Sliding Sync: Update filters to be robust against remote invite rooms (#17450)

Update `filters.is_encrypted` and `filters.types`/`filters.not_types` to
be robust when dealing with remote invite rooms in Sliding Sync.

Part of
[MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575):
Sliding Sync

Follow-up to https://github.com/element-hq/synapse/pull/17434

We now take into account current state, fallback to stripped state
for invite/knock rooms, then historical state. If we can't determine
the info needed to filter a room (either from state or stripped state),
it is filtered out.

1 files changed, 8 insertions, 0 deletions

diff --git a/synapse/api/constants.py b/synapse/api/constants.py

index 85001d9676..7dcb1e01fd 100644
--- a/synapse/api/constants.py
+++ b/synapse/api/constants.py
@@ -225,6 +225,11 @@ class EventContentFields:
     # This is deprecated in MSC2175.
     ROOM_CREATOR: Final = "creator"
 
+    # The version of the room for `m.room.create` events.
+    ROOM_VERSION: Final = "room_version"
+
+    ROOM_NAME: Final = "name"
+
     # Used in m.room.guest_access events.
     GUEST_ACCESS: Final = "guest_access"
 
@@ -237,6 +242,9 @@ class EventContentFields:
     # an unspecced field added to to-device messages to identify them uniquely-ish
     TO_DEVICE_MSGID: Final = "org.matrix.msgid"
 
+    # `m.room.encryption`` algorithm field
+    ENCRYPTION_ALGORITHM: Final = "algorithm"
+
 
 class EventUnsignedContentFields:
     """Fields found inside the 'unsigned' data on events"""