re PR c++/58466 (ICE in cxx_eval_constant_expression)

	PR c++/58466
	* pt.c (unify_pack_expansion): Call expand_template_argument_pack.

From-SVN: r207283

gcc/cp/ChangeLog

 2014-01-29  Jason Merrill  <jason@redhat.com>
 
+	PR c++/58466
+	* pt.c (unify_pack_expansion): Call expand_template_argument_pack.
+
 	PR c++/59956
 	* friend.c (do_friend): Pass the TEMPLATE_DECL to add_friend if we
 	have a friend template in a class template.

gcc/cp/pt.c

@@ -16897,6 +16897,9 @@ unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
   tree pattern = PACK_EXPANSION_PATTERN (parm);
   tree pack, packs = NULL_TREE;
   int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
+
+  packed_args = expand_template_argument_pack (packed_args);
+
   int len = TREE_VEC_LENGTH (packed_args);
 
   /* Determine the parameter packs we will be deducing from the

gcc/testsuite/g++.dg/cpp0x/variadic147.C

+// PR c++/58466
+// { dg-require-effective-target c++11 }
+
+template<char, char...> struct A;
+
+template<typename> struct B;
+
+template<char... C> struct B<A<C...>> {};
+
+B<A<'X'>> b;