Correct manual shutdown detection on channel closure

In 5e874c3 we'd intended to not
reveal the dummy funding transaction in `Event::DiscardFunding`.
However, instead of looking at the channel that was just closed,
the logic only looks at any other channels which were funded as a
part of the same batch. Because manually-funded transactions
cannot currently be done for batch funding, this was actually dead
code, preventing the new changes from taking effect.

Author: TheBlueMatt

lightning/src/ln/channel.rs

@@ -936,6 +936,7 @@ pub(crate) struct ShutdownResult {
 	pub(crate) user_channel_id: u128,
 	pub(crate) channel_capacity_satoshis: u64,
 	pub(crate) counterparty_node_id: PublicKey,
+	pub(crate) is_manual_broadcast: bool,
 	pub(crate) unbroadcasted_funding_tx: Option<Transaction>,
 	pub(crate) channel_funding_txo: Option<OutPoint>,
 }
@@ -3540,6 +3541,7 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
 			channel_capacity_satoshis: self.channel_value_satoshis,
 			counterparty_node_id: self.counterparty_node_id,
 			unbroadcasted_funding_tx,
+			is_manual_broadcast: self.is_manual_broadcast,
 			channel_funding_txo: self.get_funding_txo(),
 		}
 	}
@@ -6243,6 +6245,7 @@ impl<SP: Deref> Channel<SP> where
 					channel_capacity_satoshis: self.context.channel_value_satoshis,
 					counterparty_node_id: self.context.counterparty_node_id,
 					unbroadcasted_funding_tx: self.context.unbroadcasted_funding(),
+					is_manual_broadcast: self.context.is_manual_broadcast,
 					channel_funding_txo: self.context.get_funding_txo(),
 				};
 				let tx = self.build_signed_closing_transaction(&mut closing_tx, &msg.signature, &sig);
@@ -6275,6 +6278,7 @@ impl<SP: Deref> Channel<SP> where
 						channel_capacity_satoshis: self.context.channel_value_satoshis,
 						counterparty_node_id: self.context.counterparty_node_id,
 						unbroadcasted_funding_tx: self.context.unbroadcasted_funding(),
+						is_manual_broadcast: self.context.is_manual_broadcast,
 						channel_funding_txo: self.context.get_funding_txo(),
 					};
 					if closing_signed.is_some() {

lightning/src/ln/channelmanager.rs

@@ -3510,7 +3510,6 @@ where
 			let _ = self.chain_monitor.update_channel(funding_txo, &monitor_update);
 		}
 		let mut shutdown_results = Vec::new();
-		let mut is_manual_broadcast = false;
 		if let Some(txid) = shutdown_res.unbroadcasted_batch_funding_txid {
 			let mut funding_batch_states = self.funding_batch_states.lock().unwrap();
 			let affected_channels = funding_batch_states.remove(&txid).into_iter().flatten();
@@ -3520,10 +3519,6 @@ where
 				if let Some(peer_state_mutex) = per_peer_state.get(&counterparty_node_id) {
 					let mut peer_state = peer_state_mutex.lock().unwrap();
 					if let Some(mut chan) = peer_state.channel_by_id.remove(&channel_id) {
-						// We override the previous value, so we could change from true -> false,
-						// but this is fine because if a channel has manual_broadcast set to false
-						// we should choose the safier condition.
-						is_manual_broadcast = chan.context().is_manual_broadcast();
 						update_maps_on_chan_removal!(self, &chan.context());
 						shutdown_results.push(chan.context_mut().force_shutdown(false, ClosureReason::FundingBatchClosure));
 					}
@@ -3548,7 +3543,7 @@ where
 			}, None));
 
 			if let Some(transaction) = shutdown_res.unbroadcasted_funding_tx {
-				let funding_info = if is_manual_broadcast {
+				let funding_info = if shutdown_res.is_manual_broadcast {
 					FundingInfo::OutPoint {
 						outpoint: shutdown_res.channel_funding_txo
 							.expect("We had an unbroadcasted funding tx, so should also have had a funding outpoint"),