1 files changed, 11 insertions, 11 deletions

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index df5d1f68b86..72b0c4f18b2 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -171,7 +171,7 @@ static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
 static void regenerate_decl_from_template (tree, tree);
 static tree most_specialized_class (tree, tree, tsubst_flags_t);
 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
-static tree tsubst_arg_types (tree, tree, tsubst_flags_t, tree);
+static tree tsubst_arg_types (tree, tree, tree, tsubst_flags_t, tree);
 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
 static bool check_specialization_scope (void);
 static tree process_partial_specialization (tree);
@@ -10500,11 +10500,14 @@ tsubst_decl (tree t, tree args, tsubst_flags_t complain)
   return r;
 }
 
-/* Substitute into the ARG_TYPES of a function type.  */
+/* Substitute into the ARG_TYPES of a function type.
+   If END is a TREE_CHAIN, leave it and any following types
+   un-substituted.  */
 
 static tree
 tsubst_arg_types (tree arg_types,
 		  tree args,
+		  tree end,
 		  tsubst_flags_t complain,
 		  tree in_decl)
 {
@@ -10514,11 +10517,11 @@ tsubst_arg_types (tree arg_types,
   tree expanded_args = NULL_TREE;
   tree default_arg;
 
-  if (!arg_types || arg_types == void_list_node)
+  if (!arg_types || arg_types == void_list_node || arg_types == end)
     return arg_types;
 
   remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
-					  args, complain, in_decl);
+					  args, end, complain, in_decl);
   if (remaining_arg_types == error_mark_node)
     return error_mark_node;
 
@@ -10643,7 +10646,7 @@ tsubst_function_type (tree t,
     }
 
   /* Substitute the argument types.  */
-  arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
+  arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args, NULL_TREE,
 				complain, in_decl);
   if (arg_types == error_mark_node)
     return error_mark_node;
@@ -16757,12 +16760,9 @@ check_undeduced_parms (tree targs, tree args, tree end)
       }
   if (found)
     {
-      for (; args != end; args = TREE_CHAIN (args))
-	{
-	  tree substed = tsubst (TREE_VALUE (args), targs, tf_none, NULL_TREE);
-	  if (substed == error_mark_node)
-	    return true;
-	}
+      tree substed = tsubst_arg_types (args, targs, end, tf_none, NULL_TREE);
+      if (substed == error_mark_node)
+	return true;
     }
   return false;
 }