register_record function doesn't add proof to distribution_list

[Yoekkul]

Within smartphone.rsthe distribution_list is used to keep track of all entitlements which have been proved (and thus distributed).
It seems to me that the register_record method should insert all proofs given to it into the list. (And should thus look the following)

pub fn register_record(&mut self, p: &HouseholdDisclosureProof, ent: &Scalar, r: &Scalar) {
        self.distribution_list.push(p.tau); // <---------------------------------- THIS IS MISSING?
        self.audit_records.push((p.clone(), ent.clone(), r.clone()));
    }

If this were not the case double spends could only be detected during an audit (and not at the distribution station).

The following test should highlight the issue

    #[test]
    fn double_spend_failure() {
        let mut rng = ChaCha20Rng::seed_from_u64(42 as u64);
        let mut registration_station = RegistrationStation::new(&mut rng);
        let mut distribution_station = DistributionStation::new(&registration_station.pedersen_params);
        let pk = registration_station.register("foo", &Scalar::from(1234u64), &mut rng).unwrap();

        let builder = HouseholdPhoneBuilder::new(&pk, &mut rng);
        let (request, state) = builder.issue_request(&mut rng).unwrap();
        let signature = registration_station.sign_issue_request("foo", &request, &mut rng).unwrap();
        let mut phone = builder.unblind(&signature, &state, &registration_station.pedersen_params).unwrap();

        let epoch = 1668172689u64;

        let (proof, r) = phone.create_disclosure_proof(epoch, &registration_station.blocklist, &mut rng).unwrap();
        assert!(distribution_station.verify_entitlement(&phone.credential.attributes[ATTR_IDX_ENTITLEMENT], &proof.com_ent, &r));
        assert!(distribution_station.verify_disclosure_proof(&pk, epoch, &registration_station.blocklist, &proof).unwrap());

        distribution_station.register_record(&proof, &phone.credential.attributes[ATTR_IDX_ENTITLEMENT], &r);

        // Double spend is attempted
        let (proof, r) = phone.create_disclosure_proof(epoch, &registration_station.blocklist, &mut rng).unwrap();
        assert!(distribution_station.verify_entitlement(&phone.credential.attributes[ATTR_IDX_ENTITLEMENT], &proof.com_ent, &r));
        let is_double_spend_allowed = distribution_station.verify_disclosure_proof(&pk, epoch, &registration_station.blocklist, &proof).unwrap();
        assert!(is_double_spend_allowed == false);
    }