TeX logo with LuaTeX and Linux Biolinum O/G

Question

Something is wrong with TeX and LaTeX logos with the font Linux Biolinum O under LuaTeX. I am using MiKTeX 2.9 on Windows. Here is a minimal working example:

\documentclass{minimal}

\usepackage{fontspec}
\newfontfamily\LinBioO{Linux Biolinum O}
\newfontfamily\LinBioG{Linux Biolinum G}

\begin{document}
{\LinBioO\LaTeX}\quad{\LinBioG\LaTeX}
\end{document}

With LuaTeX, I get

,

while with XɘTeX you get the correct result:

I did not really try other fonts, except Linux Libertine O and G, which both give a correct alignment of the ‘E’. Is the problem specific to the Linux Biolinum O font?

Answer 1

Though it is a bug in the font, with LuaTeX we can “patch” fonts on the fly, and here is a possible fix:

\directlua {
local function fix_biolinum_xheight(fontdata)
  if fontdata.fullname:find("Linux Biolinum") then
    if fontdata.characters[string.byte("x")] then
      fontdata.parameters.x_height = fontdata.characters[string.byte("x")].height
    end
  end
end

luatexbase.add_to_callback("luaotfload.patch_font", fix_biolinum_xheight, "mypatch.fix_biolinum_xheight")
}

Adding those lines just after loading fontspec should do the trick.