Fix trampoline onion encoding to match doc-declared CLTV rules

diff --git a/lightning/src/ln/blinded_payment_tests.rs b/lightning/src/ln/blinded_payment_tests.rs
index b945b89..e148ce2 100644
--- a/lightning/src/ln/blinded_payment_tests.rs
+++ b/lightning/src/ln/blinded_payment_tests.rs
@@ -1852,7 +1852,7 @@ fn test_combined_trampoline_onion_creation_vectors() {
 				short_channel_id: (572330 << 40) + (42 << 16) + 2821,
 				channel_features: ChannelFeatures::empty(),
 				fee_msat: 153_000,
-				cltv_expiry_delta: 0,
+				cltv_expiry_delta: 24 + 36,
 				maybe_announced_channel: false,
 			},
 		],
@@ -1947,7 +1947,7 @@ fn test_trampoline_inbound_payment_decoding() {
 				short_channel_id: (572330 << 40) + (42 << 16) + 2821,
 				channel_features: ChannelFeatures::empty(),
 				fee_msat: 150_153_000,
-				cltv_expiry_delta: 0,
+				cltv_expiry_delta: 24 + 36,
 				maybe_announced_channel: false,
 			},
 		],
@@ -2115,7 +2115,7 @@ fn test_trampoline_forward_payload_encoded_as_receive() {
 		blinded_path::utils::construct_blinded_hops(
 			&secp_ctx, path.into_iter(), &trampoline_session_priv,
 		)
-  };
+	};
 
 	let route = Route {
 		paths: vec![Path {
@@ -2138,7 +2138,7 @@ fn test_trampoline_forward_payload_encoded_as_receive() {
 					short_channel_id: bob_carol_scid,
 					channel_features: ChannelFeatures::empty(),
 					fee_msat: 0,
-					cltv_expiry_delta: 48,
+					cltv_expiry_delta: 24 + 39,
 					maybe_announced_channel: false,
 				}
 			],
@@ -2149,7 +2149,7 @@ fn test_trampoline_forward_payload_encoded_as_receive() {
 						pubkey: carol_node_id,
 						node_features: Features::empty(),
 						fee_msat: amt_msat,
-						cltv_expiry_delta: 24,
+						cltv_expiry_delta: 24 + 39,
 					},
 				],
 				hops: carol_blinded_hops,
@@ -2176,7 +2176,7 @@ fn test_trampoline_forward_payload_encoded_as_receive() {
 		});
 
 		let recipient_onion_fields = RecipientOnionFields::spontaneous_empty(amt_msat);
-		let (mut trampoline_payloads, outer_total_msat, outer_starting_htlc_offset) = onion_utils::build_trampoline_onion_payloads(&blinded_tail, &recipient_onion_fields, 32, &None).unwrap();
+		let (mut trampoline_payloads, outer_total_msat) = onion_utils::build_trampoline_onion_payloads(&blinded_tail, &recipient_onion_fields, 32, &None).unwrap();
 
 		// pop the last dummy hop
 		trampoline_payloads.pop();
@@ -2191,7 +2191,7 @@ fn test_trampoline_forward_payload_encoded_as_receive() {
 		).unwrap();
 
