From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: The unwarranted scrolling assumption Date: Fri, 18 Jun 2010 17:20:21 +0300 Message-ID: <83wrtwh17e.fsf@gnu.org> References: <87ocfcj7r4.fsf@mail.jurta.org> <87631jvpzg.fsf@gmail.com> <4C18211C.3070106@harpegolden.net> <83typ2isns.fsf@gnu.org> <83mxuuicjc.fsf@gnu.org> <8339wkiheo.fsf@gnu.org> Reply-To: Eli Zaretskii NNTP-Posting-Host: lo.gmane.org X-Trace: dough.gmane.org 1276871631 16674 80.91.229.12 (18 Jun 2010 14:33:51 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Fri, 18 Jun 2010 14:33:51 +0000 (UTC) Cc: emacs-devel@gnu.org To: Lennart Borgman Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Fri Jun 18 16:33:50 2010 connect(): No such file or directory Return-path: Envelope-to: ged-emacs-devel@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 1OPcdh-0007Do-Nt for ged-emacs-devel@m.gmane.org; Fri, 18 Jun 2010 16:33:50 +0200 Original-Received: from localhost ([127.0.0.1]:33335 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OPcdg-0005Th-Uy for ged-emacs-devel@m.gmane.org; Fri, 18 Jun 2010 10:33:49 -0400 Original-Received: from [140.186.70.92] (port=59237 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OPccZ-0004al-Jc for emacs-devel@gnu.org; Fri, 18 Jun 2010 10:32:40 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OPcR7-0000FS-L2 for emacs-devel@gnu.org; Fri, 18 Jun 2010 10:20:50 -0400 Original-Received: from mtaout20.012.net.il ([80.179.55.166]:55243) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OPcR7-0000FG-DL for emacs-devel@gnu.org; Fri, 18 Jun 2010 10:20:49 -0400 Original-Received: from conversion-daemon.a-mtaout20.012.net.il by a-mtaout20.012.net.il (HyperSendmail v2007.08) id <0L4700500RR1FH00@a-mtaout20.012.net.il> for emacs-devel@gnu.org; Fri, 18 Jun 2010 17:20:36 +0300 (IDT) Original-Received: from HOME-C4E4A596F7 ([77.127.88.125]) by a-mtaout20.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0L47003KMRUB8T50@a-mtaout20.012.net.il>; Fri, 18 Jun 2010 17:20:36 +0300 (IDT) In-reply-to: X-012-Sender: halo1@inter.net.il X-detected-operating-system: by eggs.gnu.org: Solaris 10 (beta) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:126166 Archived-At: > From: Lennart Borgman > Date: Fri, 18 Jun 2010 15:56:38 +0200 > Cc: david@harpegolden.net, monnier@iro.umontreal.ca, emacs-devel@gnu.org > > Can you please explain why window_end_valid flag should be involved? This flag indicates that the redisplay finished and the current glyph matrix is up to date. It is imperative to know that, because try_scrolling, the function you are trying to get called, reuses portions of the current glyph matrix (to avoid redrawing the entire window). It is unsafe to reuse the current matrix if it is not guaranteed to be up to date. > Can you please also comment on the point where to check if clipping > has changed? Is not the entry of redisplay_window the right point for > this? What do you mean by ``where to check if clipping has changed''? The clip_changed flag is checked in many places during redisplay.