bits-1.  work is a writable array of at least
+   lens shorts, which is used as a work area.  type is the type of code
+   to be generated, CODES, LENS, or DISTS.  On return, zero is success,
+   -1 is an invalid code, and +1 means that ENOUGH isn't enough.  table
+   on return points to the next available entry's address.  bits is the
+   requested root table index bits, and on return it is the actual root
+   table index bits.  It will differ if the request is greater than the
+   longest code or if it is less than the shortest code.
+ */
+int ZLIB_INTERNAL inflate_table(type, lens, codes, table, bits, work)
+codetype type;
+unsigned short FAR *lens;
+unsigned codes;
+code FAR * FAR *table;
+unsigned FAR *bits;
+unsigned short FAR *work;
+{
+    unsigned len;               /* a code's length in bits */
+    unsigned sym;               /* index of code symbols */
+    unsigned min, max;          /* minimum and maximum code lengths */
+    unsigned root;              /* number of index bits for root table */
+    unsigned curr;              /* number of index bits for current table */
+    unsigned drop;              /* code bits to drop for sub-table */
+    int left;                   /* number of prefix codes available */
+    unsigned used;              /* code entries in table used */
+    unsigned huff;              /* Huffman code */
+    unsigned incr;              /* for incrementing code, index */
+    unsigned fill;              /* index for replicating entries */
+    unsigned low;               /* low bits for current root entry */
+    unsigned mask;              /* mask for low root bits */
+    code here;                  /* table entry for duplication */
+    code FAR *next;             /* next available space in table */
+    const unsigned short FAR *base;     /* base value table to use */
+    const unsigned short FAR *extra;    /* extra bits table to use */
+    unsigned match;             /* use base and extra for symbol >= match */
+    unsigned short count[MAXBITS+1];    /* number of codes of each length */
+    unsigned short offs[MAXBITS+1];     /* offsets in table for each length */
+    static const unsigned short lbase[31] = { /* Length codes 257..285 base */
+        3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
+        35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
+    static const unsigned short lext[31] = { /* Length codes 257..285 extra */
+        16, 16, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 18,
+        19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 16, 77, 202};
+    static const unsigned short dbase[32] = { /* Distance codes 0..29 base */
+        1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
+        257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
+        8193, 12289, 16385, 24577, 0, 0};
+    static const unsigned short dext[32] = { /* Distance codes 0..29 extra */
+        16, 16, 16, 16, 17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22,
+        23, 23, 24, 24, 25, 25, 26, 26, 27, 27,
+        28, 28, 29, 29, 64, 64};
+
+    /*
+       Process a set of code lengths to create a canonical Huffman code.  The
+       code lengths are lens[0..codes-1].  Each length corresponds to the
+       symbols 0..codes-1.  The Huffman code is generated by first sorting the
+       symbols by length from short to long, and retaining the symbol order
+       for codes with equal lengths.  Then the code starts with all zero bits
+       for the first code of the shortest length, and the codes are integer
+       increments for the same length, and zeros are appended as the length
+       increases.  For the deflate format, these bits are stored backwards
+       from their more natural integer increment ordering, and so when the
+       decoding tables are built in the large loop below, the integer codes
+       are incremented backwards.
+
+       This routine assumes, but does not check, that all of the entries in
+       lens[] are in the range 0..MAXBITS.  The caller must assure this.
+       1..MAXBITS is interpreted as that code length.  zero means that that
+       symbol does not occur in this code.
+
+       The codes are sorted by computing a count of codes for each length,
+       creating from that a table of starting indices for each length in the
+       sorted table, and then entering the symbols in order in the sorted
+       table.  The sorted table is work[], with that space being provided by
+       the caller.
+
+       The length counts are used for other purposes as well, i.e. finding
+       the minimum and maximum length codes, determining if there are any
+       codes at all, checking for a valid set of lengths, and looking ahead
+       at length counts to determine sub-table sizes when building the
+       decoding tables.
+     */
+
+    /* accumulate lengths for codes (assumes lens[] all in 0..MAXBITS) */
+    for (len = 0; len <= MAXBITS; len++)
+        count[len] = 0;
+    for (sym = 0; sym < codes; sym++)
+        count[lens[sym]]++;
+
+    /* bound code lengths, force root to be within code lengths */
+    root = *bits;
+    for (max = MAXBITS; max >= 1; max--)
+        if (count[max] != 0) break;
+    if (root > max) root = max;
+    if (max == 0) {                     /* no symbols to code at all */
+        here.op = (unsigned char)64;    /* invalid code marker */
+        here.bits = (unsigned char)1;
+        here.val = (unsigned short)0;
+        *(*table)++ = here;             /* make a table to force an error */
+        *(*table)++ = here;
+        *bits = 1;
+        return 0;     /* no symbols, but wait for decoding to report error */
+    }
+    for (min = 1; min < max; min++)
+        if (count[min] != 0) break;
+    if (root < min) root = min;
+
+    /* check for an over-subscribed or incomplete set of lengths */
+    left = 1;
+    for (len = 1; len <= MAXBITS; len++) {
+        left <<= 1;
+        left -= count[len];
+        if (left < 0) return -1;        /* over-subscribed */
+    }
+    if (left > 0 && (type == CODES || max != 1))
+        return -1;                      /* incomplete set */
+
+    /* generate offsets into symbol table for each length for sorting */
+    offs[1] = 0;
+    for (len = 1; len < MAXBITS; len++)
+        offs[len + 1] = offs[len] + count[len];
+
+    /* sort symbols by length, by symbol order within each length */
+    for (sym = 0; sym < codes; sym++)
+        if (lens[sym] != 0) work[offs[lens[sym]]++] = (unsigned short)sym;
+
+    /*
+       Create and fill in decoding tables.  In this loop, the table being
+       filled is at next and has curr index bits.  The code being used is huff
+       with length len.  That code is converted to an index by dropping drop
+       bits off of the bottom.  For codes where len is less than drop + curr,
+       those top drop + curr - len bits are incremented through all values to
+       fill the table with replicated entries.
+
+       root is the number of index bits for the root table.  When len exceeds
+       root, sub-tables are created pointed to by the root entry with an index
+       of the low root bits of huff.  This is saved in low to check for when a
+       new sub-table should be started.  drop is zero when the root table is
+       being filled, and drop is root when sub-tables are being filled.
+
+       When a new sub-table is needed, it is necessary to look ahead in the
+       code lengths to determine what size sub-table is needed.  The length
+       counts are used for this, and so count[] is decremented as codes are
+       entered in the tables.
+
+       used keeps track of how many table entries have been allocated from the
+       provided *table space.  It is checked for LENS and DIST tables against
+       the constants ENOUGH_LENS and ENOUGH_DISTS to guard against changes in
