completion in incremental search doesn't work

[Janusz S. Bień]

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

M-TAB (entered as M-C-i) shows the completion list, but doesn't
complete the search string.

In more details:

C-h C-n C-s P o l C-w C-s <return> <C-end> C-r R u 
C-w C-r <return> <C-home> C-s M-TAB

shows the list of Polish and Russian, but

P o M-TAB

results in `No completion' message.

In GNU Emacs 21.3.50.1 (i686-pc-linux-gnu, X toolkit)
 of 2003-04-17 on galicja
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: nil
  locale-coding-system: nil
  default-enable-multibyte-characters: t

Recent input:
C-h C-n C-s P o l C-w C-s <return> <C-end> C-r R u 
C-w C-r <return> <C-home> C-s M-TAB P o M-TAB <return> 
C-x 1 <help-echo> <help-echo> <help-echo> <help-echo> 
<menu-bar> <help-menu> <report-emacs-bug>

Recent messages:
Loading outline...done
Loading vc-cvs...done
View mode: type C-h for help, h for commands, q to quit.
Mark saved where search started
Mark set
Mark saved where search started
Mark set
Loading help-mode...done
Mark saved where search started
Loading emacsbug...done

-- 
                     ,   
dr hab. Janusz S. Bien, prof. UW
Prof. Janusz S. Bien, Warsaw Uniwersity
http://www.orient.uw.edu.pl/~jsbien/