From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.bugs Subject: bug#18141: 24.4.50; saving .gz file breaks file coding Date: Thu, 07 Aug 2014 15:08:41 -0400 Message-ID: References: <9pzjfrwvsl.fsf@fencepost.gnu.org> <83iom5ptwv.fsf@gnu.org> <83tx5po5eo.fsf@gnu.org> <83ha1onxgg.fsf@gnu.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1407438569 25627 80.91.229.3 (7 Aug 2014 19:09:29 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 7 Aug 2014 19:09:29 +0000 (UTC) Cc: 18141@debbugs.gnu.org, vincent@vinc17.net, yamaoka@jpl.org To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Thu Aug 07 21:09:22 2014 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1XFT3x-0002wT-IL for geb-bug-gnu-emacs@m.gmane.org; Thu, 07 Aug 2014 21:09:21 +0200 Original-Received: from localhost ([::1]:47851 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XFT3x-0005DZ-2W for geb-bug-gnu-emacs@m.gmane.org; Thu, 07 Aug 2014 15:09:21 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:43770) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XFT3m-0005C6-Gn for bug-gnu-emacs@gnu.org; Thu, 07 Aug 2014 15:09:18 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XFT3e-0005SN-QQ for bug-gnu-emacs@gnu.org; Thu, 07 Aug 2014 15:09:10 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:55565) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XFT3e-0005SJ-NP for bug-gnu-emacs@gnu.org; Thu, 07 Aug 2014 15:09:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.80) (envelope-from ) id 1XFT3e-0006Q1-7E for bug-gnu-emacs@gnu.org; Thu, 07 Aug 2014 15:09:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Stefan Monnier Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Thu, 07 Aug 2014 19:09:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 18141 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 18141-submit@debbugs.gnu.org id=B18141.140743853124655 (code B ref 18141); Thu, 07 Aug 2014 19:09:02 +0000 Original-Received: (at 18141) by debbugs.gnu.org; 7 Aug 2014 19:08:51 +0000 Original-Received: from localhost ([127.0.0.1]:34275 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1XFT3S-0006Pa-HH for submit@debbugs.gnu.org; Thu, 07 Aug 2014 15:08:51 -0400 Original-Received: from ironport2-out.teksavvy.com ([206.248.154.181]:35315) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1XFT3P-0006PJ-NA for 18141@debbugs.gnu.org; Thu, 07 Aug 2014 15:08:48 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: ArYGAIDvNVPAqyKr/2dsb2JhbABZgwaDSr0vgw6BFxd0giUBAQEBAgFWIwULCzQSFBgNJIgECNIZF44PE1gHhDgEqwODTCGBLA X-IPAS-Result: ArYGAIDvNVPAqyKr/2dsb2JhbABZgwaDSr0vgw6BFxd0giUBAQEBAgFWIwULCzQSFBgNJIgECNIZF44PE1gHhDgEqwODTCGBLA X-IronPort-AV: E=Sophos;i="4.97,753,1389762000"; d="scan'208";a="82401629" Original-Received: from 192-171-34-171.cpe.pppoe.ca (HELO pastel.home) ([192.171.34.171]) by ironport2-out.teksavvy.com with ESMTP/TLS/DHE-RSA-AES256-SHA; 07 Aug 2014 15:08:41 -0400 Original-Received: by pastel.home (Postfix, from userid 20848) id 7900C60787; Thu, 7 Aug 2014 15:08:41 -0400 (EDT) In-Reply-To: <83ha1onxgg.fsf@gnu.org> (Eli Zaretskii's message of "Thu, 07 Aug 2014 18:14:39 +0300") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.4.50 (gnu/linux) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.15 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 140.186.70.43 X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:92278 Archived-At: > Again, that's how write-region always worked. And with magic file > names, this is actually the right approach: Emacs has no idea how to > set up the encoding for such files, so it must delegate that > responsibility to the handler. choose-write-coding-system works only > for local (a.k.a. "non-magic") files, it cannot possibly DTRT for > files that have handlers. I'm beginning to understand, so yes I guess the unintended consequences of the patch should be rather limited. > Why not move the call to backup-buffer (and surrounding code that > deals with backup complications) from basic-save-buffer-2 to a > separate function, and then call that function directly from > write-region, right before it is about to write the new contents? That's the hook I suggested. It's indeed a valid approach. But it suffers from two problems: - currently write-region doesn't itself perform backups, so if we make it do them always, it's an incompatible change. - if write-region sometimes performs backups, it'd probably be controlled by some dynamic-scoped var (e.g. a hook), in which case we could get "spurious" backups if write-region gets called during the execution of write-region. > While at that, we should IMO make the backup-then-write sequence a > transaction, by using the suitable unwind-protect functions, and > perhaps also make sure that unwind-protect function runs if Emacs is > killed half-way through the sequence, to keep the transaction promise. I'm not terribly worried about this "time window" especially since I think it's pretty clear that we can't completely eliminate it anyway. Stefan