+       the initial root table size constants.  See the comments in inftrees.h
+       for more information.
+
+       sym increments through all symbols, and the loop terminates when
+       all codes of length max, i.e. all codes, have been processed.  This
+       routine permits incomplete codes, so another loop after this one fills
+       in the rest of the decoding tables with invalid code markers.
+     */
+
+    /* set up for code type */
+    switch (type) {
+    case CODES:
+        base = extra = work;    /* dummy value--not used */
+        match = 20;
+        break;
+    case LENS:
+        base = lbase;
+        extra = lext;
+        match = 257;
+        break;
+    default:    /* DISTS */
+        base = dbase;
+        extra = dext;
+        match = 0;
+    }
+
+    /* initialize state for loop */
+    huff = 0;                   /* starting code */
+    sym = 0;                    /* starting code symbol */
+    len = min;                  /* starting code length */
+    next = *table;              /* current table to fill in */
+    curr = root;                /* current table index bits */
+    drop = 0;                   /* current bits to drop from code for index */
+    low = (unsigned)(-1);       /* trigger new sub-table when len > root */
+    used = 1U << root;          /* use root table entries */
+    mask = used - 1;            /* mask for comparing low */
+
+    /* check available table space */
+    if ((type == LENS && used > ENOUGH_LENS) ||
+        (type == DISTS && used > ENOUGH_DISTS))
+        return 1;
+
+    /* process all codes and make table entries */
+    for (;;) {
+        /* create table entry */
+        here.bits = (unsigned char)(len - drop);
+        if (work[sym] + 1U < match) {
+            here.op = (unsigned char)0;
+            here.val = work[sym];
+        }
+        else if (work[sym] >= match) {
+            here.op = (unsigned char)(extra[work[sym] - match]);
+            here.val = base[work[sym] - match];
+        }
+        else {
+            here.op = (unsigned char)(32 + 64);         /* end of block */
+            here.val = 0;
+        }
+
+        /* replicate for those indices with low len bits equal to huff */
+        incr = 1U << (len - drop);
+        fill = 1U << curr;
+        min = fill;                 /* save offset to next table */
+        do {
+            fill -= incr;
+            next[(huff >> drop) + fill] = here;
+        } while (fill != 0);
+
+        /* backwards increment the len-bit code huff */
+        incr = 1U << (len - 1);
+        while (huff & incr)
+            incr >>= 1;
+        if (incr != 0) {
+            huff &= incr - 1;
+            huff += incr;
+        }
+        else
+            huff = 0;
+
+        /* go to next symbol, update count, len */
+        sym++;
+        if (--(count[len]) == 0) {
+            if (len == max) break;
+            len = lens[work[sym]];
+        }
+
+        /* create new sub-table if needed */
+        if (len > root && (huff & mask) != low) {
+            /* if first time, transition to sub-tables */
+            if (drop == 0)
+                drop = root;
+
+            /* increment past last table */
+            next += min;            /* here min is 1 << curr */
+
+            /* determine length of next table */
+            curr = len - drop;
+            left = (int)(1 << curr);
+            while (curr + drop < max) {
+                left -= count[curr + drop];
+                if (left <= 0) break;
+                curr++;
+                left <<= 1;
+            }
+
+            /* check for enough space */
+            used += 1U << curr;
+            if ((type == LENS && used > ENOUGH_LENS) ||
+                (type == DISTS && used > ENOUGH_DISTS))
+                return 1;
+
+            /* point entry in root table to sub-table */
+            low = huff & mask;
+            (*table)[low].op = (unsigned char)curr;
+            (*table)[low].bits = (unsigned char)root;
+            (*table)[low].val = (unsigned short)(next - *table);
+        }
+    }
+
+    /* fill in remaining table entry if code is incomplete (guaranteed to have
+       at most one remaining entry, since if the code is incomplete, the
+       maximum code length that was allowed to get this far is one bit) */
+    if (huff != 0) {
+        here.op = (unsigned char)64;            /* invalid code marker */
+        here.bits = (unsigned char)(len - drop);
+        here.val = (unsigned short)0;
+        next[huff] = here;
+    }
+
+    /* set return parameters */
+    *table += used;
+    *bits = root;
+    return 0;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/inftrees.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/inftrees.h	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,62 @@
+/* inftrees.h -- header to use inftrees.c
+ * Copyright (C) 1995-2005, 2010 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+/* Structure for decoding tables.  Each entry provides either the
+   information needed to do the operation requested by the code that
+   indexed that table entry, or it provides a pointer to another
+   table that indexes more bits of the code.  op indicates whether
+   the entry is a pointer to another table, a literal, a length or
+   distance, an end-of-block, or an invalid code.  For a table
+   pointer, the low four bits of op is the number of index bits of
+   that table.  For a length or distance, the low four bits of op
+   is the number of extra bits to get after the code.  bits is
+   the number of bits in this code or part of the code to drop off
+   of the bit buffer.  val is the actual byte to output in the case
+   of a literal, the base length or distance, or the offset from
+   the current table to the next table.  Each entry is four bytes. */
+typedef struct {
+    unsigned char op;           /* operation, extra bits, table bits */
+    unsigned char bits;         /* bits in this part of the code */
+    unsigned short val;         /* offset in table or code value */
+} code;
+
+/* op values as set by inflate_table():
+    00000000 - literal
+    0000tttt - table link, tttt != 0 is the number of table index bits
+    0001eeee - length or distance, eeee is the number of extra bits
+    01100000 - end of block
+    01000000 - invalid code
+ */
+
+/* Maximum size of the dynamic table.  The maximum number of code structures is
+   1444, which is the sum of 852 for literal/length codes and 592 for distance
+   codes.  These values were found by exhaustive searches using the program
+   examples/enough.c found in the zlib distribtution.  The arguments to that
+   program are the number of symbols, the initial root table size, and the
+   maximum bit length of a code.  "enough 286 9 15" for literal/length codes
+   returns returns 852, and "enough 30 6 15" for distance codes returns 592.
+   The initial root table size (9 or 6) is found in the fifth argument of the
+   inflate_table() calls in inflate.c and infback.c.  If the root table size is
+   changed, then these maximum sizes would be need to be recalculated and
+   updated. */
+#define ENOUGH_LENS 852
+#define ENOUGH_DISTS 592
+#define ENOUGH (ENOUGH_LENS+ENOUGH_DISTS)
+
+/* Type of code to build for inflate_table() */
+typedef enum {
+    CODES,
+    LENS,
+    DISTS
+} codetype;
+
+int ZLIB_INTERNAL inflate_table OF((codetype type, unsigned short FAR *lens,
+                             unsigned codes, code FAR * FAR *table,
+                             unsigned FAR *bits, unsigned short FAR *work));
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/mkfile
--- a/sys/src/ape/lib/z/mkfile	Sun Mar 01 23:23:01 2020 +0100
+++ b/sys/src/ape/lib/z/mkfile	Mon Mar 02 00:58:11 2020 -0400
@@ -1,48 +1,41 @@
 APE=/sys/src/ape
 <$APE/config
 
