Never let the hole escape...

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 940120541e4ca51be3861fa72dca83c97b44fa80..bb2f2d3d3bb52a3270f896bd39bda9f0484a2767 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -4694,7 +4694,7 @@ Object* JSObject::LookupAccessor(String* name, AccessorComponent component) {
           Object* element = dictionary->ValueAt(entry);
           if (dictionary->DetailsAt(entry).type() == CALLBACKS &&
               element->IsAccessorPair()) {
-            return AccessorPair::cast(element)->get(component);
+            return AccessorPair::cast(element)->SafeGet(component);
           }
         }
       }
@@ -4710,7 +4710,7 @@ Object* JSObject::LookupAccessor(String* name, AccessorComponent component) {
         if (result.type() == CALLBACKS) {
           Object* obj = result.GetCallbackObject();
           if (obj->IsAccessorPair()) {
-            return AccessorPair::cast(obj)->get(component);
+            return AccessorPair::cast(obj)->SafeGet(component);
           }
         }
       }
@@ -5947,6 +5947,12 @@ MaybeObject* AccessorPair::CopyWithoutTransitions() {
 }
 
 
+Object* AccessorPair::SafeGet(AccessorComponent component) {
+    Object* accessor = get(component);
+    return accessor->IsTheHole() ? GetHeap()->undefined_value() : accessor;
+}
+
+
 MaybeObject* DeoptimizationInputData::Allocate(int deopt_entry_count,
                                                PretenureFlag pretenure) {
   ASSERT(deopt_entry_count > 0);