Refactor out first-closing-sent creation

diff --git a/src/ln/channel.rs b/src/ln/channel.rs
index 8cc03759ea036a1dc522260c378eb61a37122daa..ba8d1533db1aec6ee775773d8f0823eb8b9ace6d 100644 (file)
--- a/src/ln/channel.rs
+++ b/src/ln/channel.rs
@@ -2365,6 +2365,30 @@ impl Channel {
                }
        }
 
+       fn maybe_propose_first_closing_signed(&mut self, fee_estimator: &FeeEstimator) -> Option<msgs::ClosingSigned> {
+               if !self.channel_outbound || !self.pending_inbound_htlcs.is_empty() || !self.pending_outbound_htlcs.is_empty() {
+                       return None;
+               }
+
+               let mut proposed_feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
+               if self.feerate_per_kw > proposed_feerate {
+                       proposed_feerate = self.feerate_per_kw;
+               }
+               let tx_weight = Self::get_closing_transaction_weight(&self.get_closing_scriptpubkey(), self.their_shutdown_scriptpubkey.as_ref().unwrap());
+               let proposed_total_fee_satoshis = proposed_feerate * tx_weight / 1000;
+
+               let (closing_tx, total_fee_satoshis) = self.build_closing_transaction(proposed_total_fee_satoshis, false);
+               let funding_redeemscript = self.get_funding_redeemscript();
+               let sighash = Message::from_slice(&bip143::SighashComponents::new(&closing_tx).sighash_all(&closing_tx.input[0], &funding_redeemscript, self.channel_value_satoshis)[..]).unwrap();
+
+               self.last_sent_closing_fee = Some((proposed_feerate, total_fee_satoshis));
+               Some(msgs::ClosingSigned {
+                       channel_id: self.channel_id,
+                       fee_satoshis: total_fee_satoshis,
+                       signature: self.secp_ctx.sign(&sighash, &self.local_keys.funding_key),
+               })
+       }
+
        pub fn shutdown(&mut self, fee_estimator: &FeeEstimator, msg: &msgs::Shutdown) -> Result<(Option<msgs::Shutdown>, Option<msgs::ClosingSigned>, Vec<(HTLCSource, [u8; 32])>), ChannelError> {
                if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
                        return Err(ChannelError::Close("Peer sent shutdown when we needed a channel_reestablish"));
@@ -2404,23 +2428,6 @@ impl Channel {
                        self.their_shutdown_scriptpubkey = Some(msg.scriptpubkey.clone());
                }
 
-               let our_closing_script = self.get_closing_scriptpubkey();
-
-               let (proposed_feerate, proposed_fee, our_sig) = if self.channel_outbound && self.pending_inbound_htlcs.is_empty() && self.pending_outbound_htlcs.is_empty() {
-                       let mut proposed_feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
-                       if self.feerate_per_kw > proposed_feerate {
-                               proposed_feerate = self.feerate_per_kw;
-                       }
-                       let tx_weight = Self::get_closing_transaction_weight(&our_closing_script, &msg.scriptpubkey);
-                       let proposed_total_fee_satoshis = proposed_feerate * tx_weight / 1000;
-
-                       let (closing_tx, total_fee_satoshis) = self.build_closing_transaction(proposed_total_fee_satoshis, false);
-                       let funding_redeemscript = self.get_funding_redeemscript();
-                       let sighash = Message::from_slice(&bip143::SighashComponents::new(&closing_tx).sighash_all(&closing_tx.input[0], &funding_redeemscript, self.channel_value_satoshis)[..]).unwrap();
-
-                       (Some(proposed_feerate), Some(total_fee_satoshis), Some(self.secp_ctx.sign(&sighash, &self.local_keys.funding_key)))
-               } else { (None, None, None) };
-
                // From here on out, we may not fail!
 
                self.channel_state |= ChannelState::RemoteShutdownSent as u32;
@@ -2450,24 +2457,13 @@ impl Channel {
                } else {
                        Some(msgs::Shutdown {
                                channel_id: self.channel_id,
-                               scriptpubkey: our_closing_script,
+                               scriptpubkey: self.get_closing_scriptpubkey(),
                        })
                };
 
                self.channel_state |= ChannelState::LocalShutdownSent as u32;
                self.channel_update_count += 1;
-               if self.pending_inbound_htlcs.is_empty() && self.pending_outbound_htlcs.is_empty() && self.channel_outbound {
-                       // There are no more HTLCs and we're the funder, this means we start the closing_signed
-                       // dance with an initial fee proposal!
-                       self.last_sent_closing_fee = Some((proposed_feerate.unwrap(), proposed_fee.unwrap()));
-                       Ok((our_shutdown, Some(msgs::ClosingSigned {
-                               channel_id: self.channel_id,
-                               fee_satoshis: proposed_fee.unwrap(),
-                               signature: our_sig.unwrap(),
-                       }), dropped_outbound_htlcs))
-               } else {
-                       Ok((our_shutdown, None, dropped_outbound_htlcs))
-               }
+               Ok((our_shutdown, self.maybe_propose_first_closing_signed(fee_estimator), dropped_outbound_htlcs))
        }
 
        pub fn closing_signed(&mut self, fee_estimator: &FeeEstimator, msg: &msgs::ClosingSigned) -> Result<(Option<msgs::ClosingSigned>, Option<Transaction>), HandleError> {