-LIB=/$objtype/lib/ape/libz.a
+LIB=libz.a$O
 
-OFILES=\
-	adler32.$O\
-	compress.$O\
-	crc32.$O\
-	deflate.$O\
-	gzio.$O\
-	infback.$O\
-	inffast.$O\
-	inflate.$O\
-	inftrees.$O\
-	trees.$O\
-	uncompr.$O\
-	zutil.$O\
-
-TARG=\
-	example\
-	minigzip\
-
-TOOLS=${TARG:%=$O.%}
-
-HFILES=\
-	/sys/include/ape/zlib.h\
-
-UPDATE=\
-	mkfile\
-	$HFILES\
-	${OFILES:%.$O=%.c}\
-	${LIB:/$objtype/%=/386/%}\
-
-CLEANFILES=$TOOLS
+OFILES=adler32.$O compress.$O crc32.$O deflate.$O gzclose.$O gzlib.$O gzread.$O \
+	gzwrite.$O infback.$O inffast.$O inflate.$O inftrees.$O trees.$O uncompr.$O \
+	zutil.$O 
 
 </sys/src/cmd/mksyslib
 
-CFLAGS=-c -D_POSIX_SOURCE -D_C99_SNPRINTF_EXTENSION
+CFLAGS=-c -B -D_POSIX_SOURCE -DHAVE_UNISTD_H -DHAVE_STDARG_H -DHAVE_MEMCPY -DHAVE_VSNPRINTF -DHAS_vsnprintf_void
 
-%.$O: /sys/src/cmd/gs/zlib/%.c
-	$CC $CFLAGS /sys/src/cmd/gs/zlib/$stem.c
+zutil.$O: zlib.h gzguts.h zutil.h 
+uncompr.$O: zlib.h 
+trees.$O: trees.h deflate.h 
+inftrees.$O: inftrees.h zutil.h 
+inflate.$O: inffixed.h inffast.h inflate.h inftrees.h zutil.h
+inffast.$O: inffast.h inflate.h inftrees.h zutil.h 
+infback.$O: inffixed.h inffast.h inflate.h inftrees.h zutil.h 
+gzwrite.$O: zlib.h gzguts.h 
+gzread.$O: zlib.h gzguts.h 
+gzlib.$O: zlib.h gzguts.h 
+gzclose.$O: zlib.h gzguts.h 
+deflate.$O: zutil.h deflate.h 
+crc32.$O: crc32.h zutil.h 
+compress.$O: zlib.h 
+adler32.$O: zconf.h zlib.h zutil.h 
 
-$O.%: %.$O $LIB
-	$LD -o $target $prereq
+nuke:V:
+	mk clean
+	rm -f $LIB
+	rm -f /$objtype/lib/ape/libz.a
+	rm -f /sys/include/ape/zlib.h
+	rm -f /sys/include/ape/zconf.h
 
