bug#11480: 24.1.50; ediff command frame auto-shrinks to 1 column wide

[Keith Rautenbach]

emacs-snapshot -Q -eval "(set-variable 'mail-host-address \"ntlworld.com\")" 
--eval "(find-file \"file-A.txt\")" --eval "(find-file \"file-B.txt\")" --eval 
"(ediff-buffers \"file-A.txt\" \"file-B.txt\")"

The contents of the files do not seem to matter.
In this example the files were trivial:
   $ cat file-A.txt
   This is file A
   $ cat file-B.txt
   This is file A

I saw this problem with emacs 23.3.1 after upgrading to Ubuntu 12.04 and
then tested again with emacs-snapshot.

Typing ediff command '?' initially redraws the command frame at the
correct size and then auto-shrinks the width down to 1.

I am seeing the problem happen most (but not all) the time. Perhaps 95%.
I think that a particular run of emacs will either happen 100% or 0%.


In GNU Emacs 24.1.50.1 (i686-pc-linux-gnu, GTK+ Version 3.4.1)
 of 2012-05-10 on radium, modified by Debian
 (emacs-snapshot package, version 2:20120510-1~ppa1~precise1)
Windowing system distributor `The X.Org Foundation', version 11.0.11103000
Configured using:
 `configure '--build' 'i686-linux-gnu' '--host' 'i686-linux-gnu'
 '--prefix=/usr' '--sharedstatedir=/var/lib' '--libexecdir=/usr/lib'
 '--localstatedir=/var' '--infodir=/usr/share/info'
 '--mandir=/usr/share/man' '--with-pop=yes'
 
'--enable-locallisppath=/etc/emacs-snapshot:/etc/emacs:/usr/local/share/emacs/24.1.50/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/24.1.50/site-lisp:/usr/share/emacs/site-lisp'
 '--without-compress-info' '--with-crt-dir=/usr/lib/i386-linux-gnu/'
 '--with-x=yes' '--with-x-toolkit=gtk3' '--with-imagemagick=yes'
 'build_alias=i686-linux-gnu' 'host_alias=i686-linux-gnu'
 'CFLAGS=-DDEBIAN -DSITELOAD_PURESIZE_EXTRA=5000 -g -O2' 'LDFLAGS=-g
 -Wl,--as-needed -znocombreloc' 'CPPFLAGS=-D_FORTIFY_SOURCE=2''

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

Major mode: Text

Minor modes in effect:
  tooltip-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
<help-echo> <switch-frame> <down-mouse-1> <mouse-1> 
M-x r e p o r t <tab> <return>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Computing differences between file-A.txt and file-B.txt ...
Buffer A: Processing difference region 0 of 1
Buffer B: Processing difference region 0 of 1
Processing difference regions ... done

Load-path shadows:
/usr/share/emacs/24.1.50/site-lisp/debian-startup hides 
/usr/share/emacs/site-lisp/debian-startup
/usr/share/emacs/24.1.50/site-lisp/cmake-data/cmake-mode hides 
/usr/share/emacs/site-lisp/cmake-mode

Features:
(shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev
gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util
mail-prsvr mail-utils ediff-merg ediff-diff ediff-wind ediff-help
ediff-util ediff-mult ediff-init ediff cus-edit easymenu cus-start
cus-load wid-edit time-date tooltip ediff-hook vc-hooks lisp-float-type
mwheel x-win x-dnd tool-bar dnd fontset image regexp-opt fringe
tabulated-list newcomment lisp-mode register page menu-bar rfn-eshadow
timer select scroll-bar mouse jit-lock font-lock syntax facemenu
font-core frame cham georgian utf-8-lang misc-lang vietnamese tibetan
thai tai-viet lao korean japanese hebrew greek romanian slovak czech
european ethiopic indian cyrillic chinese case-table epa-hook
jka-cmpr-hook help simple abbrev minibuffer loaddefs button faces
cus-face files text-properties overlay sha1 md5 base64 format env
code-pages mule custom widget hashtable-print-readable backquote
make-network-process dbusbind dynamic-setting system-font-setting
font-render-setting move-toolbar gtk x-toolkit x multi-tty emacs)