Simplejson 2.3.0 object dictionary encode issue

simplejson2.3.0_encode_issue.py

from simplejson import JSONEncoder

class ObjectDictWorks(dict):
    """ Makes a dictionary behave like an object. """
    def __getattr__(self, name):
        try:
            return self[name]
        except KeyError:
            raise AttributeError(name)

    def __setattr__(self, name, value):
        self[name] = value

class ObjectDictBroke(dict):
    """ Makes a dictionary behave like an object. But allow a default
    for getattr never raising exceptions.
    """
    def __getattr__(self, name, default=None):
        try:
            return self[name]
        except KeyError:
            return default

    def __setattr__(self, name, value):
        self[name] = value

if __name__ == "__main__":
    je = JSONEncoder()

    # This will succeed
    print je.encode(ObjectDictWorks({'test': 1234}))

    # This will not
    print je.encode(ObjectDictBroke({'test': 1234}))

    # This is the exception raised running under lucid32 ubuntu server
    # simplejson 2.3.0 python2.7 with c speedups being used.
    # Also happens with same py and SJ on osx snow leopard and lion.
    exception_raised = '''
Traceback (most recent call last):
  File "test.py", line 34, in <module>
    print je.encode(ObjectDictBroke({'test': 1234}))
  File "/usr/local/lib/python2.6/dist-packages/simplejson/encoder.py", line 226, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "/usr/local/lib/python2.6/dist-packages/simplejson/encoder.py", line 296, in iterencode
    return _iterencode(o, 0)
TypeError: attribute of type 'NoneType' is not callable
'''