[Bug fortran/67367] New: Program crashes on READ(IOSTAT=IOS, ...) on directory OPEN()ed without error

["urbanjost at comcast dot net" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67367

            Bug ID: 67367
           Summary: Program crashes on READ(IOSTAT=IOS, ...) on directory
                    OPEN()ed without error
           Product: gcc
           Version: 4.9.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: urbanjost at comcast dot net
  Target Milestone: ---

Created attachment 36257
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36257&action=edit
commands and their output show system type, compiler version, source code and
saved temp files

When I read a list of filenames from the command line the list can easily
contain non-standard-file names such as directories. If I OPEN() a name that is
a directory with default options I get an error on the OPEN() (IOSTAT=21) and
IOMSG reports "file is a directory". But I am opening the files as read-only
streams. With those options the OPEN() gives no errors. But the first READ() of
the files causes the program to halt abruptly with no messages. No core file is
produced; I/O on open files is not flushed or closed properly.

I would have expected the OPEN() to have failed with an error; or if it is
legal to open a directory as a stream (which would be useful but surprising) I
would expect the READ to have trapped the error as the READ() uses IOSTAT=.