[XeTeX] bug using \underbrace with unicode-math package

[Will Robertson]

On 2011-09-12 06:24:38 +0930, Daniel Greenhoe 
<dgreenhoe at gmail.com> said:

> Using \underbrace with the unicode-math package under XeLaTeX produces
> garbage output. Here is a minimal example:
> 
> \documentclass{book}
>  \usepackage{unicode-math}
>  \setmathfont{xits-math.otf}
> \begin{document}%
>  \[ \underbrace{xyz} \]
> \end{document}%
> 
> Using the mathspec package instead of unicode-math seems to be OK.
> The \underbrace with unicode-math problem was discussed almost one year ago.
> Does anyone have a solution?

Sorry for the tardiness on this issue and for all the inconvenience 
caused. The next version of unicode-math will, I hope, fix this 
problem. It should arrive sometime day if I'm lucky. (Make sure you 
also update the packages fontspec and l3kernel as well.)

Best wishes,
Will