[luatex] dofile(nil) in batchmode

[Manuel Pégourié-Gonnard]

Hi,

As I understand it, \batchmode disables all interaction, including reading
things from standard input. So, I wonder if dofile() without arguments shouldn't
result in an error rather than hang forever.

Also, in non-batch modes, it would be nice to have some indication that luatex
is waiting for some input.

Of course these are details, but I just lost 15 minutes trying to understand why
one of my loops wouldn't properly terminate before I noticed the dofile() right
before the loop. (Yeah, I know, assert() is my friend.)

Thanks,
Manuel.