[HarfBuzz] A problem in thai shaper

[Khaled Hosny]

On Tue, Apr 24, 2012 at 03:43:44PM -0400, Behdad Esfahbod wrote:
> On 04/18/2012 02:16 AM, Jonathan Kew wrote:
> 
> >> Interesting.  I'm undecided about this as of now.
> > 
> > Just adding my vote in favor of Khaled's position.
> 
> Ok, looks like we have consensus here.  I'll implement it! (ie. do nothing :-D)
> 
> I do want to point out that if I type two Fatha's on the same base character
> in Arabic, I wouldn't mind the renderer bringing it to my attention by putting
> the second one on a circle.  But this is certianly an authoring issue, not
> rendering.

Pre Unicode 6.1, two consecutive Fatha’s (or Damma, or Kasra) was the
only way to represent the Quraʾnic successive Tanwin U+08F0-08F2, and it
worked universally (given proper font support) except with Uniscribe.

In short, there can always be legitimate uses of what seems like invalid
input and thus it is not rendering engine’s job to enforce it.

Regards,
 Khaled