Normalize the object before updating getter/setter info.

src/objects.cc

 // Copyright 2006-2009 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 2822 matching lines @@
     }
   } else {
     // Lookup the name.
     LookupResult result;
     LocalLookup(name, &result);
     if (result.IsValid()) {
       if (result.IsReadOnly()) return Heap::undefined_value();
       if (result.type() == CALLBACKS) {
         Object* obj = result.GetCallbackObject();
         if (obj->IsFixedArray()) {
+          // The object might be in fast mode even though it has
+          // a getter/setter.
+          Object* ok = NormalizeProperties(CLEAR_INOBJECT_PROPERTIES, 0);
+          if (ok->IsFailure()) return ok;
+
           PropertyDetails details = PropertyDetails(attributes, CALLBACKS);
           SetNormalizedProperty(name, obj, details);
           return obj;
         }
       }
     }
   }
 
   // Allocate the fixed array to hold getter and setter.
   Object* structure = Heap::AllocateFixedArray(2, TENURED);
@@ skipping 5544 matching lines @@
   if (break_point_objects()->IsUndefined()) return 0;
   // Single beak point.
   if (!break_point_objects()->IsFixedArray()) return 1;
   // Multiple break points.
   return FixedArray::cast(break_point_objects())->length();
 }
 #endif
 
 
 } }  // namespace v8::internal