Menu bar display bug

[Stephen Berman]

1. Emacs -Q

2. Txpe `M-x gnus', select a group, open it and click on an article,
so that you have vertically split windows, with the Gnus Summary
buffer on top and the Gnus Article buffer on the bottom.  (To get to
this stage, it is irrelevant whether or not you set
gnus-select-method, if not, it also suffices to open a doc-group,
e.g. `G f emacs/etc/gnus-tut.txt'.)

3. Make a header line in the window of the Gnus Summary buffer,
e.g. by doing `M-x ruler-mode' (other header lines will also do,
e.g. `M-: (setq header-line-format default-mode-line-format)').  Then
do 'C-x o' to switch to the Gnus Article buffer and then make a header
line in that window.  Now when you do `C-x o' to switch back to the
Summary buffer you should see the following (I turned off the tool bar
to make smaller pictures for this report, but I also get the same
display bug when it is enabled):

4. If you leave Emacs alone for about a minute, the menu bar changes
to the following:

5. If you wait about another minute, the spurious Help menu
disappears, leaving the usual menu bar for gnus-summary-mode.

3'. If after step 3 you click on the Agent menu, the mouse pointer
changes to the shape seen when you can drag a mode line, i.e.:
 ^
-+-
 v
and both Emacs windows freeze, responding to neither mouse nor
keyboard.  However, you can click on the menu bar, and this unfreezes
the windows and also restores the normal menu bar.  If instead of
clicking on the Agent menu you click on the Help menu, the menu bar
changes briefly to the second picture above, then switches to its
normal appearance.

I have only been able to reproduce this bug using the above window
configuration with Gnus Summary and Article buffers.  I note that the
menu bar in gnus-summary-mode has a lot of menus; maybe the bug is
related to that (I couldn't find another mode with as many menus in
the menu bar), though again, there's no display bug if the other
window is not the Gnus Article buffer.  The reason I added header
lines, which is necessary to see the bug, is because I originally
observed it with tabbar-mode enabled (from David Ponce's package
tabbar.el), which adds a header line of buffer tabs to each window.


In GNU Emacs 22.0.96.5 (i686-pc-linux-gnu, GTK+ Version 2.10.6)
 of 2007-03-27 on escher
Windowing system distributor `The X.Org Foundation', version 11.0.70199902
configured using `configure  '--with-x-toolkit=gtk''

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
  locale-coding-system: utf-8
  default-enable-multibyte-characters: t

Major mode: Article

Minor modes in effect:
  tooltip-mode: t
  tool-bar-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  unify-8859-on-encoding-mode: t
  utf-translate-cjk-mode: t
  auto-compression-mode: t
  line-number-mode: t

Recent input:
C-b C-x o C-x 1 C-x 2 C-x b C-g C-h i C-x o C-x o C-x 
o M-x a l l o u <tab> m <tab> o <tab> <return> C-x 
o C-x o C-x o C-x o C-x o C-x o C-x o C-x o <return> 
<f1> C-g C-x 1 <return> q <return> <return> C-x o C-x 
o M-: <up> <return> C-x o C-x o C-x o C-x o C-x o C-x 
o C-x o C-x o Q y <return> <return> M-: <up> <return> 
C-x o C-x o C-x o C-x o C-x o C-x o C-x o C-x o C-x 
o C-x o C-h v C-g C-x C-x i C-x k <return> SPC <help-echo> 
<help-echo> <down-mouse-1> <mouse-1> <help-echo> <down-mouse-1> 
<mouse-movement> <mouse-1> <help-echo> <down-mouse-1> 
<mouse-1> <help-echo> <down-mouse-1> <mouse-1> <help-echo> 
<down-mouse-1> <mouse-1> C-h v m o u <tab> a u <tab> 
<return> <help-echo> <down-mouse-5> <mouse-5> <help-echo> 
<down-mouse-1> <mouse-2> <help-echo> <help-echo> <down-mouse-1> 
<help-echo> <help-echo> <help-echo> <help-echo> <down-mouse-1> 
<mouse-1> <help-echo> <select-window> <help-echo> <select-window> 
<select-window> <help-echo> <select-window> <select-window> 
<help-echo> <select-window> <select-window> <help-echo> 
<select-window> <down-mouse-1> <mouse-1> h <select-window> 
<select-window> <help-echo> <select-window> <select-window> 
<help-echo> <select-window> <select-window> <help-echo> 
<select-window> <select-window> <help-echo> <select-window> 
<select-window> <help-echo> <select-window> <select-window> 
<help-echo> <select-window> <select-window> <help-echo> 
Q y <return> <return> <help-echo> <select-window> <select-window> 
<select-window> <select-window> <help-echo> <select-window> 
<select-window> <help-echo> <select-window> <select-window> 
<help-echo> <select-window> <select-window> <help-echo> 
<select-window> <select-window> <help-echo> <select-window> 
<select-window> <help-echo> <select-window> <select-window> 
<help-echo> <select-window> <select-window> <help-echo> 
<select-window> <select-window> <help-echo> C-x 1 C-x 
C-g C-h i C-x b <return> h <help-echo> <select-window> 
<help-echo> <select-window> <select-window> <help-echo> 
<select-window> <select-window> <help-echo> <select-window> 
<select-window> <help-echo> <help-echo> <select-window> 
<select-window> <help-echo> <select-window> <select-window> 
<help-echo> <select-window> <select-window> <help-echo> 
<select-window> <select-window> <help-echo> <select-window> 
<select-window> <help-echo> <select-window> <select-window> 
<help-echo> <select-window> <select-window> <help-echo> 
<select-window> <select-window> <select-window> <select-window> 
<help-echo> C-x o C-x o C-x o C-x o <help-echo> <select-window> 
<select-window> <select-window> <help-echo> <down-mouse-1> 
<mouse-1> M-x r e p o r <tab> <return>

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