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#9159: 24.0.50; `undo' is not as good as it should be wrt property changes Date: Tue, 02 Aug 2011 15:10:26 -0400 Message-ID: References: <2770D343D58A43A6A97AC158A2C6B677@us.oracle.com> <7FC41925A39D4B16A7F1CB3CCF4A4371@us.oracle.com> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; CHARSET=US-ASCII Content-Transfer-Encoding: 7BIT X-Trace: dough.gmane.org 1312312241 11084 80.91.229.12 (2 Aug 2011 19:10:41 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Tue, 2 Aug 2011 19:10:41 +0000 (UTC) Cc: 9159@debbugs.gnu.org To: Drew Adams Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Tue Aug 02 21:10:37 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 1QoKMP-0008OO-6a for geb-bug-gnu-emacs@m.gmane.org; Tue, 02 Aug 2011 21:10:37 +0200 Original-Received: from localhost ([::1]:55934 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QoKMO-0006th-My for geb-bug-gnu-emacs@m.gmane.org; Tue, 02 Aug 2011 15:10:36 -0400 Original-Received: from eggs.gnu.org ([140.186.70.92]:41084) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QoKML-0006sn-L2 for bug-gnu-emacs@gnu.org; Tue, 02 Aug 2011 15:10:34 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QoKMK-0007BA-Oo for bug-gnu-emacs@gnu.org; Tue, 02 Aug 2011 15:10:33 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:53115) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QoKMK-0007B6-Lv for bug-gnu-emacs@gnu.org; Tue, 02 Aug 2011 15:10:32 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.69) (envelope-from ) id 1QoKMn-0000Xp-Rj; Tue, 02 Aug 2011 15:11:01 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Stefan Monnier Original-Sender: debbugs-submit-bounces@debbugs.gnu.org Resent-To: owner@debbugs.gnu.org Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Tue, 02 Aug 2011 19:11:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 9159 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 9159-submit@debbugs.gnu.org id=B9159.13123122592084 (code B ref 9159); Tue, 02 Aug 2011 19:11:01 +0000 Original-Received: (at 9159) by debbugs.gnu.org; 2 Aug 2011 19:10:59 +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 1QoKMl-0000XZ-5o for submit@debbugs.gnu.org; Tue, 02 Aug 2011 15:10:59 -0400 Original-Received: from relais.videotron.ca ([24.201.245.36]) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1QoKMj-0000XS-4j for 9159@debbugs.gnu.org; Tue, 02 Aug 2011 15:10:57 -0400 Original-Received: from ceviche.home ([70.80.89.35]) by vl-mh-mrz25.ip.videotron.ca (Sun Java(tm) System Messaging Server 6.3-8.01 (built Dec 16 2008; 32bit)) with ESMTP id <0LPB00L9LEH7UJB0@vl-mh-mrz25.ip.videotron.ca> for 9159@debbugs.gnu.org; Tue, 02 Aug 2011 15:07:55 -0400 (EDT) Original-Received: by ceviche.home (Postfix, from userid 20848) id E9D70660CF; Tue, 02 Aug 2011 15:10:26 -0400 (EDT) In-reply-to: <7FC41925A39D4B16A7F1CB3CCF4A4371@us.oracle.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.0.50 (gnu/linux) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.11 Precedence: list Resent-Date: Tue, 02 Aug 2011 15:11:01 -0400 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 1) 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:49826 Archived-At: >> > C-M-_ to undo the last change. >> > With point in the same place, do `C-u C-x ='. >> > That shows that there is property `foo' there, with value nil. >> Do you have an example situation where the difference matters? > What does "matters" mean? By "matters" I mean that the difference is reflected in a different behavior for "the end user". I'm sure you know what I mean. > Evidently it does not matter much to you. Not until I see that it has some more serious consequence. What you show is a mostly cosmetic difference. >> Usually we handle the absence of a text property as synonym to a nil >> value of that property. > Yes, I know that. And this is a good example where it makes > a difference. If you accept the fact that "nothing == nil" for text-properties, then the difference you show is indeed not a difference, it's just a cosmetically different way to represent the same state. Stefan