bug#229: 23.0.60; Weird X11 input-related hang

bug#229: 23.0.60; Weird X11 input-related hang

[corbet]

For quite some time I have seen a strange bug where emacs (running under
X11) would occasionally stop responding to keyboard and mouse events.  The
editor is still alive, and will change the cursor block in response to
focus events, but mouse clicks and keystrokes have no effect.  The only way
I've found to recover is to kill the emacs process and start over.

Today I figured out how to reproduce it: move the pointer to the menubar at
the top of the window, then move the scroll wheel for a click or two.
Works every time.  Does not appear to be dependent on major mode.

This happens with stock emacs as shipped by Fedora and my own pretest
builds too.


In GNU Emacs 23.0.60.1 (x86_64-unknown-linux-gnu, GTK+ Version 2.12.0)
 of 2007-12-15 on vena
Windowing system distributor `The X.Org Foundation', version 11.0.10499901
configured using `configure  '--with-gtk' '--enable-font-backend' '--with-xft' '--with-gif=no''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default-enable-multibyte-characters: t

Major mode: MH-Folder

Minor modes in effect:
  hl-line-mode: t
  display-time-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  global-auto-composition-mode: t
  auto-composition-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
<help-echo> i d M-x r e p o r t - b u g <return> <backspace> 
<backspace> <backspace> e m a c s - b u g <return>

Recent messages:
nmh 1.2 installed as MH variant
Loading /home/corbet/emacs/lwn.el (source)...done
For information about GNU Emacs and the GNU system, type C-h C-a.
Scanning +inbox...done
Threading +inbox...done
inc +inbox...done
No more undeleted messages

bug#229: 23.0.60; Weird X11 input-related hang

[Chong Yidong]

corbet@lwn.net wrote:

> For quite some time I have seen a strange bug where emacs (running
> under X11) would occasionally stop responding to keyboard and mouse
> events.  The editor is still alive, and will change the cursor block
> in response to focus events, but mouse clicks and keystrokes have no
> effect.  The only way I've found to recover is to kill the emacs
> process and start over.
>
> Today I figured out how to reproduce it: move the pointer to the
> menubar at the top of the window, then move the scroll wheel for a
> click or two.  Works every time.  Does not appear to be dependent on
> major mode.
>
> This happens with stock emacs as shipped by Fedora and my own pretest
> builds too.
>
> In GNU Emacs 23.0.60.1 (x86_64-unknown-linux-gnu, GTK+ Version 2.12.0)
> of 2007-12-15 on vena

I can't reproduce this on 23.0.60.50 (i686-pc-linux-gnu, GTK+ Version
2.12.9).

Can anyone on the list reproduce this problem?

bug#229: 23.0.60; Weird X11 input-related hang

[George White]

On Tue, 13 May 2008, Chong Yidong wrote:

> corbet@lwn.net wrote:
>
>> For quite some time I have seen a strange bug where emacs (running
>> under X11) would occasionally stop responding to keyboard and mouse
>> events.  The editor is still alive, and will change the cursor block
>> in response to focus events, but mouse clicks and keystrokes have no
>> effect.  The only way I've found to recover is to kill the emacs
>> process and start over.
>>
>> Today I figured out how to reproduce it: move the pointer to the
>> menubar at the top of the window, then move the scroll wheel for a
>> click or two.  Works every time.  Does not appear to be dependent on
>> major mode.
>>
>> This happens with stock emacs as shipped by Fedora and my own pretest
>> builds too.
>>
>> In GNU Emacs 23.0.60.1 (x86_64-unknown-linux-gnu, GTK+ Version 2.12.0)
>> of 2007-12-15 on vena
>
> I can't reproduce this on 23.0.60.50 (i686-pc-linux-gnu, GTK+ Version
> 2.12.9).
>
> Can anyone on the list reproduce this problem?

Yes and no.  Emacs appears "hung", but clicking on a menu releases it.
I assume that moving the scroll wheel "activate" the menus, and Emacs
is just waiting for further instructions.  Changing focus to another
window seems to work as well.  I'm using:

23.0.60.1 (i686-redhat-linux-gnu, GTK+ Version 2.12.8)

--
George White <aa056@chebucto.ns.ca> <gnw3@acm.org>
189 Parklea Dr., Head of St. Margarets Bay, Nova Scotia  B3Z 2G6