Avoid redundant broadcast of local commitment transaction

[rust-lightning] / lightning / src / chain / channelmonitor.rs

diff --git a/lightning/src/chain/channelmonitor.rs b/lightning/src/chain/channelmonitor.rs
index a41d853311ce924f388eaa5efbbb2ceb79489a64..db17810599d66e4d472d96ec96af76f1ced407f3 100644 (file)
--- a/lightning/src/chain/channelmonitor.rs
+++ b/lightning/src/chain/channelmonitor.rs
@@ -2325,6 +2325,17 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                        log_trace!(logger, "Updating ChannelMonitor: channel force closed, should broadcast: {}", should_broadcast);
                                        self.lockdown_from_offchain = true;
                                        if *should_broadcast {
+                                               // There's no need to broadcast our commitment transaction if we've seen one
+                                               // confirmed (even with 1 confirmation) as it'll be rejected as
+                                               // duplicate/conflicting.
+                                               let detected_funding_spend = self.funding_spend_confirmed.is_some() ||
+                                                       self.onchain_events_awaiting_threshold_conf.iter().find(|event| match event.event {
+                                                               OnchainEvent::FundingSpendConfirmation { .. } => true,
+                                                               _ => false,
+                                                       }).is_some();
+                                               if detected_funding_spend {
+                                                       continue;
+                                               }
                                                self.broadcast_latest_holder_commitment_txn(broadcaster, logger);
                                                // If the channel supports anchor outputs, we'll need to emit an external
                                                // event to be consumed such that a child transaction is broadcast with a