Issue in width of hyperlink box in vbox (RTL context)

Question

Why in this example clickable box appears in RTL context very larger from what I have declared (2cm), in left to right context width of box is fine

% lualatex
\documentclass[12pt]{article}
\usepackage{hyperref}


\begin{document}

%\pardir TRT \textdir TRT \linedir TRT

a
{\hypersetup{pdfhighlight={/P},pdfborder={0 0 4}}%
\vbox{\hyperlink{thesentence}{\vbox to 3cm{\hbox  to 2cm{ \hfil}\vfil}}}}

\newpage

Text \hypertarget{thesentence}{this sentence}

\end{document}

Result in LTR context

Result in RTL context

Answer 1

While this is a LuaTeX bug there is a rather simple workaround until it's fixed in the engine: LuaTeX has two codepaths to calculate the dimensions of a link. A simpler (and faster) one (which has the bug) and a more complicated one (which works correctly). So you only have to force LuaTeX to use the more complicated code, e.g. by setting a PDF transformation matrix:

\documentclass[12pt]{article}
\usepackage{hyperref}

\AddToHook{shipout/background}{% Insert on every page
  \pdfextension setmatrix{1 0 0 1}% {1 0 0 1} describes an identity matrix and doesn't actually do anything, but it stops LuaTeX from using simpler link calculations.
}

\begin{document}

\pardir TRT \textdir TRT \linedir TRT

a
{\hypersetup{pdfhighlight={/P},pdfborder={0 0 4}}%
\vbox{\hyperlink{thesentence}{\vbox to 3cm{\hbox  to 2cm{ \hfil}\vfil}}}}

\newpage

Text \hypertarget{thesentence}{this sentence}

\end{document}