From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Unicode confusables and reordering characters considered harmful, a simple solution Date: Thu, 04 Nov 2021 09:16:24 +0200 Message-ID: <83pmrgfl13.fsf@gnu.org> References: <875ytag0hb.fsf@yahoo.com> <87zgqmd5np.fsf@mat.ucm.es> <83wnlqk3rn.fsf@gnu.org> <72dd5c2a-42c7-b12e-05ed-e93adbd89727@gmail.com> <83ilxajyhw.fsf@gnu.org> <83fssejxf8.fsf@gnu.org> <835ytajsv2.fsf@gnu.org> <831r3yjqo9.fsf@gnu.org> <83v91aibe7.fsf@gnu.org> <87o872s0wf.fsf_-_@db48x.net> <83lf25gm1j.fsf@gnu.org> <86h7ctyupr.fsf@mail.linkov.net> <11d5fecb44ffbf6b7dd1@heytings.org> <838ry5ggy9.fsf@gnu.org> <11d5fecb446ff1ae06b6@heytings.org> <83zgqlf0c2.fsf@gnu.org> <11d5fecb4494b19a9730@heytings.org> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="18359"; mail-complaints-to="usenet@ciao.gmane.io" Cc: juri@linkov.net, cpitclaudel@gmail.com, stefan@marxist.se, emacs-devel@gnu.org, db48x@db48x.net, monnier@iro.umontreal.ca, yuri.v.khan@gmail.com To: Gregory Heytings Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Thu Nov 04 08:25:44 2021 Return-path: Envelope-to: ged-emacs-devel@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 1miX83-0004Zs-F2 for ged-emacs-devel@m.gmane-mx.org; Thu, 04 Nov 2021 08:25:43 +0100 Original-Received: from localhost ([::1]:35210 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1miX82-0003FM-F1 for ged-emacs-devel@m.gmane-mx.org; Thu, 04 Nov 2021 03:25:42 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:56974) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1miWz6-0005Kv-OH for emacs-devel@gnu.org; Thu, 04 Nov 2021 03:16:28 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:57194) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1miWz3-0000lB-8c; Thu, 04 Nov 2021 03:16:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=References:Subject:In-Reply-To:To:From:Date: mime-version; bh=VCQSt6T/pB3YDu4eT5v7fROJpqRw4w1ClW0lWYXa6CY=; b=dSjrj8Kc2wgD t62g8Ns/NcBai8II5pPUn0MTUX6vf30Jt3sKMi4kBBwmVThQY9+t5iBNlv9oVk8zGbB/D51k9wzkY li+yJ92BHvEviaGKDJlchkvzjvswvboKXS4xZBCn6TGgNGmqFyicvDHBM8DtiOSSHU4F+ACIFoIML o6zeJfzgZ5Qjtgj38BDIQpE5q35e/9pb4ytRyBlDwtW/lcsHPQ1C7HiuXx/7FSHrgUw4PuF4tOrc+ dghmx7cXimUWNqKQfWKsgxkSNDpyRZ1d6eXWZALdMQbLLWV1w2VedfEeu4kYE2HK/8RahQqgcX40z IV256XVVQ/LSoeSLXCHDWA==; Original-Received: from [87.69.77.57] (port=2469 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1miWz2-0000Hx-QG; Thu, 04 Nov 2021 03:16:25 -0400 In-Reply-To: <11d5fecb4494b19a9730@heytings.org> (message from Gregory Heytings on Wed, 03 Nov 2021 21:16:56 +0000) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 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-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:278651 Archived-At: > Date: Wed, 03 Nov 2021 21:16:56 +0000 > From: Gregory Heytings > cc: cpitclaudel@gmail.com, yuri.v.khan@gmail.com, stefan@marxist.se, > emacs-devel@gnu.org, db48x@db48x.net, monnier@iro.umontreal.ca, > juri@linkov.net > > >> I tried various of the predefined colors with highlight-regexp, of > >> course those with a distinct background, and none make any of those > >> characters more visible. Not even with a single pixel wide bar. > > > > That's very strange, because I see them even if I make the region span > > only a single such character. The default background of the region face > > is quite pale, and still I see them quite clearly, even with the default > > light theme. > > > > Here's a screenshot with emacs -Q (current trunk). I did M-x > highlight-regexp RET y RET hi-green RET M-x highlight-regexp all reordering characters> RET hi-green RET. There's one reordering > character between each of the "abcdefghij" string. I zoomed that picture, > I see absolutely nothing. If you configured highlight-regexp to highlight only the formatting controls, how come 'y' is highlighted in green on the image you sent? Is 'y' one of the characters that are supposed to be highlighted? Or maybe your configuration of highlight-regexp was incorrect? Or could there be some subtle bug/misfeature in highlight-regexp (I didn't try it myself)? If you shift-highlight one of these formatting control characters, and only one such character, don't you see a thin whitespace shown in the background color of the region face?