Fixed a regression in forms changed_data

                else:

                    initial_prefixed_name = self.add_initial_prefix(name)

                    hidden_widget = field.hidden_widget()

                    try:

                        initial_value = field.to_python(hidden_widget.value_from_datadict(

                            self.data, self.files, initial_prefixed_name))

                    except ValidationError:

                        # Always assume data has changed if validation fails.

                        self._changed_data.append(name)

                        continue

                if hasattr(field.widget, '_has_changed'):

                    warnings.warn("The _has_changed method on widgets is deprecated,"

                        " define it at field level instead.",

<option value="w">whiz</option>

</select></li>""")

    def test_changed_data(self):

        class Person(Form):

            first_name = CharField(initial='Hans')

            last_name = CharField(initial='Greatel')

            birthday = DateField(initial=datetime.date(1974, 8, 16))

        p = Person(data={'first_name': 'Hans', 'last_name': 'Scrmbl',

                         'birthday': '1974-08-16'})

        self.assertTrue(p.is_valid())

        self.assertNotIn('first_name', p.changed_data)

        self.assertIn('last_name', p.changed_data)

        self.assertNotIn('birthday', p.changed_data)

        # Test that field raising ValidationError is always in changed_data

        class PedanticField(forms.Field):

            def to_python(self, value):

                raise ValidationError('Whatever')

        class Person2(Person):

            pedantic = PedanticField(initial='whatever', show_hidden_initial=True)

        p = Person2(data={'first_name': 'Hans', 'last_name': 'Scrmbl',

                         'birthday': '1974-08-16', 'initial-pedantic': 'whatever'})

        self.assertFalse(p.is_valid())

        self.assertIn('pedantic', p.changed_data)

    def test_boundfield_values(self):

        # It's possible to get to the value which would be used for rendering

        # the widget for a field by using the BoundField's value method.