From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Alan Mackenzie Newsgroups: gmane.emacs.devel Subject: "... the window start at a meaningless point within a line." Date: Wed, 30 Sep 2015 20:45:13 +0000 Message-ID: <20150930204513.GA3174@acm.fritz.box> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1443685338 30722 80.91.229.3 (1 Oct 2015 07:42:18 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 1 Oct 2015 07:42:18 +0000 (UTC) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Oct 01 09:42:10 2015 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1ZhYVG-0007mP-3N for ged-emacs-devel@m.gmane.org; Thu, 01 Oct 2015 09:42:10 +0200 Original-Received: from localhost ([::1]:39966 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZhYVF-00024n-91 for ged-emacs-devel@m.gmane.org; Thu, 01 Oct 2015 03:42:09 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:60286) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZhOEB-0000vy-4Q for emacs-devel@gnu.org; Wed, 30 Sep 2015 16:43:52 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZhOE6-0007iE-W4 for emacs-devel@gnu.org; Wed, 30 Sep 2015 16:43:51 -0400 Original-Received: from mail.muc.de ([193.149.48.3]:29344) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZhOE6-0007at-NX for emacs-devel@gnu.org; Wed, 30 Sep 2015 16:43:46 -0400 Original-Received: (qmail 79915 invoked by uid 3782); 30 Sep 2015 20:43:45 -0000 Original-Received: from acm.muc.de (p5B147BA3.dip0.t-ipconnect.de [91.20.123.163]) by colin.muc.de (tmda-ofmipd) with ESMTP; Wed, 30 Sep 2015 22:43:44 +0200 Original-Received: (qmail 3227 invoked by uid 1000); 30 Sep 2015 20:45:13 -0000 Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) X-Delivery-Agent: TMDA/1.1.12 (Macallan) X-Primary-Address: acm@muc.de X-detected-operating-system: by eggs.gnu.org: FreeBSD 9.x X-Received-From: 193.149.48.3 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:190528 Archived-At: Hello, Emacs. In the Elisp manual, page "Window Start and End", it's described how, if in (set-window-start x) x is a position not at the start of a line, the display engine will, instead of x, choose some value near x as the window start. Is this really necessary? It causes problems. The particular problem I'm looking at is with Follow Mode, where a pair of adjacent windows are of unequal width. This is a very common scenario - I frequently use Follow Mode with three side by side windows of widths 79, 79, and 80 (as measured by window-body-width). The problem occurs when there's a long line at the bottom of window 2 and its continuation line at the top of window 3. The display manager chops off the line in W2 after 78 characters, and inserts a \ sign. It then starts the continuation line in W3 at character 80 (counting from 1), assuming as it does, that the previous line in this window would be 79 characters long. So character 79 appears neither on the first portion of the line in W2, nor in its continuation in W3. This is suboptimal. This problem would not occur if there were a flag to set-window-start meaning "this value really is where I want the window to start, not some beginning of line nearby". How difficult would it be to relax the constraint on window start positions and implement this flag? -- Alan Mackenzie (Nuremberg, Germany).