 		let recipient_onion_fields = RecipientOnionFields::spontaneous_empty(outer_total_msat);
-		let (outer_payloads, _, _) = onion_utils::test_build_onion_payloads(&route.paths[0], &recipient_onion_fields, outer_starting_htlc_offset, &None, None, Some(trampoline_packet)).unwrap();
+		let (outer_payloads, _, _) = onion_utils::test_build_onion_payloads(&route.paths[0], &recipient_onion_fields, 32, &None, None, Some(trampoline_packet)).unwrap();
 		let outer_onion_keys = onion_utils::construct_onion_keys(&secp_ctx, &route.clone().paths[0], &outer_session_priv);
 		let outer_packet = onion_utils::construct_onion_packet(
 			outer_payloads,
@@ -2304,7 +2304,7 @@ fn do_test_trampoline_single_hop_receive(success: bool) {
 					short_channel_id: bob_carol_scid,
 					channel_features: ChannelFeatures::empty(),
 					fee_msat: 0,
-					cltv_expiry_delta: 48,
+					cltv_expiry_delta: 104 + 39,
 					maybe_announced_channel: false,
 				}
 			],
@@ -2315,7 +2315,7 @@ fn do_test_trampoline_single_hop_receive(success: bool) {
 						pubkey: carol_node_id,
 						node_features: Features::empty(),
 						fee_msat: amt_msat,
-						cltv_expiry_delta: 104,
+						cltv_expiry_delta: 104 + 39,
 					},
 				],
 				hops: blinded_path.blinded_hops().to_vec(),
@@ -2423,8 +2423,8 @@ fn test_trampoline_blinded_receive() {
 /// Creates a blinded tail where Carol receives via a blinded path.
 fn create_blinded_tail(
 	secp_ctx: &Secp256k1<All>, override_random_bytes: [u8; 32], carol_node_id: PublicKey,
-	carol_auth_key: ReceiveAuthKey, trampoline_cltv_expiry_delta: u32, final_value_msat: u64,
-	payment_secret: PaymentSecret,
+	carol_auth_key: ReceiveAuthKey, trampoline_cltv_expiry_delta: u32,
+	excess_final_cltv_delta: u32, final_value_msat: u64, payment_secret: PaymentSecret,
 ) -> BlindedTail {
 	let outer_session_priv = SecretKey::from_slice(&override_random_bytes).unwrap();
 	let trampoline_session_priv = onion_utils::compute_trampoline_session_priv(&outer_session_priv);
@@ -2455,11 +2455,11 @@ fn create_blinded_tail(
 			pubkey: carol_node_id,
 			node_features: Features::empty(),
 			fee_msat: final_value_msat,
-			cltv_expiry_delta: trampoline_cltv_expiry_delta,
+			cltv_expiry_delta: trampoline_cltv_expiry_delta + excess_final_cltv_delta,
 		}],
 		hops: carol_blinded_hops,
 		blinding_point: carol_blinding_point,
-		excess_final_cltv_expiry_delta: 39,
+		excess_final_cltv_expiry_delta: excess_final_cltv_delta,
 		final_value_msat,
 	}
 }
@@ -2468,8 +2468,9 @@ fn create_blinded_tail(
 // payloads that send to unblinded receives and invalid payloads.
 fn replacement_onion(
 	test_case: TrampolineTestCase, secp_ctx: &Secp256k1<All>, override_random_bytes: [u8; 32],
-	route: Route, original_amt_msat: u64, starting_htlc_offset: u32, original_trampoline_cltv: u32,
-	payment_hash: PaymentHash, payment_secret: PaymentSecret, blinded: bool,
+	route: Route, original_amt_msat: u64, starting_htlc_offset: u32, excess_final_cltv: u32,
+	original_trampoline_cltv: u32, payment_hash: PaymentHash, payment_secret: PaymentSecret,
+	blinded: bool,
 ) -> msgs::OnionPacket {
 	let outer_session_priv = SecretKey::from_slice(&override_random_bytes[..]).unwrap();
 	let trampoline_session_priv = onion_utils::compute_trampoline_session_priv(&outer_session_priv);
@@ -2480,8 +2481,8 @@ fn replacement_onion(
 	// Rebuild our trampoline packet from the original route. If we want to test Carol receiving
 	// as an unblinded trampoline hop, we switch out her inner trampoline onion with a direct
 	// receive payload because LDK doesn't support unblinded trampoline receives.
-	let (trampoline_packet, outer_total_msat, outer_starting_htlc_offset) = {
-		let (mut trampoline_payloads, outer_total_msat, outer_starting_htlc_offset) =
+	let (trampoline_packet, outer_total_msat) = {
+		let (mut trampoline_payloads, outer_total_msat) =
 			onion_utils::build_trampoline_onion_payloads(
 				&blinded_tail,
 				&recipient_onion_fields,
@@ -2497,7 +2498,9 @@ fn replacement_onion(
 					total_msat: original_amt_msat,
 				}),
 				sender_intended_htlc_amt_msat: original_amt_msat,
-				cltv_expiry_height: original_trampoline_cltv + starting_htlc_offset,
+				cltv_expiry_height: original_trampoline_cltv
+					+ starting_htlc_offset
+					+ excess_final_cltv,
 			}];
 		}
 
