What is the ruling on the expiation (kaffara) obligatory upon someone who broke an oath after resolving not to do something, but then was unable to adhere to their oath?

If a person swears by Allah not to do a certain thing, then does it, an expiation for breaking an oath (kaffarat yamin) becomes incumbent upon them. Their oath is dissolved by the first breach, so the expiation is not repeated if the action is done again. However, the expiation may be repeated if the swearer intended its repetition with the repetition of the action, or if the wording of their oath implied repetition, such as: "Every time" or "Whenever I do this thing, an expiation for breaking an oath is incumbent upon me."