[XeTeX] Fonts without proper combining diacritic placement

[Khaled Hosny]

On Fri, May 31, 2013 at 06:21:33PM +0200, BPJ wrote:
> Did Khaled post a while back that recent versions will center
> (and rise/lower?) combining diacritics based on calculations
> of the base character's bounding box if the font lacks proper
> instructions, or did I dream that?

Yes, if the font does not have a GPOS table, but if it has one (even if
only for, say, kerning), the automatism will not be used.

Regards,
Khaled