What is the ruling on a fasting person who hears the second call to dawn prayer (Fajr) while food is in their mouth: should they swallow it or spit it out, and is their fast complete?

You are permitted to eat and drink until the dawn becomes clear. If the second call to prayer (adhan) is made at dawn, you must cease from all things that break the fast. If one intentionally swallows something after this point, their fast is invalidated, and they must abstain [for the rest of the day] and make up for that day.