From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Chong Yidong Newsgroups: gmane.emacs.bugs Subject: bug#6671: moving point and scroll-conservatively Date: Wed, 23 Mar 2011 20:42:49 -0400 Message-ID: <87vcz9s60m.fsf@stupidchicken.com> References: NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: dough.gmane.org 1300928853 20628 80.91.229.12 (24 Mar 2011 01:07:33 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Thu, 24 Mar 2011 01:07:33 +0000 (UTC) To: 6671@debbugs.gnu.org Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Thu Mar 24 02:07:29 2011 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Q2Z1L-0000ho-IX for geb-bug-gnu-emacs@m.gmane.org; Thu, 24 Mar 2011 02:07:27 +0100 Original-Received: from localhost ([127.0.0.1]:59558 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Q2Z1K-0005jy-Vh for geb-bug-gnu-emacs@m.gmane.org; Wed, 23 Mar 2011 21:07:27 -0400 Original-Received: from [140.186.70.92] (port=51435 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Q2Z19-0005h1-N3 for bug-gnu-emacs@gnu.org; Wed, 23 Mar 2011 21:07:16 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Q2Z18-0007vM-H3 for bug-gnu-emacs@gnu.org; Wed, 23 Mar 2011 21:07:15 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:49670) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Q2Z18-0007vI-FH for bug-gnu-emacs@gnu.org; Wed, 23 Mar 2011 21:07:14 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.69) (envelope-from ) id 1Q2Ydh-0003pD-Mn; Wed, 23 Mar 2011 20:43:01 -0400 X-Loop: help-debbugs@gnu.org In-Reply-To: Resent-From: Chong Yidong Original-Sender: debbugs-submit-bounces@debbugs.gnu.org Resent-To: owner@debbugs.gnu.org Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Thu, 24 Mar 2011 00:43:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 6671 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 6671-submit@debbugs.gnu.org id=B6671.130092737714694 (code B ref 6671); Thu, 24 Mar 2011 00:43:01 +0000 Original-Received: (at 6671) by debbugs.gnu.org; 24 Mar 2011 00:42:57 +0000 Original-Received: from localhost ([127.0.0.1] helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1Q2Ydd-0003ow-8M for submit@debbugs.gnu.org; Wed, 23 Mar 2011 20:42:57 -0400 Original-Received: from vm-emlprdomr-04.its.yale.edu ([130.132.50.145]) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1Q2Ydc-0003oj-5a for 6671@debbugs.gnu.org; Wed, 23 Mar 2011 20:42:56 -0400 Original-Received: from furball (dhcp128036014081.central.yale.edu [128.36.14.81]) (authenticated bits=0) by vm-emlprdomr-04.its.yale.edu (8.14.4/8.14.4) with ESMTP id p2O0goaX024696 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT) for <6671@debbugs.gnu.org>; Wed, 23 Mar 2011 20:42:50 -0400 Original-Received: by furball (Postfix, from userid 1000) id 1EB0F1607C6; Wed, 23 Mar 2011 20:42:50 -0400 (EDT) X-Scanned-By: MIMEDefang 2.71 on 130.132.50.145 X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.11 Precedence: list Resent-Date: Wed, 23 Mar 2011 20:43:01 -0400 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) 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: , Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:45298 Archived-At: > Did any of you who set scroll-conservatively to most-positive-fixnum > notice that moving around an unmodified buffer became much slower, > since revno 100620, when point moves far away? > > This happens because the try_scrolling method would previously give up > when point was more than 10 screen lines below the current end of the > window. Emacs would then perform a complete redisplay of the window, > with point located on the middle line. This "recentering" annoyed > users who set scroll-conservatively to most-positive-fixnum, so revno > 100620 modified try_scrolling to _never_ give up due to point being > too far away, when scroll-conservatively is set to such a large value. > However, try_scrolling is used not only for scroll commands such as > the C-n or C-v, but for _any_ motion in a buffer that didn't change. > Thus the unintended effect described above. I don't think it's reasonable to make the iterator slog through thousands of lines in an attempt to "scroll" general point motions. Is the "unintended recentering" problem purely associated with the commands next-line and previous-line? If so, maybe we should investigate ways to prevent point motion from "running ahead" of redisplay in those specific instances.