From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#8657: 24.0.50; Emacs code that seems to use `*-single-char-property-change' incorrectly Date: Thu, 12 May 2011 00:44:33 -0400 Message-ID: References: Reply-To: Eli Zaretskii NNTP-Posting-Host: lo.gmane.org X-Trace: dough.gmane.org 1305175513 24647 80.91.229.12 (12 May 2011 04:45:13 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Thu, 12 May 2011 04:45:13 +0000 (UTC) Cc: 8657@debbugs.gnu.org To: Stefan Monnier Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Thu May 12 06:45:09 2011 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([140.186.70.17]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1QKNlt-000832-8x for geb-bug-gnu-emacs@m.gmane.org; Thu, 12 May 2011 06:45:09 +0200 Original-Received: from localhost ([::1]:45638 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QKNlr-0007H2-Df for geb-bug-gnu-emacs@m.gmane.org; Thu, 12 May 2011 00:45:07 -0400 Original-Received: from eggs.gnu.org ([140.186.70.92]:37108) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QKNlo-0007FX-SX for bug-gnu-emacs@gnu.org; Thu, 12 May 2011 00:45:05 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QKNln-0007HR-Nc for bug-gnu-emacs@gnu.org; Thu, 12 May 2011 00:45:04 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:34047) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QKNln-0007HL-Lk for bug-gnu-emacs@gnu.org; Thu, 12 May 2011 00:45:03 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.69) (envelope-from ) id 1QKNln-0005h2-1u; Thu, 12 May 2011 00:45:03 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: debbugs-submit-bounces@debbugs.gnu.org Resent-To: owner@debbugs.gnu.org Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Thu, 12 May 2011 04:45:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 8657 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 8657-submit@debbugs.gnu.org id=B8657.130517548221842 (code B ref 8657); Thu, 12 May 2011 04:45:02 +0000 Original-Received: (at 8657) by debbugs.gnu.org; 12 May 2011 04:44:42 +0000 Original-Received: from localhost ([127.0.0.1] helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1QKNlR-0005gF-Ok for submit@debbugs.gnu.org; Thu, 12 May 2011 00:44:42 -0400 Original-Received: from fencepost.gnu.org ([140.186.70.10]) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1QKNlP-0005g3-8i for 8657@debbugs.gnu.org; Thu, 12 May 2011 00:44:39 -0400 Original-Received: from eliz by fencepost.gnu.org with local (Exim 4.71) (envelope-from ) id 1QKNlJ-0001p9-CC; Thu, 12 May 2011 00:44:33 -0400 In-reply-to: (message from Stefan Monnier on Thu, 12 May 2011 00:05:46 -0300) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.11 Precedence: list Resent-Date: Thu, 12 May 2011 00:45:03 -0400 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) X-Received-From: 140.186.70.43 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-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:46411 Archived-At: > From: Stefan Monnier > Date: Thu, 12 May 2011 00:05:46 -0300 > Cc: 8657@debbugs.gnu.org > > > In particular, IIUC, the return value can never be nil. > > Yet I see code such as this: > > > gnus-summary-show-thread: > > (or (next-single-char-property-change end 'invisible) (point-max)) > > > comint-next-prompt: > > (setq pos (next-single-char-property-change pos 'field)) > > (cond (or (null pos)... > > > Isn't this incorrect? > > The behavior might have changed at some point in time, explaining the > above code. Or maybe the author was confusing next-single-char-property-change with next-single-property-change. In any case, those tests are redundant, because next-single-char-property-change already returns point-max when it finds no change in properties.