Wrong common substring highlighted in Completion buffer

[Juri Linkov <juri@jurta.org>]

After typing `C-h f read-mini C-b C-b C-b C-b TAB' wrong common
substrings are highlighted in the *Completions* buffer.  The
substring "read-mini" is highlighted, but really completion is
performed on the substring "read-" before point in the minibuffer.

The function returning the right minibuffer substring is
minibuffer_completion_contents.  I believe the following patch
is correct.

Index: src/minibuf.c
===================================================================
RCS file: /cvsroot/emacs/emacs/src/minibuf.c,v
retrieving revision 1.294
diff -c -r1.294 minibuf.c
*** src/minibuf.c	6 Dec 2005 15:53:58 -0000	1.294
--- src/minibuf.c	10 Dec 2005 10:10:42 -0000
***************
*** 2563,2569 ****
  display_completion_list_1 (list)
       Lisp_Object list;
  {
!   return Fdisplay_completion_list (list, Qnil);
  }
  
  DEFUN ("minibuffer-completion-help", Fminibuffer_completion_help, Sminibuffer_completion_help,
--- 2565,2571 ----
  display_completion_list_1 (list)
       Lisp_Object list;
  {
!   return Fdisplay_completion_list (list, minibuffer_completion_contents ());
  }
  
  DEFUN ("minibuffer-completion-help", Fminibuffer_completion_help, Sminibuffer_completion_help,

-- 
Juri Linkov
http://www.jurta.org/emacs/