Matrices in subsection titles fails (md -> PDF)

[avonmoll]

Version: 1.16.0.2

Files:
mwe.md

## $\begin{bmatrix}0 &0 &0\end{bmatrix}$

header

\usepackage{amsmath}

Output:

$ pandoc mwe.md -o test.pdf -H header`
! Argument of \@sect has an extra }.
<inserted text>
                \par
l.56 ...}0 \&0 \&0\textbackslash{}end\{bmatrix\}}}

pandoc.exe: Error producing PDF

My expected output is a PDF with a subsection heading with this matrix:

[jgm]

Reproduced in dev version.

[jgm]

Current output:

\subsection{\texorpdfstring{\(\begin{bmatrix}0 &0 &0\end{bmatrix}\)}{\textbackslash{}begin\{bmatrix\}0 \&0 \&0\textbackslash{}end\{bmatrix\}}}\label{beginbmatrix0-0-0endbmatrix}}

Note that this works fine:

\subsection[foo]{\texorpdfstring{\(\begin{bmatrix}0 &0 &0\end{bmatrix}\)}{\textbackslash{}begin\{bmatrix\}0 \&0 \&0\textbackslash{}end\{bmatrix\}}}\label{beginbmatrix0-0-0endbmatrix}}

[jgm]

There's an approach here:
https://tex.stackexchange.com/questions/228274/matrix-in-section-heading
but it would be cumbersome to implement automatically.

[jgm]

Adding \protect before \begin and \end worked for me:

\subsection{\texorpdfstring{\(\protect\begin{bmatrix}0 &0 &0\protect\end{bmatrix}\)}{\textbackslash{}begin\{bmatrix\}0 \&0 \&0\textbackslash{}end\{bmatrix\}}

[jgm]

Adding the \protect to the Markdown source also works (and doesn't require changes to pandoc):

## $\protect\begin{bmatrix}0 &0 &0\protect\end{bmatrix}$

[jgm]

Looks like adding \protect before each \begin and \end in math in a section heading would do the trick.