From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Alan Mackenzie Newsgroups: gmane.emacs.bugs Subject: bug#21869: Redisplay: after echo area diminishes in size, Follow Mode windows aren't resynchronised. Date: Mon, 9 Nov 2015 18:18:33 +0000 (UTC) Organization: muc.de e.V. Message-ID: References: NNTP-Posting-Host: plane.gmane.org X-Trace: ger.gmane.org 1447108066 23184 80.91.229.3 (9 Nov 2015 22:27:46 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Mon, 9 Nov 2015 22:27:46 +0000 (UTC) To: gnu-emacs-bug@moderators.isc.org Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Mon Nov 09 23:27:33 2015 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 1ZvuuS-00011e-Kw for geb-bug-gnu-emacs@m.gmane.org; Mon, 09 Nov 2015 23:27:32 +0100 Original-Received: from localhost ([::1]:55984 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZvuuS-0002qD-3I for geb-bug-gnu-emacs@m.gmane.org; Mon, 09 Nov 2015 17:27:32 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:54096) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zvr30-0001d6-4v for bug-gnu-emacs@gnu.org; Mon, 09 Nov 2015 13:20:07 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zvr2x-0001m4-Fo for bug-gnu-emacs@gnu.org; Mon, 09 Nov 2015 13:20:06 -0500 Original-Received: from debbugs.gnu.org ([208.118.235.43]:40502) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zvr2x-0001lu-Dg for bug-gnu-emacs@gnu.org; Mon, 09 Nov 2015 13:20:03 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.80) (envelope-from ) id 1Zvr2w-0007O3-Rp for bug-gnu-emacs@gnu.org; Mon, 09 Nov 2015 13:20:03 -0500 X-Loop: help-debbugs@gnu.org In-Reply-To: <20151109093546.GA2284@acm.fritz.box> Resent-From: Alan Mackenzie Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Mon, 09 Nov 2015 18:20:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 21869 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by submit@debbugs.gnu.org id=B.144709314528319 (code B ref -1); Mon, 09 Nov 2015 18:20:02 +0000 Original-Received: (at submit) by debbugs.gnu.org; 9 Nov 2015 18:19:05 +0000 Original-Received: from localhost ([127.0.0.1]:59443 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1Zvr20-0007Mg-H4 for submit@debbugs.gnu.org; Mon, 09 Nov 2015 13:19:04 -0500 Original-Received: from eggs.gnu.org ([208.118.235.92]:43823) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1Zvr1g-0007Lw-Mh for submit@debbugs.gnu.org; Mon, 09 Nov 2015 13:19:03 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zvr1c-0001VF-Gx for submit@debbugs.gnu.org; Mon, 09 Nov 2015 13:18:44 -0500 Original-Received: from lists.gnu.org ([2001:4830:134:3::11]:37184) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zvr1c-0001VB-ED for submit@debbugs.gnu.org; Mon, 09 Nov 2015 13:18:40 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:53825) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zvr1b-0001EG-CW for bug-gnu-emacs@gnu.org; Mon, 09 Nov 2015 13:18:40 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zvr1Y-0001UQ-Er for bug-gnu-emacs@gnu.org; Mon, 09 Nov 2015 13:18:39 -0500 Original-Received: from xvm-90.mit.edu ([18.181.2.90]:49419 helo=mod-relay.xvm.mit.edu) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zvr1Y-0001UM-BY for bug-gnu-emacs@gnu.org; Mon, 09 Nov 2015 13:18:36 -0500 Original-Received: by mod-relay.xvm.mit.edu (Postfix) id 3689BA38; Mon, 9 Nov 2015 13:18:35 -0500 (EST) Original-Received: from mail.muc.de (mail.muc.de [193.149.48.3]) by mod-relay.xvm.mit.edu (Postfix) with ESMTPS id F2CACA05 for ; Mon, 9 Nov 2015 13:18:34 -0500 (EST) Original-Received: (qmail 97054 invoked by uid 8); 9 Nov 2015 18:18:33 -0000 Original-Path: not-for-mail Original-Newsgroups: gnu.emacs.bug Original-Lines: 56 Original-NNTP-Posting-Host: news.muc.de Original-X-Trace: colin.muc.de 1447093113 97052 193.149.48.2 (9 Nov 2015 18:18:33 GMT) Original-X-Complaints-To: news-admin@muc.de Original-NNTP-Posting-Date: Mon, 9 Nov 2015 18:18:33 +0000 (UTC) User-Agent: tin/2.3.1-20141224 ("Tallant") (UNIX) (FreeBSD/10.1-RELEASE-p16 (amd64)) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). 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: 208.118.235.43 X-Mailman-Approved-At: Mon, 09 Nov 2015 17:26:43 -0500 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:108609 Archived-At: Alan Mackenzie wrote: > With a recent copy of the git master, in either X windows or a Linux tty, > emacs -Q > If necessary, make the window wide with the mouse. > C-x C-f src/xdisp.c ; or any other non-small file. > C-x 3 > M-x follow-mode > Note the content of the lines around the window division. > M-: (message "x\ny\nz") > The echo area expands, and the two Follow Mode windows get correctly > synchronised. Again, note the content of the lines around the window > division. > C-f > The echo area shrinks back to its normal size. Note the content of the > lines around the window division. The two lines at the bottom of the > left hand window are also displayed at the top of the right hand window. > The windows have NOT been synchronised after the change in the echo area > size. This is a bug. > ######################################################################### > Tentative analysis: > Follow Mode puts a function on window-size-change-functions which should be > called any time a window changes size. At the C-f above, > window-size-change-functions is not being invoked. > The one single place where window-size-change-functions is invoked is in > the function prepare_menu_bars in xdisp.c. > The one single place where prepare_menu_bars is called is fairly early on > in redisplay_internal, at L+137. This is before the echo area is resized > at L+164. Thus, the check on changed window sizes happens too early, > before the change in the echo area size. I withdraw my complaint: the doc of w-s-c-functions says it is called BEFORE REDISPLAY when a window size has changed. It says nothing about being called when the window sizes change DURING redisplay. However, that leaves a gap: how is application software to be informed that this change in window sizes has happened? Perhaps changing the hook's definition, such that it would be invoked both before redisplay and during it would be a neat solution. It seems that the chances of the hook being invoked twice on a redisplay cycle would not be high. -- Alan Mackenzie (Nuremberg, Germany).