Support stable identifiers for MSC2285: private read receipts. (#13273)

This adds support for the stable identifiers of MSC2285 while
continuing to support the unstable identifiers behind the configuration
flag. These will be removed in a future version.

2 files changed, 30 insertions, 17 deletions

diff --git a/synapse/handlers/initial_sync.py b/synapse/handlers/initial_sync.py
index 85b472f250..6484e47e5f 100644
--- a/synapse/handlers/initial_sync.py
+++ b/synapse/handlers/initial_sync.py
@@ -143,8 +143,8 @@ class InitialSyncHandler:
             joined_rooms,
             to_key=int(now_token.receipt_key),
         )
-        if self.hs.config.experimental.msc2285_enabled:
-            receipt = ReceiptEventSource.filter_out_private_receipts(receipt, user_id)
+
+        receipt = ReceiptEventSource.filter_out_private_receipts(receipt, user_id)
 
         tags_by_room = await self.store.get_tags_for_user(user_id)
 
@@ -456,11 +456,8 @@ class InitialSyncHandler:
             )
             if not receipts:
                 return []
-            if self.hs.config.experimental.msc2285_enabled:
-                receipts = ReceiptEventSource.filter_out_private_receipts(
-                    receipts, user_id
-                )
-            return receipts
+
+            return ReceiptEventSource.filter_out_private_receipts(receipts, user_id)
 
         presence, receipts, (messages, token) = await make_deferred_yieldable(
             gather_results(
diff --git a/synapse/handlers/receipts.py b/synapse/handlers/receipts.py
index 43d2882b0a..d4a866b346 100644
--- a/synapse/handlers/receipts.py
+++ b/synapse/handlers/receipts.py
@@ -163,7 +163,10 @@ class ReceiptsHandler:
         if not is_new:
             return
 
-        if self.federation_sender and receipt_type != ReceiptTypes.READ_PRIVATE:
+        if self.federation_sender and receipt_type not in (
+            ReceiptTypes.READ_PRIVATE,
+            ReceiptTypes.UNSTABLE_READ_PRIVATE,
+        ):
             await self.federation_sender.send_read_receipt(receipt)
 
 
@@ -203,24 +206,38 @@ class ReceiptEventSource(EventSource[int, JsonDict]):
             for event_id, orig_event_content in room.get("content", {}).items():
                 event_content = orig_event_content
                 # If there are private read receipts, additional logic is necessary.
-                if ReceiptTypes.READ_PRIVATE in event_content:
+                if (
+                    ReceiptTypes.READ_PRIVATE in event_content
+                    or ReceiptTypes.UNSTABLE_READ_PRIVATE in event_content
+                ):
                     # Make a copy without private read receipts to avoid leaking
                     # other user's private read receipts..
                     event_content = {
                         receipt_type: receipt_value
                         for receipt_type, receipt_value in event_content.items()
-                        if receipt_type != ReceiptTypes.READ_PRIVATE
+                        if receipt_type
+                        not in (
+                            ReceiptTypes.READ_PRIVATE,
+                            ReceiptTypes.UNSTABLE_READ_PRIVATE,
+                        )
                     }
 
                     # Copy the current user's private read receipt from the
                     # original content, if it exists.
-                    user_private_read_receipt = orig_event_content[
-                        ReceiptTypes.READ_PRIVATE
-                    ].get(user_id, None)
+                    user_private_read_receipt = orig_event_content.get(
+                        ReceiptTypes.READ_PRIVATE, {}
+                    ).get(user_id, None)
                     if user_private_read_receipt:
                         event_content[ReceiptTypes.READ_PRIVATE] = {
                             user_id: user_private_read_receipt
                         }
+                    user_unstable_private_read_receipt = orig_event_content.get(
+                        ReceiptTypes.UNSTABLE_READ_PRIVATE, {}
+                    ).get(user_id, None)
+                    if user_unstable_private_read_receipt:
+                        event_content[ReceiptTypes.UNSTABLE_READ_PRIVATE] = {
+                            user_id: user_unstable_private_read_receipt
+                        }
 
                 # Include the event if there is at least one non-private read
                 # receipt or the current user has a private read receipt.
@@ -256,10 +273,9 @@ class ReceiptEventSource(EventSource[int, JsonDict]):
             room_ids, from_key=from_key, to_key=to_key
         )
 
-        if self.config.experimental.msc2285_enabled:
-            events = ReceiptEventSource.filter_out_private_receipts(
-                events, user.to_string()
-            )
+        events = ReceiptEventSource.filter_out_private_receipts(
+            events, user.to_string()
+        )
 
         return events, to_key