\setmainfont{Linux Libertine O} uses pfb files instead of otf

Question

(This is sort of a follow-up to libertineotf and xelatex - bold smallcaps broken?, based on a problem that I had noticed earlier, but hadn't put my finger on.)

\documentclass{article}
\usepackage{fontspec}
    \setmainfont{Linux Libertine O}% 1
%   \setmainfont{LinLibertine_R_0.otf}% 2
%   \usepackage{libertineotf}% 3
\begin{document}
Foo bar. \textsc{Foo bar \textbf{baz!}}
\end{document}

Unexpectedly, this file doesn't use the otf Linux Libertine O files in C:\Windows\Fonts\, but the pfb files in my texmf tree (cf. log snippets below). I presume this is why the small caps don't work as described in Herbert's answer here, and also why doing any OpenType magic à la \addfontfeauture doesn't work either.

I'm not quite sure where the problem is coming from. Variant 2, which calls the otf font directly, runs, but doesn't use small caps; I assume that's because this font file is too specific for fontspec to automatically find the small caps font, so that I'd have to specify the file with the SmallCapsFont option manually. Variant 3 works pretty well, but as outlined in the question linked above, the calling of small caps is buggy there (and I want to solve the problem, not circumvent it).

As for background, I'm using MiKTeX 2.9, all up-to-date; and I have version 5.3 of the Linux Libertine fonts installed in C:\Windows\Fonts\ (independently from LaTeX, these are the ones I would've expected fontspec to use).

Some seemingly relevant bits from the log file (of variant 1):

Requested font "Linux Libertine O" at 10.0pt
 -> C:/Program Files (x86)/MiKTeX 2.9/fonts/type1/public/libertine/LinLibertine
O.pfb
Requested font "Linux Libertine O/ICU" at 10.0pt
 -> C:/Program Files (x86)/MiKTeX 2.9/fonts/type1/public/libertine/LinLibertine
O.pfb

[and a number of similar lines, but then:]

Requested font "Linux Libertine O/BI/ICU" at 10.0pt
 -> C:/Windows/Fonts/LinLibertine_RB.otf
Requested font "Linux Libertine O/BI/BI/ICU" at 10.0pt
 -> C:/Windows/Fonts/LinLibertine_RB.otf

I don't really have a specific question, other than: What's going on here, and how can I fix it?

Answer 1

For some reason XeTeX is finding the Type1 fonts first¹, you can tell FontConfig not to use Type1 fonts by blacklistling them by putting something like this in your local FontConfig configuration file (see How to make XeLaTeX recognize linked fonts with Windows? for more details).

<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
  <selectfont>
    <rejectfont>
      <glob>C:/Program Files (x86)/MiKTeX 2.9/fonts/type1/public/libertine/*</glob>
    </rejectfont>
  </selectfont>
</fontconfig>

You can even blacklist all Type1 fonts in TEXMF tree by using C:/Program Files (x86)/MiKTeX 2.9/fonts/type1/* instead.

¹ But not essentially using them for typesetting, fontspec loads the font first to collect some info about it, before loading it for “real”. To see the actual fonts that went into the PDF, try running xelatex with the option --output-driver="xdvipdfmx -v" to get some verbose output.

Update: This is more or less fixed now in XeTeX; TrueType/OpenType are given high priority over Type1, so it should be fixed in TeX Live 2013 (and the equivalent MiKTeX update).