[XeTeX] Very nasty bug with accented greek capitals in some fonts (TL 2010)

[Nikos Platis]

Consider the following minimal file:

-----------
\documentclass[a4paper,10pt]{article}
\usepackage{fontspec}
\setmainfont{Candara}
\begin{document}
ά Ά έ Έ ή Ή ί Ί ϊ Ϊ ΐ ό Ό ύ Ύ ϋ Ϋ ΰ ώ Ώ
\end{document}
-----------

Using a fully updated TL2010 it produces the following, obviously wrong, output:

ά Α έ Ε ή Η ί Ι ϊ Ϊ Ϊ ό Ο ύ Υ ϋ Ϋ Ϋ ώ Ω

It can be observed that all accented capitals come out unaccented, and
the lower-case letters with accent and diairesis come out as capitals
with diairesis (!)

This seems to happen will the "new" Microsoft OpenType fonts
(Constantia, Corbel, etc.) but not with several other fonts that I
tested (Arial, Liberation, Droid). Under TL2009 everything works OK.


Nikos Platis