-tools: $LIB
-	mk $TOOLS
+install:V:
+	cp libz.a$O /$objtype/lib/ape/libz.a
+	cp zconf.h /sys/include/ape/
+	cp zlib.h /sys/include/ape/
+
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/test/example.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/test/example.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,602 @@
+/* example.c -- usage example of the zlib compression library
+ * Copyright (C) 1995-2006, 2011, 2016 Jean-loup Gailly
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* @(#) $Id$ */
+
+#include "zlib.h"
+#include <stdio.h>
+
+#ifdef STDC
+#  include <string.h>
+#  include <stdlib.h>
+#endif
+
+#if defined(VMS) || defined(RISCOS)
+#  define TESTFILE "foo-gz"
+#else
+#  define TESTFILE "foo.gz"
+#endif
+
+#define CHECK_ERR(err, msg) { \
+    if (err != Z_OK) { \
+        fprintf(stderr, "%s error: %d\n", msg, err); \
+        exit(1); \
+    } \
+}
+
+static z_const char hello[] = "hello, hello!";
+/* "hello world" would be more standard, but the repeated "hello"
+ * stresses the compression code better, sorry...
+ */
+
+static const char dictionary[] = "hello";
+static uLong dictId;    /* Adler32 value of the dictionary */
+
+void test_deflate       OF((Byte *compr, uLong comprLen));
+void test_inflate       OF((Byte *compr, uLong comprLen,
+                            Byte *uncompr, uLong uncomprLen));
+void test_large_deflate OF((Byte *compr, uLong comprLen,
+                            Byte *uncompr, uLong uncomprLen));
+void test_large_inflate OF((Byte *compr, uLong comprLen,
+                            Byte *uncompr, uLong uncomprLen));
+void test_flush         OF((Byte *compr, uLong *comprLen));
+void test_sync          OF((Byte *compr, uLong comprLen,
+                            Byte *uncompr, uLong uncomprLen));
+void test_dict_deflate  OF((Byte *compr, uLong comprLen));
+void test_dict_inflate  OF((Byte *compr, uLong comprLen,
+                            Byte *uncompr, uLong uncomprLen));
+int  main               OF((int argc, char *argv[]));
+
+
+#ifdef Z_SOLO
+
+void *myalloc OF((void *, unsigned, unsigned));
+void myfree OF((void *, void *));
+
+void *myalloc(q, n, m)
+    void *q;
+    unsigned n, m;
+{
+    (void)q;
+    return calloc(n, m);
+}
+
+void myfree(void *q, void *p)
+{
+    (void)q;
+    free(p);
+}
+
+static alloc_func zalloc = myalloc;
+static free_func zfree = myfree;
+
+#else /* !Z_SOLO */
+
+static alloc_func zalloc = (alloc_func)0;
+static free_func zfree = (free_func)0;
+
+void test_compress      OF((Byte *compr, uLong comprLen,
+                            Byte *uncompr, uLong uncomprLen));
+void test_gzio          OF((const char *fname,
+                            Byte *uncompr, uLong uncomprLen));
+
+/* ===========================================================================
+ * Test compress() and uncompress()
+ */
+void test_compress(compr, comprLen, uncompr, uncomprLen)
+    Byte *compr, *uncompr;
+    uLong comprLen, uncomprLen;
+{
+    int err;
+    uLong len = (uLong)strlen(hello)+1;
+
+    err = compress(compr, &comprLen, (const Bytef*)hello, len);
+    CHECK_ERR(err, "compress");
+
+    strcpy((char*)uncompr, "garbage");
+
+    err = uncompress(uncompr, &uncomprLen, compr, comprLen);
+    CHECK_ERR(err, "uncompress");
+
+    if (strcmp((char*)uncompr, hello)) {
+        fprintf(stderr, "bad uncompress\n");
+        exit(1);
+    } else {
+        printf("uncompress(): %s\n", (char *)uncompr);
+    }
+}
+
+/* ===========================================================================
+ * Test read/write of .gz files
+ */
+void test_gzio(fname, uncompr, uncomprLen)
+    const char *fname; /* compressed file name */
+    Byte *uncompr;
+    uLong uncomprLen;
+{
+#ifdef NO_GZCOMPRESS
+    fprintf(stderr, "NO_GZCOMPRESS -- gz* functions cannot compress\n");
+#else
+    int err;
+    int len = (int)strlen(hello)+1;
+    gzFile file;
+    z_off_t pos;
+
+    file = gzopen(fname, "wb");
+    if (file == NULL) {
+        fprintf(stderr, "gzopen error\n");
+        exit(1);
+    }
+    gzputc(file, 'h');
+    if (gzputs(file, "ello") != 4) {
+        fprintf(stderr, "gzputs err: %s\n", gzerror(file, &err));
+        exit(1);
+    }
+    if (gzprintf(file, ", %s!", "hello") != 8) {
+        fprintf(stderr, "gzprintf err: %s\n", gzerror(file, &err));
+        exit(1);
+    }
+    gzseek(file, 1L, SEEK_CUR); /* add one zero byte */
+    gzclose(file);
+
+    file = gzopen(fname, "rb");
+    if (file == NULL) {
+        fprintf(stderr, "gzopen error\n");
+        exit(1);
+    }
+    strcpy((char*)uncompr, "garbage");
+
+    if (gzread(file, uncompr, (unsigned)uncomprLen) != len) {
+        fprintf(stderr, "gzread err: %s\n", gzerror(file, &err));
+        exit(1);
+    }
+    if (strcmp((char*)uncompr, hello)) {
+        fprintf(stderr, "bad gzread: %s\n", (char*)uncompr);
+        exit(1);
+    } else {
+        printf("gzread(): %s\n", (char*)uncompr);
+    }
+
+    pos = gzseek(file, -8L, SEEK_CUR);
+    if (pos != 6 || gztell(file) != pos) {
+        fprintf(stderr, "gzseek error, pos=%ld, gztell=%ld\n",
+                (long)pos, (long)gztell(file));
+        exit(1);
+    }
+
+    if (gzgetc(file) != ' ') {
+        fprintf(stderr, "gzgetc error\n");
+        exit(1);
+    }
+
+    if (gzungetc(' ', file) != ' ') {
+        fprintf(stderr, "gzungetc error\n");
+        exit(1);
+    }
+
+    gzgets(file, (char*)uncompr, (int)uncomprLen);
+    if (strlen((char*)uncompr) != 7) { /* " hello!" */
+        fprintf(stderr, "gzgets err after gzseek: %s\n", gzerror(file, &err));
+        exit(1);
+    }
+    if (strcmp((char*)uncompr, hello + 6)) {
+        fprintf(stderr, "bad gzgets after gzseek\n");
+        exit(1);
+    } else {
+        printf("gzgets() after gzseek: %s\n", (char*)uncompr);
+    }
+
+    gzclose(file);
+#endif
+}
+
+#endif /* Z_SOLO */
+
+/* ===========================================================================
+ * Test deflate() with small buffers
+ */
+void test_deflate(compr, comprLen)
+    Byte *compr;
+    uLong comprLen;
+{
+    z_stream c_stream; /* compression stream */
+    int err;
+    uLong len = (uLong)strlen(hello)+1;
+
+    c_stream.zalloc = zalloc;
+    c_stream.zfree = zfree;
+    c_stream.opaque = (voidpf)0;
+
+    err = deflateInit(&c_stream, Z_DEFAULT_COMPRESSION);
+    CHECK_ERR(err, "deflateInit");
+
+    c_stream.next_in  = (z_const unsigned char *)hello;
+    c_stream.next_out = compr;
+
+    while (c_stream.total_in != len && c_stream.total_out < comprLen) {
+        c_stream.avail_in = c_stream.avail_out = 1; /* force small buffers */
+        err = deflate(&c_stream, Z_NO_FLUSH);
+        CHECK_ERR(err, "deflate");
+    }
+    /* Finish the stream, still forcing small buffers: */
+    for (;;) {
+        c_stream.avail_out = 1;
+        err = deflate(&c_stream, Z_FINISH);
+        if (err == Z_STREAM_END) break;
+        CHECK_ERR(err, "deflate");
+    }
+
+    err = deflateEnd(&c_stream);
+    CHECK_ERR(err, "deflateEnd");
+}
+
+/* ===========================================================================
+ * Test inflate() with small buffers
+ */
