[XeTeX] Diacritics in color

[Aleksandr Andreev]

Heiko Oberdiek writes:

>> * LuaTeX: "A" + U+0308 gets combined to one glyph U+00C4, the color attribute of the diaeresis vanishes and the result is black (3).

On my machine, in LuaTeX (3) results in a correctly positioned *red*
diaeresis over a black A. (4) results in a red diaeresis with
incorrect positioning, both vertical and horizontal. I'm running
Ubuntu 11.10 and TexLive 2011.

>> XeTeX: The color special prevents the glyph recombination and U+0308 is processed separately without knowing the base character (3 and 4)

Yes, I can confirm this also.

>> Thus the workaround would be to prevent the recombination and to fix the placement manually.

Would it be possible to read the positioning data out of GPOS in order
to do this manual placement? It could then be handled by a macro.

Aleks