@@ -2515,7 +2518,7 @@ fn replacement_onion(
 		)
 		.unwrap();
 
-		(trampoline_packet, outer_total_msat, outer_starting_htlc_offset)
+		(trampoline_packet, outer_total_msat)
 	};
 
 	// Use a different session key to construct the replacement onion packet. Note that the
@@ -2524,7 +2527,7 @@ fn replacement_onion(
 	let (mut outer_payloads, _, _) = onion_utils::test_build_onion_payloads(
 		&route.paths[0],
 		&recipient_onion_fields,
-		outer_starting_htlc_offset,
+		starting_htlc_offset,
 		&None,
 		None,
 		Some(trampoline_packet),
@@ -2542,7 +2545,7 @@ fn replacement_onion(
 			..
 		} => {
 			*amt_to_forward = test_case.outer_onion_amt(original_amt_msat);
-			let outer_cltv = original_trampoline_cltv + starting_htlc_offset;
+			let outer_cltv = original_trampoline_cltv + starting_htlc_offset + excess_final_cltv;
 			*outgoing_cltv_value = test_case.outer_onion_cltv(outer_cltv);
 		},
 		_ => panic!("final payload is not trampoline entrypoint"),
@@ -2577,11 +2580,9 @@ fn do_test_trampoline_relay(blinded: bool, test_case: TrampolineTestCase) {
 	let alice_bob_chan = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
 	let bob_carol_chan = create_announced_chan_between_nodes_with_value(&nodes, 1, 2, 1_000_000, 0);
 
+	let starting_htlc_offset = (TOTAL_NODE_COUNT as u32) * CHAN_CONFIRM_DEPTH + 1;
 	for i in 0..TOTAL_NODE_COUNT {
-		connect_blocks(
-			&nodes[i],
-			(TOTAL_NODE_COUNT as u32) * CHAN_CONFIRM_DEPTH + 1 - nodes[i].best_block_info().1,
-		);
+		connect_blocks(&nodes[i], starting_htlc_offset - nodes[i].best_block_info().1);
 	}
 
 	let alice_node_id = nodes[0].node.get_our_node_id();
@@ -2592,8 +2593,11 @@ fn do_test_trampoline_relay(blinded: bool, test_case: TrampolineTestCase) {
 	let bob_carol_scid = get_scid_from_channel_id(&nodes[1], bob_carol_chan.2);
 
 	let original_amt_msat = 1000;
-	let original_trampoline_cltv = 72;
-	let starting_htlc_offset = 32;
+	// Note that for TrampolineTestCase::OuterCLTVLessThanTrampoline to work properly,
+	// (starting_htlc_offset + excess_final_cltv) / 2 < (starting_htlc_offset + excess_final_cltv + original_trampoline_cltv)
+	// otherwise dividing the CLTV value by 2 won't kick us under the outer trampoline CLTV.
+	let original_trampoline_cltv = 42;
+	let excess_final_cltv = 70;
 
