[HarfBuzz] Multiple substitution and mark positioning

[Behdad Esfahbod]

On 07/25/2012 06:14 PM, Jonathan Kew wrote:
> On 25/7/12 22:13, Khaled Hosny wrote:
>> This only applies to the marks that result of multiple substitution i.e.
>> in Amiri the middle lam of لله is substituted with
>> <lam><shadda><smallalef>, I don’t think Arabic Typesetting has something
>> like that.
>>
> 
> Just wondering (without checking the code yet...) - is it possible that we're
> failing to set the glyph category from GDEF properly for marks that are
> inserted by GSUB rules like this, and as a result the GPOS lookups don't match
> as expected?

No, I think I know where the problem is.  It's somewhere in the lig_id /
lig_comp matching code...  Lemme see.

b