[Bug libfortran/66861] [5/6 Regression] Segmentation fault in gcc/testsuite/gfortran.dg/streamio_5.f90

[jb at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66861

--- Comment #3 from Janne Blomqvist <jb at gcc dot gnu.org> ---
Or rather, also fixing another similar potential issue, you might instead want
to test this:

diff --git a/libgfortran/io/unix.c b/libgfortran/io/unix.c
index e5fc6e1..a1ce9a3 100644
--- a/libgfortran/io/unix.c
+++ b/libgfortran/io/unix.c
@@ -1525,7 +1525,10 @@ compare_file_filename (gfc_unit *u, const char *name,
int len)
       goto done;
     }
 # endif
-  ret = (strcmp(path, u->filename) == 0);
+  if (u->filename)
+    ret = (strcmp(path, u->filename) == 0);
+  else
+    ret = 0;
 #endif
  done:
   free (path);
@@ -1570,7 +1573,7 @@ find_file0 (gfc_unit *u, FIND_FILE0_DECL)
     }
   else
 # endif
-    if (strcmp (u->filename, path) == 0)
+    if (u->filename && strcmp (u->filename, path) == 0)
       return u;
 #endif