[XeTeX] Superscript in Linux Libertine

[Till Rettig]

Hi,

I tried recently to set a document with Linux Libertine (O) that should 
have old style numbers. Apparently this caused the use of normal old 
style numbers also for superscript numbers (e.g. for footnotes). It 
doesn't happen when the old style numbers aren't selected. Fonts like 
Minion Pro don't show this behaviour. Is it a bug of the font (like a 
missing mapping of otf superscript to normal superscript) or a 
missbehaviour of xetex? And is there something I can do about it?

Greetings
Till

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\documentclass{scrartcl}
\usepackage{fontspec,xunicode,xltxtra}

\setmainfont[Numbers=OldStyle,Mapping=tex-text]{Linux Libertine O}
%\setmainfont{Linux Libertine O}
%This is also true for Linux Libertine, the ttf version.
\begin{document}
The number of the footnote\footnote{Test.} ist normal old style number, not
the superscript\footnote{Test2.} that should be used.

\end{document}
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