+void test_inflate(compr, comprLen, uncompr, uncomprLen)
+    Byte *compr, *uncompr;
+    uLong comprLen, uncomprLen;
+{
+    int err;
+    z_stream d_stream; /* decompression stream */
+
+    strcpy((char*)uncompr, "garbage");
+
+    d_stream.zalloc = zalloc;
+    d_stream.zfree = zfree;
+    d_stream.opaque = (voidpf)0;
+
+    d_stream.next_in  = compr;
+    d_stream.avail_in = 0;
+    d_stream.next_out = uncompr;
+
+    err = inflateInit(&d_stream);
+    CHECK_ERR(err, "inflateInit");
+
+    while (d_stream.total_out < uncomprLen && d_stream.total_in < comprLen) {
+        d_stream.avail_in = d_stream.avail_out = 1; /* force small buffers */
+        err = inflate(&d_stream, Z_NO_FLUSH);
+        if (err == Z_STREAM_END) break;
+        CHECK_ERR(err, "inflate");
+    }
+
+    err = inflateEnd(&d_stream);
+    CHECK_ERR(err, "inflateEnd");
+
+    if (strcmp((char*)uncompr, hello)) {
+        fprintf(stderr, "bad inflate\n");
+        exit(1);
+    } else {
+        printf("inflate(): %s\n", (char *)uncompr);
+    }
+}
+
+/* ===========================================================================
+ * Test deflate() with large buffers and dynamic change of compression level
+ */
+void test_large_deflate(compr, comprLen, uncompr, uncomprLen)
+    Byte *compr, *uncompr;
+    uLong comprLen, uncomprLen;
+{
+    z_stream c_stream; /* compression stream */
+    int err;
+
+    c_stream.zalloc = zalloc;
+    c_stream.zfree = zfree;
+    c_stream.opaque = (voidpf)0;
+
+    err = deflateInit(&c_stream, Z_BEST_SPEED);
+    CHECK_ERR(err, "deflateInit");
+
+    c_stream.next_out = compr;
+    c_stream.avail_out = (uInt)comprLen;
+
+    /* At this point, uncompr is still mostly zeroes, so it should compress
+     * very well:
+     */
+    c_stream.next_in = uncompr;
+    c_stream.avail_in = (uInt)uncomprLen;
+    err = deflate(&c_stream, Z_NO_FLUSH);
+    CHECK_ERR(err, "deflate");
+    if (c_stream.avail_in != 0) {
+        fprintf(stderr, "deflate not greedy\n");
+        exit(1);
+    }
+
+    /* Feed in already compressed data and switch to no compression: */
+    deflateParams(&c_stream, Z_NO_COMPRESSION, Z_DEFAULT_STRATEGY);
+    c_stream.next_in = compr;
+    c_stream.avail_in = (uInt)comprLen/2;
+    err = deflate(&c_stream, Z_NO_FLUSH);
+    CHECK_ERR(err, "deflate");
+
+    /* Switch back to compressing mode: */
+    deflateParams(&c_stream, Z_BEST_COMPRESSION, Z_FILTERED);
+    c_stream.next_in = uncompr;
+    c_stream.avail_in = (uInt)uncomprLen;
+    err = deflate(&c_stream, Z_NO_FLUSH);
+    CHECK_ERR(err, "deflate");
+
+    err = deflate(&c_stream, Z_FINISH);
+    if (err != Z_STREAM_END) {
+        fprintf(stderr, "deflate should report Z_STREAM_END\n");
+        exit(1);
+    }
+    err = deflateEnd(&c_stream);
+    CHECK_ERR(err, "deflateEnd");
+}
+
+/* ===========================================================================
+ * Test inflate() with large buffers
+ */
+void test_large_inflate(compr, comprLen, uncompr, uncomprLen)
+    Byte *compr, *uncompr;
+    uLong comprLen, uncomprLen;
+{
+    int err;
+    z_stream d_stream; /* decompression stream */
+
+    strcpy((char*)uncompr, "garbage");
+
+    d_stream.zalloc = zalloc;
+    d_stream.zfree = zfree;
+    d_stream.opaque = (voidpf)0;
+
+    d_stream.next_in  = compr;
+    d_stream.avail_in = (uInt)comprLen;
+
+    err = inflateInit(&d_stream);
+    CHECK_ERR(err, "inflateInit");
+
+    for (;;) {
+        d_stream.next_out = uncompr;            /* discard the output */
+        d_stream.avail_out = (uInt)uncomprLen;
+        err = inflate(&d_stream, Z_NO_FLUSH);
+        if (err == Z_STREAM_END) break;
+        CHECK_ERR(err, "large inflate");
+    }
+
+    err = inflateEnd(&d_stream);
+    CHECK_ERR(err, "inflateEnd");
+
+    if (d_stream.total_out != 2*uncomprLen + comprLen/2) {
+        fprintf(stderr, "bad large inflate: %ld\n", d_stream.total_out);
+        exit(1);
+    } else {
+        printf("large_inflate(): OK\n");
+    }
+}
+
+/* ===========================================================================
+ * Test deflate() with full flush
+ */
+void test_flush(compr, comprLen)
+    Byte *compr;
+    uLong *comprLen;
+{
+    z_stream c_stream; /* compression stream */
+    int err;
+    uInt len = (uInt)strlen(hello)+1;
+
+    c_stream.zalloc = zalloc;
+    c_stream.zfree = zfree;
+    c_stream.opaque = (voidpf)0;
+
+    err = deflateInit(&c_stream, Z_DEFAULT_COMPRESSION);
+    CHECK_ERR(err, "deflateInit");
+
+    c_stream.next_in  = (z_const unsigned char *)hello;
+    c_stream.next_out = compr;
+    c_stream.avail_in = 3;
+    c_stream.avail_out = (uInt)*comprLen;
+    err = deflate(&c_stream, Z_FULL_FLUSH);
+    CHECK_ERR(err, "deflate");
+
+    compr[3]++; /* force an error in first compressed block */
+    c_stream.avail_in = len - 3;
+
+    err = deflate(&c_stream, Z_FINISH);
+    if (err != Z_STREAM_END) {
+        CHECK_ERR(err, "deflate");
+    }
+    err = deflateEnd(&c_stream);
+    CHECK_ERR(err, "deflateEnd");
+
+    *comprLen = c_stream.total_out;
+}
+
+/* ===========================================================================
+ * Test inflateSync()
+ */
+void test_sync(compr, comprLen, uncompr, uncomprLen)
+    Byte *compr, *uncompr;
+    uLong comprLen, uncomprLen;
+{
+    int err;
+    z_stream d_stream; /* decompression stream */
+
+    strcpy((char*)uncompr, "garbage");
+
+    d_stream.zalloc = zalloc;
+    d_stream.zfree = zfree;
+    d_stream.opaque = (voidpf)0;
+
+    d_stream.next_in  = compr;
+    d_stream.avail_in = 2; /* just read the zlib header */
+
+    err = inflateInit(&d_stream);
+    CHECK_ERR(err, "inflateInit");
+
+    d_stream.next_out = uncompr;
+    d_stream.avail_out = (uInt)uncomprLen;
+
+    err = inflate(&d_stream, Z_NO_FLUSH);
+    CHECK_ERR(err, "inflate");
+
+    d_stream.avail_in = (uInt)comprLen-2;   /* read all compressed data */
+    err = inflateSync(&d_stream);           /* but skip the damaged part */
+    CHECK_ERR(err, "inflateSync");
+
+    err = inflate(&d_stream, Z_FINISH);
+    if (err != Z_DATA_ERROR) {
+        fprintf(stderr, "inflate should report DATA_ERROR\n");
+        /* Because of incorrect adler32 */
+        exit(1);
+    }
+    err = inflateEnd(&d_stream);
+    CHECK_ERR(err, "inflateEnd");
+
+    printf("after inflateSync(): hel%s\n", (char *)uncompr);
+}
+
+/* ===========================================================================
+ * Test deflate() with preset dictionary
+ */
+void test_dict_deflate(compr, comprLen)
+    Byte *compr;
+    uLong comprLen;
+{
+    z_stream c_stream; /* compression stream */
+    int err;
+
+    c_stream.zalloc = zalloc;
+    c_stream.zfree = zfree;
+    c_stream.opaque = (voidpf)0;
+
+    err = deflateInit(&c_stream, Z_BEST_COMPRESSION);
+    CHECK_ERR(err, "deflateInit");
+
+    err = deflateSetDictionary(&c_stream,
+                (const Bytef*)dictionary, (int)sizeof(dictionary));
+    CHECK_ERR(err, "deflateSetDictionary");
+
+    dictId = c_stream.adler;
+    c_stream.next_out = compr;
+    c_stream.avail_out = (uInt)comprLen;
+
+    c_stream.next_in = (z_const unsigned char *)hello;
