(a) Within 120 days after a will is admitted to probate, any interested person, other than a party to a will contest and other than a person who had actual notice of a will contest in time to have joined in the contest, may petition the court to revoke the probate of the will. The petition shall include objections setting forth written grounds of opposition.
(b) Notwithstanding subdivision (a), a person who was a minor or who was incompetent and had no guardian or conservator at the time a will was admitted to probate may petition the court to revoke the probate of the will at any time before entry of an order for final distribution.