Dont broadcast HTLC-Timeouts when closing a channel until locktime

diff --git a/lightning/src/chain/channelmonitor.rs b/lightning/src/chain/channelmonitor.rs
index 95043da1b27a5c833c158a24ed53d2bd9d04e291..26187ce34166d5a189a48a3be2522a46a181ceba 100644 (file)
--- a/lightning/src/chain/channelmonitor.rs
+++ b/lightning/src/chain/channelmonitor.rs
@@ -1899,7 +1899,7 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                self.holder_tx_signed = true;
                let commitment_tx = self.onchain_tx_handler.get_fully_signed_holder_tx(&self.funding_redeemscript);
                let txid = commitment_tx.txid();
-               let mut res = vec![commitment_tx];
+               let mut holder_transactions = vec![commitment_tx];
                for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
                        if let Some(vout) = htlc.0.transaction_output_index {
                                let preimage = if !htlc.0.offered {
@@ -1907,24 +1907,32 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                                // We can't build an HTLC-Success transaction without the preimage
                                                continue;
                                        }
+                               } else if htlc.0.cltv_expiry > self.best_block.height() + 1 {
+                                       // Don't broadcast HTLC-Timeout transactions immediately as they don't meet the
+                                       // current locktime requirements on-chain. We will broadcast them in
+                                       // `block_confirmed` when `would_broadcast_at_height` returns true.
+                                       // Note that we add + 1 as transactions are broadcastable when they can be
+                                       // confirmed in the next block.
+                                       continue;
                                } else { None };
                                if let Some(htlc_tx) = self.onchain_tx_handler.get_fully_signed_htlc_tx(
                                        &::bitcoin::OutPoint { txid, vout }, &preimage) {
-                                       res.push(htlc_tx);
+                                       holder_transactions.push(htlc_tx);
                                }
                        }
                }
                // We throw away the generated waiting_first_conf data as we aren't (yet) confirmed and we don't actually know what the caller wants to do.
                // The data will be re-generated and tracked in check_spend_holder_transaction if we get a confirmation.
-               return res;
+               holder_transactions
        }
 
        #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
+       /// Note that this includes possibly-locktimed-in-the-future transactions!
        fn unsafe_get_latest_holder_commitment_txn<L: Deref>(&mut self, logger: &L) -> Vec<Transaction> where L::Target: Logger {
                log_trace!(logger, "Getting signed copy of latest holder commitment transaction!");
                let commitment_tx = self.onchain_tx_handler.get_fully_signed_copy_holder_tx(&self.funding_redeemscript);
                let txid = commitment_tx.txid();
-               let mut res = vec![commitment_tx];
+               let mut holder_transactions = vec![commitment_tx];
                for htlc in self.current_holder_commitment_tx.htlc_outputs.iter() {
                        if let Some(vout) = htlc.0.transaction_output_index {
                                let preimage = if !htlc.0.offered {
@@ -1935,11 +1943,11 @@ impl<Signer: Sign> ChannelMonitorImpl<Signer> {
                                } else { None };
                                if let Some(htlc_tx) = self.onchain_tx_handler.unsafe_get_fully_signed_htlc_tx(
                                        &::bitcoin::OutPoint { txid, vout }, &preimage) {
-                                       res.push(htlc_tx);
+                                       holder_transactions.push(htlc_tx);
                                }
                        }
                }
-               return res
+               holder_transactions
        }
 
        pub fn block_connected<B: Deref, F: Deref, L: Deref>(&mut self, header: &BlockHeader, txdata: &TransactionData, height: u32, broadcaster: B, fee_estimator: F, logger: L) -> Vec<TransactionOutputs>