From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: wgreenhouse-sGOZH3hwPm2sTnJN9+BGXg@public.gmane.org (W. Greenhouse) Newsgroups: gmane.emacs.help Subject: Re: Reverting but keeping undo Date: Thu, 16 May 2013 05:29:38 +0000 Message-ID: <87sj1neblp.fsf@riseup.net> References: <87mwrwede7.fsf@wanadoo.es> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Trace: ger.gmane.org 1368682214 4838 80.91.229.3 (16 May 2013 05:30:14 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 16 May 2013 05:30:14 +0000 (UTC) To: help-gnu-emacs-mXXj517/zsQ@public.gmane.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org-mXXj517/zsQ@public.gmane.org Thu May 16 07:30:14 2013 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 1Ucqla-0001YT-4u for geh-help-gnu-emacs@m.gmane.org; Thu, 16 May 2013 07:30:14 +0200 Original-Received: from localhost ([::1]:54978 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UcqlZ-0002bT-P3 for geh-help-gnu-emacs@m.gmane.org; Thu, 16 May 2013 01:30:13 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:33127) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UcqlK-0002ZC-HC for help-gnu-emacs-mXXj517/zsQ@public.gmane.org; Thu, 16 May 2013 01:30:05 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UcqlE-0007Z0-3b for help-gnu-emacs-mXXj517/zsQ@public.gmane.org; Thu, 16 May 2013 01:29:58 -0400 Original-Received: from plane.gmane.org ([80.91.229.3]:53501) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UcqlD-0007Yo-TF for help-gnu-emacs-mXXj517/zsQ@public.gmane.org; Thu, 16 May 2013 01:29:52 -0400 Original-Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1UcqlC-0001Hm-II for help-gnu-emacs-mXXj517/zsQ@public.gmane.org; Thu, 16 May 2013 07:29:50 +0200 Original-Received: from torproject.org.all.de ([212.84.206.250]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 16 May 2013 07:29:50 +0200 Original-Received: from wgreenhouse by torproject.org.all.de with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 16 May 2013 07:29:50 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 39 Original-X-Complaints-To: usenet-dbVV3NMTNubNLxjTenLetw@public.gmane.org X-Gmane-NNTP-Posting-Host: torproject.org.all.de X-Archive: encrypt User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) Cancel-Lock: sha1:OpD6P1R+UqJPJQGS1fjuwYBnzL4= 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-mXXj517/zsQ@public.gmane.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-mXXj517/zsQ@public.gmane.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org-mXXj517/zsQ@public.gmane.org Xref: news.gmane.org gmane.emacs.help:90834 Archived-At: Óscar Fuentes writes: > `revert-buffer' discards undo history. I can understand that undo > history might be in conflict with the new contents of the buffer. How > dangerous is that? Apart from that, what could be wrong with using the > recipe published in > > http://www.emacswiki.org/emacs/RevertBuffer#toc4 > > ? > > For your convenience, this is the recipe: > > (defun revert-buffer-keep-undo (&rest -) > "Revert buffer but keep undo history." > (interactive) > (let ((inhibit-read-only t)) > (erase-buffer) > (insert-file-contents (buffer-file-name)) > (set-visited-file-modtime (visited-file-modtime)) > (set-buffer-modified-p nil))) > > Install in command ‘revert-buffer’ with > > (setq revert-buffer-function 'revert-buffer-keep-undo) This looks like a nice simple hack, but it doesn't do half of the things that revert-buffer does, such as resetting local variables and possibly picking a different major mode and file encoding if the change in file contents warrants it. From looking at the code of `revert-buffer', this problem could be solved without getting rid of all those nice features if you put an advice around revert-buffer that stashed `buffer-undo-list' away inside a let-bound variable before revertying, and then reset `buffer-undo-list' from that variable afterwards. -- BOFH excuse #453: Spider infestation in warm case parts