From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: How can I undo a change from a modification-hook? Date: Wed, 26 Apr 2017 14:43:38 -0400 Message-ID: References: <2448005f-9fc4-78b2-3203-9fc8204f6f5b@mit.edu> <87fd6638-f46a-95f2-8b70-f271f5daeb63@gmail.com> <7f8bb205-c311-3360-ad0e-df205240199b@gmail.com> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1493232267 6354 195.159.176.226 (26 Apr 2017 18:44:27 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 26 Apr 2017 18:44:27 +0000 (UTC) User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.0.50 (gnu/linux) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed Apr 26 20:44:24 2017 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1d3RvM-0001Zu-3T for ged-emacs-devel@m.gmane.org; Wed, 26 Apr 2017 20:44:24 +0200 Original-Received: from localhost ([::1]:56663 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d3RvS-0003md-2I for ged-emacs-devel@m.gmane.org; Wed, 26 Apr 2017 14:44:30 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:42675) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d3Ruo-0003mX-Lw for emacs-devel@gnu.org; Wed, 26 Apr 2017 14:43:51 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d3Rum-0001DQ-3j for emacs-devel@gnu.org; Wed, 26 Apr 2017 14:43:50 -0400 Original-Received: from [195.159.176.226] (port=55008 helo=blaine.gmane.org) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1d3Rul-0001Cq-Tr for emacs-devel@gnu.org; Wed, 26 Apr 2017 14:43:48 -0400 Original-Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1d3Rue-0000V2-7j for emacs-devel@gnu.org; Wed, 26 Apr 2017 20:43:40 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 12 Original-X-Complaints-To: usenet@blaine.gmane.org Cancel-Lock: sha1:GDyNRcmcNCHvxzib8cxkDgBCue4= X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 195.159.176.226 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:214318 Archived-At: >>>> In the case of PG, I'd suggest you treat such a case as >>>> a non-whitespace change. >>> But I can't, can I? The damage (the change) is already done at that point, >>> and I can't revert it. >> But you can "retract" until the beginning of the changed area. > No, not if the current subprocess is busy. Not sure why it matters: you queue the retraction commands for execution when the subprocess is done with its current command(s). Stefan