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.

1 files changed, 21 insertions, 13 deletions

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:
             (