Display engine completely thrown off in connection with images.

[David Kastrup]

This bug report will be sent to the Free Software Foundation,
not to your local site managers!
Please write in English if possible, because the Emacs maintainers
usually do not have translators to read other languages for them.

Your bug report will be posted to the address@hidden mailing list.

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

It would be pretty hard to construct a stand-alone test case, but
maybe somebody reading this report has access to preview-latex.

Open the file circ.tex in the preview-latex distribution.  Generate
previews with C-c C-p C-d.  Run the cursor through some previews by
using cursor right/cursor left.  This adjusts cursor positions from
within post-command-hook.  Also images will get turned active and
inactive within post-command-hook.

The effects are too horrible to describe.  The cursor gets
reduplicated at other screen locations, screen updates stop
completely, C-l triggers an "out of range" error, the mode line gets
overdrawn and so on and so on.

In short: really bad things happen.  A lot.  It looks like the data
structures get lopsided.

In GNU Emacs 21.3.50.25 (i686-pc-linux-gnu, GTK+ Version 2.2.1)
 of 2004-04-29 on lola.goethe.zz
configured using `configure '--prefix=/usr/local/emacs-21' '--with-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
  locale-coding-system: iso-latin-1
  default-enable-multibyte-characters: t

Major mode: LaTeX

Minor modes in effect:
  reftex-mode: t
  auto-compression-mode: t
  desktop-save-mode: t
  display-time-mode: t
  iswitchb-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  unify-8859-on-encoding-mode: t
  line-number-mode: t

Recent input:
C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k 
C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k 
C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k 
C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k C-k 
C-k C-k C-k C-k C-k C-k C-k C-SPC <up> <up> <up> <up> 
<up> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up> 
<up> <up> <up> <up> C-w C-x k <return> y e s <return> 
M-x r e p o r t - e m a <tab> <return>

Recent messages:
Scanning `tex-site.el'
Scanning `subr.el'
Expansion found in 'subr.el'
Scanning `subr.el' [2 times]
Scanning `prv-emacs.el'
Expansion found in 'prv-emacs.el'
Auto-saving...done
Buffer *mail* has shrunk a lot; auto save disabled in that buffer until next 
real save
Mark set
Loading emacsbug...done

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum