From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.help Subject: Re: Scrolling jumpy when line-spacing > 0 Date: Fri, 21 Apr 2017 17:40:25 +0300 Message-ID: <83inlxako6.fsf@gnu.org> References: NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Trace: blaine.gmane.org 1492785624 29561 195.159.176.226 (21 Apr 2017 14:40:24 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Fri, 21 Apr 2017 14:40:24 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Fri Apr 21 16:40:18 2017 Return-path: Envelope-to: geh-help-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 1d1ZjO-0007Ud-1i for geh-help-gnu-emacs@m.gmane.org; Fri, 21 Apr 2017 16:40:18 +0200 Original-Received: from localhost ([::1]:59971 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d1ZjQ-0002Xs-LK for geh-help-gnu-emacs@m.gmane.org; Fri, 21 Apr 2017 10:40:20 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:37760) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d1Ziz-0002Xl-IB for help-gnu-emacs@gnu.org; Fri, 21 Apr 2017 10:39:54 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d1Ziu-0000rz-LR for help-gnu-emacs@gnu.org; Fri, 21 Apr 2017 10:39:53 -0400 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:35650) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d1Ziu-0000rv-IY for help-gnu-emacs@gnu.org; Fri, 21 Apr 2017 10:39:48 -0400 Original-Received: from 84.94.185.246.cable.012.net.il ([84.94.185.246]:2162 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1d1Zis-0001rn-VE for help-gnu-emacs@gnu.org; Fri, 21 Apr 2017 10:39:48 -0400 In-reply-to: (message from Yuri Khan on Fri, 21 Apr 2017 17:13:32 +0700) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2001:4830:134:3::e X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Original-Sender: "help-gnu-emacs" Xref: news.gmane.org gmane.emacs.help:112840 Archived-At: > From: Yuri Khan > Date: Fri, 21 Apr 2017 17:13:32 +0700 > > (defun yk-scroll-up () > (interactive) > (scroll-up 1)) > (defun yk-scroll-down () > (interactive) > (scroll-down 1)) > (global-set-key (kbd "C-") 'yk-scroll-down) > (global-set-key (kbd "C-") 'yk-scroll-up) > > This works so far. > > Next, I also want my lines spaced a bit more widely. > > (setq line-spacing 0.5) > > And this is where I have a problem. (Why do people report bugs here, rather than with report-emacs-bug?) > $ emacs -Q > M-x emacs-version RET > GNU Emacs 24.5.1 (x86_64-pc-linux-gnu, GTK+ Version 3.18.9) of > 2016-04-17 on lgw01-04, modified by Debian > M-x view-emacs-news RET > M-x set-variable RET line-spacing RET 0.5 RET > M-x split-window-vertically > > Use the mouse to drag the top window’s modeline so that it is > immediately (two pixels or so) after the line, “See files NEWS.23, > NEWS.22, NEWS.21, NEWS.20, NEWS.19, NEWS.18,”. > > Position the point on that line, using a mouse click. > > M-: (scroll-up 1) > > Observed behavior: Point is on the same line and the line is at the > top of window. I can see this in Emacs 24.5 and in Emacs 25, but not on the master branch. On the master branch, when you click on the bottom line of the window, which is only partially visible in the above scenario, Emacs scrolls the window half-window up. To be able to put point on the bottom line, you will need to set window-resize-pixelwise non-nil, and drag the mode line down pixel by pixel until Emacs lets you put point there. Once this happens, "M-: (scroll-up 1) RET" produces the effect you expected. What happens in Emacs 25 and older is that Emacs decides that the window-start is no good and needs to be recomputed. It then makes point the window-start point, and that has the effect of a full window scroll.