Rendering of U+0653 ARABIC MADDAH ABOVE

Wondering if anyone knows (or has an educated guess):

When an Arabic combining character sequence includes both

  * U+0653 ARABIC MADDAH ABOVE and
  * an Arabic vowel mark above (e.g., U+064E ARABIC FATHA or maybe
    U+065A ARABIC VOWEL SIGN SMALL V ABOVE),

should the maddah be rendered above the vowel, or the vowel above the
maddah?

(Combining class doesn't help -- or at least is notoriously misleading
as far as correct rendering of Arabic -- so I'm not trusting it to
provide the correct answer here, either).

Thanks for any help you can provide.

Bob
Received on Wed Jul 20 2011 - 14:45:18 CDT