Fixed #24844 -- Corrected has_changed implementation for HStoreField.

        for key, val in value.items():

            value[key] = six.text_type(val)

        return value

    def has_changed(self, initial, data):

        """

        Return True if data differs from initial.

        """

        # For purposes of seeing whether something has changed, None is

        # the same as an empty dict, if the data or initial value we get

        # is None, replace it w/ {}.

        initial_value = self.to_python(initial)

        return super(forms.HStoreField, self).has_changed(initial_value, data)

        if conn_timezone_name != self.timezone_name:

            cursor = self.connection.cursor()

            try:

                print "UPS"

                cursor.execute(self.ops.set_time_zone_sql(), [self.timezone_name])

            finally:

                cursor.close()

        form_field = model_field.formfield()

        self.assertIsInstance(form_field, forms.HStoreField)

    def test_empty_field_has_not_changed(self):

        class HStoreFormTest(forms.Form):

            f1 = HStoreField()

        form_w_hstore = HStoreFormTest()

        self.assertFalse(form_w_hstore.has_changed())

class TestValidator(PostgresSQLTestCase):