f - Fix inflight_htlc_msat calculation

diff --git a/lightning/src/routing/router.rs b/lightning/src/routing/router.rs
index 19a65f92f99bd04131d5f9d75675769d84b2ead6..a0fafc342d516a837bd4004c10ec4f3509dae60f 100644 (file)
--- a/lightning/src/routing/router.rs
+++ b/lightning/src/routing/router.rs
@@ -848,10 +848,10 @@ where L::Target: Logger {
                        // - for first and last hops early in get_route
                        if $src_node_id != $dest_node_id {
                                let short_channel_id = $candidate.short_channel_id();
-                               let available_liquidity_msat = available_channel_liquidities
-                                       .entry(short_channel_id)
-                                       .or_insert_with(|| $candidate.available_liquidity())
-                                       .as_msat();
+                               let available_liquidity = available_channel_liquidities
+                                       .entry((short_channel_id, $src_node_id < $dest_node_id))
+                                       .or_insert_with(|| $candidate.available_liquidity());
+                               let available_liquidity_msat = available_liquidity.as_msat();
 
                                // It is tricky to substract $next_hops_fee_msat from available liquidity here.
                                // It may be misleading because we might later choose to reduce the value transferred
@@ -999,7 +999,7 @@ where L::Target: Logger {
                                                        let effective_capacity_msat = $candidate.effective_capacity().as_msat();
                                                        let params = ChannelUseParameters {
                                                                amount_msat: amount_to_transfer_over_msat,
-                                                               inflight_htlc_msat: effective_capacity_msat - available_liquidity_msat,
+                                                               inflight_htlc_msat: effective_capacity_msat - available_liquidity.remaining_capacity_msat,
                                                                fees_msat: cmp::max(total_fee_msat, path_htlc_minimum_msat),
                                                                effective_capacity_msat,
                                                        };
@@ -1384,10 +1384,12 @@ where L::Target: Logger {
                                // Remember that we used these channels so that we don't rely
                                // on the same liquidity in future paths.
                                let mut prevented_redundant_path_selection = false;
-                               for (payment_hop, _) in payment_path.hops.iter() {
-                                       let spent_on_hop_msat = value_contribution_msat + payment_hop.next_hops_fee_msat;
+                               let prev_hop_iter = core::iter::once(&our_node_id)
+                                       .chain(payment_path.hops.iter().map(|(hop, _)| &hop.node_id));
+                               for (prev_hop, (hop, _)) in prev_hop_iter.zip(payment_path.hops.iter()) {
+                                       let spent_on_hop_msat = value_contribution_msat + hop.next_hops_fee_msat;
                                        let available_liquidity_msat = available_channel_liquidities
-                                               .get_mut(&payment_hop.candidate.short_channel_id())
+                                               .get_mut(&(hop.candidate.short_channel_id(), *prev_hop < hop.node_id))
                                                .unwrap()
                                                .reduce_by(spent_on_hop_msat)
                                                .as_msat();
@@ -1403,7 +1405,8 @@ where L::Target: Logger {
                                        // Decrease the available liquidity of a hop in the middle of the path.
                                        let victim_scid = payment_path.hops[(payment_path.hops.len() - 1) / 2].0.candidate.short_channel_id();
                                        log_trace!(logger, "Disabling channel {} for future path building iterations to avoid duplicates.", victim_scid);
-                                       available_channel_liquidities.get_mut(&victim_scid).unwrap().exhaust();
+                                       available_channel_liquidities.get_mut(&(victim_scid, false)).map(|l| l.exhaust());
+                                       available_channel_liquidities.get_mut(&(victim_scid, true)).map(|l| l.exhaust());
                                }
 
                                // Track the total amount all our collected paths allow to send so that we: