From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Alan Mackenzie Newsgroups: gmane.emacs.bugs Subject: bug#63535: Master branch: Error in forw_comment (syntax.c) handling of escaped LFs Date: Tue, 16 May 2023 16:58:55 +0000 Message-ID: References: <83ttwcz3gg.fsf@gnu.org> <83edngz1cp.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="7188"; mail-complaints-to="usenet@ciao.gmane.io" Cc: 63535@debbugs.gnu.org To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Tue May 16 19:00:23 2023 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 1pyy2A-0001ds-4r for geb-bug-gnu-emacs@m.gmane-mx.org; Tue, 16 May 2023 19:00:22 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pyy1s-0005iz-LK; Tue, 16 May 2023 13:00:04 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pyy1r-0005io-5A for bug-gnu-emacs@gnu.org; Tue, 16 May 2023 13:00:03 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1pyy1q-0001BU-SG for bug-gnu-emacs@gnu.org; Tue, 16 May 2023 13:00:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1pyy1q-0007Qh-K4 for bug-gnu-emacs@gnu.org; Tue, 16 May 2023 13:00:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Alan Mackenzie Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Tue, 16 May 2023 17:00:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 63535 X-GNU-PR-Package: emacs Original-Received: via spool by 63535-submit@debbugs.gnu.org id=B63535.168425634428450 (code B ref 63535); Tue, 16 May 2023 17:00:02 +0000 Original-Received: (at 63535) by debbugs.gnu.org; 16 May 2023 16:59:04 +0000 Original-Received: from localhost ([127.0.0.1]:47261 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1pyy0t-0007Oo-Py for submit@debbugs.gnu.org; Tue, 16 May 2023 12:59:04 -0400 Original-Received: from mx3.muc.de ([193.149.48.5]:41638) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1pyy0s-0007OI-AN for 63535@debbugs.gnu.org; Tue, 16 May 2023 12:59:02 -0400 Original-Received: (qmail 4763 invoked by uid 3782); 16 May 2023 18:58:56 +0200 Original-Received: from acm.muc.de (p4fe15025.dip0.t-ipconnect.de [79.225.80.37]) (using STARTTLS) by colin.muc.de (tmda-ofmipd) with ESMTP; Tue, 16 May 2023 18:58:55 +0200 Original-Received: (qmail 16770 invoked by uid 1000); 16 May 2023 16:58:55 -0000 Content-Disposition: inline In-Reply-To: <83edngz1cp.fsf@gnu.org> X-Submission-Agent: TMDA/1.3.x (Ph3nix) X-Primary-Address: acm@muc.de 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-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.bugs:261798 Archived-At: Hello, Eli. On Tue, May 16, 2023 at 19:29:26 +0300, Eli Zaretskii wrote: > > Date: Tue, 16 May 2023 16:15:24 +0000 > > Cc: 63535@debbugs.gnu.org > > From: Alan Mackenzie > > > > && !(comment_end_can_be_escaped && char_quoted (from, from_byte)) > > > > .. Checking char_quoted is wrong. Instead the function should check the > > > > current parse state. > > > Why not both? IOW, please explain why char_quoted is not TRT here. > > Because parse-partial-sexp is not scanning the backslash. The scan > > starts one character after the backslash, and the syntactic effect of > > that backslash is not in the OLDSTATE argument to parse-partial-sexp. > Sorry, I still don't follow: char_quoted doesn't call > parse-partial-sexp, AFAICT. parse-partial-sexp calls forw_comment which (wrongly) calls char_quoted. > So why does it matter what parse-partial-sexp does when we are > discussing why char_quoted is not TRT? parse-partial-sexp is the context in which the bug becomes evident. If, in the C++ line comment with escaped NL, you start parse-partial-sexp at the NL, it behaves as though the scan started at the backslash. This is the bug. The cause of the bug is the use of char_quoted at line 42 of forw_comment. -- Alan Mackenzie (Nuremberg, Germany).