What is the ruling on a traveler's prayer if he intended to stay for more than four days, then his travel leader informed him of a shortened duration and an unknown return date, and the stay continued for more than four days?

If a traveler intends to stay for four days or more, he is obligated to pray in full. However, if he is accompanying a travel leader who has not intended to stay or is undecided, then he must follow his leader in shortening the prayer, because obedience to him is obligatory in matters pertaining to travel. But if he is not accompanying such a leader and shortens the prayer while intending to stay for four days, then, according to the majority of scholars, he must repeat the prayer.