[HarfBuzz] Better handling variation selectors

[Martin Hosken]

On Thu, 06 Jun 2013 18:00:21 -0400
Behdad Esfahbod <behdad at behdad.org> wrote:

> On 13-04-20 05:49 AM, Jonathan Kew wrote:
> > 
> > The remaining question is what to do about a VS that was part of a valid
> > sequence, but the font being used didn't handle it.
> 
> So, apparently Mongolian fonts in the wild implement the Mongolian Variation
> Selectors using GSUB, not cmap. [1]
> 
> So, we either need to keep the "unused" variation selectors in the glyph
> stream, or remove the Mongolian ones from the cmap processing.

Or can we do it based on the presence of the format 14 cmap subtable? If it's present then use it else assume GSUB will handle it.

GB,
Martin