Cannot put `---` in `\section{}`

[haoyun]

The following code

\section{something --- else}

will produce error.

I have not found the reason.

[atYuguo]

报错如下

! Extra \fi.
 ...62144-1)/2)/262144*262144\relax \fi 
                                                  \fi  \expandafter \else \e...
l.584 \section{something --- else}

不是发生在我们文档里的，而且我在别的文档中试验也有这个问题，估计是某个宏包的bug.

[haoyun]

I think it's a bug of xeCJK. It conflict with hyperref. I have report this problem on the ctex bbs.
See, this post.