Redis subscriber does not get new scan events on existing parents

def test_start_subscriber_after_parent_nodes_created(session):
    # Make sure the scan parents already exist before the watcher starts
    session.scan_saving.get_parent_node()

    started_event = gevent.event.Event()

    events = list()

    def watcher():
        node = get_session_node(session.name)
        for ev in node.walk_on_new_events(started_event=started_event):
            events.append(ev)
            if ev.type == ev.type.END_SCAN:
                break

    g = gevent.spawn(watcher)
    assert started_event.wait(timeout=3)

    diode = session.env_dict["diode"]
    s = scans.loopscan(1, .1, diode)
    g.join(timeout=3)
    try:
        assert not g, "Did not receive END_SCAN event"
    except AssertionError:
        g.kill(timeout=3)
        raise

    assert len(events) == 15

@marcus.oscarsson I think this is the same as the BM29 issues with the session watcher.