Subject to the provisions of this Act, when a bill has been dishonoured by non-acceptance or by non-payment, notice of dishonour must be given to the drawer and each indorser, and any drawer or indorser to whom such notice is not given is discharged: Provided that -
(1) Where a bill is dishonoured by non-acceptance, and notice of dishonour is not given, the rights of a holder in due course, subsequent to the omission, shall not be prejudiced by the omission.
(2) Where a bill is dishonoured by non-acceptance, and due notice of dishonour is given, it shall not be necessary to give notice of a subsequent dishonour by non-payment unless the bill shall in the meantime have been accepted.