Don't require permutation uniqueness.

Author: tnull

lightning/src/routing/router.rs

@@ -1453,26 +1453,17 @@ where L::Target: Logger {
 	let mut random_index_bytes = [0u8; ::core::mem::size_of::<usize>()];
 
 	let num_permutations = payment_paths.len();
-	let mut seen_permutation_scids: HashSet<Vec<Vec<u64>>> = HashSet::new();
 	for _ in 0..num_permutations {
 		let mut cur_route = Vec::<PaymentPath>::new();
 		let mut aggregate_route_value_msat = 0;
 
 		// Step (6).
-		// Do a Fisher-Yates shuffle to create a unique permutation of the payment paths
-		loop {
-			for cur_index in (1..payment_paths.len()).rev() {
-				prng.process_in_place(&mut random_index_bytes);
-				let random_index = usize::from_be_bytes(random_index_bytes).wrapping_rem(cur_index+1);
-				payment_paths.swap(cur_index, random_index);
-			}
-			let cur_perm_scids = payment_paths.iter().map(|path|
-				path.hops.iter().map(|(hop,_)| hop.candidate.short_channel_id()).collect::<Vec<u64>>()
-				).collect::<Vec<Vec<u64>>>();
-			if seen_permutation_scids.insert(cur_perm_scids) {
-				break;
-			}
-		};
+		// Do a Fisher-Yates shuffle to create a random permutation of the payment paths
+		for cur_index in (1..payment_paths.len()).rev() {
+			prng.process_in_place(&mut random_index_bytes);
+			let random_index = usize::from_be_bytes(random_index_bytes).wrapping_rem(cur_index+1);
+			payment_paths.swap(cur_index, random_index);
+		}
 
 		// Step (7).
 		for payment_path in &payment_paths {