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: Wed, 2 Nov 2022 11:34:37 +0000 Message-ID: References: <83wn8fcgvd.fsf@gnu.org> <83iljydh7e.fsf@gnu.org> <838rkud9d5.fsf@gnu.org> <83v8nybnuk.fsf@gnu.org> <83pme6bls8.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="33037"; 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@gnu.org Wed Nov 02 12:36:04 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 1oqC2O-0008KL-15 for ged-emacs-devel@m.gmane-mx.org; Wed, 02 Nov 2022 12:36:04 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oqC1S-0001vU-81; Wed, 02 Nov 2022 07:35:06 -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 1oqC19-0001sV-Bh for emacs-devel@gnu.org; Wed, 02 Nov 2022 07:34:47 -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 1oqC17-0001Vy-8E for emacs-devel@gnu.org; Wed, 02 Nov 2022 07:34:47 -0400 Original-Received: (qmail 28673 invoked by uid 3782); 2 Nov 2022 12:34:39 +0100 Original-Received: from acm.muc.de (p4fe15d2a.dip0.t-ipconnect.de [79.225.93.42]) (using STARTTLS) by colin.muc.de (tmda-ofmipd) with ESMTP; Wed, 02 Nov 2022 12:34:39 +0100 Original-Received: (qmail 4637 invoked by uid 1000); 2 Nov 2022 11:34:37 -0000 Content-Disposition: inline In-Reply-To: <83pme6bls8.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=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: , Original-Sender: "Emacs-devel" Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:299002 Archived-At: Hello, Eli. On Tue, Nov 01, 2022 at 19:57:11 +0200, Eli Zaretskii wrote: > > Date: Tue, 1 Nov 2022 17:24:26 +0000 > > Cc: emacs-devel@gnu.org > > From: Alan Mackenzie > This now gets me back to the inability to reproduce the problem with > your recipe. If that depends on edebug-save-windows, not on > edebug-save-displayed-buffer-points, and since edebug-save-windows is > t by default, why wasn't I able to reproduce the problem? I've stumbled across a possible reason why you couldn't reproduce the bug. There was a crucial step missing from the recipe. I've inserted that step into the previous recipe as (iv)a: 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. (iv)a Put point into window *scratch*. (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. There are bits of code that don't restore buffer-point in the current buffer. One of these is probably the explanation why the bug doesn't trigger with point starting in emacs.README. -- Alan Mackenzie (Nuremberg, Germany).