Deduplicate presence in _update_states

1 files changed, 6 insertions, 0 deletions

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

index 7a3c16a8aa..16dbddee03 100644
--- a/synapse/handlers/presence.py
+++ b/synapse/handlers/presence.py
@@ -265,6 +265,12 @@ class PresenceHandler(object):
             to_notify = {}  # Changes we want to notify everyone about
             to_federation_ping = {}  # These need sending keep-alives
 
+            # Only bother handling the last presence change for each user
+            new_states_dict = {}
+            for new_state in new_states:
+                new_states_dict[new_state.user_id] = new_state
+            new_state = new_states_dict.values()
+
             for new_state in new_states:
                 user_id = new_state.user_id