re PR c++/56543 (ICE on valid code in copy_node_stat)

	PR c++/56543
	* tree.c (strip_typedefs): Don't copy args if they are NULL.

	* g++.dg/template/typename20.C: New test.

From-SVN: r196491

gcc/cp/ChangeLog

+2013-03-06  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/56543
+	* tree.c (strip_typedefs): Don't copy args if they are NULL.
+
 2013-03-05  Jakub Jelinek  <jakub@redhat.com>
 
 	* parser.c (cp_parser_braced_list): For {} initialize

gcc/cp/tree.c

@@ -1222,7 +1222,8 @@ strip_typedefs (tree t)
     case TYPENAME_TYPE:
       {
 	tree fullname = TYPENAME_TYPE_FULLNAME (t);
-	if (TREE_CODE (fullname) == TEMPLATE_ID_EXPR)
+	if (TREE_CODE (fullname) == TEMPLATE_ID_EXPR
+	    && TREE_OPERAND (fullname, 1))
 	  {
 	    tree args = TREE_OPERAND (fullname, 1);
 	    tree new_args = copy_node (args);

gcc/testsuite/ChangeLog

+2013-03-06  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/56543
+	* g++.dg/template/typename20.C: New test.
+
 2013-03-05  Jakub Jelinek  <jakub@redhat.com>
 
 	PR debug/56510

gcc/testsuite/g++.dg/template/typename20.C

+// PR c++/56543
+
+template <typename>
+struct S;
+
+template <typename T>
+struct U
+{
+  typedef typename S <T>::template V <> W;
+  S <W> x;
+};