[luatex] LuaLaTeX / fontspec bug

[Khaled Hosny]

On Fri, Nov 18, 2011 at 12:42:25PM -0500, amphiboly at gmail.com wrote:
> I submitted the following to the Libertine bugtracker on Sourceforge a while
> back as
> 
> Biolinum LuaLaTeX fontspec matchlowercase problem - ID: 3434775
> 
> and Michael Niedermair there just responded to me that it is a fontspec
> problem. Note that the problem occurs with fontspec under LuaLaTeX, but not
> under XeLaTeX.
> 
> Using C:/Program Files (x86)/MiKTeX 2.9/fonts/opentype/public/libertine/
> fxbr.otf (version 1.0.4).
> 
> The following gives oversized sf text. replacing line 4 with line 5 gives a
> proper result, as does removing both lines 4 and 5 (I need to have fontspec
> manage the font so that I can use fontspec's addfontfeature for letterspacing).
> This is not a problem if Libertine is specified as the sans font (for testing)
> or is XeLaTeX is used instead of LuaLaTeX.
> 
> \documentclass{article}
> \usepackage{fontspec}
> \usepackage{libertine}
> \setsansfont[Scale=MatchLowercase]{fxbr.otf}
> %\setsansfont[Scale=MatchUppercase]{fxbr.otf}
> \begin{document}
> Testing, {\sffamily testing}, {\rmfamily testing}.
> \end{document}
> 
> Can you confirm that this is, indeed, a fontspec under LuaLaTeX issue? If so,
> is there a resolution?

Most likely there is is a bug in the calculation of x and cap height as
fontspec does it by its own under luatex (and the code is very crude; I
wrote it :p). I'll try to have a look.

Regards,
 Khaled