From unknown Sun Jun 22 07:57:47 2025 X-Loop: help-debbugs@gnu.org Subject: bug#6388: Should not match data be set on misses? Resent-From: Lennart Borgman Original-Sender: debbugs-submit-bounces@debbugs.gnu.org Resent-To: owner@debbugs.gnu.org Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Thu, 10 Jun 2010 00:50:03 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: report 6388 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: To: 6388@debbugs.gnu.org X-Debbugs-Original-To: Emacs Bugs Received: via spool by submit@debbugs.gnu.org id=B.127613098523134 (code B ref -1); Thu, 10 Jun 2010 00:50:03 +0000 Received: (at submit) by debbugs.gnu.org; 10 Jun 2010 00:49:45 +0000 Received: from localhost ([127.0.0.1] helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OMVxo-000615-Rs for submit@debbugs.gnu.org; Wed, 09 Jun 2010 20:49:45 -0400 Received: from mail.gnu.org ([199.232.76.166] helo=mx10.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OMVxm-000610-1B for submit@debbugs.gnu.org; Wed, 09 Jun 2010 20:49:42 -0400 Received: from lists.gnu.org ([199.232.76.165]:48821) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1OMVxh-0004I7-Tu for submit@debbugs.gnu.org; Wed, 09 Jun 2010 20:49:38 -0400 Received: from [140.186.70.92] (port=40622 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OMVxg-0001YC-NB for bug-gnu-emacs@gnu.org; Wed, 09 Jun 2010 20:49:37 -0400 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on eggs.gnu.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM, T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OMVxf-0006av-LS for bug-gnu-emacs@gnu.org; Wed, 09 Jun 2010 20:49:36 -0400 Received: from mail-gy0-f169.google.com ([209.85.160.169]:42165) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OMVxf-0006ag-JJ for bug-gnu-emacs@gnu.org; Wed, 09 Jun 2010 20:49:35 -0400 Received: by gyg4 with SMTP id 4so5317760gyg.0 for ; Wed, 09 Jun 2010 17:49:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:mime-version:received:from:date :message-id:subject:to:content-type; bh=ll9mX6CvtLUNO39Xo5p5fI0VSqSNaTuR0qEM6z/XMmA=; b=hGUwWcyT0fdOsPQEv5EFhP+Cizzqw+xpFZK4YoStGUALk7cDs7OaVa7OA0u98XX4oV 2KBzMoVMLUUEk/d6kjTwJfCuMhKHWMPBjpcPCPK1KhT9JZFASsv9MWDX8FoRGukf9EDo IiJz3es+cKruAc/EUQRuk8Zj+G9MaJRs4I0x0= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:from:date:message-id:subject:to:content-type; b=NIns8hI0Grgo0H7nyyQWYcrVxoSh1lUIMKvodrFJIn8yu1dTwUxQ9Q0zPdbllbwtF2 99ykG5+DP/XyuFHuuMY5MDn4TMyX82xwNipjnq+w9pKQH8rqsZ8ff6EqOZS/za+kyKML sL39uqglu63/zYKqSzEPlbtPEvTwwuiKr3idE= Received: by 10.101.203.9 with SMTP id f9mr19298135anq.208.1276130974465; Wed, 09 Jun 2010 17:49:34 -0700 (PDT) MIME-Version: 1.0 Received: by 10.100.154.15 with HTTP; Wed, 9 Jun 2010 17:42:59 -0700 (PDT) From: Lennart Borgman Date: Thu, 10 Jun 2010 02:42:59 +0200 Message-ID: Content-Type: text/plain; charset=UTF-8 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 2) X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.6, seldom 2.4 (older, 4) X-Spam-Score: -4.6 (----) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: debbugs-submit-bounces@debbugs.gnu.org Errors-To: debbugs-submit-bounces@debbugs.gnu.org X-Spam-Score: -4.6 (----) (let ((ret (re-search-forward "some weird thing" (point-at-eol) t))) (message "ret=%s, mb0=%s, 1" ret (match-beginning 0) (match-beginning 1))) gives me messages like ret=nil, mb0=517, 1 I expected ret=nil, mb0=nil, nil From unknown Sun Jun 22 07:57:47 2025 MIME-Version: 1.0 X-Mailer: MIME-tools 5.427 (Entity 5.427) X-Loop: help-debbugs@gnu.org From: help-debbugs@gnu.org (GNU bug Tracking System) To: Lennart Borgman Subject: bug#6388: closed (Re: bug#6388: Should not match data be set on misses?) Message-ID: References: X-Gnu-PR-Message: they-closed 6388 X-Gnu-PR-Package: emacs Reply-To: 6388@debbugs.gnu.org Date: Thu, 10 Jun 2010 02:04:02 +0000 Content-Type: