From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#41005: problem with rendering Persian text in Emacs 27 Date: Sat, 06 Jun 2020 12:24:54 +0300 Message-ID: <83y2p08s2h.fsf@gnu.org> References: <831rmwc9ke.fsf@gnu.org> <35A46479-A62C-42FF-995B-B295FE3408C0@gnu.org> <08A9D65F-0C9C-4EE2-B3B9-2AA25BFFAD54@gnu.org> <878sh35j6f.fsf@gmail.com> <83y2p3as6c.fsf@gnu.org> <87pnae4nhx.fsf@gmail.com> <83lfl2av8z.fsf@gnu.org> <834krpbrnu.fsf@gnu.org> <87a71h1x3s.fsf@gmail.com> <831rmtbny0.fsf@gnu.org> <87d06czj00.fsf@gmail.com> <831rmsa7ln.fsf@gnu.org> <875zc4zhh3.fsf@gmail.com> Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="46062"; mail-complaints-to="usenet@ciao.gmane.io" Cc: valizadeh.ho@gmail.com, 41005@debbugs.gnu.org, nicholasdrozd@gmail.com To: Pip Cet Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Sat Jun 06 11:26:11 2020 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jhV5e-000Br8-Mw for geb-bug-gnu-emacs@m.gmane-mx.org; Sat, 06 Jun 2020 11:26:10 +0200 Original-Received: from localhost ([::1]:38266 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jhV5d-00068g-5j for geb-bug-gnu-emacs@m.gmane-mx.org; Sat, 06 Jun 2020 05:26:09 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:48604) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jhV5W-00068R-Jm for bug-gnu-emacs@gnu.org; Sat, 06 Jun 2020 05:26:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:39190) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jhV5W-00034w-Aj for bug-gnu-emacs@gnu.org; Sat, 06 Jun 2020 05:26:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1jhV5W-0007xW-78 for bug-gnu-emacs@gnu.org; Sat, 06 Jun 2020 05:26:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sat, 06 Jun 2020 09:26:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 41005 X-GNU-PR-Package: emacs Original-Received: via spool by 41005-submit@debbugs.gnu.org id=B41005.159143551330535 (code B ref 41005); Sat, 06 Jun 2020 09:26:02 +0000 Original-Received: (at 41005) by debbugs.gnu.org; 6 Jun 2020 09:25:13 +0000 Original-Received: from localhost ([127.0.0.1]:50736 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jhV4i-0007wR-NG for submit@debbugs.gnu.org; Sat, 06 Jun 2020 05:25:12 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:35650) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jhV4h-0007wE-Bq for 41005@debbugs.gnu.org; Sat, 06 Jun 2020 05:25:11 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:58359) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jhV4c-0002gu-3O; Sat, 06 Jun 2020 05:25:06 -0400 Original-Received: from [176.228.60.248] (port=3132 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1jhV4Z-0002bC-3x; Sat, 06 Jun 2020 05:25:03 -0400 In-Reply-To: <875zc4zhh3.fsf@gmail.com> (message from Pip Cet on Sat, 06 Jun 2020 09:11:36 +0000) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list 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-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:181602 Archived-At: > From: Pip Cet > Cc: valizadeh.ho@gmail.com, 41005@debbugs.gnu.org, nicholasdrozd@gmail.com > Date: Sat, 06 Jun 2020 09:11:36 +0000 > > Eli Zaretskii writes: > > >> From: Pip Cet > >> Cc: valizadeh.ho@gmail.com, 41005@debbugs.gnu.org, nicholasdrozd@gmail.com > >> Date: Sat, 06 Jun 2020 08:38:39 +0000 > >> > >> >> Given these two bugs, I wonder whether it wouldn't be more reasonable > >> >> always to let HarfBuzz guess the direction, at least for Emacs-27: > ~~~~~~~~~~~~~~~~~~~~~ > > I should have been clearer here and said I was only concerned with Emacs 27. Ah, okay. That settles some of the misunderstanding. But even in emacs-27, I think passing the right direction where we know it is better. For example, the use case with directional override is only problematic in emacs-27 if the following conditions are both true: . the same sequence of characters is used elsewhere, but without the override . the font glyphs produced by the shaper are different for different directions The first is somewhat likely to happen, but the second happens only for some specific scripts, such as Arabic (again, if we consider the scope of what is supported well by Emacs 27, which, for example, excludes ligatures). And the use case with directional overrides is itself very rare. The more frequent use cases which hit on this deficiency in emacs-27 are those which you just fixed on emacs-27, and the fix is indeed to let HarfBuzz guess.