f always add shadow offset to blinded paths

Author: valentinewallace

lightning/src/routing/router.rs

@@ -2111,8 +2111,6 @@ fn add_random_cltv_offset(route: &mut Route, payment_params: &PaymentParameters,
 	let network_nodes = network_graph.nodes();
 
 	for path in route.paths.iter_mut() {
-		if path.blinded_tail.as_ref().map_or(false, |tail| tail.hops.len() > 1) { continue }
-
 		let mut shadow_ctlv_expiry_delta_offset: u32 = 0;
 
 		// Remember the last three nodes of the random walk and avoid looping back on them.
@@ -2184,8 +2182,7 @@ fn add_random_cltv_offset(route: &mut Route, payment_params: &PaymentParameters,
 		if let Some(tail) = path.blinded_tail.as_mut() {
 			tail.final_cltv_expiry_delta = tail.final_cltv_expiry_delta
 				.checked_add(shadow_ctlv_expiry_delta_offset).unwrap_or(tail.final_cltv_expiry_delta);
-		}
-		if let Some(last_hop) = path.hops.last_mut() {
+		} else if let Some(last_hop) = path.hops.last_mut() {
 			last_hop.cltv_expiry_delta = last_hop.cltv_expiry_delta
 				.checked_add(shadow_ctlv_expiry_delta_offset).unwrap_or(last_hop.cltv_expiry_delta);
 		}
@@ -5880,7 +5877,7 @@ mod tests {
 
 	#[test]
 	fn blinded_path_cltv_shadow_offset() {
-		// Don't add a shadow offset to blinded paths with more than 1 hop.
+		// Make sure we add a shadow offset when sending to blinded paths.
 		let blinded_path = BlindedPath {
 			introduction_node_id: ln_test_utils::pubkey(43),
 			blinding_point: ln_test_utils::pubkey(44),
@@ -5918,11 +5915,6 @@ mod tests {
 		let payment_params = PaymentParameters::from_node_id(ln_test_utils::pubkey(47), 18);
 		let (_, network_graph, _, _, _) = build_line_graph();
 		add_random_cltv_offset(&mut route, &payment_params, &network_graph.read_only(), &[0; 32]);
-		assert_eq!(route.paths[0].blinded_tail.as_ref().unwrap().final_cltv_expiry_delta, 0);
-
-		// Add a shadow offset if we're sending to a 1-hop blinded path.
-		route.paths[0].blinded_tail.as_mut().unwrap().hops.pop();
-		add_random_cltv_offset(&mut route, &payment_params, &network_graph.read_only(), &[0; 32]);
 		assert_eq!(route.paths[0].blinded_tail.as_ref().unwrap().final_cltv_expiry_delta, 40);
 	}
 }