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: Fri, 2 Sep 2022 13:39:51 +0000 Message-ID: References: <87edx28cl1.fsf@disroot.org> <83y1v7w6eu.fsf@gnu.org> <2f302d1c3966849477b3@heytings.org> <83mtbiovzr.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="18706"; mail-complaints-to="usenet@ciao.gmane.io" Cc: gregory@heytings.org, 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 Fri Sep 02 15:41:43 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 1oU6vX-0004lC-1R for ged-emacs-devel@m.gmane-mx.org; Fri, 02 Sep 2022 15:41:43 +0200 Original-Received: from localhost ([::1]:60746 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oU6vV-00037P-L9 for ged-emacs-devel@m.gmane-mx.org; Fri, 02 Sep 2022 09:41:41 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:45930) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oU6tp-0001Pr-Ch for emacs-devel@gnu.org; Fri, 02 Sep 2022 09:39:57 -0400 Original-Received: from mx3.muc.de ([193.149.48.5]:25688) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oU6tm-0002AT-Qy for emacs-devel@gnu.org; Fri, 02 Sep 2022 09:39:56 -0400 Original-Received: (qmail 54026 invoked by uid 3782); 2 Sep 2022 15:39:52 +0200 Original-Received: from acm.muc.de (p2e5d5e67.dip0.t-ipconnect.de [46.93.94.103]) (using STARTTLS) by colin.muc.de (tmda-ofmipd) with ESMTP; Fri, 02 Sep 2022 15:39:51 +0200 Original-Received: (qmail 8693 invoked by uid 1000); 2 Sep 2022 13:39:51 -0000 Content-Disposition: inline In-Reply-To: <83mtbiovzr.fsf@gnu.org> X-Submission-Agent: TMDA/1.3.x (Ph3nix) X-Primary-Address: acm@muc.de Received-SPF: pass client-ip=193.149.48.5; envelope-from=acm@muc.de; helo=mx3.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=unavailable 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:294553 Archived-At: Hello, Eli. On Fri, Sep 02, 2022 at 14:29:12 +0300, Eli Zaretskii wrote: > > Date: Fri, 2 Sep 2022 11:12:32 +0000 > > Cc: Richard Stallman , eliz@gnu.org, emacs-devel@gnu.org > > From: Alan Mackenzie [ .... ] > > I agree with Richard that there should be an option for displaying > > characters outside of the current font as "�" rather than "\u2022". > I already explained how to set that up, so what exactly does the > "should be" part here want to say? The way you explained involves hacking Lisp and finding out precise character ranges. That's a lot different from being able just to set an option. > There is already such a way in Emacs. Just use it, if that's what you > want. There appears to be no easy way to get the old behaviour back, where characters undisplayable on the console got displayed with \ufffd instead. You've characterised this old behaviour as a bug, but in the preferences of two actual Linux console users (Richard and myself), the solution is not better than the bug. > > It is a feature of the Linux console that all such characters are > > displayed that way. > That feature provides no way of using it via standard terminfo > interfaces. Heck, even the way to ask the console which characters it > supports is a kludge specific to that console! Yes, I remember looking into that to try to find a way. Somebody brighter than me clearly managed it. :-) > > There is no possibility of any character causing an undefined > > action. > Famous last words. (And we don't send characters to the console, we > send bytes.) OK, bytes. Have there been any untoward effects reported, by sending valid Unicode strings of bytes to the Linux console? -- Alan Mackenzie (Nuremberg, Germany).