f readability improvements from Val

Author: TheBlueMatt

lightning/src/ln/functional_tests.rs

@@ -3623,7 +3623,7 @@ fn test_drop_messages_peer_disconnect_dual_htlc() {
 	claim_payment(&nodes[0], &[&nodes[1]], payment_preimage_2, 1_000_000);
 }
 
-fn do_test_htlc_timeout(subpath: bool) {
+fn do_test_htlc_timeout(send_partial_mpp: bool) {
 	// If the user fails to claim/fail an HTLC within the HTLC CLTV timeout we fail it for them
 	// to avoid our counterparty failing the channel.
 	let chanmon_cfgs = create_chanmon_cfgs(2);
@@ -3633,14 +3633,18 @@ fn do_test_htlc_timeout(subpath: bool) {
 
 	create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::supported(), InitFeatures::supported());
 
-	let our_payment_hash = if subpath {
+	let our_payment_hash = if send_partial_mpp {
 		let route = nodes[0].router.get_route(&nodes[1].node.get_our_node_id(), None, &Vec::new(), 100000, TEST_FINAL_CLTV).unwrap();
 		let (_, our_payment_hash) = get_payment_preimage_hash!(&nodes[0]);
 		let payment_secret = PaymentSecret([0xdb; 32]);
+		// Use the utility function send_payment_along_path to send the payment with MPP data which
+		// indicates there are more HTLCs coming.
 		nodes[0].node.send_payment_along_path(&route.paths[0], &our_payment_hash, &Some(payment_secret), 200000, CHAN_CONFIRM_DEPTH).unwrap();
 		check_added_monitors!(nodes[0], 1);
 		let mut events = nodes[0].node.get_and_clear_pending_msg_events();
 		assert_eq!(events.len(), 1);
+		// Now do the relevant commitment_signed/RAA dances along the path, noting that the final
+		// hop should *not* yet generate any PaymentReceived event(s).
 		pass_along_path(&nodes[0], &[&nodes[1]], 100000, our_payment_hash, Some(payment_secret), events.drain(..).next().unwrap(), false);
 		our_payment_hash
 	} else {