Fallback close_channel_internal to force close unfunded channels

Author: dunxen

lightning/src/ln/channelmanager.rs

@@ -698,6 +698,18 @@ impl <Signer: ChannelSigner> PeerState<Signer> {
 			self.outbound_v1_channel_by_id.contains_key(channel_id) ||
 			self.inbound_v1_channel_by_id.contains_key(channel_id)
 	}
+
+	/// Returns a bool indicating whether the given `channel_id` matches a channel we have with this
+	/// peer that is in one of our pending (unfunded) channel maps.
+	///
+	/// NOTE: Although V1 established channels will always have a `temporary_channel_id` if they're
+	///       in `(outbound/inbound)_v1_channel_by_id`, we use the more general `channel_id` as V2
+	///       established channels will have a fixed `channel_id` already after the `accept_channel2`
+	///       message is sent/received.
+	fn has_pending_channel(&self, channel_id: &[u8; 32]) -> bool {
+		self.outbound_v1_channel_by_id.contains_key(channel_id) ||
+			self.inbound_v1_channel_by_id.contains_key(channel_id)
+	}
 }
 
 /// Stores a PaymentSecret and any other data we may need to validate an inbound payment is
@@ -2387,6 +2399,14 @@ where
 
 			let mut peer_state_lock = peer_state_mutex.lock().unwrap();
 			let peer_state = &mut *peer_state_lock;
+
+			if peer_state.has_pending_channel(&channel_id) {
+				// If the channel was still in an unfunded channel map, then we force-close the channel, ignoring
+				// any channel-not-found errors.
+				let _ = self.force_close_channel_with_peer(&channel_id, counterparty_node_id, None, false);
+				return Ok(());
+			}
+
 			match peer_state.channel_by_id.entry(channel_id.clone()) {
 				hash_map::Entry::Occupied(mut chan_entry) => {
 					let funding_txo_opt = chan_entry.get().context.get_funding_txo();