[HarfBuzz] The canonical ordering of hamza marks

[Khaled Hosny]

On Mon, Aug 27, 2012 at 01:15:10AM +0200, Khaled Hosny wrote:
> Hi Behdad,
> 
> I just noticed that hamza above and below marks (U+0654, U+0655), are
> reordered after Arabic vowel marks because they have much higher
> combining classes, 230 and 222 (the "generic" combining class above and

220 not 222, sorry.

> below, respectively), which breaks mkmk positioning.
> 
> I tried to make a patch to handle them like the shadda, but I'm not sure
> how safe it is with such generic combining classes.
> 
> Regards,
>  Khaled