Fix deduplicating of membership events to not create unused state groups. (#17164)

We try and deduplicate in two places: 1) really early on, and 2) just
before we persist the event. The first case was broken due to it
occuring before the profile information was added, and so it thought the
event contents were different.

The second case did catch it and handle it correctly, however doing so
creates a redundant state group leading to bloat.

Fixes #3791

1 files changed, 0 insertions, 32 deletions

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

index ccaa5508ff..de5bd44a5f 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -496,13 +496,6 @@ class EventCreationHandler:
 
         self.room_prejoin_state_types = self.hs.config.api.room_prejoin_state
 
-        self.membership_types_to_include_profile_data_in = {
-            Membership.JOIN,
-            Membership.KNOCK,
-        }
-        if self.hs.config.server.include_profile_data_on_invite:
-            self.membership_types_to_include_profile_data_in.add(Membership.INVITE)
-
         self.send_event = ReplicationSendEventRestServlet.make_client(hs)
         self.send_events = ReplicationSendEventsRestServlet.make_client(hs)
 
@@ -594,8 +587,6 @@ class EventCreationHandler:
         Creates an FrozenEvent object, filling out auth_events, prev_events,
         etc.
 
-        Adds display names to Join membership events.
-
         Args:
             requester
             event_dict: An entire event
@@ -672,29 +663,6 @@ class EventCreationHandler:
 
         self.validator.validate_builder(builder)
 
-        if builder.type == EventTypes.Member:
-            membership = builder.content.get("membership", None)
-            target = UserID.from_string(builder.state_key)
-
-            if membership in self.membership_types_to_include_profile_data_in:
-                # If event doesn't include a display name, add one.
-                profile = self.profile_handler
-                content = builder.content
-
-                try:
-                    if "displayname" not in content:
-                        displayname = await profile.get_displayname(target)
-                        if displayname is not None:
-                            content["displayname"] = displayname
-                    if "avatar_url" not in content:
-                        avatar_url = await profile.get_avatar_url(target)
-                        if avatar_url is not None:
-                            content["avatar_url"] = avatar_url
-                except Exception as e:
-                    logger.info(
-                        "Failed to get profile information for %r: %s", target, e
-                    )
-
         is_exempt = await self._is_exempt_from_privacy_policy(builder, requester)
         if require_consent and not is_exempt:
             await self.assert_accepted_privacy_policy(requester)