# Strange behavior of XITS Math in XeLaTeX for \underset and \underaccent commands

Prompted in part by the question Is there an "underscript" command?, I started wondering if the \underset (from amsmath) and \underaccent (from accents) commands work equally when using XeLaTeX instead of pdflatex. The following code and associated output show that this is not the case for the XITS Math package:

\documentclass{standalone}
\usepackage{amsmath,accents}
\usepackage[no-math]{fontspec}
\usepackage{unicode-math}
\setmathfont[version=cambria]{Cambria Math}
\setmathfont[version=lm]{Latin Modern Math}
\setmathfont[version=asana]{Asana Math}
\setmathfont[version=xits]{XITS Math}
\newcommand\undersetunderaccent{$\underset{x}{A} \ \underaccent{x}{A}$}
\begin{document}\Huge

\noindent
\mathversion{lm}Latin Modern Math:       \undersetunderaccent\\
\mathversion{cambria} Cambria Math:      \undersetunderaccent\\
\mathversion{asana}   Asana Math:        \undersetunderaccent\\
\mathversion{xits}    XITS Math:         \undersetunderaccent
\end{document}


Clearly, the output of the two commands is rather different [!] when "XITS Math" is the math font. Does the XITS Math package have to be loaded with special options to suppress this behavior, or should I plan on sending a bug report to the maintainers of the XITS Math font and/or the maintainers of the unicode-math package?

Addenda: (i) I can generate the output above using both TeXLive 2011 and MiKTeX 2.9 (both updated yesterday); the OS is Windows Vista; all math fonts on my system are the latest ones available. (ii) The problems with "XITS Math" do not arise if I run the example code above under luatlatex instead of under xelatex.

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This doesn't happen for me. Which versions are you using? – Caramdir Nov 16 '11 at 19:17
The same thing happens for me, except that it is the Asana version that is the problem, and I get a z over a w. Works fine with lualatex though. – Torbjørn T. Nov 16 '11 at 19:25
@TorbjørnT. and Caramdir: I've provided an addendum to my question in which I provide more details on the TeX distributions and the OS in question. I also report that the problem does not arise when compiling the code under lualatex. – Mico Nov 16 '11 at 20:02
Make sure you don't have a two different versions of xits font accessible to xetex, this is likely to be the case. – Khaled Hosny Nov 16 '11 at 20:13

You can use \XeTeXtracingfonts=1 in your document, and compile it with xelatex --output-driver="xdvipdfmx -vv" file.tex to see which fonts are loaded by the engine and driver.