CVS GNU Emacs change in font lock behaviour

["Paul Moore" <p.f.moore@gmail.com>]

I just upgraded to CVS GNU Emacs, and I'm getting a change in the way
the *scratch* buffer displays fontified text with font-lock mode
switched on.

If I executed (insert (propertize "abc" 'face 'my-red-face)) in the
*scratch* buffer with my old Emacs (CVS from some time way back in
2004), the text was inserted and displayed in red. With the new
version, the face property is lost.

I assume this is related to font-lock mode being switched on, as
switching it off fixes the problem (at the expense of losing syntax
highlighting on the Lisp code, obviously...)

The old behaviour was extremely useful for testing fontification code,
and it's a pain that it has gone. But I can learn to work with the new
behaviour if I need to.

Is this a deliberate change, rather than a bug?

Thanks,
Paul.