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 18:03:36 +0300 Message-ID: <83sk4kgz7b.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> <83wrtwh17e.fsf@gnu.org> Reply-To: Eli Zaretskii NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE X-Trace: dough.gmane.org 1276874146 26858 80.91.229.12 (18 Jun 2010 15:15:46 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Fri, 18 Jun 2010 15:15:46 +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 17:15:45 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 1OPdIG-00043o-8J for ged-emacs-devel@m.gmane.org; Fri, 18 Jun 2010 17:15:44 +0200 Original-Received: from localhost ([127.0.0.1]:32768 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OPdIF-0000OR-A2 for ged-emacs-devel@m.gmane.org; Fri, 18 Jun 2010 11:15:43 -0400 Original-Received: from [140.186.70.92] (port=53008 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OPd7V-00008c-5y for emacs-devel@gnu.org; Fri, 18 Jun 2010 11:04:38 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OPd7T-0007WQ-G0 for emacs-devel@gnu.org; Fri, 18 Jun 2010 11:04:36 -0400 Original-Received: from mtaout20.012.net.il ([80.179.55.166]:65203) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OPd7T-0007W9-9R for emacs-devel@gnu.org; Fri, 18 Jun 2010 11:04:35 -0400 Original-Received: from conversion-daemon.a-mtaout20.012.net.il by a-mtaout20.012.net.il (HyperSendmail v2007.08) id <0L4700600SXWFT00@a-mtaout20.012.net.il> for emacs-devel@gnu.org; Fri, 18 Jun 2010 18:04:00 +0300 (IDT) Original-Received: from HOME-C4E4A596F7 ([77.127.88.125]) by a-mtaout20.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0L470034FTULA7A0@a-mtaout20.012.net.il>; Fri, 18 Jun 2010 18:03:58 +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:126170 Archived-At: > From: Lennart Borgman > Date: Fri, 18 Jun 2010 16:32:07 +0200 > Cc: emacs-devel@gnu.org >=20 > On Fri, Jun 18, 2010 at 4:20 PM, Eli Zaretskii wrote= : > >> 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 invol= ved? > > > > This flag indicates that the redisplay finished and the current g= lyph > > matrix is up to date. =C2=A0It is imperative to know that, becaus= e > > try_scrolling, the function you are trying to get called, reuses > > portions of the current glyph matrix (to avoid redrawing the enti= re > > window). =C2=A0It is unsafe to reuse the current matrix if it is = not > > guaranteed to be up to date. >=20 >=20 > Thanks, that is a clear description. >=20 > But how is that involved here? I save the old clipping in > reconsider_clip_changes when window_end_valid is non-nil. You save it when window_end_valid is non-nil, but you use it without testing window_end_valid. > Sorry, I was unclear. I meant where it is set to 1. narrow_to_regio= n > etc set it to 1 and that is not something they should do since they= do > not (and should not) know about the redisplay state. This flag means that narrowing was changed since the last redisplay. So yes, setting it in narrow_to_region is the right thing.