f use util method

Author: TheBlueMatt

lightning/src/ln/peer_handler.rs

@@ -397,7 +397,8 @@ struct Peer {
 	///
 	/// This is set only after we've processed the [`msgs::Init`] message and called relevant
 	/// `peer_connected` handler methods. Thus, this field is set *iff* we've finished our
-	/// handshake and can talk to this peer normally.
+	/// handshake and can talk to this peer normally (though use [`Peer::handshake_complete`] to
+	/// check this.
 	their_features: Option<InitFeatures>,
 	their_net_address: Option<NetAddress>,
 
@@ -429,6 +430,13 @@ struct Peer {
 }
 
 impl Peer {
+	/// True after we've processed the [`msgs::Init`] message and called relevant `peer_connected`
+	/// handler methods. Thus, this implies we've finished our handshake and can talk to this peer
+	/// normally.
+	fn handshake_complete(&self) -> bool {
+		self.their_features.is_some()
+	}
+
 	/// Returns true if the channel announcements/updates for the given channel should be
 	/// forwarded to this peer.
 	/// If we are sending our routing table to this peer and we have not yet sent channel
@@ -1908,7 +1916,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
 	}
 
 	fn do_disconnect(&self, mut descriptor: Descriptor, peer: &Peer, reason: &'static str) {
-		if peer.their_features.is_none() {
+		if !peer.handshake_complete() {
 			log_trace!(self.logger, "Disconnecting peer which hasn't completed handshake due to {}", reason);
 			descriptor.disconnect_socket();
 			return;
@@ -1934,7 +1942,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
 			},
 			Some(peer_lock) => {
 				let peer = peer_lock.lock().unwrap();
-				if peer.their_features.is_none() { return; }
+				if !peer.handshake_complete() { return; }
 				debug_assert!(peer.their_node_id.is_some());
 				if let Some((node_id, _)) = peer.their_node_id {
 					log_trace!(self.logger,
@@ -2066,7 +2074,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
 		if !descriptors_needing_disconnect.is_empty() {
 			{
 				let mut peers_lock = self.peers.write().unwrap();
-				for descriptor in descriptors_needing_disconnect.drain(..) {
+				for descriptor in descriptors_needing_disconnect {
 					if let Some(peer_mutex) = peers_lock.remove(&descriptor) {
 						let peer = peer_mutex.lock().unwrap();
 						if let Some((node_id, _)) = peer.their_node_id {