From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: "Drew Adams" Newsgroups: gmane.emacs.bugs Subject: bug#9159: 24.0.50; `undo' is not as good as it should be wrt property changes Date: Tue, 2 Aug 2011 13:48:03 -0700 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 1312318123 19893 80.91.229.12 (2 Aug 2011 20:48:43 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Tue, 2 Aug 2011 20:48:43 +0000 (UTC) Cc: 9159@debbugs.gnu.org To: "'Stefan Monnier'" Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Tue Aug 02 22:48:39 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 1QoLtF-00047m-4K for geb-bug-gnu-emacs@m.gmane.org; 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Tue, 2 Aug 2011 20:48:08 GMT Original-Received: from abhmt109.oracle.com (abhmt109.oracle.com [141.146.116.61]) by acsmt357.oracle.com (8.12.11.20060308/8.12.11) with ESMTP id p72Km3Eq008439; Tue, 2 Aug 2011 15:48:03 -0500 Original-Received: from dradamslap1 (/130.35.178.194) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 02 Aug 2011 13:48:02 -0700 X-Mailer: Microsoft Office Outlook 11 In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6109 Thread-Index: AcxRR9tCSOFh4iigRACWqLaJbb0KVAAC8b4Q X-Source-IP: acsinet22.oracle.com [141.146.126.238] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090207.4E38628A.00CB:SCFMA922111,ss=1,re=-4.000,fgs=0 X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.11 Precedence: list Resent-Date: Tue, 02 Aug 2011 16:49:01 -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:49845 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. I _described_ a visible difference for the end user. That is pretty much the only things I care about in general: user-visible behavior. What is not user-visible in the behavior I reported? The whole point of the report was about the behavior being confusing to an end user. > > 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. Call it such a name if that makes you feel better. It is a user-visible difference that promotes confusion. No, it is not the most important problem Emacs has. And it is unlikely to cause mass destruction. > >> 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. A user-visible difference, I might have added. > 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. Whatever. If you don't think this difference in what the user sees and what s?he is likely to expect/understand promotes confusion, or if you see it but don't care, nothing I say will change your mind. I already said in the OP that "while correct" (N.B.) "it would be better for the property `foo' to simply be removed." We agree that the value shown is correct. I say that although correct it is confusing. You say that it's just cosmetic - bad looks. Your poor cosmetics can confuse users. And that was the point, from the beginning.