From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Mark H Weaver Newsgroups: gmane.emacs.bugs Subject: bug#31653: 26.1; comint-scroll-show-maximum-output nil regression Date: Wed, 30 May 2018 01:56:13 -0400 Message-ID: <87k1rlbsaq.fsf@netris.org> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1527659770 29246 195.159.176.226 (30 May 2018 05:56:10 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 30 May 2018 05:56:10 +0000 (UTC) To: 31653@debbugs.gnu.org Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Wed May 30 07:56:05 2018 Return-path: Envelope-to: geb-bug-gnu-emacs@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 1fNu5a-0007Ni-Rv for geb-bug-gnu-emacs@m.gmane.org; Wed, 30 May 2018 07:56:02 +0200 Original-Received: from localhost ([::1]:36341 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fNu7g-0005ro-6X for geb-bug-gnu-emacs@m.gmane.org; Wed, 30 May 2018 01:58:12 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:55609) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fNu7Z-0005rh-Mk for bug-gnu-emacs@gnu.org; Wed, 30 May 2018 01:58:06 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fNu7W-0001IC-Lm for bug-gnu-emacs@gnu.org; Wed, 30 May 2018 01:58:05 -0400 Original-Received: from debbugs.gnu.org ([208.118.235.43]:46672) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1fNu7W-0001I8-HX for bug-gnu-emacs@gnu.org; Wed, 30 May 2018 01:58:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1fNu7W-0003FH-B5 for bug-gnu-emacs@gnu.org; Wed, 30 May 2018 01:58:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Mark H Weaver Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Wed, 30 May 2018 05:58:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: report 31653 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: X-Debbugs-Original-To: bug-gnu-emacs@gnu.org Original-Received: via spool by submit@debbugs.gnu.org id=B.152765986012445 (code B ref -1); Wed, 30 May 2018 05:58:02 +0000 Original-Received: (at submit) by debbugs.gnu.org; 30 May 2018 05:57:40 +0000 Original-Received: from localhost ([127.0.0.1]:54569 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1fNu7A-0003Ef-0Z for submit@debbugs.gnu.org; Wed, 30 May 2018 01:57:40 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:36387) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1fNu79-0003EU-4u for submit@debbugs.gnu.org; Wed, 30 May 2018 01:57:39 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fNu73-0001G4-4q for submit@debbugs.gnu.org; Wed, 30 May 2018 01:57:33 -0400 Original-Received: from lists.gnu.org ([2001:4830:134:3::11]:49042) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fNu73-0001Fy-1c for submit@debbugs.gnu.org; Wed, 30 May 2018 01:57:33 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:55591) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fNu71-0005r3-Nh for bug-gnu-emacs@gnu.org; Wed, 30 May 2018 01:57:32 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fNu6y-0001FS-LE for bug-gnu-emacs@gnu.org; Wed, 30 May 2018 01:57:31 -0400 Original-Received: from world.peace.net ([64.112.178.59]:35124) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fNu6y-0001FM-H9 for bug-gnu-emacs@gnu.org; Wed, 30 May 2018 01:57:28 -0400 Original-Received: from mhw by world.peace.net with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1fNu6x-00014U-6w; Wed, 30 May 2018 01:57:27 -0400 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6.x 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:146736 Archived-At: Emacs 26.1 has introduced a regression compared with 25.3 in the handling of 'comint-scroll-show-maximum-output', which I prefer to set to nil. Here's how to reproduce the problem: * Run "emacs-26.1 -Q", with or without "-nw" as you prefer. * M-x shell * M-: (setq comint-scroll-show-maximum-output nil) * Press RET repeatedly until the window starts scrolling. Observe that after the point reaches the bottom of the window, it is subsequently kept at the bottom of the window by aggressively scrolling one line at a time. If you perform the same steps above with emacs-25.3, you'll see that it always recenters, so that scrolling occurs only once for every ~N/2 lines of output, where N is the window height. Note that (setq comint-scroll-show-maximum-output nil) still has some effect. After performing the steps above, try this: * C-l * Press RET repeatedly until the window starts scrolling. * M-: (setq comint-scroll-show-maximum-output t) * C-l * Press RET just once. Observe that with 'comint-scroll-show-maximum-output' set to t, the first RET after C-l immediately scrolls the window to show the maximum output. If you can suggest a workaround or a patch to fix this issue, I would be grateful. Thanks very much for your work on Emacs. Mark