Set initial_routing_sync in InitFeatures

The initial_routing_sync feature is set by peer_handler whenever a full
sync of the network graph is desired. It is not explicitly set when
creating features with InitFeatures::supported().

An upcoming refactor will change supported() to known(), which will
return all features known by the implementation. Thus, the
initial_routing_sync flag will need to be set by default. This commit
makes the behavior change ahead of the refactor.

Author: jkczyz

lightning/src/ln/features.rs

@@ -81,7 +81,7 @@ impl InitFeatures {
 	/// Create a Features with the features we support
 	pub fn supported() -> InitFeatures {
 		InitFeatures {
-			flags: vec![2 | 1 << 5, 1 << (9-8) | 1 << (15 - 8), 1 << (17 - 8*2)],
+			flags: vec![2 | 1 << 3 | 1 << 5, 1 << (9-8) | 1 << (15 - 8), 1 << (17 - 8*2)],
 			mark: PhantomData,
 		}
 	}
@@ -286,11 +286,9 @@ impl<T: sealed::InitialRoutingSync> Features<T> {
 	pub(crate) fn initial_routing_sync(&self) -> bool {
 		self.flags.len() > 0 && (self.flags[0] & (1 << 3)) != 0
 	}
-	pub(crate) fn set_initial_routing_sync(&mut self) {
-		if self.flags.len() == 0 {
-			self.flags.resize(1, 1 << 3);
-		} else {
-			self.flags[0] |= 1 << 3;
+	pub(crate) fn clear_initial_routing_sync(&mut self) {
+		if self.flags.len() > 0 {
+			self.flags[0] &= !(1 << 3);
 		}
 	}
 }
@@ -364,9 +362,9 @@ mod tests {
 		assert!(NodeFeatures::supported().supports_basic_mpp());
 
 		let mut init_features = InitFeatures::supported();
-		init_features.set_initial_routing_sync();
-		assert!(!init_features.requires_unknown_bits());
-		assert!(!init_features.supports_unknown_bits());
+		assert!(init_features.initial_routing_sync());
+		init_features.clear_initial_routing_sync();
+		assert!(!init_features.initial_routing_sync());
 	}
 
 	#[test]
@@ -381,8 +379,8 @@ mod tests {
 	#[test]
 	fn test_node_with_known_relevant_init_flags() {
 		// Create an InitFeatures with initial_routing_sync supported.
-		let mut init_features = InitFeatures::supported();
-		init_features.set_initial_routing_sync();
+		let init_features = InitFeatures::supported();
+		assert!(init_features.initial_routing_sync());
 
 		// Attempt to pull out non-node-context feature flags from these InitFeatures.
 		let res = NodeFeatures::with_known_relevant_init_flags(&init_features);

lightning/src/ln/peer_handler.rs

@@ -549,8 +549,8 @@ impl<Descriptor: SocketDescriptor, CM: Deref> PeerManager<Descriptor, CM> where
 									peer.their_node_id = Some(their_node_id);
 									insert_node_id!();
 									let mut features = InitFeatures::supported();
-									if self.message_handler.route_handler.should_request_full_sync(&peer.their_node_id.unwrap()) {
-										features.set_initial_routing_sync();
+									if !self.message_handler.route_handler.should_request_full_sync(&peer.their_node_id.unwrap()) {
+										features.clear_initial_routing_sync();
 									}
 
 									let resp = msgs::Init { features };
@@ -643,8 +643,8 @@ impl<Descriptor: SocketDescriptor, CM: Deref> PeerManager<Descriptor, CM> where
 
 												if !peer.outbound {
 													let mut features = InitFeatures::supported();
-													if self.message_handler.route_handler.should_request_full_sync(&peer.their_node_id.unwrap()) {
-														features.set_initial_routing_sync();
+													if !self.message_handler.route_handler.should_request_full_sync(&peer.their_node_id.unwrap()) {
+														features.clear_initial_routing_sync();
 													}
 
 													let resp = msgs::Init { features };