GNU bug report logs - #7496
23.2; copy recursive keymap cause crash

Previous Next

Package: emacs;

Reported by: ARISAWA Akihiro <ari <at> mbf.ocn.ne.jp>

Date: Sat, 27 Nov 2010 01:04:02 UTC

Severity: minor

Tags: fixed

Found in version 23.2

Fixed in version 27.1

Done: Lars Ingebrigtsen <larsi <at> gnus.org>

Bug is archived. No further changes may be made.

Full log

Message #8 received at 7496 <at> debbugs.gnu.org (full text, mbox):

From: Stefan Monnier <monnier <at> iro.umontreal.ca>
To: ARISAWA Akihiro <ari <at> mbf.ocn.ne.jp>
Cc: 7496 <at> debbugs.gnu.org
Subject: Re: bug#7496: 23.2; copy recursive keymap cause crash
Date: Fri, 26 Nov 2010 22:01:28 -0500

> When I call `copy-keymap' with a keymap which contains recursive binding,
> the emacs crashed.
> I can reproduce it by following sexp.

> (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.
- don't use cyclic keymaps and especially don't copy them.
- don't use copy-keymap, instead: inherit.


        Stefan
This bug report was last modified 5 years and 283 days ago.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.