bug#1123: 23.0.60; delete-minibuffer-contents does not delete all input

[Drew Adams]

emacs -Q
 
(defun foo ()
  (interactive)
  (delete-minibuffer-contents))
 
(define-key minibuffer-local-map "\M-k" 'foo)
 
In directory c:/foo, say, do C-x C-f. You see:
 
Find file: c:/foo/
 
Type c:/bar, so you see:
Find file: c:/foo/c:/bar, with c:/foo/ greyed out.
 
M-k should erase the entire user input, leaving you with just
Find file: 
 
But it erases only the last part, leaving you with:
Find file: c:/foo/
 
This contradicts the doc string, which says:
 
 "Delete all user input in a minibuffer."
 

In GNU Emacs 23.0.60.1 (i386-mingw-nt5.1.2600)
 of 2008-10-03 on LENNART-69DE564
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (3.4) --no-opt --cflags -Ic:/g/include
-fno-crossjumping'