46.—Where the court makes an order for the grant of a decree of nullity, it may declare either of the spouses concerned to be unfit to have custody of any dependent member of the family who is a minor and, if it does so and the spouse to whom the declaration relates is a parent of any dependent member of the family who is a minor, that spouse shall not, on the death of the other spouse, be entitled as of right to the custody of that minor.