From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.help Subject: Re: How to determine buffer change Date: Sat, 05 Apr 2014 10:00:26 -0400 Message-ID: References: <877g74dmve.fsf@gmail.com> <83d2gw7zsp.fsf@gnu.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1396706751 10682 80.91.229.3 (5 Apr 2014 14:05:51 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 5 Apr 2014 14:05:51 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Sat Apr 05 16:05:42 2014 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1WWRE5-0007YC-C4 for geh-help-gnu-emacs@m.gmane.org; Sat, 05 Apr 2014 16:05:41 +0200 Original-Received: from localhost ([::1]:54765 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WWRE4-0005oU-W2 for geh-help-gnu-emacs@m.gmane.org; Sat, 05 Apr 2014 10:05:40 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:52711) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WWRDd-0005o7-Rl for help-gnu-emacs@gnu.org; Sat, 05 Apr 2014 10:05:21 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WWRDW-0003s6-79 for help-gnu-emacs@gnu.org; Sat, 05 Apr 2014 10:05:13 -0400 Original-Received: from plane.gmane.org ([80.91.229.3]:47298) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WWRDW-0003r6-1g for help-gnu-emacs@gnu.org; Sat, 05 Apr 2014 10:05:06 -0400 Original-Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1WWRDT-00071s-Tt for help-gnu-emacs@gnu.org; Sat, 05 Apr 2014 16:05:03 +0200 Original-Received: from 192-171-35-19.cpe.pppoe.ca ([192.171.35.19]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 05 Apr 2014 16:05:03 +0200 Original-Received: from monnier by 192-171-35-19.cpe.pppoe.ca with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 05 Apr 2014 16:05:03 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 28 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: 192-171-35-19.cpe.pppoe.ca User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.4.50 (gnu/linux) Cancel-Lock: sha1:a0I8HsqCMV4y8cItJwchVUnuydc= X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 80.91.229.3 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:97010 Archived-At: >> in a program I insert text in an empty temporary edit-buffer, what of >> course modifies the `buffer-undo-list'. >> Assume that at this moment (lets call it time T1) >> >> ,------------------------------ >> | M-: (length buffer-undo-list) >> `------------------------------ >> >> returns 9. >> >> Now when there are changes to the text in the edit-buffer, these are >> copied to the original buffer after quitting. But when nothing has >> changed after the insertion of the original text, it would be better to >> simply discard the edit-buffer and not touch the original buffer at >> all. >> >> I could remember the length of the buffer-undo-list at time T1 and then >> check if it changed when quitting, but this does not seem very robust, >> since this length grows and shrinks in both directions. > Did you try using buffer-modified-tick? Indeed, I'd either use buffer-chars-modified-tick, or set buffer-undo-list to nil (after all, so you really want the user to be able to un-insert the initial text?). Stefan