Do not check the ordering of HTLCs in PaymentClaim[able,ed]

In the next commit we'll change the order of HTLCs in
`PaymentClaim[able,ed]` events. This shouldn't break anything, but
our current functional tests check that the HTLCs are provided in
the order they expect (the order they were received). Instead, here
we only validate that each claimed HTLC matches one expected path.

Author: TheBlueMatt

lightning/src/ln/functional_test_utils.rs

@@ -1083,19 +1083,29 @@ macro_rules! check_added_monitors {
 	}
 }
 
-/// Checks whether the claimed HTLC for the specified path has the correct channel information.
-///
-/// This will panic if the path is empty, if the HTLC's channel ID is not actually a channel that
-/// connects the final two nodes in the path, or if the `user_channel_id` is incorrect.
-pub fn check_claimed_htlc_channel<'a, 'b, 'c>(origin_node: &Node<'a, 'b, 'c>, path: &[&Node<'a, 'b, 'c>], htlc: &ClaimedHTLC) {
+fn claimed_htlc_matches_path<'a, 'b, 'c>(origin_node: &Node<'a, 'b, 'c>, path: &[&Node<'a, 'b, 'c>], htlc: &ClaimedHTLC) -> bool {
 	let mut nodes = path.iter().rev();
 	let dest = nodes.next().expect("path should have a destination").node;
 	let prev = nodes.next().unwrap_or(&origin_node).node;
 	let dest_channels = dest.list_channels();
 	let ch = dest_channels.iter().find(|ch| ch.channel_id == htlc.channel_id)
 		.expect("HTLC's channel should be one of destination node's channels");
-	assert_eq!(htlc.user_channel_id, ch.user_channel_id);
-	assert_eq!(ch.counterparty.node_id, prev.get_our_node_id());
+	htlc.user_channel_id == ch.user_channel_id &&
+		ch.counterparty.node_id == prev.get_our_node_id()
+}
+
+fn check_claimed_htlcs_match_route<'a, 'b, 'c>(origin_node: &Node<'a, 'b, 'c>, route: &[&[&Node<'a, 'b, 'c>]], htlcs: &[ClaimedHTLC]) {
+	assert_eq!(route.len(), htlcs.len());
+	for path in route {
+		let mut found_matching_htlc = false;
+		for htlc in htlcs {
+			if claimed_htlc_matches_path(origin_node, path, htlc) {
+				found_matching_htlc = true;
+				break;
+			}
+		}
+		assert!(found_matching_htlc);
+	}
 }
 
 pub fn _reload_node<'a, 'b, 'c>(node: &'a Node<'a, 'b, 'c>, default_config: UserConfig, chanman_encoded: &[u8], monitors_encoded: &[&[u8]]) -> TestChannelManager<'b, 'c> {
@@ -2832,7 +2842,7 @@ pub fn pass_claimed_payment_along_route(args: ClaimAlongRouteArgs) -> u64 {
 			assert_eq!(htlcs.len(), expected_paths.len());  // One per path.
 			assert_eq!(htlcs.iter().map(|h| h.value_msat).sum::<u64>(), amount_msat);
 			assert_eq!(onion_fields.as_ref().unwrap().custom_tlvs, custom_tlvs);
-			expected_paths.iter().zip(htlcs).for_each(|(path, htlc)| check_claimed_htlc_channel(origin_node, path, htlc));
+			check_claimed_htlcs_match_route(origin_node, expected_paths, htlcs);
 			fwd_amt_msat = amount_msat;
 		},
 		Event::PaymentClaimed {
@@ -2849,7 +2859,7 @@ pub fn pass_claimed_payment_along_route(args: ClaimAlongRouteArgs) -> u64 {
 			assert_eq!(htlcs.len(), expected_paths.len());  // One per path.
 			assert_eq!(htlcs.iter().map(|h| h.value_msat).sum::<u64>(), amount_msat);
 			assert_eq!(onion_fields.as_ref().unwrap().custom_tlvs, custom_tlvs);
-			expected_paths.iter().zip(htlcs).for_each(|(path, htlc)| check_claimed_htlc_channel(origin_node, path, htlc));
+			check_claimed_htlcs_match_route(origin_node, expected_paths, htlcs);
 			fwd_amt_msat = amount_msat;
 		}
 		_ => panic!(),