Fixed #11860. Changed NullBooleanSelect's _has_changed method to repect...

                False: False}.get(value, None)

    def _has_changed(self, initial, data):

        # Sometimes data or initial could be None or u'' which should be the

        # same thing as False.

        return bool(initial) != bool(data)

        # For a NullBooleanSelect, None (unknown) and False (No)

        # are not the same

        if initial is not None:

            initial = bool(initial)

        if data is not None:

            data = bool(data)

        return initial != data

class SelectMultiple(Select):

    def render(self, name, value, attrs=None, choices=()):

<option value="2">Yes</option>

<option value="3" selected="selected">No</option>

</select>

>>> w._has_changed(False, None)

True

>>> w._has_changed(None, False)

True

>>> w._has_changed(None, None)

False

>>> w._has_changed(False, False)

False

>>> w._has_changed(True, False)

True

>>> w._has_changed(True, None)

True

>>> w._has_changed(True, True)

False

""" + \

r""" # [This concatenation is to keep the string below the jython's 32K limit].