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#41645: 27.0.91; Combining Grapheme Joiner (#x34f) gui artifacts Date: Wed, 03 Jun 2020 18:58:28 +0300 Message-ID: <834krscfa3.fsf@gnu.org> References: <83zh9merd4.fsf@gnu.org> <83wo4qepab.fsf@gnu.org> <83lfl6eiod.fsf@gnu.org> <83zh9lcuyg.fsf@gnu.org> <87o8q1xohw.fsf@gmail.com> <83d06gcjtp.fsf@gnu.org> <87d06g6vsw.fsf@gmail.com> Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="94945"; mail-complaints-to="usenet@ciao.gmane.io" Cc: dfussner@googlemail.com, 41645@debbugs.gnu.org To: Pip Cet Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Wed Jun 03 17:59:10 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 1jgVnJ-000OYO-1i for geb-bug-gnu-emacs@m.gmane-mx.org; Wed, 03 Jun 2020 17:59:09 +0200 Original-Received: from localhost ([::1]:46232 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jgVnH-0002Lj-O8 for geb-bug-gnu-emacs@m.gmane-mx.org; Wed, 03 Jun 2020 11:59:07 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:44052) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jgVnC-0002LO-Cg for bug-gnu-emacs@gnu.org; Wed, 03 Jun 2020 11:59:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:32898) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jgVnC-0008Li-4B for bug-gnu-emacs@gnu.org; Wed, 03 Jun 2020 11:59:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1jgVnC-0001O2-2p for bug-gnu-emacs@gnu.org; Wed, 03 Jun 2020 11:59:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Wed, 03 Jun 2020 15:59:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 41645 X-GNU-PR-Package: emacs Original-Received: via spool by 41645-submit@debbugs.gnu.org id=B41645.15911999325313 (code B ref 41645); Wed, 03 Jun 2020 15:59:02 +0000 Original-Received: (at 41645) by debbugs.gnu.org; 3 Jun 2020 15:58:52 +0000 Original-Received: from localhost ([127.0.0.1]:44444 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jgVn2-0001Nd-BI for submit@debbugs.gnu.org; Wed, 03 Jun 2020 11:58:52 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:59404) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jgVn1-0001NS-7T for 41645@debbugs.gnu.org; Wed, 03 Jun 2020 11:58:51 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:43867) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jgVmv-00086E-TI; Wed, 03 Jun 2020 11:58:45 -0400 Original-Received: from [176.228.60.248] (port=4303 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1jgVmu-0000V5-7q; Wed, 03 Jun 2020 11:58:45 -0400 In-Reply-To: <87d06g6vsw.fsf@gmail.com> (message from Pip Cet on Wed, 03 Jun 2020 14:58:07 +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:181464 Archived-At: > From: Pip Cet > Cc: dfussner@googlemail.com, 41645@debbugs.gnu.org > Date: Wed, 03 Jun 2020 14:58:07 +0000 > > > I'm not sure I follow. What do you mean by "reject"? I thought the > > code which ignores the metric and sets the font_not_found_p flag when > > we get a zero-width glyph is a kind of "rejection". > > I mean "treat the glyph as non-existent". Currently, for (3), glyphs > with lbearing but no pixel width are treated as valid and expanded to > cover a single pixel, which is all but invisible on my screen. They are hard to spot, but if one looks close enough, IME they are visible. We could perhaps introduce a feature whereby such thin-space glyphs are somehow made to stand out more, but that would be a separate feature, because right now we have these 1-pixel thin spaces with many control characters. > > If you disable auto-composition-mode, and use the > > fonts which shows CGJ as zero-width glyph, do you still see display > > artifacts? > > No. Then I think your suggestion to handle such lgstrings as we do with simple characters is sufficient to fix situations such as this one. > > If not, what do you see and why is this kind of > > 'rejection" not enough? > > CGJ is displayed as a black box as wide as a space, which is perfectly > fine. It's U+301 that's not. Hmm... how does U+301 enter this picture? What problems do you see with its display?