 	let (payment_preimage, payment_hash, payment_secret) =
 		get_payment_preimage_hash(&nodes[2], Some(original_amt_msat), None);
@@ -2620,7 +2624,7 @@ fn do_test_trampoline_relay(blinded: bool, test_case: TrampolineTestCase) {
 					short_channel_id: bob_carol_scid,
 					channel_features: ChannelFeatures::empty(),
 					fee_msat: 0,
-					cltv_expiry_delta: 48,
+					cltv_expiry_delta: original_trampoline_cltv + excess_final_cltv,
 					maybe_announced_channel: false,
 				},
 			],
@@ -2633,6 +2637,7 @@ fn do_test_trampoline_relay(blinded: bool, test_case: TrampolineTestCase) {
 				carol_node_id,
 				nodes[2].keys_manager.get_receive_auth_key(),
 				original_trampoline_cltv,
+				excess_final_cltv,
 				original_amt_msat,
 				payment_secret,
 			)),
@@ -2675,6 +2680,7 @@ fn do_test_trampoline_relay(blinded: bool, test_case: TrampolineTestCase) {
 			original_amt_msat,
 			starting_htlc_offset,
 			original_trampoline_cltv,
+			excess_final_cltv,
 			payment_hash,
 			payment_secret,
 			blinded,
@@ -2691,8 +2697,9 @@ fn do_test_trampoline_relay(blinded: bool, test_case: TrampolineTestCase) {
 	);
 
 	let amt_bytes = test_case.outer_onion_amt(original_amt_msat).to_be_bytes();
-	let cltv_bytes =
-		test_case.outer_onion_cltv(original_trampoline_cltv + starting_htlc_offset).to_be_bytes();
+	let cltv_bytes = test_case
+		.outer_onion_cltv(original_trampoline_cltv + starting_htlc_offset + excess_final_cltv)
+		.to_be_bytes();
 	let payment_failure = test_case.payment_failed_conditions(&amt_bytes, &cltv_bytes).map(|p| {
 		if blinded {
 			PaymentFailedConditions::new()
@@ -2706,7 +2713,8 @@ fn do_test_trampoline_relay(blinded: bool, test_case: TrampolineTestCase) {
 			.without_claimable_event()
 			.expect_failure(HTLCHandlingFailureType::Receive { payment_hash })
 	} else {
-		args.with_payment_secret(payment_secret)
+		let htlc_cltv = starting_htlc_offset + original_trampoline_cltv + excess_final_cltv;
+		args.with_payment_secret(payment_secret).with_payment_claimable_cltv(htlc_cltv)
 	};
 
 	do_pass_along_path(args);
@@ -2792,7 +2800,7 @@ fn test_trampoline_forward_rejection() {
 					short_channel_id: bob_carol_scid,
 					channel_features: ChannelFeatures::empty(),
 					fee_msat: 0,
-					cltv_expiry_delta: 48,
+					cltv_expiry_delta: 24 + 24 + 39,
 					maybe_announced_channel: false,
 				}
 			],
@@ -2811,7 +2819,7 @@ fn test_trampoline_forward_rejection() {
 						pubkey: alice_node_id,
 						node_features: Features::empty(),
 						fee_msat: amt_msat,
-						cltv_expiry_delta: 24,
+						cltv_expiry_delta: 24 + 39,
 					},
 				],
 				hops: vec![BlindedHop{
diff --git a/lightning/src/ln/functional_test_utils.rs b/lightning/src/ln/functional_test_utils.rs
index 16616e5..680a0d9 100644
--- a/lightning/src/ln/functional_test_utils.rs
+++ b/lightning/src/ln/functional_test_utils.rs
@@ -11,7 +11,7 @@
 //! nodes for functional tests.
 
