[Bug fortran/61933] Inquire on internal units

[jvdelisle at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61933

--- Comment #8 from Jerry DeLisle <jvdelisle at gcc dot gnu.org> ---
You might notice that we redefined existence to be whether or not it is
connected.  Units get connected when opened so your sample code needs only ask:

IF ((.NOT.is_open).AND.(istat == 0)) RETURN

Whether this is what we really want to do of course is open to discussion.

The other definition for existence is .true. for all units except -1 which is
moot because -1 will give an error and the test for existence is always .true.
and not needed.  Also unit existence is processor dependent.

In your opinion, should we change it to the other definition?  Unit existence
is sort of a nebulous situation.  Will your code be more portable without the
test for existence?