[HarfBuzz] Sinhala split matra

[Behdad Esfahbod]

I'll reiterate the HarfBuzz development philosophy and what happened about
this Sinhala issue. =

As far as I'm concerned, when I say, on behalf of HarfBuzz, that "we don't
support X", what I mean is: "we currently don't support X, and we currently
don't plan to support X, but we may do in the future."  And I think that's
quite representative of most Free Software / Open Source projects.  I don't
think we need to explain why we changed designs.  We did, because we found it
more suitable for our users.

Now to the specific issue at hand: From what I understand, in the
August/September release of HarfBuzz, we broke some fonts that used to work
with old HarfBuzz / Pango.  Those fonts were NOT working correctly with
Uniscribe.  Back then, we decided that we only want to support the
Uniscribe-correct fonts.  Now, in November 2012, based on various input
(Firefox, Chrome Linux, GNOME), we decided that we want to support both
categories of fonts: those that work fine with Uniscribe, and those that used
to work with old HarfBuzz / Pango.  I don't see how that can be a limitation
to a user.  As such, I have no interest in arguing about how that decision was
made, and I don't think it's relevant to any user of HarfBuzz.  If you have a
font that is not addressed correctly with HarfBuzz as is, let us know and we
will try to accommodate that.

behdad