Never let the hole escape...

test/mjsunit/object-define-property.js

 // Copyright 2010 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 1057 matching lines @@
     value:2,
     writable:false
   });
   // Here arguments[0] is no alias at all.
   Object.defineProperty(arguments, "0", {
     value:3
   });
   assertEquals(2, arg0);
   assertEquals(3, arguments[0]);
 })(0);
+
+
+// Regression test: We should never observe the hole value.
+var objectWithGetter = {};
+objectWithGetter.__defineGetter__('foo', function() {});
+assertEquals(undefined, objectWithGetter.__lookupSetter__('foo'));
+
+var objectWithSetter = {};
+objectWithSetter.__defineSetter__('foo', function(x) {});
+assertEquals(undefined, objectWithSetter.__lookupGetter__('foo'));