From mboxrd@z Thu Jan  1 00:00:00 1970
X-Msuck: nntp://news.gmane.io/gmane.emacs.gnus.general/16693
Path: main.gmane.org!not-for-mail
From: Hrvoje Niksic <hniksic@srce.hr>
Newsgroups: gmane.emacs.gnus.general
Subject: Re: decode-coding-region
Date: 04 Sep 1998 14:09:20 +0200
Sender: owner-ding@hpc.uh.edu
Message-ID: <kig90k0m64v.fsf@jagor.srce.hr>
References: <kigg1e9nt1u.fsf@jagor.srce.hr> <m31zpthqog.fsf@sparky.gnus.org>
NNTP-Posting-Host: coloc-standby.netfonds.no
X-Trace: main.gmane.org 1035155525 29361 80.91.224.250 (20 Oct 2002 23:12:05 GMT)
X-Complaints-To: usenet@main.gmane.org
NNTP-Posting-Date: Sun, 20 Oct 2002 23:12:05 +0000 (UTC)
Return-Path: <owner-ding@hpc.uh.edu>
Original-Received: from gizmo.hpc.uh.edu (gizmo.hpc.uh.edu [129.7.102.31])
	by sclp3.sclp.com (8.8.5/8.8.5) with ESMTP id IAA13492
	for <jason@mailhost.sclp.com>; Fri, 4 Sep 1998 08:11:28 -0400 (EDT)
Original-Received: from sina.hpc.uh.edu (sina.hpc.uh.edu [129.7.3.5]) by gizmo.hpc.uh.edu (8.7.6/8.7.3) with ESMTP id GAF10154; Fri, 4 Sep 1998 06:42:30 -0500
Original-Received: by sina.hpc.uh.edu (TLB v0.09a (1.20 tibbs 1996/10/09 22:03:07)); Fri, 04 Sep 1998 07:09:47 -0500 (CDT)
Original-Received: from sclp3.sclp.com (root@sclp3.sclp.com [209.195.19.139]) by sina.hpc.uh.edu (8.7.3/8.7.3) with ESMTP id HAA15934 for <ding@hpc.uh.edu>; Fri, 4 Sep 1998 07:09:38 -0500 (CDT)
Original-Received: from jagor.srce.hr (hniksic@jagor.srce.hr [161.53.2.130])
	by sclp3.sclp.com (8.8.5/8.8.5) with ESMTP id IAA13485
	for <ding@gnus.org>; Fri, 4 Sep 1998 08:09:28 -0400 (EDT)
Original-Received: (from hniksic@localhost)
	by jagor.srce.hr (8.9.0/8.9.0) id OAA07710;
	Fri, 4 Sep 1998 14:09:20 +0200 (MET DST)
Original-To: ding@gnus.org
X-Attribution: Hrvoje
X-Face: Mie8:rOV<\c/~z{s.X4A{!?vY7{drJ([U]0O=W/<W*SMo/Mv:58:*_y~ki>xDi&N7XG
        KV^$k0m3Oe/)'e%3=$PCR&3ITUXH,cK>]bci&<qQ>Ff%x_>1`T(+M2Gg/fgndU%k*ft
        [(7._6e0n-V%|%'[c|q:;}td$#INd+;?!-V=c8Pqf}3J
In-Reply-To: Lars Magne Ingebrigtsen's message of "03 Sep 1998 22:44:31 +0200"
Original-Lines: 46
X-Mailer: Pterodactyl Gnus v0.13/XEmacs 21.0 - "Danish Landrace"
Precedence: list
X-Majordomo: 1.94.jlt7
Xref: main.gmane.org gmane.emacs.gnus.general:16693
X-Report-Spam: http://spam.gmane.org/gmane.emacs.gnus.general:16693

Lars Magne Ingebrigtsen <larsi@gnus.org> writes:

> Hrvoje Niksic <hniksic@srce.hr> writes:
> 
> > FYI, decode-coding-region and encode-coding-region also thrash the
> > extents under XEmacs.  If you need a workaround for that, please let
> > me know.
> 
> It would be nice to preserve the extents.

You might want to try something like this until we fix the primitives:

(defmacro gnus-xmas-preserve-extents (&rest body)
  (let ((extents (gensym "extents-")))
    `(let (,extents)
       (map-extents (lambda (extent ignored)
		      (push (list extent
				  (extent-start-position extent)
				  (extent-end-position extent))
			    ,extents)
		      (detach-extent extent)
		      nil)
		    buffer start end)
       ,@body
       (dolist (extent ,extents)
	 (set-extent-endpoints (first extent) (second extent) (third extent))))))

(defun gnus-xmas-decode-coding-region (start end coding-system &optional buffer)
  "Like decode-coding-region, but preserves extents."
  (gnus-xmas-preserve-extents
   (decode-coding-region start end coding-system buffer)))

(defun gnus-xmas-encode-coding-region (start end coding-system &optional buffer)
  "Like encode-coding-region, but preserves extents."
  (gnus-xmas-preserve-extents
   (encode-coding-region start end coding-system buffer)))

However, this will fail to work correctly when the decoding changes
the number of characters, because the extent indices will not be
preserved correctly.

-- 
Hrvoje Niksic <hniksic@srce.hr> | Student at FER Zagreb, Croatia
--------------------------------+--------------------------------
Thou Who might be our Father Who perhaps may be in Heaven...
                                                -- Roger Zelazny