Page shipout in infinite loop

[Uwe Siart]

Since today's update the following MWE causes 'latex' (not 'pdflatex') to
ship out empty pages in an infinite loop:

\documentclass{article}
\usepackage{mhchem}
\usepackage{geometry}
\geometry{landscape}
\begin{document}
\begin{center}
  \rule{1.1\linewidth}{1.1\linewidth}
\end{center}
\end{document}

The infinite loop disappears when I either comment mhchem or
\geometry{landscape}.

Please excuse if this is the wrong place to report this. I suspect that
one of 'mhchem', 'geometry' or the l3* packages needs fixing, but I
can't tell who is the culprit.

-- 
Uwe