Re: [ft] Large delta_y for hinted vs unhinted "COMBINING CARON BELOW" glyph

[Werner LEMBERG]

> I've copy/pasted the ttx below. Looking at uni032C, uni032D (my
> problematic glyph indexes 733 and 734), I see that these (composite)
> glyphs have hinting instructions.  The others in that list do not.
> It could be a bug in the font, and that freetype is working as
> intended in that the ALIGNRP instruction is causing the large
> delta_y.  Or it still could be a bug in freetype if, for some
> reason, some graphics / hinting state is incorrect by the time the
> ALIGNRP is executed.

It's a bug in the interpreter, as far as I can see.  I think it
wrongly sets the phantom points for composite glyphs.  This glyph is
the first time ever I've seen an alignment on a vertical phantom
point; this might be the reason that the problem hasn't been
discovered earlier.

However, documentation regarding this issue is completely missing in
the OpenType specification, so I wait for an answer from MS for
clarification (their font team is very helpful).


    Werner