Also in ClearNonLiveTransitions we have to check if there still is a transition array before we acc…

src/objects.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 7348 matching lines @@
   bool getter = ClearAccessorComponent(heap, accessors, ACCESSOR_GETTER);
   bool setter = ClearAccessorComponent(heap, accessors, ACCESSOR_SETTER);
   return getter && setter;
 }
 
 
 // TODO(mstarzinger): This method should be moved into MarkCompactCollector,
 // because it cannot be called from outside the GC and we already have methods
 // depending on the transitions layout in the GC anyways.
 void Map::ClearNonLiveTransitions(Heap* heap) {
-  TransitionArray* t = transitions();
   // If there are no transitions to be cleared, return.
   // TODO(verwaest) Should be an assert, otherwise back pointers are not
   // properly cleared.
-  if (t == NULL) return;
+  if (!HasTransitionArray()) return;
+
+  TransitionArray* t = transitions();
 
   int transition_index = 0;
 
   // Compact all live descriptors to the left.
   for (int i = 0; i < t->number_of_transitions(); ++i) {
     if (!ClearNonLiveTransition(heap, t, i)) {
       if (i != transition_index) {
         String* key = t->GetKey(i);
         Object* value = t->GetValue(i);
         t->SetKey(transition_index, key);
@@ skipping 5879 matching lines @@
   set_year(Smi::FromInt(year), SKIP_WRITE_BARRIER);
   set_month(Smi::FromInt(month), SKIP_WRITE_BARRIER);
   set_day(Smi::FromInt(day), SKIP_WRITE_BARRIER);
   set_weekday(Smi::FromInt(weekday), SKIP_WRITE_BARRIER);
   set_hour(Smi::FromInt(hour), SKIP_WRITE_BARRIER);
   set_min(Smi::FromInt(min), SKIP_WRITE_BARRIER);
   set_sec(Smi::FromInt(sec), SKIP_WRITE_BARRIER);
 }
 
 } }  // namespace v8::internal