Is it obligatory to fulfill a vow of fasting if it was made in a moment of anger due to a disagreement with one's sister?

This type of vow is called a conditional vow, and it is disliked because the Prophet, peace and blessings be upon him, forbade it, saying: "It does not avert anything, but rather it is used to extract [something] from the miserly." However, it must be fulfilled if the condition upon which it was made is met, due to the Prophet's saying, peace and blessings be upon him: "Whoever vows to obey Allah, let him obey Him"; and due to the general meaning of Allah's Almighty saying: "O YOU WHO HAVE BELIEVED, FULFILL [YOUR] CONTRACTS."