From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Alan Mackenzie Newsgroups: gmane.emacs.devel Subject: Re: Display of undisplayable characters: \U01F3A8 instead of diamond Date: Sun, 28 Aug 2022 11:07:24 +0000 Message-ID: References: <834jxxymbp.fsf@gnu.org> <83v8qcy83q.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="22818"; mail-complaints-to="usenet@ciao.gmane.io" Cc: rms@gnu.org, emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sun Aug 28 13:08:07 2022 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 1oSG99-0005gh-KE for ged-emacs-devel@m.gmane-mx.org; Sun, 28 Aug 2022 13:08:07 +0200 Original-Received: from localhost ([::1]:54102 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oSG98-00037n-Mo for ged-emacs-devel@m.gmane-mx.org; Sun, 28 Aug 2022 07:08:06 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:39396) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oSG8Y-0002Kx-7E for emacs-devel@gnu.org; Sun, 28 Aug 2022 07:07:30 -0400 Original-Received: from mail.muc.de ([193.149.48.3]:13477) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oSG8W-00074V-2e for emacs-devel@gnu.org; Sun, 28 Aug 2022 07:07:29 -0400 Original-Received: (qmail 20028 invoked by uid 3782); 28 Aug 2022 13:07:25 +0200 Original-Received: from acm.muc.de (p2e5d5a4e.dip0.t-ipconnect.de [46.93.90.78]) (using STARTTLS) by colin.muc.de (tmda-ofmipd) with ESMTP; Sun, 28 Aug 2022 13:07:24 +0200 Original-Received: (qmail 5692 invoked by uid 1000); 28 Aug 2022 11:07:24 -0000 Content-Disposition: inline In-Reply-To: <83v8qcy83q.fsf@gnu.org> X-Submission-Agent: TMDA/1.3.x (Ph3nix) X-Primary-Address: acm@muc.de Received-SPF: pass client-ip=193.149.48.3; envelope-from=acm@muc.de; helo=mail.muc.de X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action 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:294233 Archived-At: Hello, Eli. On Sun, Aug 28, 2022 at 13:29:13 +0300, Eli Zaretskii wrote: > > Date: Sun, 28 Aug 2022 10:07:00 +0000 > > Cc: rms@gnu.org, emacs-devel@gnu.org > > From: Alan Mackenzie > > > > Can we modify info.el so as to display those characters > > > > as the curresponding ASCII punctuation characters? > > > It already does, where an ASCII equivalent exists. See > > > info-symbols-and-replacements. Alan didn't report any details, so I > > > don't have any idea why it doesn't work for him (if indeed it doesn't). > > I didn't actually know about that feature, which you added in October > > 2019 (commit 8dd18bbb6f3c09a4988cf2e06378aa24b098fb85). It fails on my > > Linux console because of a guarding clause in the `unless' which > > surrounds the initialisation of buffer-display-table: > > (unless (or (display-multi-font-p) > > (coding-system-equal <==================== > > (coding-system-base (terminal-coding-system)) <========== > > 'utf-8)) <==================== > > (dolist (elt info-symbols-and-replacements) > > (let ((ch (car elt)) > > (repl (cdr elt))) > > (or (char-displayable-p ch) > > (aset (or buffer-display-table > > (setq buffer-display-table (make-display-table))) > > ch (vconcat (mapcar (lambda (c) > > (make-glyph-code c 'homoglyph)) > > repl))))))) > > On my setup that (coding-system-equal .... 'utf-8) returns t, so > > buffer-display-table never gets initialised. > > Why is that coding-system-equal form there? > It was written based on the assumption that a terminal that supports > the UTF-8 encoding can also display the original characters reasonably > enough. Are you saying that the Linux console lies about that, and > those characters are displayed as hex codes? Well, I think "lies" is a bit strong, here. The Linux console uses UTF-8 characters, but is restricted to an arbitrary selection of 256 of them. An attempt to display any other character on the screen gets \ufffd displayed instead. Possibly, double-width characters aren't correctly handled, I don't know. My console is configured to use Latin-1, and it also includes some line graphic characters, but not the punctuation characters used by makeinfo. Those characters were indeed displayed as hex codes, until I applied the patch below. > If so, please try the patch below. > diff --git a/lisp/info.el b/lisp/info.el > index 739116c..5655e3f 100644 > --- a/lisp/info.el > +++ b/lisp/info.el > @@ -4446,9 +4446,12 @@ Info-mode > (setq buffer-read-only t) > (setq Info-tag-table-marker (make-marker)) > (unless (or (display-multi-font-p) > - (coding-system-equal > - (coding-system-base (terminal-coding-system)) > - 'utf-8)) > + (and (coding-system-equal > + (coding-system-base (terminal-coding-system)) > + 'utf-8) > + ;; The Linux console has limited character > + ;; repertoire even when its encoding is UTF-8. > + (not (equal (tty-type) "linux")))) > (dolist (elt info-symbols-and-replacements) > (let ((ch (car elt)) > (repl (cdr elt))) This works for me. :-) -- Alan Mackenzie (Nuremberg, Germany).