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: Sat, 25 Nov 2023 17:36:37 +0000 Message-ID: References: <83il5qe00e.fsf@gnu.org> <83edgecce4.fsf@gnu.org> <8334wuc7cn.fsf@gnu.org> <83y1elbzny.fsf@gnu.org> <83sf4tbx2q.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="17745"; mail-complaints-to="usenet@ciao.gmane.io" Cc: 67196@debbugs.gnu.org, acm@muc.de, monnier@iro.umontreal.ca To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Sat Nov 25 18:37:26 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 1r6waq-0004R8-QV for geb-bug-gnu-emacs@m.gmane-mx.org; Sat, 25 Nov 2023 18:37:24 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1r6waR-0003Zh-M4; Sat, 25 Nov 2023 12:36:59 -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 1r6waP-0003ZI-Ut for bug-gnu-emacs@gnu.org; Sat, 25 Nov 2023 12:36:57 -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 1r6waP-00063i-Mj for bug-gnu-emacs@gnu.org; Sat, 25 Nov 2023 12:36:57 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1r6waU-00019x-IY for bug-gnu-emacs@gnu.org; Sat, 25 Nov 2023 12:37:02 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Alan Mackenzie Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sat, 25 Nov 2023 17:37:02 +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=B67196.17009338124442 (code B ref 67196); Sat, 25 Nov 2023 17:37:02 +0000 Original-Received: (at 67196) by debbugs.gnu.org; 25 Nov 2023 17:36:52 +0000 Original-Received: from localhost ([127.0.0.1]:40159 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1r6waJ-00019Y-P4 for submit@debbugs.gnu.org; Sat, 25 Nov 2023 12:36:52 -0500 Original-Received: from mail.muc.de ([193.149.48.3]:37210) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1r6waH-00019H-IM for 67196@debbugs.gnu.org; Sat, 25 Nov 2023 12:36:50 -0500 Original-Received: (qmail 5615 invoked by uid 3782); 25 Nov 2023 18:36:38 +0100 Original-Received: from acm.muc.de (pd953a2e3.dip0.t-ipconnect.de [217.83.162.227]) (using STARTTLS) by colin.muc.de (tmda-ofmipd) with ESMTP; Sat, 25 Nov 2023 18:36:38 +0100 Original-Received: (qmail 19863 invoked by uid 1000); 25 Nov 2023 17:36:37 -0000 Content-Disposition: inline In-Reply-To: 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:275004 Archived-At: Hello again, Eli. On Sat, Nov 25, 2023 at 16:57:21 +0000, Alan Mackenzie wrote: > On Sat, Nov 25, 2023 at 18:46:05 +0200, Eli Zaretskii wrote: > > > Date: Sat, 25 Nov 2023 16:40:40 +0000 > > > Cc: monnier@iro.umontreal.ca, 67196@debbugs.gnu.org, acm@muc.de > > > From: Alan Mackenzie > > > > > Instead, the new internal variable > > > > > debug-from--eval-expression gets set to e-e-debug-on-error. > > > > Exactly. And that value can be non-nil, but also not t. That is the > > > > change I see, and your doc string suggests that it is intentional. > > > > Thus, we have a behavior change wrt to the value that the body of > > > > eval-expression will see. And non-nil, non-t values have special > > > > meaning there. > > > OK, I'm with you, now. The non-nil, non-t value in the internal variable > > > debug-from--e-e won't be seen by any Lisp code. It can be seen by Lisp > > > code in eval-expression-debug-on-error. > > > This is an extension of e-e-debug-on-error to match what debug-on-error > > > does. I wouldn't think that d-o-e gets set to a list of conditions very > > > often, but when it does, it's likely very useful. It seemed logical to > > > extend the same facility to e-e-debug-on-error. Do you think this is a > > > bad idea? [Clearly, some entries in NEWS will be needed, as well as > > > amendments to the Elisp manual.] > > I don't know yet if it is a good idea, I just wanted to point out that > > your change is not just a bugfix: it actually changes the behavior of > > eval-expression. > OK. It's a change that would be trivially easy to reverse. > My guess is that debug-on-error was originally a DEFVAR_BOOL, and at some > stage it was extended to handle a list of conditions. But for some > reason eval-expression-debug-on-error was not extended in the same way. > Perhaps this was an oversight. If so, now would be a good time to fix > this. > Maybe there is some evidence of what happened in the repository. I'll > have a look. eval-expression-debug-on-error came into existence with this commit: commit b49df39ddcfc578234530208eba8e288f604db1b Author: Richard M. Stallman Date: Tue Sep 14 07:00:04 1999 +0000 (eval-expression-print-level): New variable. (eval-expression-print-length): New variable. (eval-expression-debug-on-error): New variable. (eval-expression): Bind print-level, print-length and debug-on-error from those vars. .. debug-on-error got its list value with this commit: commit 128c0f667926dd4296411b9189125ee8c5b78b79 Author: Roland McGrath Date: Thu Jun 4 04:33:43 1992 +0000 *** empty log message *** .. So debug-on-error had its list of conditions value 7 years before eval-expression-debug-on-error existed. It's not clear why this new variable didn't take over the enhanced semantics from debug-on-error. -- Alan Mackenzie (Nuremberg, Germany).