spawn/dos_exec_in_path crashes if the pointer to the filename to execute
is al NULL pointer.
the bug appears if redir.exe (v2.01) ist started with an option ( e.g. -t )
but without an filename.

IMHO, it's in its best right to do so. There is an error here, but it's
not in spawn or another library function, I'd say: it's in the source
of redir.exe.

Solved in v2.02.

Solved.