From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#34038: 26.1; set-window-start sometimes fails to set window start Date: Thu, 28 Mar 2019 18:21:53 +0200 Message-ID: <83pnqbj7fi.fsf@gnu.org> References: <83sgxzhe04.fsf@gnu.org> <87ef9je67i.fsf@metalevel.at> <20190111212357.GA5201@ACM> <87h8edt3kz.fsf@metalevel.at> <5C3AF974.1030906@gmx.at> <5029BB09-30CA-41BE-819D-E15101DCF38C@gnu.org> <5C3B3FCC.8080006@gmx.at> <83tviceg83.fsf@gnu.org> <87wokoa7c4.fsf@metalevel.at> <83ef6wnpvq.fsf@gnu.org> <874l7sxczx.fsf@metalevel.at> Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="3929"; mail-complaints-to="usenet@blaine.gmane.org" Cc: 34038@debbugs.gnu.org, acm@muc.de To: Markus Triska Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Thu Mar 28 17:23:14 2019 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1h9Xo9-0000sT-EB for geb-bug-gnu-emacs@m.gmane.org; Thu, 28 Mar 2019 17:23:13 +0100 Original-Received: from localhost ([127.0.0.1]:38997 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h9Xo8-0000C3-G4 for geb-bug-gnu-emacs@m.gmane.org; Thu, 28 Mar 2019 12:23:12 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:49742) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h9Xnz-0000Be-UU for bug-gnu-emacs@gnu.org; Thu, 28 Mar 2019 12:23:06 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1h9Xny-0003pp-T2 for bug-gnu-emacs@gnu.org; Thu, 28 Mar 2019 12:23:03 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:49262) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1h9Xny-0003pj-Mg for bug-gnu-emacs@gnu.org; Thu, 28 Mar 2019 12:23:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1h9Xny-0000KN-Et for bug-gnu-emacs@gnu.org; Thu, 28 Mar 2019 12:23:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Thu, 28 Mar 2019 16:23:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 34038 X-GNU-PR-Package: emacs Original-Received: via spool by 34038-submit@debbugs.gnu.org id=B34038.15537901241164 (code B ref 34038); Thu, 28 Mar 2019 16:23:02 +0000 Original-Received: (at 34038) by debbugs.gnu.org; 28 Mar 2019 16:22:04 +0000 Original-Received: from localhost ([127.0.0.1]:34573 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1h9Xn2-0000Ii-0M for submit@debbugs.gnu.org; Thu, 28 Mar 2019 12:22:04 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:35202) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1h9Xmz-0000IB-HU for 34038@debbugs.gnu.org; Thu, 28 Mar 2019 12:22:02 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:39678) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h9Xmt-0003dO-Cb; Thu, 28 Mar 2019 12:21:55 -0400 Original-Received: from [176.228.60.248] (port=2408 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1h9Xms-0003C5-Kl; Thu, 28 Mar 2019 12:21:55 -0400 In-reply-to: <874l7sxczx.fsf@metalevel.at> (message from Markus Triska on Sun, 24 Mar 2019 20:56:34 +0100) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] 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: 209.51.188.43 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:156884 Archived-At: > From: Markus Triska > Cc: rudalics@gmx.at, acm@muc.de, 34038@debbugs.gnu.org > Date: Sun, 24 Mar 2019 20:56:34 +0100 > > Eli Zaretskii writes: > > > describing what you thought should have happened here, step by step, > > My expectation is that, when the snippet terminates with the message > that window-start is unexpectedly at a position different from 1, and I > *then* do: > > M-: (set-window-start nil 1) RET > > that the window-start is set to 1. However, in such cases, at least on > my machine and in the cases I found, the window start is *not* set to 1, > but unexpectedly retained at a position different from 1. This is actually quite expected: you cannot rely on set-window-start to always produce what you want, if the start position doesn't guarantee that point will be on a fully visible line. If with the start point you set point is not fully visible, redisplay is free not to obey that start point. It does make an attempt to use the start point you provide and move point into the view-port, but the attempt is half-hearted, and is likely to fail when the size of the default face's font is different from the frame's default font, because the last screen line of the window is then typically only partially visible. Can you describe what you are trying to achieve by using set-window-start? It's somewhat unusual to use that API without also moving point accordingly.