From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Text Properties And Buffer Modification Date: Wed, 05 Dec 2018 21:09:50 +0200 Message-ID: <831s6v94e9.fsf@gnu.org> References: <83y3948ov2.fsf@gnu.org> <87wooofnqf.fsf@fastmail.fm> <83o9a08jfq.fsf@gnu.org> <834lbr95nq.fsf@gnu.org> <5C082139.6060802@gmx.at> NNTP-Posting-Host: blaine.gmane.org X-Trace: blaine.gmane.org 1544037500 9766 195.159.176.226 (5 Dec 2018 19:18:20 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 5 Dec 2018 19:18:20 +0000 (UTC) Cc: monnier@iro.umontreal.ca, emacs-devel@gnu.org To: martin rudalics Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed Dec 05 20:18:16 2018 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 1gUcga-0002Rc-F7 for ged-emacs-devel@m.gmane.org; Wed, 05 Dec 2018 20:18:16 +0100 Original-Received: from localhost ([::1]:36340 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gUcih-0001SW-1y for ged-emacs-devel@m.gmane.org; Wed, 05 Dec 2018 14:20:27 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:51695) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gUciN-0001OB-9h for emacs-devel@gnu.org; Wed, 05 Dec 2018 14:20:10 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gUcYT-0007ZI-90 for emacs-devel@gnu.org; Wed, 05 Dec 2018 14:09:58 -0500 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:60623) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gUcYT-0007Z2-2l; Wed, 05 Dec 2018 14:09:53 -0500 Original-Received: from [176.228.60.248] (port=2495 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1gUcYS-0002Bh-5m; Wed, 05 Dec 2018 14:09:52 -0500 In-reply-to: <5C082139.6060802@gmx.at> (message from martin rudalics on Wed, 05 Dec 2018 20:04:25 +0100) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2001:4830:134:3::e 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:231642 Archived-At: > Date: Wed, 05 Dec 2018 20:04:25 +0100 > From: martin rudalics > CC: emacs-devel@gnu.org > > >>> Don't forget that the modified status is important for more than > >>> just saving to a file: it is important for redisplaying the > >>> buffer, for example. > >> > >> Really? > > > > Is that a rhetorical question? > > I would have thought that buffer redisplay is triggered only by > bset_redisplay and BUF_COMPUTE_UNCHANGED which IIUC are called the > same way for overlays and text properties. Am I wrong? Yes. The display engine sometimes needs to know not only whether the buffer needs to be redisplayed, but also _why_. Search xdisp.c for MODIFF, and you will see.