 use crate::blinded_path::payment::DummyTlvs;
-use crate::chain::channelmonitor::ChannelMonitor;
+use crate::chain::channelmonitor::{ChannelMonitor, HTLC_FAIL_BACK_BUFFER};
 use crate::chain::transaction::OutPoint;
 use crate::chain::{BestBlock, ChannelMonitorUpdateStatus, Confirm, Listen, Watch};
 use crate::events::bump_transaction::sync::BumpTransactionEventHandlerSync;
@@ -3490,6 +3490,7 @@ pub struct PassAlongPathArgs<'a, 'b, 'c, 'd> {
 	pub custom_tlvs: Vec<(u64, Vec<u8>)>,
 	pub payment_metadata: Option<Vec<u8>>,
 	pub expected_failure: Option<HTLCHandlingFailureType>,
+	pub payment_claimable_cltv: Option<u32>,
 }
 
 impl<'a, 'b, 'c, 'd> PassAlongPathArgs<'a, 'b, 'c, 'd> {
@@ -3512,6 +3513,7 @@ impl<'a, 'b, 'c, 'd> PassAlongPathArgs<'a, 'b, 'c, 'd> {
 			custom_tlvs: Vec::new(),
 			payment_metadata: None,
 			expected_failure: None,
+			payment_claimable_cltv: None,
 		}
 	}
 	pub fn without_clearing_recipient_events(mut self) -> Self {
@@ -3552,6 +3554,10 @@ impl<'a, 'b, 'c, 'd> PassAlongPathArgs<'a, 'b, 'c, 'd> {
 		self.dummy_tlvs = dummy_tlvs.to_vec();
 		self
 	}
+	pub fn with_payment_claimable_cltv(mut self, cltv: u32) -> Self {
+		self.payment_claimable_cltv = Some(cltv);
+		self
+	}
 }
 
 pub fn do_pass_along_path<'a, 'b, 'c>(args: PassAlongPathArgs) -> Option<Event> {
@@ -3570,6 +3576,7 @@ pub fn do_pass_along_path<'a, 'b, 'c>(args: PassAlongPathArgs) -> Option<Event>
 		custom_tlvs,
 		payment_metadata,
 		expected_failure,
+		payment_claimable_cltv,
 	} = args;
 
 	let mut payment_event = SendEvent::from_event(ev);
@@ -3685,6 +3692,12 @@ pub fn do_pass_along_path<'a, 'b, 'c>(args: PassAlongPathArgs) -> Option<Event>
 							assert_eq!(*user_chan_id, Some(chan.user_channel_id));
 						}
 						assert!(claim_deadline.unwrap() > node.best_block_info().1);
+						if let Some(expected_cltv) = payment_claimable_cltv {
+							assert_eq!(
+								claim_deadline.unwrap(),
+								expected_cltv - HTLC_FAIL_BACK_BUFFER,
+							);
+						}
 					},
 					_ => panic!("Unexpected event"),
 				}
diff --git a/lightning/src/ln/onion_route_tests.rs b/lightning/src/ln/onion_route_tests.rs
index ceb9300..019d8fa 100644
--- a/lightning/src/ln/onion_route_tests.rs
+++ b/lightning/src/ln/onion_route_tests.rs
@@ -1918,7 +1918,7 @@ fn test_trampoline_onion_payload_assembly_values() {
 				short_channel_id: (572330 << 40) + (42 << 16) + 2821,
 				channel_features: ChannelFeatures::empty(),
 				fee_msat: 153_000,
-				cltv_expiry_delta: 0,
+				cltv_expiry_delta: 36 + 24, // Last hop should include the CLTV of the trampoline hops
 				maybe_announced_channel: false,
 			},
 		],
@@ -1974,17 +1974,15 @@ fn test_trampoline_onion_payload_assembly_values() {
 		SecretKey::from_slice(&<Vec<u8>>::from_hex(SECRET_HEX).unwrap()).unwrap().secret_bytes(),
 	);
 	let recipient_onion_fields = RecipientOnionFields::secret_only(payment_secret, amt_msat);
-	let (trampoline_payloads, outer_total_msat, outer_starting_htlc_offset) =
-		onion_utils::build_trampoline_onion_payloads(
-			&path.blinded_tail.as_ref().unwrap(),
-			&recipient_onion_fields,
-			cur_height,
-			&None,
-		)
-		.unwrap();
+	let (trampoline_payloads, outer_total_msat) = onion_utils::build_trampoline_onion_payloads(
+		&path.blinded_tail.as_ref().unwrap(),
+		&recipient_onion_fields,
+		cur_height,
+		&None,
+	)
+	.unwrap();
 	assert_eq!(trampoline_payloads.len(), 3);
 	assert_eq!(outer_total_msat, 150_153_000);
-	assert_eq!(outer_starting_htlc_offset, 800_060);
 
