[tex-live] Fontspec overriding default paper size with LuaTeX

[Akira Kakuto]

Dear Bruno,

> On a TL 2016 pretest setup (installed via MacTeX), complete with all updates etc.,
> and A4 as the default paper size, typesetting the attached 
> minimal test file with LuaLaTeX yields A4 PDF output.
> But as soon as fontspec is called, output switches to US Letter.

Confirmed on windows.
If I put an empty luatex.def in the current directory,
I obtain an a4 pdf. So I suspect that luatex.def does change
the paper size.

Best,
Akira