If a polytheist makes a vow and then becomes Muslim, what is said about it?

Hazrat Umar says that I made a vow in the time of ignorance, then I became a Muslim. I asked the Holy Prophet (peace and blessings be upon him) about it. He (peace and blessings be upon him) commanded me to fulfill my vow.

Hazrat Tawus says that every oath by which a vow is taken is an act of goodness and kindness for Allah, so it should be fulfilled in Islam as well.

Hazrat Tawus was asked about a person who made a vow during the period of ignorance and then became a Muslim. He replied: He should fulfill his vow.

Hazrat Al-Hazli narrates that a woman who was a Christian made a vow to light a lamp in a church. Later, she became a Muslim, and then she intended to fulfill her vow. Hasan and Hazrat Qatadah said that she should light lamps in the mosques of the Muslims. Hazrat Ibn Sirin said that nothing is required of her. Hazrat Al-Hazli says that I presented their statements before Hazrat Sha’bi, and he said: The one who hears well (Ibn Sirin) has spoken correctly, and your companions have erred. Islam demolishes what came before it.

12831 - Ibn Sirin said: There is nothing upon her.

12832 - Their statements were presented to al-Sha‘bi, and he said: The deaf one was correct and your two companions were mistaken. Islam demolishes what came before it.