f missing recv payload case

Author: valentinewallace

lightning/src/blinded_path/mod.rs

@@ -98,6 +98,7 @@ impl BlindedPath {
 				found_recv_payload = true;
 			} else if found_recv_payload { return Err(()) }
 		}
+		if !found_recv_payload { return Err(()) }
 
 		let blinding_secret_bytes = entropy_source.get_secure_random_bytes();
 		let blinding_secret = SecretKey::from_slice(&blinding_secret_bytes[..]).expect("RNG is busted");

lightning/src/blinded_path/payment.rs

@@ -312,5 +312,20 @@ mod tests {
 			},
 		})];
 		assert!(BlindedPath::new_for_payment(&multiple_recv_payloads_path[..], &keys_manager, &secp_ctx).is_err());
+
+		let missing_recv_payload_path = vec![(dummy_pk, BlindedPaymentTlvs::Forward {
+			short_channel_id: 0,
+			payment_relay: PaymentRelay {
+				cltv_expiry_delta: 144,
+				fee_proportional_millionths: 500,
+				fee_base_msat: 100,
+			},
+			payment_constraints: PaymentConstraints {
+				max_cltv_expiry: 0,
+				htlc_minimum_msat: 100,
+			},
+			features: BlindedHopFeatures::empty(),
+		})];
+		assert!(BlindedPath::new_for_payment(&missing_recv_payload_path[..], &keys_manager, &secp_ctx).is_err());
 	}
 }