multipart/mixed; boundary="----------=_1276135442-24908-1" This is a multi-part message in MIME format... ------------=_1276135442-24908-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Your bug report #6388: Should not match data be set on misses? which was filed against the emacs package, has been closed. The explanation is attached below, along with your original report. If you require more details, please reply to 6388@debbugs.gnu.org. --=20 6388: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=3D6388 GNU Bug Tracking System Contact help-debbugs@gnu.org with problems ------------=_1276135442-24908-1 Content-Type: message/rfc822 Content-Disposition: inline Content-Transfer-Encoding: 7bit Received: (at 6388-done) by debbugs.gnu.org; 10 Jun 2010 02:03:15 +0000 Received: from localhost ([127.0.0.1] helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OMX6w-0006TY-Ro for submit@debbugs.gnu.org; Wed, 09 Jun 2010 22:03:15 -0400 Received: from fencepost.gnu.org ([140.186.70.10]) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OMX6u-0006TT-Nm for 6388-done@debbugs.gnu.org; Wed, 09 Jun 2010 22:03:13 -0400 Received: from eliz by fencepost.gnu.org with local (Exim 4.69) (envelope-from ) id 1OMX6q-0004aE-VV; Wed, 09 Jun 2010 22:03:08 -0400 From: Eli Zaretskii To: Lennart Borgman In-reply-to: (message from Lennart Borgman on Thu, 10 Jun 2010 02:42:59 +0200) Subject: Re: bug#6388: Should not match data be set on misses? References: Message-Id: Date: Wed, 09 Jun 2010 22:03:08 -0400 X-Spam-Score: -6.5 (------) X-Debbugs-Envelope-To: 6388-done Cc: 6388-done@debbugs.gnu.org X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.11 Precedence: list Reply-To: Eli Zaretskii List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: debbugs-submit-bounces@debbugs.gnu.org Errors-To: debbugs-submit-bounces@debbugs.gnu.org X-Spam-Score: -6.5 (------) > From: Lennart Borgman > Date: Thu, 10 Jun 2010 02:42:59 +0200 > Cc: > > (let ((ret (re-search-forward "some weird thing" (point-at-eol) t))) > (message "ret=%s, mb0=%s, 1" ret (match-beginning 0) (match-beginning 1))) > > gives me messages like > > ret=nil, mb0=517, 1 > > I expected > > ret=nil, mb0=nil, nil I'm closing this bug report because the ELisp manual explicitly documents the current behavior: Every successful search sets the match data. Therefore, you should query the match data immediately after searching, before calling any other function that might perform another search. Alternatively, you may save and restore the match data (*note Saving Match Data::) around the call to functions that could perform another search. A search which fails may or may not alter the match data. In the past, a failing search did not do this, but we may change it in the future. So don't try to rely on the value of the match data after a failing search. Patches welcome to "change this in the future" (unless Stefan or Yidong object to such a change). ------------=_1276135442-24908-1 Content-Type: message/rfc822 Content-Disposition: inline Content-Transfer-Encoding: 7bit Received: (at submit) by debbugs.gnu.org; 10 Jun 2010 00:49:45 +0000 Received: from localhost ([127.0.0.1] helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OMVxo-000615-Rs for submit@debbugs.gnu.org; Wed, 09 Jun 2010 20:49:45 -0400 Received: from mail.gnu.org ([199.232.76.166] helo=mx10.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OMVxm-000610-1B for submit@debbugs.gnu.org; Wed, 09 Jun 2010 20:49:42 -0400 Received: from lists.gnu.org ([199.232.76.165]:48821) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1OMVxh-0004I7-Tu for submit@debbugs.gnu.org; Wed, 09 Jun 2010 20:49:38 -0400 Received: from [140.186.70.92] (port=40622 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OMVxg-0001YC-NB for bug-gnu-emacs@gnu.org; Wed, 09 Jun 2010 20:49:37 -0400 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on eggs.gnu.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM, T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OMVxf-0006av-LS for bug-gnu-emacs@gnu.org; Wed, 09 Jun 2010 20:49:36 -0400 Received: from mail-gy0-f169.google.com ([209.85.160.169]:42165) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OMVxf-0006ag-JJ for bug-gnu-emacs@gnu.org; Wed, 09 Jun 2010 20:49:35 -0400 Received: by gyg4 with SMTP id 4so5317760gyg.0 for ; Wed, 09 Jun 2010 17:49:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:mime-version:received:from:date :message-id:subject:to:content-type; bh=ll9mX6CvtLUNO39Xo5p5fI0VSqSNaTuR0qEM6z/XMmA=; b=hGUwWcyT0fdOsPQEv5EFhP+Cizzqw+xpFZK4YoStGUALk7cDs7OaVa7OA0u98XX4oV 2KBzMoVMLUUEk/d6kjTwJfCuMhKHWMPBjpcPCPK1KhT9JZFASsv9MWDX8FoRGukf9EDo IiJz3es+cKruAc/EUQRuk8Zj+G9MaJRs4I0x0= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:from:date:message-id:subject:to:content-type; b=NIns8hI0Grgo0H7nyyQWYcrVxoSh1lUIMKvodrFJIn8yu1dTwUxQ9Q0zPdbllbwtF2 99ykG5+DP/XyuFHuuMY5MDn4TMyX82xwNipjnq+w9pKQH8rqsZ8ff6EqOZS/za+kyKML sL39uqglu63/zYKqSzEPlbtPEvTwwuiKr3idE= Received: by 10.101.203.9 with SMTP id f9mr19298135anq.208.1276130974465; Wed, 09 Jun 2010 17:49:34 -0700 (PDT) MIME-Version: 1.0 Received: by 10.100.154.15 with HTTP; Wed, 9 Jun 2010 17:42:59 -0700 (PDT) From: Lennart Borgman Date: Thu, 10 Jun 2010 02:42:59 +0200 Message-ID: Subject: Should not match data be set on misses? To: Emacs Bugs Content-Type: text/plain; charset=UTF-8 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 2) X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.6, seldom 2.4 (older, 4) X-Spam-Score: -4.6 (----) X-Debbugs-Envelope-To: submit X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: debbugs-submit-bounces@debbugs.gnu.org Errors-To: debbugs-submit-bounces@debbugs.gnu.org X-Spam-Score: -4.6 (----) (let ((ret (re-search-forward "some weird thing" (point-at-eol) t))) (message "ret=%s, mb0=%s, 1" ret (match-beginning 0) (match-beginning 1))) gives me messages like ret=nil, mb0=517, 1 I expected ret=nil, mb0=nil, nil ------------=_1276135442-24908-1-- From unknown Sun Jun 22 07:57:47 2025 X-Loop: help-debbugs@gnu.org Subject: bug#6388: Should not match data be set on misses? Resent-From: Stefan Monnier Original-Sender: debbugs-submit-bounces@debbugs.gnu.org Resent-To: owner@debbugs.gnu.org Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Thu, 10 Jun 2010 13:05:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 6388 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: To: 6388@debbugs.gnu.org Cc: eliz@gnu.org Received: via spool by 6388-submit@debbugs.gnu.org id=B6388.127617505611710 (code B ref 6388); Thu, 10 Jun 2010 13:05:02 +0000 Received: (at 6388) by debbugs.gnu.org; 10 Jun 2010 13:04:16 +0000 Received: from localhost ([127.0.0.1] helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OMhQe-00032p-Hc for submit@debbugs.gnu.org; Thu, 10 Jun 2010 09:04:16 -0400 Received: from ironport2-out.teksavvy.com ([206.248.154.181] helo=ironport2-out.pppoe.ca) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OMhQc-00032j-C9 for 6388@debbugs.gnu.org; Thu, 10 Jun 2010 09:04:15 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Ar8FACd/EExMCqeQ/2dsb2JhbACSUYwKcr4WhRgEjHY X-IronPort-AV: E=Sophos;i="4.53,398,1272859200"; d="scan'208";a="67751751" Received: from 76-10-167-144.dsl.teksavvy.com (HELO pastel.home) ([76.10.167.144]) by ironport2-out.pppoe.ca with ESMTP; 10 Jun 2010 09:04:09 -0400 Received: by pastel.home (Postfix, from userid 20848) id D81858056; Thu, 10 Jun 2010 09:04:08 -0400 (EDT) From: Stefan Monnier Message-ID: References: Date: Thu, 10 Jun 2010 09:04:08 -0400 In-Reply-To: (Eli Zaretskii's message of "Wed, 09 Jun 2010 22:03:08 -0400") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.0.