 	let trampoline_carol_payload = &trampoline_payloads[0];
 	let trampoline_dave_payload = &trampoline_payloads[1];
@@ -2042,7 +2040,7 @@ fn test_trampoline_onion_payload_assembly_values() {
 	let (outer_payloads, total_msat, total_htlc_offset) = test_build_onion_payloads(
 		&path,
 		&recipient_onion_fields,
-		outer_starting_htlc_offset,
+		cur_height,
 		&None,
 		None,
 		Some(trampoline_packet),
@@ -2067,7 +2065,7 @@ fn test_trampoline_onion_payload_assembly_values() {
 		outer_bob_payload
 	{
 		assert_eq!(amt_to_forward, &150_153_000);
-		assert_eq!(outgoing_cltv_value, &800_084);
+		assert_eq!(outgoing_cltv_value, &800_060);
 	} else {
 		panic!("Bob payload must be Forward");
 	}
diff --git a/lightning/src/ln/onion_utils.rs b/lightning/src/ln/onion_utils.rs
index a95012d..5c00368 100644
--- a/lightning/src/ln/onion_utils.rs
+++ b/lightning/src/ln/onion_utils.rs
@@ -416,7 +416,7 @@ pub(super) fn construct_trampoline_onion_keys<T: secp256k1::Signing>(
 pub(super) fn build_trampoline_onion_payloads<'a>(
 	blinded_tail: &'a BlindedTail, recipient_onion: &'a RecipientOnionFields,
 	starting_htlc_offset: u32, keysend_preimage: &Option<PaymentPreimage>,
-) -> Result<(Vec<msgs::OutboundTrampolinePayload<'a>>, u64, u32), APIError> {
+) -> Result<(Vec<msgs::OutboundTrampolinePayload<'a>>, u64), APIError> {
 	let mut res: Vec<msgs::OutboundTrampolinePayload> =
 		Vec::with_capacity(blinded_tail.trampoline_hops.len() + blinded_tail.hops.len());
 	let blinded_tail_with_hop_iter = BlindedTailDetails::DirectEntry {
@@ -426,7 +426,7 @@ pub(super) fn build_trampoline_onion_payloads<'a>(
 		excess_final_cltv_expiry_delta: blinded_tail.excess_final_cltv_expiry_delta,
 	};
 
-	let (value_msat, cltv) = build_onion_payloads_callback(
+	let (value_msat, _) = build_onion_payloads_callback(
 		blinded_tail.trampoline_hops.iter(),
 		Some(blinded_tail_with_hop_iter),
 		recipient_onion,
@@ -438,7 +438,7 @@ pub(super) fn build_trampoline_onion_payloads<'a>(
 			PayloadCallbackAction::PushFront => res.insert(0, payload),
 		},
 	)?;
-	Ok((res, value_msat, cltv))
+	Ok((res, value_msat))
 }
 