+    c_stream.avail_in = (uInt)strlen(hello)+1;
+
+    err = deflate(&c_stream, Z_FINISH);
+    if (err != Z_STREAM_END) {
+        fprintf(stderr, "deflate should report Z_STREAM_END\n");
+        exit(1);
+    }
+    err = deflateEnd(&c_stream);
+    CHECK_ERR(err, "deflateEnd");
+}
+
+/* ===========================================================================
+ * Test inflate() with a preset dictionary
+ */
+void test_dict_inflate(compr, comprLen, uncompr, uncomprLen)
+    Byte *compr, *uncompr;
+    uLong comprLen, uncomprLen;
+{
+    int err;
+    z_stream d_stream; /* decompression stream */
+
+    strcpy((char*)uncompr, "garbage");
+
+    d_stream.zalloc = zalloc;
+    d_stream.zfree = zfree;
+    d_stream.opaque = (voidpf)0;
+
+    d_stream.next_in  = compr;
+    d_stream.avail_in = (uInt)comprLen;
+
+    err = inflateInit(&d_stream);
+    CHECK_ERR(err, "inflateInit");
+
+    d_stream.next_out = uncompr;
+    d_stream.avail_out = (uInt)uncomprLen;
+
+    for (;;) {
+        err = inflate(&d_stream, Z_NO_FLUSH);
+        if (err == Z_STREAM_END) break;
+        if (err == Z_NEED_DICT) {
+            if (d_stream.adler != dictId) {
+                fprintf(stderr, "unexpected dictionary");
+                exit(1);
+            }
+            err = inflateSetDictionary(&d_stream, (const Bytef*)dictionary,
+                                       (int)sizeof(dictionary));
+        }
+        CHECK_ERR(err, "inflate with dict");
+    }
+
+    err = inflateEnd(&d_stream);
+    CHECK_ERR(err, "inflateEnd");
+
+    if (strcmp((char*)uncompr, hello)) {
+        fprintf(stderr, "bad inflate with dict\n");
+        exit(1);
+    } else {
+        printf("inflate with dictionary: %s\n", (char *)uncompr);
+    }
+}
+
+/* ===========================================================================
+ * Usage:  example [output.gz  [input.gz]]
+ */
+
+int main(argc, argv)
+    int argc;
+    char *argv[];
+{
+    Byte *compr, *uncompr;
+    uLong comprLen = 10000*sizeof(int); /* don't overflow on MSDOS */
+    uLong uncomprLen = comprLen;
+    static const char* myVersion = ZLIB_VERSION;
+
+    if (zlibVersion()[0] != myVersion[0]) {
+        fprintf(stderr, "incompatible zlib version\n");
+        exit(1);
+
+    } else if (strcmp(zlibVersion(), ZLIB_VERSION) != 0) {
+        fprintf(stderr, "warning: different zlib version\n");
+    }
+
+    printf("zlib version %s = 0x%04x, compile flags = 0x%lx\n",
+            ZLIB_VERSION, ZLIB_VERNUM, zlibCompileFlags());
+
+    compr    = (Byte*)calloc((uInt)comprLen, 1);
+    uncompr  = (Byte*)calloc((uInt)uncomprLen, 1);
+    /* compr and uncompr are cleared to avoid reading uninitialized
+     * data and to ensure that uncompr compresses well.
+     */
+    if (compr == Z_NULL || uncompr == Z_NULL) {
+        printf("out of memory\n");
+        exit(1);
+    }
+
+#ifdef Z_SOLO
+    (void)argc;
+    (void)argv;
+#else
+    test_compress(compr, comprLen, uncompr, uncomprLen);
+
+    test_gzio((argc > 1 ? argv[1] : TESTFILE),
+              uncompr, uncomprLen);
+#endif
+
+    test_deflate(compr, comprLen);
+    test_inflate(compr, comprLen, uncompr, uncomprLen);
+
+    test_large_deflate(compr, comprLen, uncompr, uncomprLen);
+    test_large_inflate(compr, comprLen, uncompr, uncomprLen);
+
+    test_flush(compr, &comprLen);
+    test_sync(compr, comprLen, uncompr, uncomprLen);
+    comprLen = uncomprLen;
+
+    test_dict_deflate(compr, comprLen);
+    test_dict_inflate(compr, comprLen, uncompr, uncomprLen);
+
+    free(compr);
+    free(uncompr);
+
+    return 0;
+}
diff -r 0dd419f096e2 -r 83acefe9acdf sys/src/ape/lib/z/test/infcover.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/src/ape/lib/z/test/infcover.c	Mon Mar 02 00:58:11 2020 -0400
@@ -0,0 +1,671 @@
+/* infcover.c -- test zlib's inflate routines with full code coverage
+ * Copyright (C) 2011, 2016 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* to use, do: ./configure --cover && make cover */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include "zlib.h"
+
+/* get definition of internal structure so we can mess with it (see pull()),
+   and so we can call inflate_trees() (see cover5()) */
+#define ZLIB_INTERNAL
+#include "inftrees.h"
+#include "inflate.h"
+
+#define local static
+
+/* -- memory tracking routines -- */
+
+/*
+   These memory tracking routines are provided to zlib and track all of zlib's
+   allocations and deallocations, check for LIFO operations, keep a current
+   and high water mark of total bytes requested, optionally set a limit on the
+   total memory that can be allocated, and when done check for memory leaks.
+
+   They are used as follows:
+
+   z_stream strm;
+   mem_setup(&strm)         initializes the memory tracking and sets the
+                            zalloc, zfree, and opaque members of strm to use
+                            memory tracking for all zlib operations on strm
+   mem_limit(&strm, limit)  sets a limit on the total bytes requested -- a
+                            request that exceeds this limit will result in an
+                            allocation failure (returns NULL) -- setting the
+                            limit to zero means no limit, which is the default
+                            after mem_setup()
+   mem_used(&strm, "msg")   prints to stderr "msg" and the total bytes used
+   mem_high(&strm, "msg")   prints to stderr "msg" and the high water mark
+   mem_done(&strm, "msg")   ends memory tracking, releases all allocations
+                            for the tracking as well as leaked zlib blocks, if
+                            any.  If there was anything unusual, such as leaked
+                            blocks, non-FIFO frees, or frees of addresses not
+                            allocated, then "msg" and information about the
+                            problem is printed to stderr.  If everything is
+                            normal, nothing is printed. mem_done resets the
+                            strm members to Z_NULL to use the default memory
+                            allocation routines on the next zlib initialization
+                            using strm.
+ */
+
+/* these items are strung together in a linked list, one for each allocation */
+struct mem_item {
+    void *ptr;                  /* pointer to allocated memory */
+    size_t size;                /* requested size of allocation */
+    struct mem_item *next;      /* pointer to next item in list, or NULL */
+};
+
+/* this structure is at the root of the linked list, and tracks statistics */
+struct mem_zone {
+    struct mem_item *first;     /* pointer to first item in list, or NULL */
+    size_t total, highwater;    /* total allocations, and largest total */
+    size_t limit;               /* memory allocation limit, or 0 if no limit */
+    int notlifo, rogue;         /* counts of non-LIFO frees and rogue frees */
+};
+
+/* memory allocation routine to pass to zlib */
+local void *mem_alloc(void *mem, unsigned count, unsigned size)
+{
+    void *ptr;
+    struct mem_item *item;
+    struct mem_zone *zone = mem;
