Is an expiatory offering (kaffarat yamin) obligatory upon someone who swore not to perform a specific act, then performed part of it without completing it, meaning the result of the act did not materialize?

Scholars have differed concerning one who swore not to do something, then did part of it: does he break his oath or not? The Malikis held that he breaks it, while the Shafi'is and Hanafis held that he does not break it unless he does all of it. Narrations from Ahmad differ, but prudence dictates adopting the view that expiation is obligatory. This difference of opinion is specific to an absolute oath. However, if there was an intention or a circumstantial indicator, then it is relied upon.