# 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,
+    0xd37048acUL, 0xf85d1b6fUL, 0xe1462a2eUL, 0x66de36e1UL, 0x7fc507a0UL,
+    0x54e85463UL, 0x4df36522UL, 0x02b2f3e5UL, 0x1ba9c2a4UL, 0x30849167UL,
+    0x299fa026UL, 0xe4c5aeb8UL, 0xfdde9ff9UL, 0xd6f3cc3aUL, 0xcfe8fd7bUL,
+    0x80a96bbcUL, 0x99b25afdUL, 0xb29f093eUL, 0xab84387fUL, 0x2c1c24b0UL,
+    0x350715f1UL, 0x1e2a4632UL, 0x07317773UL, 0x4870e1b4UL, 0x516bd0f5UL,
+    0x7a468336UL, 0x635db277UL, 0xcbfad74eUL, 0xd2e1e60fUL, 0xf9ccb5ccUL,
+    0xe0d7848dUL, 0xaf96124aUL, 0xb68d230bUL, 0x9da070c8UL, 0x84bb4189UL,
+    0x03235d46UL, 0x1a386c07UL, 0x31153fc4UL, 0x280e0e85UL, 0x674f9842UL,
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+    0xee530937UL, 0xf7483876UL, 0xb809aeb1UL, 0xa1129ff0UL, 0x8a3fcc33UL,
+    0x9324fd72UL
+  },
+  {
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+    0xb853f606UL, 0xb9919c31UL, 0xbcde8ab4UL, 0xbd1ce083UL, 0xbf5a5edaUL,
+    0xbe9834edUL
+  },
+  {
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+    0xe9dbf6c3UL, 0x516791a6UL, 0xccb0a91fUL, 0x740cce7aUL, 0x66b96194UL,
+    0xde0506f1UL
+  },
+  {
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+    0x0dbed5e5UL, 0xb7efdc7cUL, 0x21dfdb0bUL, 0xd4d2d386UL, 0x42e2d4f1UL,
+    0xf8b3dd68UL, 0x6e83da1fUL, 0xcd16be81UL, 0x5b26b9f6UL, 0xe177b06fUL,
+    0x7747b718UL, 0xe65a0888UL, 0x706a0fffUL, 0xca3b0666UL, 0x5c0b0111UL,
+    0xff9e658fUL, 0x69ae62f8UL, 0xd3ff6b61UL, 0x45cf6c16UL, 0x78e20aa0UL,
+    0xeed20dd7UL, 0x5483044eUL, 0xc2b30339UL, 0x612667a7UL, 0xf71660d0UL,
+    0x4d476949UL, 0xdb776e3eUL, 0x4a6ad1aeUL, 0xdc5ad6d9UL, 0x660bdf40UL,
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+    0x021b685dUL, 0x942b6f2aUL, 0x37be0bb4UL, 0xa18e0cc3UL, 0x1bdf055aUL,
+    0x8def022dUL
+  },
+  {
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+    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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
+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]
+
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;
+
+  