+    size_t len = count * (size_t)size;
+
+    /* induced allocation failure */
+    if (zone == NULL || (zone->limit && zone->total + len > zone->limit))
+        return NULL;
+
+    /* perform allocation using the standard library, fill memory with a
+       non-zero value to make sure that the code isn't depending on zeros */
+    ptr = malloc(len);
+    if (ptr == NULL)
+        return NULL;
+    memset(ptr, 0xa5, len);
+
+    /* create a new item for the list */
+    item = malloc(sizeof(struct mem_item));
+    if (item == NULL) {
+        free(ptr);
+        return NULL;
+    }
+    item->ptr = ptr;
+    item->size = len;
+
+    /* insert item at the beginning of the list */
+    item->next = zone->first;
+    zone->first = item;
+
+    /* update the statistics */
+    zone->total += item->size;
+    if (zone->total > zone->highwater)
+        zone->highwater = zone->total;
+
+    /* return the allocated memory */
+    return ptr;
+}
+
+/* memory free routine to pass to zlib */
+local void mem_free(void *mem, void *ptr)
+{
+    struct mem_item *item, *next;
+    struct mem_zone *zone = mem;
+
+    /* if no zone, just do a free */
+    if (zone == NULL) {
+        free(ptr);
+        return;
+    }
+
+    /* point next to the item that matches ptr, or NULL if not found -- remove
+       the item from the linked list if found */
+    next = zone->first;
+    if (next) {
+        if (next->ptr == ptr)
+            zone->first = next->next;   /* first one is it, remove from list */
+        else {
+            do {                        /* search the linked list */
+                item = next;
+                next = item->next;
+            } while (next != NULL && next->ptr != ptr);
+            if (next) {                 /* if found, remove from linked list */
+                item->next = next->next;
+                zone->notlifo++;        /* not a LIFO free */
+            }
+
+        }
+    }
+
+    /* if found, update the statistics and free the item */
+    if (next) {
+        zone->total -= next->size;
+        free(next);
+    }
+
+    /* if not found, update the rogue count */
+    else
+        zone->rogue++;
+
+    /* in any case, do the requested free with the standard library function */
+    free(ptr);
+}
+
+/* set up a controlled memory allocation space for monitoring, set the stream
+   parameters to the controlled routines, with opaque pointing to the space */
+local void mem_setup(z_stream *strm)
+{
+    struct mem_zone *zone;
+
+    zone = malloc(sizeof(struct mem_zone));
+    assert(zone != NULL);
+    zone->first = NULL;
+    zone->total = 0;
+    zone->highwater = 0;
+    zone->limit = 0;
+    zone->notlifo = 0;
+    zone->rogue = 0;
+    strm->opaque = zone;
+    strm->zalloc = mem_alloc;
+    strm->zfree = mem_free;
+}
+
+/* set a limit on the total memory allocation, or 0 to remove the limit */
+local void mem_limit(z_stream *strm, size_t limit)
+{
+    struct mem_zone *zone = strm->opaque;
+
+    zone->limit = limit;
+}
+
+/* show the current total requested allocations in bytes */
+local void mem_used(z_stream *strm, char *prefix)
+{
+    struct mem_zone *zone = strm->opaque;
+
+    fprintf(stderr, "%s: %lu allocated\n", prefix, zone->total);
+}
+
+/* show the high water allocation in bytes */
+local void mem_high(z_stream *strm, char *prefix)
+{
+    struct mem_zone *zone = strm->opaque;
+
+    fprintf(stderr, "%s: %lu high water mark\n", prefix, zone->highwater);
+}
+
+/* release the memory allocation zone -- if there are any surprises, notify */
+local void mem_done(z_stream *strm, char *prefix)
+{
+    int count = 0;
+    struct mem_item *item, *next;
+    struct mem_zone *zone = strm->opaque;
+
+    /* show high water mark */
+    mem_high(strm, prefix);
+
+    /* free leftover allocations and item structures, if any */
+    item = zone->first;
+    while (item != NULL) {
+        free(item->ptr);
+        next = item->next;
+        free(item);
+        item = next;
+        count++;
+    }
+
+    /* issue alerts about anything unexpected */
+    if (count || zone->total)
+        fprintf(stderr, "** %s: %lu bytes in %d blocks not freed\n",
+                prefix, zone->total, count);
+    if (zone->notlifo)
+        fprintf(stderr, "** %s: %d frees not LIFO\n", prefix, zone->notlifo);
+    if (zone->rogue)
+        fprintf(stderr, "** %s: %d frees not recognized\n",
+                prefix, zone->rogue);
+
+    /* free the zone and delete from the stream */
+    free(zone);
+    strm->opaque = Z_NULL;
+    strm->zalloc = Z_NULL;
+    strm->zfree = Z_NULL;
+}
+
+/* -- inflate test routines -- */
+
+/* Decode a hexadecimal string, set *len to length, in[] to the bytes.  This
+   decodes liberally, in that hex digits can be adjacent, in which case two in
+   a row writes a byte.  Or they can be delimited by any non-hex character,
+   where the delimiters are ignored except when a single hex digit is followed
+   by a delimiter, where that single digit writes a byte.  The returned data is
+   allocated and must eventually be freed.  NULL is returned if out of memory.
+   If the length is not needed, then len can be NULL. */
+local unsigned char *h2b(const char *hex, unsigned *len)
+{
+    unsigned char *in, *re;
+    unsigned next, val;
+
+    in = malloc((strlen(hex) + 1) >> 1);
+    if (in == NULL)
+        return NULL;
+    next = 0;
+    val = 1;
+    do {
+        if (*hex >= '0' && *hex <= '9')
+            val = (val << 4) + *hex - '0';
+        else if (*hex >= 'A' && *hex <= 'F')
+            val = (val << 4) + *hex - 'A' + 10;
+        else if (*hex >= 'a' && *hex <= 'f')
+            val = (val << 4) + *hex - 'a' + 10;
+        else if (val != 1 && val < 32)  /* one digit followed by delimiter */
+            val += 240;                 /* make it look like two digits */
+        if (val > 255) {                /* have two digits */
+            in[next++] = val & 0xff;    /* save the decoded byte */
+            val = 1;                    /* start over */
+        }
+    } while (*hex++);       /* go through the loop with the terminating null */
+    if (len != NULL)
+        *len = next;
+    re = realloc(in, next);
+    return re == NULL ? in : re;
+}
+
+/* generic inflate() run, where hex is the hexadecimal input data, what is the
+   text to include in an error message, step is how much input data to feed
+   inflate() on each call, or zero to feed it all, win is the window bits
+   parameter to inflateInit2(), len is the size of the output buffer, and err
+   is the error code expected from the first inflate() call (the second
+   inflate() call is expected to return Z_STREAM_END).  If win is 47, then
+   header information is collected with inflateGetHeader().  If a zlib stream
+   is looking for a dictionary, then an empty dictionary is provided.
+   inflate() is run until all of the input data is consumed. */
+local void inf(char *hex, char *what, unsigned step, int win, unsigned len,
+               int err)
+{
+    int ret;
+    unsigned have;
+    unsigned char *in, *out;
+    z_stream strm, copy;
+    gz_header head;
+
+  

