Hi folks, The current version of lualatex distributed with TeX Live (as installed today via TeX Live's install-tl, or via Arch Linux's packages) replaces em dashes with hyphens if they're not separated by any space. For example, if given \documentclass{article} % This makes no difference: %\usepackage{fontspec} %\setmainfont[Ligatures=TeX]{Latin Modern Roman} % \begin{document} \noindent% I have \emph{no} idea why em dashes---these things---are being replaced with hyphens in Lua\LaTeX. But --- this only seems to happen if there is no space around them. \end{document} lualatex replaces the first two dashes with hyphens, but not the third. The problem goes away when I downgrade to a version from December (Arch's previous release of their texlive-core package was built December 1), and neither pdflatex or xelatex exhibit this behavior.