From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#23871: 25.1.50; Undo unexpectedly leads to blank buffer Date: Thu, 30 Jun 2016 21:21:31 +0300 Message-ID: <83d1myv8pg.fsf@gnu.org> References: <83h9cavdgj.fsf@gnu.org> <87poqyy2tc.fsf@metalevel.at> Reply-To: Eli Zaretskii NNTP-Posting-Host: plane.gmane.org X-Trace: ger.gmane.org 1467311008 5661 80.91.229.3 (30 Jun 2016 18:23:28 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 30 Jun 2016 18:23:28 +0000 (UTC) Cc: 23871@debbugs.gnu.org To: Markus Triska Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Thu Jun 30 20:23:18 2016 Return-path: Envelope-to: geb-bug-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 1bIgcO-0004P2-Jd for geb-bug-gnu-emacs@m.gmane.org; Thu, 30 Jun 2016 20:23:16 +0200 Original-Received: from localhost ([::1]:52012 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bIgcN-0002WV-QQ for geb-bug-gnu-emacs@m.gmane.org; Thu, 30 Jun 2016 14:23:15 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:44917) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bIgcF-0002Us-Cs for bug-gnu-emacs@gnu.org; Thu, 30 Jun 2016 14:23:08 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bIgcA-0006V1-8K for bug-gnu-emacs@gnu.org; Thu, 30 Jun 2016 14:23:07 -0400 Original-Received: from debbugs.gnu.org ([208.118.235.43]:48710) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bIgcA-0006Uw-5K for bug-gnu-emacs@gnu.org; Thu, 30 Jun 2016 14:23:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1bIgcA-0006iF-0I for bug-gnu-emacs@gnu.org; Thu, 30 Jun 2016 14:23:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Thu, 30 Jun 2016 18:23:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 23871 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 23871-submit@debbugs.gnu.org id=B23871.146731093525725 (code B ref 23871); Thu, 30 Jun 2016 18:23:01 +0000 Original-Received: (at 23871) by debbugs.gnu.org; 30 Jun 2016 18:22:15 +0000 Original-Received: from localhost ([127.0.0.1]:32814 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1bIgbO-0006gq-PT for submit@debbugs.gnu.org; Thu, 30 Jun 2016 14:22:14 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:53739) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1bIgbN-0006gZ-Um for 23871@debbugs.gnu.org; Thu, 30 Jun 2016 14:22:14 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bIgbE-0006J0-7g for 23871@debbugs.gnu.org; Thu, 30 Jun 2016 14:22:08 -0400 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:43784) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bIgbE-0006Ig-4G; Thu, 30 Jun 2016 14:22:04 -0400 Original-Received: from 84.94.185.246.cable.012.net.il ([84.94.185.246]:4832 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_128_CBC_SHA1:128) (Exim 4.82) (envelope-from ) id 1bIgbB-0006wx-De; Thu, 30 Jun 2016 14:22:02 -0400 In-reply-to: <87poqyy2tc.fsf@metalevel.at> (message from Markus Triska on Thu, 30 Jun 2016 20:00:31 +0200) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 208.118.235.43 X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.org gmane.emacs.bugs:120235 Archived-At: > From: Markus Triska > Cc: 23871@debbugs.gnu.org > Date: Thu, 30 Jun 2016 20:00:31 +0200 > > Eli Zaretskii writes: > > > > I suspect this is a redisplay problem, not an undo problem. How do > > you see that point is in the wrong position? What does "C-x =" say > > immediately after the undo? > > I see from two facts that it is in the wrong position: > > 1) I need to press C-p to go to the position *before* the undo. From > this I see that point after undo is at least one line off. > > 2) C-x = immediately after undo confirms this, saying: > > point=323 of 322 (EOB) column=0 > > While point before undo is point 281 of 322. I'm not sure this is not the expected behavior. This means the blank buffer you see is just the last empty line with EOB. The Emacs display engine should not normally allow that, it should show the last line before EOB. > > Can you try coming up with a recipe that doesn't involve SWI-Prolog? > > Please see #21722. It shows that point position after undo is different > from what it was before, just as in this case. When I repeat the recipe there, both with Emacs 25.0.95 and 25.1.50, point is positioned at the end of the line, both after "C-M-x C-/" and "C-h f C-g C-M-x C-/". So I see consistent behavior. Perhaps undo gurus could comment whether this is also the correct behavior. > The font and even window size definitely have an impact on this > issue. Please try a different window size, and I hope you can then > reproduce the issue, or at least #21722. Unfortunately, I can't reproduce any of them.