Say one were to go to confession, confessed sins but did not receive absolution. Would the priest still be required to keep the seal of confession?
From the Canon Law Society of America’s commentary on canon 983:
Canon 983 is concerned with any kind of betrayal of a penitent, whose confession of sins is said to be under or protected by an inviolable sacramental seal, and this even if he or she has not been absolved. It is any betrayal of a person who has simply confessed in the context of the sacrament.
CLSA’S New Commentary on the Code of Canon Law, © 2000, p.1163-4
The seal begins the moment the penitent intends to sacramentally confess his or her sins.