bug#12054: 24.1; regression? font-lock no-break-space with nil nobreak-char-display

[Drew Adams]

emacs -Q
 
(defface foo '((t (:background "Yellow"))) "" :group 'faces)

(setq nobreak-char-display nil)

(font-lock-add-keywords nil '(("[\240]+" (0 'foo t))) 'APPEND)
 
Insert a no-break space:
C-x 8 RET no-break-space (or C-q 240 RET)
 
Turn font-lock-mode off, then back on.
 
With point before the no-break-space, C-u C-x =.  That shows that the
character is indeed a no-break-space, and there is no face on it.
 
In Emacs 22, the char is shown clearly in face foo.  Am I missing
something?
 
The same recipe with non-breaking-hyphen highlights that character fine.
What is different about no-break-space?  Shouldn't it be treated
similarly?  This works in Emacs 22 but stops working in Emacs 23.
Normal?  Regression?

In GNU Emacs 24.1.1 (i386-mingw-nt5.1.2600)
 of 2012-06-10 on MARVIN
Windowing system distributor `Microsoft Corp.', version 5.1.2600
Configured using:
 `configure --with-gcc (4.6) --cflags
 -ID:/devel/emacs/libs/libXpm-3.5.8/include
 -ID:/devel/emacs/libs/libXpm-3.5.8/src
 -ID:/devel/emacs/libs/libpng-dev_1.4.3-1/include
 -ID:/devel/emacs/libs/zlib-dev_1.2.5-2/include
 -ID:/devel/emacs/libs/giflib-4.1.4-1/include
 -ID:/devel/emacs/libs/jpeg-6b-4/include
 -ID:/devel/emacs/libs/tiff-3.8.2-1/include
 -ID:/devel/emacs/libs/gnutls-3.0.9/include'