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: Edebug corrupting point in buffers. Date: Tue, 1 Nov 2022 11:41:02 +0000 Message-ID: References: <83wn8fcgvd.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="21081"; mail-complaints-to="usenet@ciao.gmane.io" Cc: emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org+ged-emacs-devel=m.gmane-mx.org@gnu.org Tue Nov 01 12:41:58 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 1oppeY-0005Il-DH for ged-emacs-devel@m.gmane-mx.org; Tue, 01 Nov 2022 12:41:58 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oppdm-0001a0-M2; Tue, 01 Nov 2022 07:41:10 -0400 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 1oppdk-0001ZT-Nb for emacs-devel@gnu.org; Tue, 01 Nov 2022 07:41:08 -0400 Original-Received: from mx3.muc.de ([193.149.48.5]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oppdi-0002Mo-6m for emacs-devel@gnu.org; Tue, 01 Nov 2022 07:41:08 -0400 Original-Received: (qmail 2806 invoked by uid 3782); 1 Nov 2022 12:41:03 +0100 Original-Received: from acm.muc.de (p4fe15c46.dip0.t-ipconnect.de [79.225.92.70]) (using STARTTLS) by colin.muc.de (tmda-ofmipd) with ESMTP; Tue, 01 Nov 2022 12:41:02 +0100 Original-Received: (qmail 4246 invoked by uid 1000); 1 Nov 2022 11:41:02 -0000 Content-Disposition: inline In-Reply-To: <83wn8fcgvd.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 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: , Original-Sender: "Emacs-devel" Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:298928 Archived-At: Hello, Eli. On Tue, Nov 01, 2022 at 08:45:42 +0200, Eli Zaretskii wrote: > > Date: Mon, 31 Oct 2022 21:25:08 +0000 > > From: Alan Mackenzie > > +(defcustom edebug-save-buffer-points nil > > + "If non-nil save and restore the buffer points in some buffers. > > + > > +Saving and restoring the buffer point in a buffer is needed if you > > +are debugging code which sets point in that buffer, particularly if > > +there is also a window displaying that buffer. Otherwise the buffer > > +point (being used by the program) will get overwritten by the > > +window point. > > + > > +If the value is a list of buffer names (recommended), only those > > +buffers will have their buffer points restored. Otherwise, t means > > +restore all buffers\\=' points, and nil means none. > If we indeed need such an option, why shouldn't it be Edebug's > business to automatically keep point in all buffers that are displayed > in some window? It doesn't strike me as the best UI to burden the > user with that task. It would be intolerable for users. Say during an edebug session, the user makes some notes in buffer my-notes.txt. Execute an instruction, then go back to my-notes.txt. Point has been "restored" to before the new notes. That would happen in every buffer. > And like Stefan, I think we still need to understand better what > exactly happens here and why. I don't think I understood that from > your original description. Sorry, I had some difficulty getting from my original problem to a reproducible test case. That's here: With test-edebug.el being ######################################################################### (defun test-edebug () (let ((A "*scratch*") (B "emacs.README")) (set-buffer A) (set-buffer B) (goto-char (point-max)) (insert "(2022-11-01)\n") ;; B's buffer-point is at point-max. (set-buffer A) (set-buffer B) ;; B's buffer-point is no longer at point-max. (insert "(2022-11-01)a\n"))) ######################################################################### , (i) Emacs -Q. (ii) On a single frame, arrange buffers *scratch*, test-edebug.el, and some other substantial buffer, that I call emacs.README. (iii) Put point in emacs.README somewhere other than point-max. (iv) Instrument test-edebug for edebug with C-u C-M-x. (v) M-: (test-edebug). (vi) Step through test-edebug using the space key. (vii) Note that the second text insertion happens where point was in the window, not at point-max. This is the bug. My patch from yesterday evening, though not in its final form, appears to solve the bug, providing the user does C-x X F in emacs.README. -- Alan Mackenzie (Nuremberg, Germany).