mark old copy of updated session as outdated

auth/sessions.go

@@ -48,6 +48,7 @@ const (
 	SessionStateLoginFinalizing
 	SessionStateLoggedIn
 	SessionStateLoginFailed
+	SessionStateOutdated
 	SessionStateRemoved
 )
 
@@ -63,6 +64,8 @@ func (s SessionState) String() string {
 		return "logged-in"
 	case SessionStateLoginFailed:
 		return "login-failed"
+	case SessionStateOutdated:
+		return "outdated"
 	case SessionStateRemoved:
 		return "removed"
 	}
@@ -279,6 +282,7 @@ func (sm *SessionManager) update(id string, s *Session) error {
 		close(old.subscribe)
 	}
 	sm.sessions[id] = s
+	old.setState(SessionStateOutdated)
 	return nil
 }