From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Michael Heerdegen Newsgroups: gmane.emacs.help Subject: Re: How to temporarily show an image in an Emacs buffer? Date: Wed, 08 Mar 2023 17:41:23 +0100 Message-ID: <87sfefi4b0.fsf@web.de> References: <87bkl3etd1.fsf@mbork.pl> <87a60nerz2.fsf@mbork.pl> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="37664"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:5kPsIE1E1m1/HgBYp08QH9H7YKU= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Wed Mar 08 17:42:14 2023 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1pZwrk-0009Xy-Er for geh-help-gnu-emacs@m.gmane-mx.org; Wed, 08 Mar 2023 17:42:12 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pZwrI-0007Cy-4P; Wed, 08 Mar 2023 11:41:45 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pZwr8-00078D-M6 for help-gnu-emacs@gnu.org; Wed, 08 Mar 2023 11:41:35 -0500 Original-Received: from ciao.gmane.io ([116.202.254.214]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pZwr7-0007mM-3C for help-gnu-emacs@gnu.org; Wed, 08 Mar 2023 11:41:34 -0500 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1pZwr3-0008f9-IU for help-gnu-emacs@gnu.org; Wed, 08 Mar 2023 17:41:29 +0100 X-Injected-Via-Gmane: http://gmane.org/ Received-SPF: pass client-ip=116.202.254.214; envelope-from=geh-help-gnu-emacs@m.gmane-mx.org; helo=ciao.gmane.io X-Spam_score_int: -13 X-Spam_score: -1.4 X-Spam_bar: - X-Spam_report: (-1.4 / 5.0 requ) BAYES_00=-1.9, FREEMAIL_FORGED_FROMDOMAIN=0.25, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.25, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.29 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-mx.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.help:142950 Archived-At: Marcin Borkowski writes: > On 2023-03-08, at 05:53, Marcin Borkowski wrote: > > > Alternatively, it _may_ change the buffer contents but in a way that is > > not recorded in `buffer-undo-list'. Is that possible? > > I did some experimenting, and this > > (defvar no-undo-marker (make-marker)) > (defun no-undo-insert () > "Test undo." > (save-excursion > (let ((buffer-undo-list)) > (set-marker no-undo-marker (point)) > (insert "this can't be undone\n")))) > [...] Regardless of what has already been said, just for the sake of completeness: AFAIK the intended way to inhibit the recording of undo is to bind buffer-undo-list to t (not to nil). There are lots of use case in the sources - see e.g. `image-toggle-display-text'. Michael.