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: A strange issue with buffer-undo-list Date: Wed, 24 Feb 2021 03:11:58 +0100 Message-ID: <87wnuy1afl.fsf@web.de> References: <87o8gbqs28.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="25843"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:jtvQ3Rx9PfENmLRf8CZdPj1wh9s= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Wed Feb 24 03:12:50 2021 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 1lEjfW-0006cj-J6 for geh-help-gnu-emacs@m.gmane-mx.org; Wed, 24 Feb 2021 03:12:50 +0100 Original-Received: from localhost ([::1]:39572 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lEjfV-00027f-LU for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 23 Feb 2021 21:12:49 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:51198) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lEjes-00027S-55 for help-gnu-emacs@gnu.org; Tue, 23 Feb 2021 21:12:10 -0500 Original-Received: from ciao.gmane.io ([116.202.254.214]:37188) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lEjeq-0006BF-AC for help-gnu-emacs@gnu.org; Tue, 23 Feb 2021 21:12:09 -0500 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1lEjeo-0005so-FK for help-gnu-emacs@gnu.org; Wed, 24 Feb 2021 03:12:06 +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: 2.1.23 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" Xref: news.gmane.io gmane.emacs.help:128218 Archived-At: Marcin Borkowski writes: > (let ((position-in-line (current-column))) > (push (point) buffer-undo-list) I wonder if it is legitimate to do this. > (line-move 1) > (transpose-lines count) > (line-move -1) > (move-to-column position-in-line))) > > > which triggers an error. Sometimes it helps in such situations to add an explicit `undo-boundary'. > 1. Why did my code confuse the change group mechanism? I can't answer that, I dunno if it is legal. Don't have enough knowledge about that (mine is also only from reading code). > 2. How do I use `undo-amalgamate-change-group'? The manual does not > provide any examples, and I only found one occurrence in the Emacs > source, and frankly, it didn't help a lot. Well, it seems very simple: you have the handle, you call `undo-amalgamate-change-group' with it, typically directly before accepting the group, and that's it...? The only example use I found is in viper-cmd.el. Seems the code never closes the opened change groups. AFAIU that's not ok. Regards, Michael.