* semantics.c (finish_template_type): Check CLASSTYPE_TEMPLATE_INFO.

From-SVN: r246680

gcc/cp/ChangeLog

+2017-04-03  Jason Merrill  <jason@redhat.com>
+
+	* semantics.c (finish_template_type): Check CLASSTYPE_TEMPLATE_INFO.
+
 2017-04-03  Jonathan Wakely  <jwakely@redhat.com>
 
 	* class.c (update_vtable_entry_for_fn): Fix typo in comment.

gcc/cp/semantics.c

@@ -3157,6 +3157,7 @@ finish_template_type (tree name, tree args, int entering_scope)
   if (flag_concepts
       && entering_scope
       && CLASS_TYPE_P (type)
+      && CLASSTYPE_TEMPLATE_INFO (type)
       && dependent_type_p (type)
       && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (type)))
     type = fixup_template_type (type);

gcc/testsuite/g++.dg/concepts/regress/alias-decl-42.C

+// PR c++/59200
+// { dg-options "-std=c++1z -fconcepts" }
+
+struct A
+{
+  static constexpr bool value = true;
+};
+
+template<typename T>
+struct B
+{
+  template<typename U>
+    using C = A;
+};
+
+template<typename T>
+template<typename U>
+  const bool B<T>::C<U>::value;  // { dg-error "too many" }