Prevent duplicate PaymentSent events

[rust-lightning] / lightning / src / ln / channelmanager.rs

diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index 9b0f78b22bc013b6f7c66097279a390091542ad4..0389bd5cd198aa28ea879ba0050bf89dafa6c66d 100644 (file)
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -3140,17 +3140,13 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                let mut session_priv_bytes = [0; 32];
                                session_priv_bytes.copy_from_slice(&session_priv[..]);
                                let mut outbounds = self.pending_outbound_payments.lock().unwrap();
-                               if let Some(sessions) = outbounds.get_mut(&mpp_id) {
-                                       if sessions.remove(&session_priv_bytes) {
-                                               self.pending_events.lock().unwrap().push(
-                                                       events::Event::PaymentSent { payment_preimage }
-                                               );
-                                               if sessions.len() == 0 {
-                                                       outbounds.remove(&mpp_id);
-                                               }
-                                       } else {
-                                               log_trace!(self.logger, "Received duplicative fulfill for HTLC with payment_preimage {}", log_bytes!(payment_preimage.0));
-                                       }
+                               let found_payment = if let Some(mut sessions) = outbounds.remove(&mpp_id) {
+                                       sessions.remove(&session_priv_bytes)
+                               } else { false };
+                               if found_payment {
+                                       self.pending_events.lock().unwrap().push(
+                                               events::Event::PaymentSent { payment_preimage }
+                                       );
                                } else {
                                        log_trace!(self.logger, "Received duplicative fulfill for HTLC with payment_preimage {}", log_bytes!(payment_preimage.0));
                                }
@@ -5691,7 +5687,8 @@ mod tests {
                nodes[0].node.handle_revoke_and_ack(&nodes[1].node.get_our_node_id(), &bs_third_raa);
                check_added_monitors!(nodes[0], 1);
 
-               // There's an existing bug that generates a PaymentSent event for each MPP path, so handle that here.
+               // Note that successful MPP payments will generate 1 event upon the first path's success. No
+               // further events will be generated for subsequence path successes.
                let events = nodes[0].node.get_and_clear_pending_events();
                match events[0] {
                        Event::PaymentSent { payment_preimage: ref preimage } => {
@@ -5699,12 +5696,6 @@ mod tests {
                        },
                        _ => panic!("Unexpected event"),
                }
-               match events[1] {
-                       Event::PaymentSent { payment_preimage: ref preimage } => {
-                               assert_eq!(payment_preimage, *preimage);
-                       },
-                       _ => panic!("Unexpected event"),
-               }
        }
 
        #[test]