From 2d1b7955aec60a2a5dabc7882b4081b794968d7c Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Mon, 18 Sep 2017 17:13:03 +0100
Subject: [PATCH] Don't filter out current state events from timeline

---
 synapse/handlers/sync.py |  7 +++++++
 synapse/visibility.py    | 14 +++++++++++---
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index c6b04a1683..bb78c25ee5 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -293,6 +293,11 @@ class SyncHandler(object):
             timeline_limit = sync_config.filter_collection.timeline_limit()
             block_all_timeline = sync_config.filter_collection.blocks_all_room_timeline()
 
+            # Pull out the current state, as we always want to include those events
+            # in the timeline if they're there.
+            current_state_ids = yield self.state.get_current_state_ids(room_id)
+            current_state_ids = frozenset(current_state_ids.itervalues())
+
             if recents is None or newly_joined_room or timeline_limit < len(recents):
                 limited = True
             else:
@@ -304,6 +309,7 @@ class SyncHandler(object):
                     self.store,
                     sync_config.user.to_string(),
                     recents,
+                    always_include_ids=current_state_ids,
                 )
             else:
                 recents = []
@@ -339,6 +345,7 @@ class SyncHandler(object):
                     self.store,
                     sync_config.user.to_string(),
                     loaded_recents,
+                    always_include_ids=current_state_ids,
                 )
                 loaded_recents.extend(recents)
                 recents = loaded_recents
diff --git a/synapse/visibility.py b/synapse/visibility.py
index 5590b866ed..d7dbdc77ff 100644
--- a/synapse/visibility.py
+++ b/synapse/visibility.py
@@ -43,7 +43,8 @@ MEMBERSHIP_PRIORITY = (
 
 
 @defer.inlineCallbacks
-def filter_events_for_clients(store, user_tuples, events, event_id_to_state):
+def filter_events_for_clients(store, user_tuples, events, event_id_to_state,
+                              always_include_ids=frozenset()):
     """ Returns dict of user_id -> list of events that user is allowed to
     see.
 
@@ -54,6 +55,8 @@ def filter_events_for_clients(store, user_tuples, events, event_id_to_state):
             * the user has not been a member of the room since the
             given events
         events ([synapse.events.EventBase]): list of events to filter
+        always_include_ids (set(event_id)): set of event ids to specifically
+            include (unless sender is ignored)
     """
     forgotten = yield preserve_context_over_deferred(defer.gatherResults([
         defer.maybeDeferred(
@@ -91,6 +94,9 @@ def filter_events_for_clients(store, user_tuples, events, event_id_to_state):
         if not event.is_state() and event.sender in ignore_list:
             return False
 
+        if event.event_id in always_include_ids:
+            return True
+
         state = event_id_to_state[event.event_id]
 
         # get the room_visibility at the time of the event.
@@ -189,7 +195,8 @@ def filter_events_for_clients(store, user_tuples, events, event_id_to_state):
 
 
 @defer.inlineCallbacks
-def filter_events_for_client(store, user_id, events, is_peeking=False):
+def filter_events_for_client(store, user_id, events, is_peeking=False,
+                             always_include_ids=frozenset()):
     """
     Check which events a user is allowed to see
 
@@ -213,6 +220,7 @@ def filter_events_for_client(store, user_id, events, is_peeking=False):
         types=types
     )
     res = yield filter_events_for_clients(
-        store, [(user_id, is_peeking)], events, event_id_to_state
+        store, [(user_id, is_peeking)], events, event_id_to_state,
+        always_include_ids=always_include_ids,
     )
     defer.returnValue(res.get(user_id, []))