Prevent historical state from being pushed to an application service via `/transactions` (MSC2716) (#11265)

Mark historical state from the MSC2716 `/batch_send` endpoint as `historical` which makes it `backfilled` and have a negative `stream_ordering` so it doesn't get queried by `/transactions`.

Fix https://github.com/matrix-org/synapse/issues/11241

Complement tests: https://github.com/matrix-org/complement/pull/221

1 files changed, 2 insertions, 0 deletions

diff --git a/synapse/handlers/room_batch.py b/synapse/handlers/room_batch.py

index 0723286383..f880aa93d2 100644
--- a/synapse/handlers/room_batch.py
+++ b/synapse/handlers/room_batch.py
@@ -221,6 +221,7 @@ class RoomBatchHandler:
                     action=membership,
                     content=event_dict["content"],
                     outlier=True,
+                    historical=True,
                     prev_event_ids=[prev_event_id_for_state_chain],
                     # Make sure to use a copy of this list because we modify it
                     # later in the loop here. Otherwise it will be the same
@@ -240,6 +241,7 @@ class RoomBatchHandler:
                     ),
                     event_dict,
                     outlier=True,
+                    historical=True,
                     prev_event_ids=[prev_event_id_for_state_chain],
                     # Make sure to use a copy of this list because we modify it
                     # later in the loop here. Otherwise it will be the same