From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#7496: 23.2; copy recursive keymap cause crash Date: Sun, 13 Oct 2019 09:58:20 +0300 Message-ID: <83zhi5ku7n.fsf@gnu.org> References: <871v67o9ns.fsf@nagi.lyrical.homelinux.net> <874l0dh2e2.fsf@gnus.org> Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="214272"; mail-complaints-to="usenet@blaine.gmane.org" Cc: ari@mbf.ocn.ne.jp, monnier@iro.umontreal.ca, 7496@debbugs.gnu.org To: Lars Ingebrigtsen Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Sun Oct 13 08:59:11 2019 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iJXqQ-000te1-J5 for geb-bug-gnu-emacs@m.gmane.org; Sun, 13 Oct 2019 08:59:10 +0200 Original-Received: from localhost ([::1]:37940 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iJXqP-0004Kb-FB for geb-bug-gnu-emacs@m.gmane.org; Sun, 13 Oct 2019 02:59:09 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:43999) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iJXqJ-0004KP-Dp for bug-gnu-emacs@gnu.org; Sun, 13 Oct 2019 02:59:04 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iJXqI-0005UD-Dw for bug-gnu-emacs@gnu.org; Sun, 13 Oct 2019 02:59:03 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:54240) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1iJXqI-0005U5-BE for bug-gnu-emacs@gnu.org; Sun, 13 Oct 2019 02:59:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1iJXqI-0001pB-92 for bug-gnu-emacs@gnu.org; Sun, 13 Oct 2019 02:59:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sun, 13 Oct 2019 06:59:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 7496 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: fixed Original-Received: via spool by 7496-submit@debbugs.gnu.org id=B7496.15709499176982 (code B ref 7496); Sun, 13 Oct 2019 06:59:02 +0000 Original-Received: (at 7496) by debbugs.gnu.org; 13 Oct 2019 06:58:37 +0000 Original-Received: from localhost ([127.0.0.1]:34828 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1iJXps-0001oY-Nm for submit@debbugs.gnu.org; Sun, 13 Oct 2019 02:58:37 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:34891) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1iJXpq-0001oJ-Tr for 7496@debbugs.gnu.org; Sun, 13 Oct 2019 02:58:35 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:54536) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1iJXpk-0005BW-AA; Sun, 13 Oct 2019 02:58:28 -0400 Original-Received: from [176.228.60.248] (port=1260 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1iJXpj-00052U-5j; Sun, 13 Oct 2019 02:58:28 -0400 In-reply-to: <874l0dh2e2.fsf@gnus.org> (message from Lars Ingebrigtsen on Sun, 13 Oct 2019 03:15:17 +0200) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.51.188.43 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.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.org gmane.emacs.bugs:169103 Archived-At: > From: Lars Ingebrigtsen > Date: Sun, 13 Oct 2019 03:15:17 +0200 > Cc: ARISAWA Akihiro , 7496@debbugs.gnu.org > > >> (let ((map (make-sparse-keymap))) > >> (define-key map " " map) > >> (copy-keymap map)) > > > > I'm not surprised. There are many ways to address it: > > - try and make sure we better handle the "using up all memory" case > > rather than crashing. This is very difficult. We already try to do > > it, but clearly it's not working that well. > > - try and detect such cycles and either signal an error or reproduce the > > same cycle in the copy. We have added such things in several other > > cases, so we should probably do that. > > While this is a pretty obscure, Emacs shouldn't crash on stuff like > this. I first considered whether just to check for EQ in Fcopy_keymap, > but it's possible to have nested keymaps that are mutually recursive, > so that won't work. > > So I just added a recursion counter and refuse to copy when we've > reached level 100. What happens in the current master without that limitation? We have since added stack overflow protection -- doesn't it kick in in this case?