incremental search and input method

[Olivier Lecarme]

When incrementally searching with no input method, everything works
well. As soon as I turn on the default input method by C-\ isearch no
longer works, with the following error message in the echo area:
isearch-process-search-multibyte-characters: Text is read-only

In GNU Emacs 22.0.95.1 (i686-pc-linux-gnu, GTK+ Version 2.8.20)
 of 2007-03-02 on pierredelune
X server distributor `AT&T Laboratories Cambridge', version 11.0.3332
configured using `configure  '--with-gtk' '--with-gif''

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: fr_FR
  locale-coding-system: iso-latin-1
  default-enable-multibyte-characters: t

Major mode: Fundamental

Minor modes in effect:
  shell-dirtrack-mode: t
  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:
<down-mouse-1> <mouse-1> C-s e n t e C-g C-\ C-s e 
n C-g <help-echo> <help-echo> C-x b * M e s s <tab> 
<return> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <menu-bar> 
<help-menu> <report-emacs-bug>

Recent messages:
Loading regexp-opt...done
Loading tex-mode...done
For information about the GNU Project and its goals, type C-h C-p.
Quit
Loading quail...done
Loading quail/latin-pre...done
Loading isearch-x...done
isearch-process-search-multibyte-characters: Text is read-only [2 times]
Quit
Loading emacsbug...done