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Spam-Score: -2.2 (--) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: debbugs-submit-bounces@debbugs.gnu.org Errors-To: debbugs-submit-bounces@debbugs.gnu.org X-Spam-Score: -2.2 (--) > I'm closing this bug report because the ELisp manual explicitly > documents the current behavior: > Every successful search sets the match data. Therefore, you should > query the match data immediately after searching, before calling any > other function that might perform another search. Alternatively, you > may save and restore the match data (*note Saving Match Data::) around > the call to functions that could perform another search. > A search which fails may or may not alter the match data. In the > past, a failing search did not do this, but we may change it in the > future. So don't try to rely on the value of the match data after a > failing search. > Patches welcome to "change this in the future" (unless Stefan or > Yidong object to such a change). Yes, there was a long discussion about this a few years ago. The main obstacle to such a change are: - it breaks some code. - it is not tremendously useful. - it is difficult to detect code that relies on the current behavior (so it's difficult to output a warning to help in the migration). The current behavior is not tremendously useful either, of course, but it has the advantage of being what we've used for many years. Stefan From unknown Sun Jun 22 07:57:47 2025 X-Loop: help-debbugs@gnu.org Subject: bug#6388: Should not match data be set on misses? Resent-From: Lennart Borgman Original-Sender: debbugs-submit-bounces@debbugs.gnu.org Resent-To: owner@debbugs.gnu.org Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Thu, 10 Jun 2010 13:36:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 6388 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: To: Stefan Monnier Cc: 6388@debbugs.gnu.org Received: via spool by 6388-submit@debbugs.gnu.org id=B6388.127617694512604 (code B ref 6388); Thu, 10 Jun 2010 13:36:01 +0000 Received: (at 6388) by debbugs.gnu.org; 10 Jun 2010 13:35:45 +0000 Received: from localhost ([127.0.0.1] helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OMhv6-0003HF-NI for submit@debbugs.gnu.org; Thu, 10 Jun 2010 09:35:45 -0400 Received: from mail-yx0-f172.google.com ([209.85.213.172]) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OMhv5-0003H9-9M for 6388@debbugs.gnu.org; Thu, 10 Jun 2010 09:35:43 -0400 Received: by yxt33 with SMTP id 33so1361355yxt.3 for <6388@debbugs.gnu.org>; Thu, 10 Jun 2010 06:35:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:mime-version:received:in-reply-to :references:from:date:message-id:subject:to:cc:content-type :content-transfer-encoding; bh=/pHQkK7LVyUd99og+7CMCfTfVhEFMoXyZfxYdchkz4Q=; b=iyI7MDuvlD7ntsrCedp5oi7OrzQRDPQdHD0sLXBkB2/UXQFO+Z6QyFKAUxiZHGqop/ Sp3QucAx2+JwV/mugPnnQAJ9ti8rITfrAj8MTs/t67NB9N+7HBVRrS/c51T49zmwn1uq zHUOaiOIgvHpWsz51aMuw53QUfAf5UVK1XCF0= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type:content-transfer-encoding; b=LixOQof5UlBEQte/Rj53rP1d3lP3YYDsqhlcB4kNkM9vfBjvCId1EiBkrTQr/72XA7 C73bgiLqnK7XPI+x2hRQtzcYVRzb8JkWaYVaJ5/lVmizby8o5p9MMbeXYudgM8+eneGC CTrpW4gC+4j9lKfF+XEvh12Hwbx0ZIX9OGLxc= Received: by 10.101.129.16 with SMTP id g16mr176010ann.76.1276176937889; Thu, 10 Jun 2010 06:35:37 -0700 (PDT) MIME-Version: 1.0 Received: by 10.100.154.15 with HTTP; Thu, 10 Jun 2010 06:35:17 -0700 (PDT) In-Reply-To: References: From: Lennart Borgman Date: Thu, 10 Jun 2010 15:35:17 +0200 Message-ID: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Spam-Score: -2.9 (--) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: debbugs-submit-bounces@debbugs.gnu.org Errors-To: debbugs-submit-bounces@debbugs.gnu.org X-Spam-Score: -2.9 (--) On Thu, Jun 10, 2010 at 3:04 PM, Stefan Monnier wrote: >> I'm closing this bug report because the ELisp manual explicitly >> documents the current behavior: > >> =C2=A0 =C2=A0 =C2=A0 Every successful search sets the match data. =C2=A0= Therefore, you should >> =C2=A0 =C2=A0query the match data immediately after searching, before ca= lling any >> =C2=A0 =C2=A0other function that might perform another search. =C2=A0Alt= ernatively, you >> =C2=A0 =C2=A0may save and restore the match data (*note Saving Match Dat= a::) around >> =C2=A0 =C2=A0the call to functions that could perform another search. > >> =C2=A0 =C2=A0 =C2=A0 A search which fails may or may not alter the match= data. =C2=A0In the >> =C2=A0 =C2=A0past, a failing search did not do this, but we may change i= t in the >> =C2=A0 =C2=A0future. =C2=A0So don't try to rely on the value of the matc= h data after a >> =C2=A0 =C2=A0failing search. > >> Patches welcome to "change this in the future" (unless Stefan or >> Yidong object to such a change). > > Yes, there was a long discussion about this a few years ago. Sorry, forgot. > The main > obstacle to such a change are: > - it breaks some code. Aka it makes some bugs (bad assumptions) surface. That is not always bad. > - it is not tremendously useful. But it is probably what a user/programmer normally expects. > - it is difficult to detect code that relies on the current behavior > =C2=A0(so it's difficult to output a warning to help in the migration). > The current behavior is not tremendously useful either, of course, but > it has the advantage of being what we've used for many years. Yes, that is true. However the current behavior probably wastes a lot of time for those unaware of it. From unknown Sun Jun 22 07:57:47 2025 X-Loop: help-debbugs@gnu.org Subject: bug#6388: Should not match data be set on misses? Resent-From: Stefan Monnier Original-Sender: debbugs-submit-bounces@debbugs.gnu.org Resent-To: owner@debbugs.gnu.org Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Thu, 10 Jun 2010 18:58:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 6388 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: To: Lennart Borgman Cc: 6388@debbugs.gnu.org Received: via spool by 6388-submit@debbugs.gnu.org id=B6388.127619622922346 (code B ref 6388); Thu, 10 Jun 2010 18:58:02 +0000 Received: (at 6388) by debbugs.gnu.org; 10 Jun 2010 18:57:09 +0000 Received: from localhost ([127.0.0.1] helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OMmw9-0005oN-HR for submit@debbugs.gnu.org; Thu, 10 Jun 2010 14:57:09 -0400 Received: from chene.dit.umontreal.ca ([132.204.246.20]) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OMmw7-0005o3-Bw for 6388@debbugs.gnu.org; Thu, 10 Jun 2010 14:57:08 -0400 Received: from faina.iro.umontreal.ca (faina.iro.umontreal.ca [132.204.26.177]) by chene.dit.umontreal.ca (8.14.1/8.14.1) with ESMTP id o5AIv1wf016528; Thu, 10 Jun 2010 14:57:01 -0400 Received: by faina.iro.umontreal.ca (Postfix, from userid 20848) id 44066B4080; Thu, 10 Jun 2010 14:57:01 -0400 (EDT) From: Stefan Monnier Message-ID: References: Date: Thu, 10 Jun 2010 14:57:01 -0400 In-Reply-To: (Lennart Borgman's message of "Thu, 10 Jun 2010 15:35:17 +0200") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.0.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-NAI-Spam-Score: 0 X-NAI-Spam-Rules: 1 Rules triggered RV3554=0 X-Spam-Score: -1.3 (-) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: debbugs-submit-bounces@debbugs.gnu.org Errors-To: debbugs-submit-bounces@debbugs.gnu.org X-Spam-Score: -2.0 (--) >> The main obstacle to such a change are: >> - it breaks some code. > Aka it makes some bugs (bad assumptions) surface. That is not always bad. I really meant bugs, as in: the code consciously takes advantage of current behavior. Those assumptions are only bad if we define them that way. > Yes, that is true. However the current behavior probably wastes a lot > of time for those unaware of it. Just like with programming with monitors where you're taught "always do the wait within a `while' loop", regexp-patching should always take place within a `if' or equivalent, Stefan