Fix a limit validation to be in integer range

Python's built-in int() function creates a long instance value
when the string expresses more than the integer range.

To validate something like the limit parameter correctly, swift3
should the type of the return value from int() built-in function.

Change-Id: I5853cf392faa77e3ee652f3dc799b63f9400141a

swift3/request.py

@@ -663,6 +663,10 @@ class Request(swob.Request):
                     raise InvalidArgument(param,
                                           self.params[param],
                                           err_msg)
+                if not isinstance(value, int):
+                    # check the instance because int() could build
+                    # a long instance
+                    raise ValueError
             except ValueError:
                 err_msg = 'Provided %s not an integer or within ' \
                           'integer range' % param

swift3/test/unit/test_request.py

@@ -179,6 +179,13 @@ class TestRequest(Swift3TestCase):
         with self.assertRaises(InvalidArgument):
             s3req.get_validated_param('max-keys', 0, 0)
 
+        # a param in the out of the integer range
+        s3req = create_s3request_with_param('max-keys', '1' * 30)
+        with self.assertRaises(InvalidArgument) as result:
+            s3req.get_validated_param('max-keys', 1)
+        self.assertTrue(
+            'not an integer or within integer range' in result.exception.body)
+
 
 if __name__ == '__main__':
     unittest.main()