 /// returns the hop data, as well as the first-hop value_msat and CLTV value we should send.
@@ -539,11 +539,7 @@ where
 		// exactly as it should be (and the next hop isn't trying to probe to find out if we're
 		// the intended recipient).
 		let value_msat = if cur_value_msat == 0 { hop.fee_msat() } else { cur_value_msat };
-		let cltv = if cur_cltv == starting_htlc_offset {
-			hop.cltv_expiry_delta().saturating_add(starting_htlc_offset)
-		} else {
-			cur_cltv
-		};
+		let cltv = hop.cltv_expiry_delta().saturating_add(cur_cltv);
 		if idx == 0 {
 			match blinded_tail.take() {
 				Some(BlindedTailDetails::DirectEntry {
@@ -591,7 +587,7 @@ where
 						PayloadCallbackAction::PushBack,
 						OP::new_trampoline_entry(
 							final_value_msat + hop.fee_msat(),
-							cur_cltv,
+							cltv,
 							&recipient_onion,
 							trampoline_packet,
 						)?,
@@ -610,7 +606,7 @@ where
 					err: "Next hop ID must be known for non-final hops".to_string(),
 				})?,
 				value_msat,
-				cltv,
+				cur_cltv,
 			);
 			callback(PayloadCallbackAction::PushFront, payload);
 		}
@@ -2638,8 +2634,6 @@ pub(crate) fn create_payment_onion_internal<T: secp256k1::Signing>(
 	prng_seed: [u8; 32], trampoline_session_priv_override: Option<SecretKey>,
 	trampoline_prng_seed_override: Option<[u8; 32]>,
 ) -> Result<(msgs::OnionPacket, u64, u32), APIError> {
-	let mut outer_starting_htlc_offset = cur_block_height;
-
 	// If we're paying to a recipient through a trampoline, we use the `payment_secret` provided in
 	// `recipient_onion` as the MPP identifier for the trampoline entry point, allowing it to
 	// detect when when it has received all the MPP parts.
@@ -2661,13 +2655,12 @@ pub(crate) fn create_payment_onion_internal<T: secp256k1::Signing>(
 		if !blinded_tail.trampoline_hops.is_empty() {
 			let trampoline_payloads;
 			let outer_total_msat;
-			(trampoline_payloads, outer_total_msat, outer_starting_htlc_offset) =
-				build_trampoline_onion_payloads(
-					&blinded_tail,
-					recipient_onion,
-					cur_block_height,
-					keysend_preimage,
-				)?;
+			(trampoline_payloads, outer_total_msat) = build_trampoline_onion_payloads(
+				&blinded_tail,
+				recipient_onion,
+				cur_block_height,
+				keysend_preimage,
+			)?;
 			trampoline_outer_onion.total_mpp_amount_msat = outer_total_msat;
 
 			let trampoline_session_priv = trampoline_session_priv_override
@@ -2698,7 +2691,7 @@ pub(crate) fn create_payment_onion_internal<T: secp256k1::Signing>(
 	let (onion_payloads, htlc_msat, htlc_cltv) = build_onion_payloads(
 		&path,
 		outer_onion,
-		outer_starting_htlc_offset,
+		cur_block_height,
 		keysend_preimage,
 		invoice_request,
 		trampoline_packet_option,
diff --git a/lightning/src/routing/router.rs b/lightning/src/routing/router.rs
index 75c6a05..ee08f9e 100644
--- a/lightning/src/routing/router.rs
+++ b/lightning/src/routing/router.rs
@@ -512,6 +512,7 @@ pub struct RouteHop {
 	/// to reach this node.
 	pub channel_features: ChannelFeatures,
 	/// The fee taken on this hop (for paying for the use of the *next* channel in the path).
+	///
 	/// If this is the last hop in [`Path::hops`]:
 	/// * if we're sending to a [`BlindedPaymentPath`], this is the fee paid for use of the entire
 	///   blinded path (including any Trampoline hops)
@@ -557,8 +558,9 @@ pub struct TrampolineHop {
 	/// the entire blinded path.
 	pub fee_msat: u64,
 	/// The CLTV delta added for this hop.
+	///
 	/// If this is the last Trampoline hop within [`BlindedTail`], this is the CLTV delta for the entire
-	/// blinded path.
+	/// blinded path (including the [`BlindedTail::excess_final_cltv_expiry_delta`]).
 	pub cltv_expiry_delta: u32,
 }