Mathematics in section titles cannot be used with pdf rendering if the engine is lualatex #40
Description
I have the section
# Variant proof that $|\cK|\leq 2m-1$ {.appendix .unnumbered}
in my submission, where \cK is a custom command for \mathcal{K}.
In the .tex file generated by the render computo-pdf command this gives the bit
\section*{\texorpdfstring{Variant proof that
\(|\mathcal{K}|\leq 2m-1\)}{Variant proof that \textbar\textbackslash mathcal\{K\}\textbar\textbackslash leq 2m-1}}\label{variant-proof-that-mathcalkleq-2m-1}
\addcontentsline{toc}{section}{Variant proof that
\(|\mathcal{K}|\leq 2m-1\)}
and it produces an error on compilation with lualate. Compilation does not fail when using pdflatex. The error message is the following:
Package hyperref Warning: Token not allowed in a PDF string (Unicode):
(hyperref) removing `math shift' on input line 2272.
Package hyperref Warning: Token not allowed in a PDF string (Unicode):
(hyperref) removing `\symcal' on input line 2272.
./algo-curve.tex:2272: Improper alphabetic constant.
<to be read again>
\leq
l.2272 \(|\mathcal{K}|\leq 2m-1\)}
Line 2272 of the .tex file is \(|\mathcal{K}|\leq 2m-1\)}.
I think that I found the root cause, I made the following minimal .tex file:
\documentclass[12pt]{article}
\usepackage{hyperref}
\begin{document}
\tableofcontents
\section*{\texorpdfstring{Variant proof that
\(|\mathcal{K}|\leq 2m-1\)}{Variant proof that \textbar\textbackslash mathcal\{K\}\textbar\textbackslash leq 2m-1}}\label{variant-proof-that-mathcalkleq-2m-1}
\addcontentsline{toc}{section}{Variant proof that
\(|\mathcal{K}|\leq 2m-1\)}
\end{document}
and with this file compilation does not fail with lualatex. However, if I add \usepackage{unicode-math}then I get the same error. The file generated by computo-pdf does not use the unicode-math package in pdflatex mode, hence why there is no error with pdflatex.