[Bug libfortran/64770] New: [5 Regression] Segmentation fault when opening a file with status="new" and the file exists.

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64770

            Bug ID: 64770
           Summary: [5 Regression] Segmentation fault when opening a file
                    with status="new" and the file exists.
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libfortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dominiq at lps dot ens.fr
                CC: jb at gcc dot gnu.org, jvdelisle at gcc dot gnu.org

Executing the code

implicit none

open(99, file="test.dat", access="stream", form="unformatted", status="new")
close(99)

end

should give

At line 3 of file eof_4_red.f90 (unit = 99, file = '')
Fortran runtime error: File 'test.dat' already exists

if the file "test.dat" exists. This is the case for 4.9 and 5.0 up to revision
r215301 (2014-09-16). However from r215328 (2014-09-17) up to r220065, running
the test gives

Program received signal SIGSEGV: Segmentation fault - invalid memory reference.

Backtrace for this error:
#0  0x10547d6c2
#1  0x10547c9e0
#2  0x7fff97f89f19
Segmentation fault

The culprit is likely r215307.

Note that I stumbled on this PR for gfortran.dg/eof_4.f90 while regtesting with
-j8.