From 3108b67232a23479f6ca5158b85635b043816ae2 Mon Sep 17 00:00:00 2001
From: Tulir Asokan <tulir@maunium.net>
Date: Sun, 12 Feb 2023 15:02:13 +0200
Subject: [PATCH] Allow custom content in read receipts

---
 synapse/handlers/read_marker.py    | 11 ++++++++---
 synapse/handlers/receipts.py       |  3 ++-
 synapse/rest/client/read_marker.py |  5 +++++
 synapse/rest/client/receipts.py    |  4 +++-
 4 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/synapse/handlers/read_marker.py b/synapse/handlers/read_marker.py
index 135a66226..f39732f2c 100644
--- a/synapse/handlers/read_marker.py
+++ b/synapse/handlers/read_marker.py
@@ -20,11 +20,12 @@
 #
 
 import logging
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, Optional
 
 from synapse.api.constants import ReceiptTypes
 from synapse.api.errors import SynapseError
 from synapse.util.async_helpers import Linearizer
+from synapse.types import JsonDict
 
 if TYPE_CHECKING:
     from synapse.server import HomeServer
@@ -39,7 +40,11 @@ class ReadMarkerHandler:
         self.read_marker_linearizer = Linearizer(name="read_marker")
 
     async def received_client_read_marker(
-        self, room_id: str, user_id: str, event_id: str
+        self,
+        room_id: str,
+        user_id: str,
+        event_id: str,
+        extra_content: Optional[JsonDict] = None,
     ) -> None:
         """Updates the read marker for a given user in a given room if the event ID given
         is ahead in the stream relative to the current read marker.
@@ -71,7 +76,7 @@ class ReadMarkerHandler:
                     should_update = event_ordering > old_event_ordering
 
             if should_update:
-                content = {"event_id": event_id}
+                content = {"event_id": event_id, **(extra_content or {})}
                 await self.account_data_handler.add_account_data_to_room(
                     user_id, room_id, ReceiptTypes.FULLY_READ, content
                 )
diff --git a/synapse/handlers/receipts.py b/synapse/handlers/receipts.py
index 8674a8fcd..cc2f49efd 100644
--- a/synapse/handlers/receipts.py
+++ b/synapse/handlers/receipts.py
@@ -181,6 +181,7 @@ class ReceiptsHandler:
         user_id: UserID,
         event_id: str,
         thread_id: Optional[str],
+        extra_content: Optional[JsonDict] = None,
     ) -> None:
         """Called when a client tells us a local user has read up to the given
         event_id in the room.
@@ -197,7 +198,7 @@ class ReceiptsHandler:
             user_id=user_id.to_string(),
             event_ids=[event_id],
             thread_id=thread_id,
-            data={"ts": int(self.clock.time_msec())},
+            data={"ts": int(self.clock.time_msec()), **(extra_content or {})},
         )
 
         is_new = await self._handle_new_receipts([receipt])
diff --git a/synapse/rest/client/read_marker.py b/synapse/rest/client/read_marker.py
index d3d3c7c41..dce29e493 100644
--- a/synapse/rest/client/read_marker.py
+++ b/synapse/rest/client/read_marker.py
@@ -80,12 +80,16 @@ class ReadMarkerRestServlet(RestServlet):
             # TODO Add validation to reject non-string event IDs.
             if not event_id:
                 continue
+            extra_content = body.get(
+                receipt_type.replace("m.", "com.beeper.") + ".extra", None
+            )
 
             if receipt_type == ReceiptTypes.FULLY_READ:
                 await self.read_marker_handler.received_client_read_marker(
                     room_id,
                     user_id=requester.user.to_string(),
                     event_id=event_id,
+                    extra_content=extra_content,
                 )
             else:
                 await self.receipts_handler.received_client_receipt(
@@ -95,6 +99,7 @@ class ReadMarkerRestServlet(RestServlet):
                     event_id=event_id,
                     # Setting the thread ID is not possible with the /read_markers endpoint.
                     thread_id=None,
+                    extra_content=extra_content,
                 )
 
         return 200, {}
diff --git a/synapse/rest/client/receipts.py b/synapse/rest/client/receipts.py
index 89203dc45..d83baaa1c 100644
--- a/synapse/rest/client/receipts.py
+++ b/synapse/rest/client/receipts.py
@@ -73,7 +73,7 @@ class ReceiptRestServlet(RestServlet):
                 f"Receipt type must be {', '.join(self._known_receipt_types)}",
             )
 
-        body = parse_json_object_from_request(request)
+        body = parse_json_object_from_request(request, allow_empty_body=False)
 
         # Pull the thread ID, if one exists.
         thread_id = None
@@ -110,6 +110,7 @@ class ReceiptRestServlet(RestServlet):
                 room_id,
                 user_id=requester.user.to_string(),
                 event_id=event_id,
+                extra_content=body,
             )
         else:
             await self.receipts_handler.received_client_receipt(
@@ -118,6 +119,7 @@ class ReceiptRestServlet(RestServlet):
                 user_id=requester.user,
                 event_id=event_id,
                 thread_id=thread_id,
+                extra_content=body,
             )
 
         return 200, {}