[O] How to font-lock diffs?

[Marcin Borkowski]

Hi all,

I hoped this:

#+begin_src diff
  @@ -1,5 +1,5 @@
  -lorem
  +Lorem
   ipsum
   dolor
   sit
  -amet
  +amet.
#+end_src

would Just Work™, i.e., the diff would be font-locked like in
diff-mode.  Well, it is not.  How do I convince Org-mode to color my
diffs?

Best,

-- 
Marcin Borkowski
http://mbork.pl