We're in the middle of properly mitigating spam caused by malicious aliases being added to a room. However, until this work fully lands, we temporarily filter out all m.room.aliases events from /sync and /messages on the CS API, to remove abusive aliases. This is considered acceptable as m.room.aliases events were never a reliable record of the given alias->id mapping and were purely informational, and in their current state do more harm than good.
We were looking at the wrong event type (`m.room.encryption` vs
`m.room.encrypted`).
Also fixup the duplicate `EvenTypes` entries.
Introduced in #6776.
When a server leaves a room it may stop sharing a room with remote
users, and thus not get any updates to their device lists. So we need to
check for this case and delete those device lists from the cache.
We don't need to do this if we stop sharing a room because the remote
user leaves the room, because we track that case via looking at
membership changes.
If we detect that the remote users' keys may have changed then we should
attempt to resync against the remote server rather than using the
(potentially) stale local cache.
We were sending device updates down both the federation stream and
device streams. This mean there was a race if the federation sender
worker processed the federation stream first, as when the sender checked
if there were new device updates the slaved ID generator hadn't been
updated with the new stream IDs and so returned nothing.
This situation is correctly handled by events/receipts/etc by not
sending updates down the federation stream and instead having the
federation sender worker listen on the other streams and poke the
transaction queues as appropriate.
Otherwise its just stale data, which may get deleted later anyway so
can't be relied on. It's also a bit of a shotgun if we're trying to get
the current state of a room we're not in.
These are easier to work with than the strings and we normally have one around.
This fixes `FederationHander._persist_auth_tree` which was passing a
RoomVersion object into event_auth.check instead of a string.
There are quite a few places that we assume that a redaction event has a
corresponding `redacts` key, which is not always the case. So lets
cheekily make it so that event.redacts just returns None instead.
