Remove UnexpectedUpdate exceptions. (#4197)

* Remove UnexpectedUpdate exceptions.

These exceptions trigger when the server sends the client back an object with a
field that doesn't exactly match what the client previously sent.

This causes unnecessary breakage in various cases, doesn't prevent any problems,
and isn't required by spec.

* Back out all UnexpectedUpdate removals except registration update.

acme/acme/client.py

@@ -134,8 +134,6 @@ class Client(object):  # pylint: disable=too-many-instance-attributes
         update = regr.body if update is None else update
         body = messages.UpdateRegistration(**dict(update))
         updated_regr = self._send_recv_regr(regr, body=body)
-        if updated_regr != regr:
-            raise errors.UnexpectedUpdate(regr)
         return updated_regr
 
     def deactivate_registration(self, regr):
@@ -301,7 +299,6 @@ class Client(object):  # pylint: disable=too-many-instance-attributes
         response = self.net.get(authzr.uri)
         updated_authzr = self._authzr_from_response(
             response, authzr.body.identifier, authzr.uri, authzr.new_cert_uri)
-        # TODO: check and raise UnexpectedUpdate
         return updated_authzr, response
 
     def request_issuance(self, csr, authzrs):

acme/acme/client_test.py

@@ -121,8 +121,6 @@ class ClientTest(unittest.TestCase):
         # TODO: split here and separate test
         self.response.json.return_value = self.regr.body.update(
             contact=()).to_json()
-        self.assertRaises(
-            errors.UnexpectedUpdate, self.client.update_registration, self.regr)
 
     def test_deactivate_account(self):
         self.response.headers['Location'] = self.regr.uri
@@ -130,14 +128,6 @@ class ClientTest(unittest.TestCase):
         self.assertEqual(self.regr,
                          self.client.deactivate_registration(self.regr))
 
-    def test_deactivate_account_bad_registration_returned(self):
-        self.response.headers['Location'] = self.regr.uri
-        self.response.json.return_value = "some wrong registration thing"
-        self.assertRaises(
-            errors.UnexpectedUpdate,
-            self.client.deactivate_registration,
-            self.regr)
-
     def test_query_registration(self):
         self.response.json.return_value = self.regr.body.to_json()
         self.assertEqual(self.regr, self.client.query_registration(self.regr))

certbot/client.py

@@ -155,8 +155,6 @@ def perform_registration(acme, config):
 
     :returns: Registration Resource.
     :rtype: `acme.messages.RegistrationResource`
-
-    :raises .UnexpectedUpdate:
     """
     try:
         return acme.register(messages.NewRegistration.from_data(email=config.email))