diff --git a/synapse/events/utils.py b/synapse/events/utils.py
index 07d1c5bcf0..be57c6d9be 100644
--- a/synapse/events/utils.py
+++ b/synapse/events/utils.py
@@ -12,8 +12,9 @@
# 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
import re
+from typing import Mapping, Union
from six import string_types
@@ -422,3 +423,37 @@ class EventClientSerializer(object):
return yieldable_gather_results(
self.serialize_event, events, time_now=time_now, **kwargs
)
+
+
+def copy_power_levels_contents(
+ old_power_levels: Mapping[str, Union[int, Mapping[str, int]]]
+):
+ """Copy the content of a power_levels event, unfreezing frozendicts along the way
+
+ Raises:
+ TypeError if the input does not look like a valid power levels event content
+ """
+ if not isinstance(old_power_levels, collections.Mapping):
+ raise TypeError("Not a valid power-levels content: %r" % (old_power_levels,))
+
+ power_levels = {}
+ for k, v in old_power_levels.items():
+
+ if isinstance(v, int):
+ power_levels[k] = v
+ continue
+
+ if isinstance(v, collections.Mapping):
+ power_levels[k] = h = {}
+ for k1, v1 in v.items():
+ # we should only have one level of nesting
+ if not isinstance(v1, int):
+ raise TypeError(
+ "Invalid power_levels value for %s.%s: %r" % (k, k1, v)
+ )
+ h[k1] = v1
+ continue
+
+ raise TypeError("Invalid power_levels value for %s: %r" % (k, v))
+
+ return power_levels
diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index a9490782b7..532ee22fa4 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -30,6 +30,7 @@ from twisted.internet import defer
from synapse.api.constants import EventTypes, JoinRules, RoomCreationPreset
from synapse.api.errors import AuthError, Codes, NotFoundError, StoreError, SynapseError
from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, RoomVersion
+from synapse.events.utils import copy_power_levels_contents
from synapse.http.endpoint import parse_and_validate_server_name
from synapse.storage.state import StateFilter
from synapse.types import (
@@ -367,6 +368,15 @@ class RoomCreationHandler(BaseHandler):
if old_event:
initial_state[k] = old_event.content
+ # deep-copy the power-levels event before we start modifying it
+ # note that if frozen_dicts are enabled, `power_levels` will be a frozen
+ # dict so we can't just copy.deepcopy it.
+ initial_state[
+ (EventTypes.PowerLevels, "")
+ ] = power_levels = copy_power_levels_contents(
+ initial_state[(EventTypes.PowerLevels, "")]
+ )
+
# Resolve the minimum power level required to send any state event
# We will give the upgrading user this power level temporarily (if necessary) such that
# they are able to copy all of the state events over, then revert them back to their
@@ -375,8 +385,6 @@ class RoomCreationHandler(BaseHandler):
# Copy over user power levels now as this will not be possible with >100PL users once
# the room has been created
- power_levels = initial_state[(EventTypes.PowerLevels, "")]
-
# Calculate the minimum power level needed to clone the room
event_power_levels = power_levels.get("events", {})
state_default = power_levels.get("state_default", 0)
@@ -386,16 +394,7 @@ 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:
- # make sure we copy the event content rather than overwriting it.
- # note that if frozen_dicts are enabled, `power_levels` will be a frozen
- # dict so we can't just copy.deepcopy it.
-
- 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
+ power_levels["users"][user_id] = needed_power_level
yield self._send_events_for_new_room(
requester,
|
