[PATCH, fortran testsuite] read_eof.f90 open file bug

[Thomas Koenig]

David Edelsohn wrote:

> 	read_eof.f90 consistently fails on AIX during nightly testsing,
> but not when run manually.  Adding additional debugging statements to
> new_unit() shows that it is failing because file /dev/null already is open
> as unit 5.  Unit 5 is associated with stdin and stdin is /dev/null when
> not associated with a terminal.

Stupid question: Why should opening /dev/null twice fail?

Or was this a manifestation of PR 18983 (can't write to /dev/null)?