Fix Harmony Maps and WeakMaps for undefined values.

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 12846 matching lines @@
   return Shrink(key);
 }
 
 
 Object* ObjectHashTable::Lookup(Object* key) {
   ASSERT(IsKey(key));
 
   // If the object does not have an identity hash, it was never used as a key.
   { MaybeObject* maybe_hash = key->GetHash(OMIT_CREATION);
     if (maybe_hash->ToObjectUnchecked()->IsUndefined()) {
-      return GetHeap()->undefined_value();
+      return GetHeap()->the_hole_value();
     }
   }
   int entry = FindEntry(key);
-  if (entry == kNotFound) return GetHeap()->undefined_value();
+  if (entry == kNotFound) return GetHeap()->the_hole_value();
   return get(EntryToIndex(entry) + 1);
 }
 
 
 MaybeObject* ObjectHashTable::Put(Object* key, Object* value) {
   ASSERT(IsKey(key));
 
   // Make sure the key object has an identity hash code.
   int hash;
   { MaybeObject* maybe_hash = key->GetHash(ALLOW_CREATION);
     if (maybe_hash->IsFailure()) return maybe_hash;
     hash = Smi::cast(maybe_hash->ToObjectUnchecked())->value();
   }
   int entry = FindEntry(key);
 
   // Check whether to perform removal operation.
-  if (value->IsUndefined()) {
+  if (value->IsTheHole()) {
     if (entry == kNotFound) return this;
     RemoveEntry(entry);
     return Shrink(key);
   }
 
   // Key is already in table, just overwrite value.
   if (entry != kNotFound) {
     set(EntryToIndex(entry) + 1, value);
     return this;
   }
@@ skipping 399 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