isearch-forward-regexp and isearch-backward-regexp return differing search results

[Dieter Wilhelm]

emacs -D -Q

please insert something in the line of

hans ooffoo ooffoo ooffoo hans
hans ooffoo ooffoo ooffoo hans

and do a "C-M-r" search for "o.*o", repeat possibly the search and
change to "C-M-s".  You will see that the search results are very
different.  Some days ago I asked on gnu.emacs.help whether there is a
reason for this behaviour.  I think one would expect the same search
results in forward and backward direction.




In GNU Emacs 22.0.92.1 (i686-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2006-12-22 on hans
X server distributor `The X.Org Foundation', version 11.0.60802000
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.UTF-8
  locale-coding-system: utf-8
  default-enable-multibyte-characters: t

Major mode: Group

Minor modes in effect:
  display-time-mode: t
  gnus-topic-mode: t
  gnus-undo-mode: t
  shell-dirtrack-mode: t
  auto-insert-mode: t
  show-paren-mode: t
  minibuffer-indicate-depth-mode: t
  delete-selection-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  unify-8859-on-encoding-mode: t
  utf-translate-cjk-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t
  abbrev-mode: t

Recent input:
<up> <up> <up> <up> <up> <up> <up> <up> <up> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <down> M-> n n n C-M-k 
SPC n SPC SPC SPC < SPC SPC SPC q g M-< n <return> 
C-n C-n C-n C-n <return> E q L C-n C-n C-n <return> 
M-> C-p C-p <return> q n n <return> <down> <down> C-M-k 
q M-< n n n <return> q M-x e m a c s - b u <tab> <M-backspace> 
<M-backspace> b u g <tab> <M-backspace> r e p <tab> 
o <tab> r <tab> b <tab> <return>

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-- 
    Best wishes

    H. Dieter Wilhelm
    Darmstadt, Germany