`vmatrix` rendered incorrectly

[SichangHe]

Math expressions that contains matrices are no longer rendered correctly.
For example,

\begin{vmatrix}a&b\\c&d\end{vmatrix}

is not parsed.

I have done some debugging and found out that the error comes from katex:

thread 'tests::test_katex_rendering_vmatrix' panicked at 'called `Result::unwrap()` on an `Err` value: JsExecError("undefined not callable (property 'fill' of [object Array]): JavaScript runtime error (TypeError)")', src/tests.rs:184:63

Changing katex back to use quick-js fixes this problem, so this regression is brought by duktype.

[SichangHe]

This issue is gone on UNIX but it is still on Windows.
Windows people, I am sorry. If you really need this, try WSL…