From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#28312: 25.2; Arabic script changes when scrolling Date: Fri, 01 Sep 2017 09:45:08 +0300 Message-ID: <83lgly29zf.fsf@gnu.org> References: Reply-To: Eli Zaretskii NNTP-Posting-Host: blaine.gmane.org X-Trace: blaine.gmane.org 1504248377 29190 195.159.176.226 (1 Sep 2017 06:46:17 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Fri, 1 Sep 2017 06:46:17 +0000 (UTC) Cc: 28312@debbugs.gnu.org To: Nick Helm Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Fri Sep 01 08:46:08 2017 Return-path: Envelope-to: geb-bug-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 1dnfiP-00071V-I2 for geb-bug-gnu-emacs@m.gmane.org; Fri, 01 Sep 2017 08:46:05 +0200 Original-Received: from localhost ([::1]:50173 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dnfiW-00071h-9b for geb-bug-gnu-emacs@m.gmane.org; Fri, 01 Sep 2017 02:46:12 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:53489) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dnfiQ-00070v-1Y for bug-gnu-emacs@gnu.org; Fri, 01 Sep 2017 02:46:07 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dnfiM-0001yF-Sy for bug-gnu-emacs@gnu.org; Fri, 01 Sep 2017 02:46:06 -0400 Original-Received: from debbugs.gnu.org ([208.118.235.43]:58428) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1dnfiM-0001yB-PV for bug-gnu-emacs@gnu.org; Fri, 01 Sep 2017 02:46:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1dnfiM-0001RY-HE for bug-gnu-emacs@gnu.org; Fri, 01 Sep 2017 02:46:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Fri, 01 Sep 2017 06:46:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 28312 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 28312-submit@debbugs.gnu.org id=B28312.15042483335456 (code B ref 28312); Fri, 01 Sep 2017 06:46:02 +0000 Original-Received: (at 28312) by debbugs.gnu.org; 1 Sep 2017 06:45:33 +0000 Original-Received: from localhost ([127.0.0.1]:38876 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dnfht-0001Pv-D2 for submit@debbugs.gnu.org; Fri, 01 Sep 2017 02:45:33 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:34202) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dnfhq-0001Pe-W4 for 28312@debbugs.gnu.org; Fri, 01 Sep 2017 02:45:31 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dnfhh-0001Zv-7K for 28312@debbugs.gnu.org; Fri, 01 Sep 2017 02:45:25 -0400 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:49003) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dnfhh-0001Zr-3p; Fri, 01 Sep 2017 02:45:21 -0400 Original-Received: from 84.94.185.246.cable.012.net.il ([84.94.185.246]:3835 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1dnfhg-00054v-AS; Fri, 01 Sep 2017 02:45:20 -0400 In-reply-to: (message from Nick Helm on Fri, 01 Sep 2017 13:03:02 +1200) 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: 208.118.235.43 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:136432 Archived-At: > From: Nick Helm > Date: Fri, 01 Sep 2017 13:03:02 +1200 > > With bidi enabled, Arabic text changes unexpectedly when scrolling or > moving point with the mouse. > > Recipe: > Emacs -Q > C-h h ;visit HELLO file > ;use the mouse to scroll slowly > > Observe the text on the line that starts with the word Arabic. As the > buffer scrolls, some of the characters in the Arabic representations of > the words "Arabic" and "Hello" change between at least two glyphs. I don't see this here, but I'm not on Darwin. Can anyone reproduce this on GNU/Linux? Does the character also change its shape if you move cursor across that line, especially when the cursor moves across the character? > Here's a quick screen cap to show what I mean: > https://ln.sync.com/dl/22d37f320/fwujc85a-dhb63yfw-cv5vhzj5-5qsis2h8 I cannot watch this movie with the software I have installed. > The problem goes away when I change the file local variable: > ;;; bidi-display-reordering: nil Not much sense in doing that for displaying Arabic! > My system defaults to Geeza Pro to display Arabic script, but the > problem also occurs with other fonts, such as Arial Unicode MS. I don't > see the problem with other RTL scripts in the HELLO file, such as > Hebrew. Arabic needs shaping support from the underlying font back-end, so (unless this will be reproduced on GNU/Linux) it sounds like something is wrong with either the back-end Emacs uses on Darwin, or its version you have installed, or with the support code in Emacs which is needed for displaying complex RTL scripts such as Arabic. FWIW, I tried Arial Unicode here, and saw no problem with that, either.