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#39390: 28.0.50; prettify-symbols-mode confuses display when start/end faces are different Date: Sun, 02 Feb 2020 19:18:52 +0200 Message-ID: <83eevcj4ar.fsf@gnu.org> References: <3184164c-5d94-6cb3-aca4-338b710bf97f@thaumogen.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="104668"; mail-complaints-to="usenet@ciao.gmane.io" Cc: 39390@debbugs.gnu.org To: Raphael 'kena' Poss Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Sun Feb 02 18:20:13 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 1iyIur-000R9m-3Z for geb-bug-gnu-emacs@m.gmane-mx.org; Sun, 02 Feb 2020 18:20:13 +0100 Original-Received: from localhost ([::1]:58164 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iyIuq-0000ty-35 for geb-bug-gnu-emacs@m.gmane-mx.org; Sun, 02 Feb 2020 12:20:12 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:36075) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iyIuj-0000ts-EJ for bug-gnu-emacs@gnu.org; Sun, 02 Feb 2020 12:20:06 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iyIuh-0006En-8d for bug-gnu-emacs@gnu.org; Sun, 02 Feb 2020 12:20:04 -0500 Original-Received: from debbugs.gnu.org ([209.51.188.43]:34490) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1iyIug-0006Ee-I5 for bug-gnu-emacs@gnu.org; Sun, 02 Feb 2020 12:20:02 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1iyIug-0001BC-DP for bug-gnu-emacs@gnu.org; Sun, 02 Feb 2020 12:20:02 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sun, 02 Feb 2020 17:20:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 39390 X-GNU-PR-Package: emacs Original-Received: via spool by 39390-submit@debbugs.gnu.org id=B39390.15806639544460 (code B ref 39390); Sun, 02 Feb 2020 17:20:02 +0000 Original-Received: (at 39390) by debbugs.gnu.org; 2 Feb 2020 17:19:14 +0000 Original-Received: from localhost ([127.0.0.1]:40463 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1iyItu-00019r-2c for submit@debbugs.gnu.org; Sun, 02 Feb 2020 12:19:14 -0500 Original-Received: from eggs.gnu.org ([209.51.188.92]:55033) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1iyItr-00019d-Tj for 39390@debbugs.gnu.org; Sun, 02 Feb 2020 12:19:12 -0500 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:53339) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1iyItm-00047M-PM; Sun, 02 Feb 2020 12:19:06 -0500 Original-Received: from [176.228.60.248] (port=2200 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1iyItm-0000z6-9V; Sun, 02 Feb 2020 12:19:06 -0500 In-reply-to: <3184164c-5d94-6cb3-aca4-338b710bf97f@thaumogen.net> (message from Raphael 'kena' Poss on Sun, 2 Feb 2020 15:45:46 +0100) 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: 209.51.188.43 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-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:175598 Archived-At: > From: Raphael 'kena' Poss > Date: Sun, 2 Feb 2020 15:45:46 +0100 > > (add-hook 'go-mode-hook > (lambda () > (push '("error" . ?⊙) prettify-symbols-alist) > ;; (push '("err != nil" . "⊙?") prettify-symbols-alist) > )) > > However if I then uncomment the second substitution for "err != nil": > all hell breaks loose: moving the cursor up and down around a source > line containing this text will mess up the display of the lines that > follow in a way that is sometimes irrecoverable. > > The display bug is exacerbated (and thus easier to recognize/reproduce) > when global-hl-line-mode is set. > > I have traced this down to substitutions where the font-lock face at the > beginning and the end of the symbol composition is different: > > - replacing "String" is OK, replacing ".String()" is not > - replacing "func" is OK, replacing "func(" is not > - replacing "Fatal" is OK, replacing "t.Fatal" is not > > This probably needs to be fixed somehow, either by preventing the > problem or by documenting the pitfall. > > I would like to know if a workaround is available? You've bumped into a fundamental limitation of the feature, called "character composition", that prettify-symbols-mode piggy-backs to do its thing: Emacs can only compose characters that all have the same face. This restriction is imposed on a very low level of the display code. So I don't think there can be a workaround, except by "fixing" the font-lock faces to use the same face on all the characters you want to substitute.