Add query parameter `ts` to allow appservices set the `origin_server_ts` for state events. (#11866)

MSC3316 declares that both /rooms/{roomId}/send and /rooms/{roomId}/state
should accept a ts parameter for appservices. This change expands support
to /state and adds tests.

2 files changed, 34 insertions, 13 deletions

diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py
index ee669eb30f..6ad2b38b8f 100644
--- a/synapse/handlers/room_member.py
+++ b/synapse/handlers/room_member.py
@@ -322,6 +322,7 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
         require_consent: bool = True,
         outlier: bool = False,
         historical: bool = False,
+        origin_server_ts: Optional[int] = None,
     ) -> Tuple[str, int]:
         """
         Internal membership update function to get an existing event or create
@@ -361,6 +362,8 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
             historical: Indicates whether the message is being inserted
                 back in time around some existing events. This is used to skip
                 a few checks and mark the event as backfilled.
+            origin_server_ts: The origin_server_ts to use if a new event is created. Uses
+                the current timestamp if set to None.
 
         Returns:
             Tuple of event ID and stream ordering position
@@ -399,6 +402,7 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
                 "state_key": user_id,
                 # For backwards compatibility:
                 "membership": membership,
+                "origin_server_ts": origin_server_ts,
             },
             txn_id=txn_id,
             allow_no_prev_events=allow_no_prev_events,
@@ -504,6 +508,7 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
         prev_event_ids: Optional[List[str]] = None,
         state_event_ids: Optional[List[str]] = None,
         depth: Optional[int] = None,
+        origin_server_ts: Optional[int] = None,
     ) -> Tuple[str, int]:
         """Update a user's membership in a room.
 
@@ -542,6 +547,8 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
             depth: Override the depth used to order the event in the DAG.
                 Should normally be set to None, which will cause the depth to be calculated
                 based on the prev_events.
+            origin_server_ts: The origin_server_ts to use if a new event is created. Uses
+                the current timestamp if set to None.
 
         Returns:
             A tuple of the new event ID and stream ID.
@@ -583,6 +590,7 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
                         prev_event_ids=prev_event_ids,
                         state_event_ids=state_event_ids,
                         depth=depth,
+                        origin_server_ts=origin_server_ts,
                     )
 
         return result
@@ -606,6 +614,7 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
         prev_event_ids: Optional[List[str]] = None,
         state_event_ids: Optional[List[str]] = None,
         depth: Optional[int] = None,
+        origin_server_ts: Optional[int] = None,
     ) -> Tuple[str, int]:
         """Helper for update_membership.
 
@@ -646,6 +655,8 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
             depth: Override the depth used to order the event in the DAG.
                 Should normally be set to None, which will cause the depth to be calculated
                 based on the prev_events.
+            origin_server_ts: The origin_server_ts to use if a new event is created. Uses
+                the current timestamp if set to None.
 
         Returns:
             A tuple of the new event ID and stream ID.
@@ -785,6 +796,7 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
                 require_consent=require_consent,
                 outlier=outlier,
                 historical=historical,
+                origin_server_ts=origin_server_ts,
             )
 
         latest_event_ids = await self.store.get_prev_events_for_room(room_id)
@@ -1030,6 +1042,7 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
             content=content,
             require_consent=require_consent,
             outlier=outlier,
+            origin_server_ts=origin_server_ts,
         )
 
     async def _should_perform_remote_join(
diff --git a/synapse/rest/client/room.py b/synapse/rest/client/room.py
index 0bca012535..b6dedbed04 100644
--- a/synapse/rest/client/room.py
+++ b/synapse/rest/client/room.py
@@ -268,15 +268,9 @@ class RoomStateEventRestServlet(TransactionRestServlet):
 
         content = parse_json_object_from_request(request)
 
-        event_dict = {
-            "type": event_type,
-            "content": content,
-            "room_id": room_id,
-            "sender": requester.user.to_string(),
-        }
-
-        if state_key is not None:
-            event_dict["state_key"] = state_key
+        origin_server_ts = None
+        if requester.app_service:
+            origin_server_ts = parse_integer(request, "ts")
 
         try:
             if event_type == EventTypes.Member:
@@ -287,8 +281,22 @@ class RoomStateEventRestServlet(TransactionRestServlet):
                     room_id=room_id,
                     action=membership,
                     content=content,
+                    origin_server_ts=origin_server_ts,
                 )
             else:
+                event_dict: JsonDict = {
+                    "type": event_type,
+                    "content": content,
+                    "room_id": room_id,
+                    "sender": requester.user.to_string(),
+                }
+
+                if state_key is not None:
+                    event_dict["state_key"] = state_key
+
+                if origin_server_ts is not None:
+                    event_dict["origin_server_ts"] = origin_server_ts
+
                 (
                     event,
                     _,
@@ -333,10 +341,10 @@ class RoomSendEventRestServlet(TransactionRestServlet):
             "sender": requester.user.to_string(),
         }
 
-        # Twisted will have processed the args by now.
-        assert request.args is not None
-        if b"ts" in request.args and requester.app_service:
-            event_dict["origin_server_ts"] = parse_integer(request, "ts", 0)
+        if requester.app_service:
+            origin_server_ts = parse_integer(request, "ts")
+            if origin_server_ts is not None:
+                event_dict["origin_server_ts"] = origin_server_ts
 
         try:
             (