Does the involuntary emission of semen due to stress and confusion, as happened during an exam, invalidate the fast and necessitate a ritual bath (ghusl)?

If semen is discharged while awake, with desire, ghusl (ritual bath) becomes obligatory, and the fast is invalidated. However, if it is discharged without desire due to illness or similar reasons, then according to the majority of jurists, nothing is entailed. Some, like the Shafi'is, mandate ghusl for it without invalidating the fast. If semen is discharged involuntarily or without pleasure, it does not invalidate the fast, and according to the majority, ghusl is not obligatory for its discharge without desire.