diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index 204d24202215..af85555a2e7e 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,12 @@
+2010-01-14 Jerry DeLisle <jvdelisle@gcc.gnu.org>
+
+	PR fortran/42684
+	* interface.c (check_interface1): Pass symbol name rather than NULL to
+	gfc_compare_interfaces.	(gfc_compare_interfaces): Add assert to
+	trap MULL.
+	* resolve.c (check_generic_tbp_ambiguity): Pass symbol name rather
+	than NULL to gfc_compare_interfaces.
+
 2010-01-14  Paul Thomas  <pault@gcc.gnu.org>
 
         PR fortran/41478
diff --git a/gcc/fortran/interface.c b/gcc/fortran/interface.c
index 0034f75b92e9..2a5ece1c465e 100644
--- a/gcc/fortran/interface.c
+++ b/gcc/fortran/interface.c
@@ -955,6 +955,8 @@ gfc_compare_interfaces (gfc_symbol *s1, gfc_symbol *s2, const char *name2,
 {
   gfc_formal_arglist *f1, *f2;
 
+  gcc_assert (name2 != NULL);
+
   if (s1->attr.function && (s2->attr.subroutine
       || (!s2->attr.function && s2->ts.type == BT_UNKNOWN
 	  && gfc_get_default_type (name2, s2->ns)->type == BT_UNKNOWN)))
@@ -1126,7 +1128,7 @@ check_interface1 (gfc_interface *p, gfc_interface *q0,
 	if (p->sym->name == q->sym->name && p->sym->module == q->sym->module)
 	  continue;
 
-	if (gfc_compare_interfaces (p->sym, q->sym, NULL, generic_flag, 0,
+	if (gfc_compare_interfaces (p->sym, q->sym, q->sym->name, generic_flag, 0,
 				    NULL, 0))
 	  {
 	    if (referenced)
diff --git a/gcc/fortran/resolve.c b/gcc/fortran/resolve.c
index 7321c0dd7675..9212521b2f39 100644
--- a/gcc/fortran/resolve.c
+++ b/gcc/fortran/resolve.c
@@ -9712,7 +9712,7 @@ check_generic_tbp_ambiguity (gfc_tbp_generic* t1, gfc_tbp_generic* t2,
     }
 
   /* Compare the interfaces.  */
-  if (gfc_compare_interfaces (sym1, sym2, NULL, 1, 0, NULL, 0))
+  if (gfc_compare_interfaces (sym1, sym2, sym2->name, 1, 0, NULL, 0))
     {
       gfc_error ("'%s' and '%s' for GENERIC '%s' at %L are ambiguous",
 		 sym1->name, sym2->name, generic_name, &where);