Fix some test failures when frozen_dicts are enabled (#6642)

Fixes #4026

changelog.d/6642.misc

@@ -0,0 +1 @@
+Fix errors when frozen_dicts are enabled.

synapse/crypto/event_signing.py

@@ -14,7 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-
+import collections.abc
 import hashlib
 import logging
 
@@ -40,8 +40,11 @@ def check_event_content_hash(event, hash_algorithm=hashlib.sha256):
     # some malformed events lack a 'hashes'. Protect against it being missing
     # or a weird type by basically treating it the same as an unhashed event.
     hashes = event.get("hashes")
-    if not isinstance(hashes, dict):
+    # nb it might be a frozendict or a dict
-        raise SynapseError(400, "Malformed 'hashes'", Codes.UNAUTHORIZED)
+    if not isinstance(hashes, collections.abc.Mapping):
+        raise SynapseError(
+            400, "Malformed 'hashes': %s" % (type(hashes),), Codes.UNAUTHORIZED
+        )
 
     if name not in hashes:
         raise SynapseError(

synapse/handlers/room.py

@@ -16,7 +16,7 @@
 # limitations under the License.
 
 """Contains functions for performing events on rooms."""
-import copy
+
 import itertools
 import logging
 import math
@@ -368,13 +368,16 @@ class RoomCreationHandler(BaseHandler):
         # Raise the requester's power level in the new room if necessary
         current_power_level = power_levels["users"][user_id]
         if current_power_level < needed_power_level:
-            # Perform a deepcopy in order to not modify the original power levels in a
+            # make sure we copy the event content rather than overwriting it.
-            # room, as its contents are preserved as the state for the old room later on
+            # note that if frozen_dicts are enabled, `power_levels` will be a frozen
-            new_power_levels = copy.deepcopy(power_levels)
+            # dict so we can't just copy.deepcopy it.
-            initial_state[(EventTypes.PowerLevels, "")] = new_power_levels
 
-            # Assign this power level to the requester
+            new_power_levels = {k: v for k, v in power_levels.items() if k != "users"}
+            new_power_levels["users"] = {
+                k: v for k, v in power_levels.get("users", {}).items() if k != user_id
+            }
             new_power_levels["users"][user_id] = needed_power_level
+            initial_state[(EventTypes.PowerLevels, "")] = new_power_levels
 
         yield self._send_events_for_new_room(
             requester,

synapse/handlers/room_member.py

@@ -507,6 +507,8 @@ class RoomMemberHandler(object):
         Returns:
             Deferred
         """
+        logger.info("Transferring room state from %s to %s", old_room_id, room_id)
+
         # Find all local users that were in the old room and copy over each user's state
         users = yield self.store.get_users_in_room(old_room_id)
         yield self.copy_user_state_on_room_upgrade(old_room_id, room_id, users)

synapse/storage/data_stores/main/state.py

@@ -12,7 +12,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-
+import collections.abc
 import logging
 from collections import namedtuple
 from typing import Iterable, Tuple
@@ -107,7 +107,7 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
         predecessor = create_event.content.get("predecessor", None)
 
         # Ensure the key is a dictionary
-        if not isinstance(predecessor, dict):
+        if not isinstance(predecessor, collections.abc.Mapping):
             return None
 
         return predecessor