What is the ruling when an oath conditions divorce upon an action involving an item partially consumed or discarded?

Primary text

If a person has a date in his mouth and swears, 'You are divorced if you eat it, drop it, or hold it,' and the wife eats part of it and drops the rest, the oath is not broken, except according to those who hold that breaking or acting upon a portion of the conditioned item fulfills the oath. If the wife intended to consume the entire date, the oath is never broken under any circumstance.