--- old/src/hotspot/share/classfile/classLoaderData.cpp	2018-09-27 22:39:01.749314405 -0400
+++ new/src/hotspot/share/classfile/classLoaderData.cpp	2018-09-27 22:39:00.341233972 -0400
@@ -345,6 +345,11 @@
   for (Klass* k = OrderAccess::load_acquire(&_klasses); k != NULL; k = k->next_link()) {
     // Do not filter ArrayKlass oops here...
     if (k->is_array_klass() || (k->is_instance_klass() && InstanceKlass::cast(k)->is_loaded())) {
+#ifdef ASSERT
+      oop m = k->java_mirror();
+      assert(m != NULL, "NULL mirror"); 
+      assert(m->is_a(SystemDictionary::Class_klass()), "invalid mirror");
+#endif
       klass_closure->do_klass(k);
     }
   }
--- old/src/hotspot/share/oops/instanceKlass.cpp	2018-09-27 22:39:06.189568057 -0400
+++ new/src/hotspot/share/oops/instanceKlass.cpp	2018-09-27 22:39:04.773487166 -0400
@@ -2304,6 +2304,9 @@
   if (is_linked()) {
     unlink_class();
   }
+
+  _init_state = allocated;
+
   {
     MutexLocker ml(Compile_lock);
     init_implementor();
@@ -2350,6 +2353,10 @@
 }
 
 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
+  // SystemDictionary::add_to_hierarchy() sets the init_state to loaded
+  // before the InstanceKlass is added to the the SystemDictionary. Make
+  // sure the current state is <loaded.
+  assert(!is_loaded(), "invalid init state");
   set_package(loader_data, CHECK);
   Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);