re PR c++/64514 (Error in template instantiation in GCC 4.9, works fine in GCC 4.8)

PR c++/64514
	* pt.c (coerce_template_parameter_pack): Return NULL for a
	zero-length fixed parameter pack with a pack expansion arg.

From-SVN: r219558

gcc/cp/ChangeLog

@@ -1,5 +1,9 @@
 2015-01-13  Jason Merrill  <jason@redhat.com>
 
+	PR c++/64514
+	* pt.c (coerce_template_parameter_pack): Return NULL for a
+	zero-length fixed parameter pack with a pack expansion arg.
+
 	PR c++/64520
 	* pt.c (unify): Don't try to deduce to std::initializer_list<T...>.
 

gcc/cp/pt.c

@@ -6825,6 +6825,9 @@ coerce_template_parameter_pack (tree parms,
               if (invalid_nontype_parm_type_p (t, complain))
                 return error_mark_node;
             }
+	  /* We don't know how many args we have yet, just
+	     use the unconverted ones for now.  */
+	  return NULL_TREE;
         }
 
       packed_args = make_tree_vec (TREE_VEC_LENGTH (packed_parms));

gcc/testsuite/g++.dg/cpp0x/variadic165.C

@@ -0,0 +1,17 @@
+// PR c++/64514
+// { dg-do compile { target c++11 } }
+
+template<typename... T>
+struct Functor
+{
+    template <T...>
+    struct Inner
+    {};
+};
+
+template struct Functor<>::Inner<>;
+
+int main()
+{
+
+}