Dear luatex devs,
if I place \limits after a math atom, i.e. {}, no error is thrown.
luatex should throw "! Limit controls must follow a math operator." as
the pdftex and xetex engines do.
Minimal example:
${}\limits$
\bye
It will typeset using luatex but will throw an error when processed
using pdftex or xetex.
Kind regards,
Henri