[web2py] auth.messages.logged_out not flashing unless next redirect specified

[weheh]

Is there a good reason why auth.messages.logged_out doesn't flash upon 
logout unless there is a next argument?

# this flashes
def logout():
    auth.messages.logged_out = 'bye bye'
    return dict(form=auth.logout(next=URL(c='mycontroller', f='index')))

# this does not flash
def logout():
    auth.messages.logged_out = 'bye bye'
    return dict(form=auth.logout())