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.bugs Subject: bug#67196: M-: uses a wrong value of debug-on-error when it is nil. Date: Wed, 15 Nov 2023 17:55:18 +0000 Message-ID: References: <83a5rfq6i2.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="13194"; mail-complaints-to="usenet@ciao.gmane.io" Cc: 67196@debbugs.gnu.org, Stefan Monnier To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Wed Nov 15 18:56:23 2023 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 1r3K7i-00039M-Iy for geb-bug-gnu-emacs@m.gmane-mx.org; Wed, 15 Nov 2023 18:56:22 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1r3K7X-0006h4-9M; Wed, 15 Nov 2023 12:56:11 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1r3K7P-0006XT-Eo for bug-gnu-emacs@gnu.org; Wed, 15 Nov 2023 12:56:03 -0500 Original-Received: from debbugs.gnu.org ([2001:470:142:5::43]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1r3K7O-0002bt-Pa for bug-gnu-emacs@gnu.org; Wed, 15 Nov 2023 12:56:03 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1r3K7N-0001z5-QU for bug-gnu-emacs@gnu.org; Wed, 15 Nov 2023 12:56:01 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Alan Mackenzie Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Wed, 15 Nov 2023 17:56:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 67196 X-GNU-PR-Package: emacs Original-Received: via spool by 67196-submit@debbugs.gnu.org id=B67196.17000709277580 (code B ref 67196); Wed, 15 Nov 2023 17:56:01 +0000 Original-Received: (at 67196) by debbugs.gnu.org; 15 Nov 2023 17:55:27 +0000 Original-Received: from localhost ([127.0.0.1]:53730 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1r3K6p-0001yA-0W for submit@debbugs.gnu.org; Wed, 15 Nov 2023 12:55:27 -0500 Original-Received: from mail.muc.de ([193.149.48.3]:33689) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1r3K6m-0001xt-61 for 67196@debbugs.gnu.org; Wed, 15 Nov 2023 12:55:25 -0500 Original-Received: (qmail 61466 invoked by uid 3782); 15 Nov 2023 18:55:19 +0100 Original-Received: from acm.muc.de (p4fe15c08.dip0.t-ipconnect.de [79.225.92.8]) (using STARTTLS) by colin.muc.de (tmda-ofmipd) with ESMTP; Wed, 15 Nov 2023 18:55:18 +0100 Original-Received: (qmail 24204 invoked by uid 1000); 15 Nov 2023 17:55:18 -0000 Content-Disposition: inline In-Reply-To: <83a5rfq6i2.fsf@gnu.org> X-Submission-Agent: TMDA/1.3.x (Ph3nix) X-Primary-Address: acm@muc.de 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-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.bugs:274406 Archived-At: Hello, Eli. On Wed, Nov 15, 2023 at 19:19:17 +0200, Eli Zaretskii wrote: > > Date: Wed, 15 Nov 2023 13:48:40 +0000 > > From: Alan Mackenzie > > Hello, Emacs. > > On the master branch (and probably any recent Emacs): > > (i) emacs -Q > > (ii) C-h v debug-on-error RET > > (iii) M-: debug-on-error RET > > >From (ii) it will be seen that debug-on-error's value is nil. > > (iii) wrongly reports that its value is t. This is a bug. > > ######################################################################### > > What is happening here is that eval-expression binds debug-on-error to > > an uninterned symbol called "t", so that d-o-e will be set to non-nil > > for the evaluation of the coming form. > > This has the unwanted side effect of ignoring the actual value of d-o-e > > in forms which use it. For example, if the variable is set to a list of > > error symbols, this value gets ignored on evaluating a form with M-:. > Aren't we doing this on purpose, Stefan? Thinking about it more clearly, we're using one variable, debug-on-error, for two conflicting purposes: (i) The calling mechanism of execute-extended-command, including the invocation of the debugger, should an error be signalled. (ii) Use in the form to be evaluated, where the variable's value outside of execute-extended-command should endure. It would seem to me we really need two distinct variables for these two purposes. I think it's clear that purpose (ii) would be the one to retain use of debug-on-error. -- Alan Mackenzie (Nuremberg, Germany).