http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59419
--- Comment #8 from Dominique d'Humieres <dominiq at lps dot ens.fr> --- The modified test gfortran.dg/open_negative_unit_1.f90 in the patch submitted at http://gcc.gnu.org/ml/fortran/2013-12/msg00124.html checks that this PR is fixed.