#189 \IfFileExists returns incorrect result when a file is under a directory and its name contains non-BMP character.

[Anonymous]

Minimal example showing the bug

Create the following files:

mkdir a
touch a/$'\U10000'.tex
touch a/$'\U4e00'.tex

Compile with xelatex

\RequirePackage{latexbug}
\documentclass{article}
\begin{document}
\IfFileExists{\detokenize{a/^^^^^^010000.tex}}{1}{0}
\IfFileExists{\detokenize{a/^^^^^^004e00.tex}}{1}{0}
\end{document}

Log file (required) and possibly PDF file

bug.log (github.com)
bug.pdf (github.com)

Expected:

PDF shows 1 1.

Actual:

PDF shows .tex” 0 1.

Other info

It works as expected when I place the files in the top level. This issue was first reported at https://github.com/latex3/latex2e/issues/753 and maintainers suggests that it is a XeTeX bug.