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#16129: 24.3.50; Emacs slow with follow-mode when buffer ends before last window Date: Mon, 06 Jan 2014 18:33:02 +0200 Message-ID: <8338l1t6ip.fsf@gnu.org> References: <83bnzpu622.fsf@gnu.org> Reply-To: Eli Zaretskii NNTP-Posting-Host: plane.gmane.org X-Trace: ger.gmane.org 1389026070 4240 80.91.229.3 (6 Jan 2014 16:34:30 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Mon, 6 Jan 2014 16:34:30 +0000 (UTC) Cc: 16129-done@debbugs.gnu.org To: Anders Lindgren Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Mon Jan 06 17:34:32 2014 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 1W0D8C-0006s8-VP for geb-bug-gnu-emacs@m.gmane.org; Mon, 06 Jan 2014 17:34:25 +0100 Original-Received: from localhost ([::1]:36107 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W0D8B-0005aw-Ko for geb-bug-gnu-emacs@m.gmane.org; Mon, 06 Jan 2014 11:34:23 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:58885) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W0D7w-0005SV-JU for bug-gnu-emacs@gnu.org; Mon, 06 Jan 2014 11:34:13 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1W0D7r-0002IX-Ee for bug-gnu-emacs@gnu.org; Mon, 06 Jan 2014 11:34:08 -0500 Original-Received: from debbugs.gnu.org ([140.186.70.43]:53007) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W0D7r-0002IS-8T for bug-gnu-emacs@gnu.org; Mon, 06 Jan 2014 11:34:03 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.80) (envelope-from ) id 1W0D7q-0002yx-UM for bug-gnu-emacs@gnu.org; Mon, 06 Jan 2014 11:34:03 -0500 Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-To: bug-gnu-emacs@gnu.org Resent-Date: Mon, 06 Jan 2014 16:34:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: cc-closed 16129 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Mail-Followup-To: 16129@debbugs.gnu.org, eliz@gnu.org, andlind@gmail.com Original-Received: via spool by 16129-done@debbugs.gnu.org id=D16129.138902601411415 (code D ref 16129); Mon, 06 Jan 2014 16:34:02 +0000 Original-Received: (at 16129-done) by debbugs.gnu.org; 6 Jan 2014 16:33:34 +0000 Original-Received: from localhost ([127.0.0.1]:38791 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1W0D7N-0002y1-Q0 for submit@debbugs.gnu.org; Mon, 06 Jan 2014 11:33:34 -0500 Original-Received: from mtaout20.012.net.il ([80.179.55.166]:50645) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1W0D7L-0002xq-4h for 16129-done@debbugs.gnu.org; Mon, 06 Jan 2014 11:33:32 -0500 Original-Received: from conversion-daemon.a-mtaout20.012.net.il by a-mtaout20.012.net.il (HyperSendmail v2007.08) id <0MYZ00I00LX36600@a-mtaout20.012.net.il> for 16129-done@debbugs.gnu.org; Mon, 06 Jan 2014 18:33:17 +0200 (IST) Original-Received: from HOME-C4E4A596F7 ([87.69.4.28]) by a-mtaout20.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0MYZ00IUHNBD6R60@a-mtaout20.012.net.il>; Mon, 06 Jan 2014 18:33:13 +0200 (IST) In-reply-to: X-012-Sender: halo1@inter.net.il X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.15 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 140.186.70.43 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-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:83065 Archived-At: > Date: Mon, 6 Jan 2014 09:20:03 +0100 > From: Anders Lindgren > Cc: Stefan Monnier , 16129@debbugs.gnu.org > > I think the incorrect state occurs when the new early exit occurs from > redsplay_window. When I added the condition "&& PT == w->last_point", both > the recentering problem and speed issues were solved. Indeed, this was my conclusion as well. (Except that PT is not quite right, as the window could be displaying a buffer that is not the current one at that early point in redisplay_window.) What this caused was that the window redisplay was mistakenly skipped, but then we marked that window's display "accurate", which confused the heck out of the display engine. So I installed the patch below to fix this regression, and I'm marking this bug done. Feel free to reopen if there are any leftovers. Btw, I strongly recommend against messing with window-start (or anything else that potentially requires redisplay) in a post-command-hook: doing so disables some important redisplay optimizations, and can easily trigger subtle misfeatures. I suggest to look for a better method to do what follow-mode needs to do, even if that means we'd have to implement a special hook we don't yet have. Thanks. === modified file 'src/xdisp.c' --- src/xdisp.c 2014-01-01 17:44:48 +0000 +++ src/xdisp.c 2014-01-06 16:21:39 +0000 @@ -15621,7 +15621,8 @@ redisplay_window (Lisp_Object window, bo && REDISPLAY_SOME_P () && !w->redisplay && !f->redisplay - && !buffer->text->redisplay) + && !buffer->text->redisplay + && BUF_PT (buffer) == w->last_point) return; /* Make sure that both W's markers are valid. */