From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Lars Ingebrigtsen Newsgroups: gmane.emacs.bugs Subject: bug#35264: "Match data clobbered by buffer modification hooks" when hooks only shifted match-data's markers Date: Fri, 02 Oct 2020 06:47:55 +0200 Message-ID: <87a6x5z11g.fsf@gnus.org> References: <87h8b119oy.fsf@gmail.com> <871s0f7det.fsf@gmail.com> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="28727"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) Cc: stefan monnier , 35264@debbugs.gnu.org To: Noam Postavsky Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Fri Oct 02 06:49:14 2020 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kOD0M-0007LK-8C for geb-bug-gnu-emacs@m.gmane-mx.org; Fri, 02 Oct 2020 06:49:14 +0200 Original-Received: from localhost ([::1]:45332 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kOD0L-0006nF-0D for geb-bug-gnu-emacs@m.gmane-mx.org; Fri, 02 Oct 2020 00:49:13 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:58190) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kOD0B-0006n1-Fs for bug-gnu-emacs@gnu.org; Fri, 02 Oct 2020 00:49:03 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:55713) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1kOD09-0002at-QM for bug-gnu-emacs@gnu.org; Fri, 02 Oct 2020 00:49:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1kOD09-0004Ag-O4 for bug-gnu-emacs@gnu.org; Fri, 02 Oct 2020 00:49:01 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Lars Ingebrigtsen Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Fri, 02 Oct 2020 04:49:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 35264 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: patch Original-Received: via spool by 35264-submit@debbugs.gnu.org id=B35264.160161409315975 (code B ref 35264); Fri, 02 Oct 2020 04:49:01 +0000 Original-Received: (at 35264) by debbugs.gnu.org; 2 Oct 2020 04:48:13 +0000 Original-Received: from localhost ([127.0.0.1]:39026 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1kOCzN-00049b-02 for submit@debbugs.gnu.org; Fri, 02 Oct 2020 00:48:13 -0400 Original-Received: from quimby.gnus.org ([95.216.78.240]:39416) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1kOCzJ-00049G-AI for 35264@debbugs.gnu.org; Fri, 02 Oct 2020 00:48:11 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnus.org; s=20200322; h=Content-Type:MIME-Version:Message-ID:In-Reply-To:Date: References:Subject:Cc:To:From:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=+9rERkCqMUUjOzgJNLh0VbnOZqDYIQNCLQh3K7RxCDk=; b=PP0VFqqsXFYUnrwvhRTCEczvHg MzUoO7a18f+W86DOyefvOdlAMrqPm3ONUHxldvhqeY+vBf34w/jhZg/v3RhF95HToiJoR7bu86sr8 qOySeRr38qlDSGQs+ZjD0lXbSSmGMOfWvCr+oo5cqBUaWuY4lrU3SaH6TaIDWp2QIO28=; Original-Received: from cm-84.212.202.86.getinternet.no ([84.212.202.86] helo=xo) by quimby with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kOCz6-0007jm-BN; Fri, 02 Oct 2020 06:48:02 +0200 X-Now-Playing: Joni Mitchell's _Travelogue (2)_: "The Dawntreader" In-Reply-To: <871s0f7det.fsf@gmail.com> (Noam Postavsky's message of "Thu, 30 May 2019 19:03:54 -0400") X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list 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-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:189614 Archived-At: Noam Postavsky writes: >> I think this is a variant of Bug#23917, there was some talk there about >> removing the check, perhaps that is the right solution. > > So, this, I guess. [...] > * src/search.c (Freplace_match): Don't test for change in search_regs > start and end, this is unreliable if change hooks modify text earlier > in the buffer. [...] > - if (search_regs.start[sub] != sub_start > - || search_regs.end[sub] != sub_end > - || search_regs.num_regs != num_regs) > + if (search_regs.num_regs != num_regs) > error ("Match data clobbered by buffer modification hooks"); > > /* Put point back where it was in the text. */ There were unfortunately no comments on this patch at the time. Noam said: > But the modification hook in question did call save-match-data. As far > as I can tell, the problem is that the match-data consists of markers, > whose position gets shifted by deletion of characters. The check for > this error uses simple integers, so there's no way it can account for > this. That does make sense, but removing this (somewhat buggy) sanity check is perhaps a bit scary. Any comments on this? -- (domestic pets only, the antidote for overdose, milk.) bloggy blog: http://lars.ingebrigtsen.no