re PR c++/61566 (ICE in write_unscoped_name)

	PR c++/61566
	* mangle.c (decl_mangling_context): Look through a TEMPLATE_DECL.

From-SVN: r212165

gcc/cp/ChangeLog

 2014-06-30  Jason Merrill  <jason@redhat.com>
 
+	PR c++/61566
+	* mangle.c (decl_mangling_context): Look through a TEMPLATE_DECL.
+
 	* decl.c (build_ptrmemfunc_type): Don't give a PMF RECORD_TYPE
 	TYPE_BINFO or TYPE_LANG_SPECIFIC.
 	* cp-tree.h (TYPE_PTRMEMFUNC_FLAG): Use TYPE_LANG_FLAG_2.

gcc/cp/mangle.c

@@ -742,6 +742,10 @@ decl_mangling_context (tree decl)
   if (tcontext != NULL_TREE)
     return tcontext;
 
+  if (TREE_CODE (decl) == TEMPLATE_DECL
+      && DECL_TEMPLATE_RESULT (decl))
+    decl = DECL_TEMPLATE_RESULT (decl);
+
   if (TREE_CODE (decl) == TYPE_DECL
       && LAMBDA_TYPE_P (TREE_TYPE (decl)))
     {

gcc/testsuite/g++.dg/cpp0x/lambda/lambda-template13.C

+// PR c++/61566
+// { dg-do compile { target c++11 } }
+
+struct function
+{
+  template < typename _Functor>
+  function (_Functor);
+};
+
+struct C
+{
+  template <typename T>
+  void foo (T, function = [] {});
+};
+
+void bar ()
+{
+  C c;
+  c.foo (1);
+}