From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Alan Mackenzie Newsgroups: gmane.emacs.devel Subject: Re: beginning-of-defun-comments bug [was: Re: 26.0.90: mark-defun problem in c-mode] Date: Sat, 30 Dec 2017 13:05:29 +0000 Message-ID: <20171230130529.GE10623@ACM> References: <834lo8fqyi.fsf@gnu.org> <20171230103432.GB10623@ACM> <20171230120136.GD10623@ACM> <83shbse5rs.fsf@gnu.org> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: blaine.gmane.org 1514639231 23853 195.159.176.226 (30 Dec 2017 13:07:11 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 30 Dec 2017 13:07:11 +0000 (UTC) User-Agent: Mutt/1.7.2 (2016-11-26) Cc: ccsmile2008@outlook.com, npostavs@gmail.com, emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Dec 30 14:07:07 2017 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1eVGqq-0005X1-AF for ged-emacs-devel@m.gmane.org; Sat, 30 Dec 2017 14:07:00 +0100 Original-Received: from localhost ([::1]:53970 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eVGsp-0002jA-7r for ged-emacs-devel@m.gmane.org; Sat, 30 Dec 2017 08:09:03 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:43730) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eVGsf-0002gl-ER for emacs-devel@gnu.org; Sat, 30 Dec 2017 08:08:54 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eVGsc-0005Zn-86 for emacs-devel@gnu.org; Sat, 30 Dec 2017 08:08:53 -0500 Original-Received: from colin.muc.de ([193.149.48.1]:40641 helo=mail.muc.de) by eggs.gnu.org with smtp (Exim 4.71) (envelope-from ) id 1eVGsc-0005XA-2d for emacs-devel@gnu.org; Sat, 30 Dec 2017 08:08:50 -0500 Original-Received: (qmail 27328 invoked by uid 3782); 30 Dec 2017 13:08:48 -0000 Original-Received: from acm.muc.de (p548C69B7.dip0.t-ipconnect.de [84.140.105.183]) by colin.muc.de (tmda-ofmipd) with ESMTP; Sat, 30 Dec 2017 14:08:47 +0100 Original-Received: (qmail 11894 invoked by uid 1000); 30 Dec 2017 13:05:29 -0000 Content-Disposition: inline In-Reply-To: <83shbse5rs.fsf@gnu.org> X-Delivery-Agent: TMDA/1.1.12 (Macallan) X-Primary-Address: acm@muc.de X-detected-operating-system: by eggs.gnu.org: FreeBSD 9.x [fuzzy] X-Received-From: 193.149.48.1 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:221471 Archived-At: Hello, Eli. On Sat, Dec 30, 2017 at 14:53:27 +0200, Eli Zaretskii wrote: > > Date: Sat, 30 Dec 2017 12:01:36 +0000 > > Cc: emacs-devel@gnu.org, zhang cc , > > Noam Postavsky > > From: Alan Mackenzie > > > I see the error, with point anywhere in the body of the second function. > > > Critical seems to be there being no blank line between the functions. > > > I think there's a bug in beginning-of-defun-comments, which I'm in the > > > middle of edebugging. It moves point into the first function. > > beginning-of-defun-comments has a bug. On doing M-x > > beginning-of-defun-comments from the inside of a function, when there's > > no blank lines between it and the previous function, point ends up > > inside that previous function, not at the comments which may separate > > them. > > Perhaps this bug should be fixed before the next Emacs-26 pretest. > How old is this problem? It looks like it's new in Emacs 26? If so, > we should try fixing it on the release branch. beginning-of-defun-comments came into existence on 2017-03-31, so this problem is definitely new in Emacs 26. I've diagnosed the bug. At one place, it is necessary to scan a line of text from BOL to detect any non-comment/non-space character. The current code tries to do this by using parse-partial-sexp with the fourth argument STOPBEFORE non-nil. This STOPBEFORE causes the scanning to stop at any character which begins a sexp. A closing brace doesn't fit into this category. The scan therefore reaches EOL, and the code therefore falsely assumes there are no non-syntactic-ws characters on that line. I'm sure I can fix this today. -- Alan Mackenzie (Nuremberg, Germany).