Multi-lined environments with \\* #2433
Description
Issue Summary
MathJax v3.
With multline and similar, \\ and \\[2ex] work as expected, but \\* and \\*[2ex] fail. The star and trailing optional argument are not absorbed.
Steps to Reproduce:
<!DOCTYPE html>
<html lang="en-US">
<head>
<script
id="MathJax-script"
src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-chtml.js"
></script>
</head>
<body>
<p>
\begin{multline}
\tan a+b < c \\
\cos (d)+sin(e) \\*
\cos (f)+sin(g) \\*[2ex]
h+i=j
\end{multline}
</p>
</body>
</html>