Dear all,
> I think the second one is more robust - like you say, this may catch
> other cases. If we have that one, we don't need the first one.
to fix the fallout I've committed to master the following patch,
which I will backport to the affected branches (9/10):
PR fortran/95104 - Segfault on a legal WAIT statement
The initial commit for this PR uncovered a latent issue with unit locking
in the Fortran run-time library. Add check for valid unit.
2020-05-28 Harald Anlauf <anl...@gmx.de>
libgfortran/
PR libfortran/95104
* io/unit.c (unlock_unit): Guard by check for NULL pointer.
diff --git a/libgfortran/io/unit.c b/libgfortran/io/unit.c
index 0030d7e8701..a3b0656cb90 100644
--- a/libgfortran/io/unit.c
+++ b/libgfortran/io/unit.c
@@ -767,9 +767,12 @@ close_unit_1 (gfc_unit *u, int locked)
void
unlock_unit (gfc_unit *u)
{
- NOTE ("unlock_unit = %d", u->unit_number);
- UNLOCK (&u->lock);
- NOTE ("unlock_unit done");
+ if (u)
+ {
+ NOTE ("unlock_unit = %d", u->unit_number);
+ UNLOCK (&u->lock);
+ NOTE ("unlock_unit done");
+ }
}
/* close_unit()-- Close a unit. The stream is closed, and any memory
