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#23949: 25.0.95; Regression in handling error caused by (string-match-p "." nil) Date: Wed, 13 Jul 2016 12:00:40 -0400 Message-ID: References: <83lh17ati6.fsf@gnu.org> <83h9bvarb6.fsf@gnu.org> <83mvllaa4u.fsf@gnu.org> <8360s9a7ts.fsf@gnu.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1468425756 8536 80.91.229.3 (13 Jul 2016 16:02:36 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 13 Jul 2016 16:02:36 +0000 (UTC) Cc: schwab@suse.de, 23949@debbugs.gnu.org, kaushal.modi@gmail.com To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Wed Jul 13 18:02:18 2016 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 1bNMc6-0005jG-67 for geb-bug-gnu-emacs@m.gmane.org; Wed, 13 Jul 2016 18:02:18 +0200 Original-Received: from localhost ([::1]:48655 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bNMc5-00032x-ID for geb-bug-gnu-emacs@m.gmane.org; Wed, 13 Jul 2016 12:02:17 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:46631) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bNMav-00020C-Fz for bug-gnu-emacs@gnu.org; Wed, 13 Jul 2016 12:01:09 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bNMas-0000Rm-Ao for bug-gnu-emacs@gnu.org; Wed, 13 Jul 2016 12:01:05 -0400 Original-Received: from debbugs.gnu.org ([208.118.235.43]:37686) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bNMas-0000Ri-7D for bug-gnu-emacs@gnu.org; Wed, 13 Jul 2016 12:01:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1bNMar-0005Vu-RH for bug-gnu-emacs@gnu.org; Wed, 13 Jul 2016 12:01:01 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Stefan Monnier Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Wed, 13 Jul 2016 16:01:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 23949 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 23949-submit@debbugs.gnu.org id=B23949.146842564921167 (code B ref 23949); Wed, 13 Jul 2016 16:01:01 +0000 Original-Received: (at 23949) by debbugs.gnu.org; 13 Jul 2016 16:00:49 +0000 Original-Received: from localhost ([127.0.0.1]:50023 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1bNMaf-0005VL-Ab for submit@debbugs.gnu.org; Wed, 13 Jul 2016 12:00:49 -0400 Original-Received: from ironport2-out.teksavvy.com ([206.248.154.181]:21139) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1bNMac-0005V6-KE for 23949@debbugs.gnu.org; Wed, 13 Jul 2016 12:00:47 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: A0A+FgA731xV/3mcpUVcgxCEAoVVwwsEAgKBPD0QAQEBAQEBAYEKQQWDXQEBAwFWIxALNBIUGA0kLogJCM8jAQEBBwIBH4s6gT0Bg0cHhC0Fsz+BRSOBZjGBfSKCeAEBAQ X-IPAS-Result: A0A+FgA731xV/3mcpUVcgxCEAoVVwwsEAgKBPD0QAQEBAQEBAYEKQQWDXQEBAwFWIxALNBIUGA0kLogJCM8jAQEBBwIBH4s6gT0Bg0cHhC0Fsz+BRSOBZjGBfSKCeAEBAQ X-IronPort-AV: E=Sophos;i="5.13,465,1427774400"; d="scan'208";a="247772368" Original-Received: from 69-165-156-121.dsl.teksavvy.com (HELO pastel.home) ([69.165.156.121]) by ironport2-out.teksavvy.com with ESMTP; 13 Jul 2016 12:00:40 -0400 Original-Received: by pastel.home (Postfix, from userid 20848) id A822B64CB1; Wed, 13 Jul 2016 12:00:40 -0400 (EDT) In-Reply-To: <8360s9a7ts.fsf@gnu.org> (Eli Zaretskii's message of "Wed, 13 Jul 2016 18:14:39 +0300") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1.50 (gnu/linux) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 208.118.235.43 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" Xref: news.gmane.org gmane.emacs.bugs:121015 Archived-At: >> > I also think that the "breaks a lot of Elisp code" part is at least a >> > tad exaggerated. >> Binding inhibit-changing-match-data to t will pretty much break any >> function that uses match-beginning or match-end. > But those functions aren't supposed to run when string-match is > called. Yet they are in bug#23949. In practice, there's always a discrepancy between what is supposed to happen and what can happen in the general case ;-) >> > (defsubst string-match-p (regexp string &optional start) >> > "\ >> > Same as `string-match' except this function does not change the match data." >> > (condition-case err >> > (let ((inhibit-changing-match-data t)) >> > (string-match regexp string start)) >> > (error (signal (car err) (cdr err))))) >> That will still cause the same problems when debug-on-signal is non-nil. > So you don't consider this an improvement that should be installed? No. A simpler and more robust solution would be (save-match-data (string-match regexp string start)) Of course, with either solution, it means that string-match-p is even worse in terms of efficiency, whereas the unsuspecting coder would rightfully expect string-match-p to be (slightly) *more* efficient than string-match. Stefan