(a) If a firefighter marries subsequent to the date of his or her retirement with any pension under this Article, and dies less than 12 months after the marriage, a surviving spouse shall receive no pension on the death of the firefighter.
     (b) Beginning January 1, 1989, this Section shall no longer disqualify the surviving spouse of a firefighter who was married to such surviving spouse for at least 12 months and died before November 18, 1985, from receiving a survivor’s pension, and any such surviving spouse who is otherwise eligible under Section 4-114 shall begin to receive a surviving spouse’s pension on July 1, 1989.