Fix presence timeouts when synchrotron restarts. (#6212)

* Fix presence timeouts when synchrotron restarts.

Handling timeouts would fail if there was an external process that had
timed out, e.g. a synchrotron restarting. This was due to a couple of
variable name typoes.

Fixes #3715.

tests/handlers/test_presence.py

@@ -22,6 +22,7 @@ from synapse.api.constants import EventTypes, Membership, PresenceState
 from synapse.events import room_version_to_event_format
 from synapse.events.builder import EventBuilder
 from synapse.handlers.presence import (
+    EXTERNAL_PROCESS_EXPIRY,
     FEDERATION_PING_INTERVAL,
     FEDERATION_TIMEOUT,
     IDLE_TIMER,
@@ -413,6 +414,44 @@ class PresenceTimeoutTestCase(unittest.TestCase):
         self.assertEquals(state, new_state)
 
 
+class PresenceHandlerTestCase(unittest.HomeserverTestCase):
+    def prepare(self, reactor, clock, hs):
+        self.presence_handler = hs.get_presence_handler()
+        self.clock = hs.get_clock()
+
+    def test_external_process_timeout(self):
+        """Test that if an external process doesn't update the records for a while
+        we time out their syncing users presence.
+        """
+        process_id = 1
+        user_id = "@test:server"
+
+        # Notify handler that a user is now syncing.
+        self.get_success(
+            self.presence_handler.update_external_syncs_row(
+                process_id, user_id, True, self.clock.time_msec()
+            )
+        )
+
+        # Check that if we wait a while without telling the handler the user has
+        # stopped syncing that their presence state doesn't get timed out.
+        self.reactor.advance(EXTERNAL_PROCESS_EXPIRY / 2)
+
+        state = self.get_success(
+            self.presence_handler.get_state(UserID.from_string(user_id))
+        )
+        self.assertEqual(state.state, PresenceState.ONLINE)
+
+        # Check that if the external process timeout fires, then the syncing
+        # user gets timed out
+        self.reactor.advance(EXTERNAL_PROCESS_EXPIRY)
+
+        state = self.get_success(
+            self.presence_handler.get_state(UserID.from_string(user_id))
+        )
+        self.assertEqual(state.state, PresenceState.OFFLINE)
+
+
 class PresenceJoinTestCase(unittest.HomeserverTestCase):
     """Tests remote servers get told about presence of users in the room when
     they join and when new local users join.