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [9front] move zlib source from ghostscript to ape/lib/z and update to latest zlib
  2020-03-02  5:15 move zlib source from ghostscript to ape/lib/z and update to latest zlib Lucas Francesco
@ 2020-03-02  8:33 ` cinap_lenrek
  2020-03-02 14:41   ` ori
  0 siblings, 1 reply; 6+ messages in thread
From: cinap_lenrek @ 2020-03-02  8:33 UTC (permalink / raw)
  To: 9front

this diff is 2MB of text! that is just insane. how are we going
to maintain this? i cannot review 2MB of code.

all the files of zlib in ghostscript is only 525k and arround
13kloc... why is there a z/contrib? why are we importing pascal
and ada files?

how did this got so bad?

--
cinap


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [9front] move zlib source from ghostscript to ape/lib/z and update to latest zlib
  2020-03-02  8:33 ` [9front] " cinap_lenrek
@ 2020-03-02 14:41   ` ori
  2020-03-05 19:17     ` cinap_lenrek
  0 siblings, 1 reply; 6+ messages in thread
From: ori @ 2020-03-02 14:41 UTC (permalink / raw)
  To: cinap_lenrek, 9front

> this diff is 2MB of text! that is just insane. how are we going
> to maintain this? i cannot review 2MB of code.
> 
> all the files of zlib in ghostscript is only 525k and arround
> 13kloc... why is there a z/contrib? why are we importing pascal
> and ada files?
> 

We should get rid of all the contrib/ dir -- it's not being built, and nothing in it is
needed. What's left is still 13k loc.



^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [9front] move zlib source from ghostscript to ape/lib/z and update to latest zlib
  2020-03-02 14:41   ` ori
@ 2020-03-05 19:17     ` cinap_lenrek
  2020-03-08 23:44       ` Lucas Francesco
  0 siblings, 1 reply; 6+ messages in thread
From: cinap_lenrek @ 2020-03-05 19:17 UTC (permalink / raw)
  To: 9front

what i'd like to see is an actual diff of what changed in zlib. i cannot
belief there are too many changes. zlib is very old library. i'm very
curious why we need a specific version of zlib and what features did
they add.

once we have a overview what we'r getting into, then we can move it out
of ghostscript.

--
cinap


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [9front] move zlib source from ghostscript to ape/lib/z and update to latest zlib
  2020-03-05 19:17     ` cinap_lenrek
@ 2020-03-08 23:44       ` Lucas Francesco
  2020-03-16  3:28         ` ori
  0 siblings, 1 reply; 6+ messages in thread
From: Lucas Francesco @ 2020-03-08 23:44 UTC (permalink / raw)
  To: 9front

[-- Attachment #1: Type: text/plain, Size: 1231 bytes --]

Hey Cinap, I didn't mean harm with the patches, it was my bad to
include contrib(I had a local zlib copy lingering for weeks with those
contrib dirs, didn't notice I still had Pascal), I think with this one
it can be made clear what changed and what didn't.

This patchset doesn't move out stuff from gs for now. Most of the diff
is on the INDEX and the Changelog files alongside the new ones. (gzio
became 4 different files, there's a new tests dir for the tests, some
bugfixes and a new test.)

Take note: I've changed the mkfile cflags on this one, they seem to be
fine, but its up to you guys to consider it uneeded or not, I guess
this is not final.

as for using APE or not, I'd love to see some separation/at least get
rid of gs for page eventually, but thats a distant future.

Em qui., 5 de mar. de 2020 às 16:18, <cinap_lenrek@felloff.net> escreveu:
>
> what i'd like to see is an actual diff of what changed in zlib. i cannot
> belief there are too many changes. zlib is very old library. i'm very
> curious why we need a specific version of zlib and what features did
> they add.
>
> once we have a overview what we'r getting into, then we can move it out
> of ghostscript.
>
> --
> cinap

[-- Attachment #2: zlibpatch.patch --]
[-- Type: application/octet-stream, Size: 675664 bytes --]

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [9front] move zlib source from ghostscript to ape/lib/z and update to latest zlib
  2020-03-08 23:44       ` Lucas Francesco
@ 2020-03-16  3:28         ` ori
  0 siblings, 0 replies; 6+ messages in thread
From: ori @ 2020-03-16  3:28 UTC (permalink / raw)
  To: lucas.francesco93, 9front

> Hey Cinap, I didn't mean harm with the patches, it was my bad to
> include contrib(I had a local zlib copy lingering for weeks with those
> contrib dirs, didn't notice I still had Pascal), I think with this one
> it can be made clear what changed and what didn't.

Thanks for updating!

This patch looks easier to review, but there seems to be some binary
junk at the end of it. Can you try resending?

> This patchset doesn't move out stuff from gs for now. Most of the diff
> is on the INDEX and the Changelog files alongside the new ones. (gzio
> became 4 different files, there's a new tests dir for the tests, some
> bugfixes and a new test.)

Out of curiosity, have you tried running the tests? Might be a good
sanity check.

> Take note: I've changed the mkfile cflags on this one, they seem to be
> fine, but its up to you guys to consider it uneeded or not, I guess
> this is not final.
> 
> as for using APE or not, I'd love to see some separation/at least get
> rid of gs for page eventually, but thats a distant future.
> 
> Em qui., 5 de mar. de 2020 às 16:18, <cinap_lenrek@felloff.net> escreveu:
>>
>> what i'd like to see is an actual diff of what changed in zlib. i cannot
>> belief there are too many changes. zlib is very old library. i'm very
>> curious why we need a specific version of zlib and what features did
>> they add.
>>
>> once we have a overview what we'r getting into, then we can move it out
>> of ghostscript.
>>
>> --
>> cinap



^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2020-03-16  3:28 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-02  5:15 move zlib source from ghostscript to ape/lib/z and update to latest zlib Lucas Francesco
2020-03-02  8:33 ` [9front] " cinap_lenrek
2020-03-02 14:41   ` ori
2020-03-05 19:17     ` cinap_lenrek
2020-03-08 23:44       ` Lucas Francesco
2020-03-16  3:28         ` ori

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