[Bug fortran/78854] [F03] DTIO namelist output not working on internal unit

[jvdelisle at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78854

--- Comment #10 from Jerry DeLisle <jvdelisle at gcc dot gnu.org> ---
We are not handling the internal unit check correctly in unit.c (get_unit) and
we return a NULL to the caller which is then interpreted as an error. I am
working on the fix now. (just a little head scratching)