grandpa: don't require justification of consensus changes on full node (#3540)

* grandpa: don't request justification for consensus changes on full node

* sync: finalize justification/finality proof requests in-order

* sync: ignore result of try_finalize_root on justification import

substrate/core/network/src/protocol/sync.rs

@@ -815,12 +815,7 @@ impl<B: BlockT> ChainSync<B> {
 	/// with or without errors.
 	pub fn on_justification_import(&mut self, hash: B::Hash, number: NumberFor<B>, success: bool) {
 		let finalization_result = if success { Ok((hash, number)) } else { Err(()) };
-		if !self.extra_justifications.try_finalize_root((hash, number), finalization_result, true) {
-			debug!(target: "sync", "Got justification import result for unknown justification {:?} {:?} request.",
-				hash,
-				number,
-			)
-		}
+		self.extra_justifications.try_finalize_root((hash, number), finalization_result, true);
 		self.is_idle = false;
 	}
 

substrate/core/network/src/protocol/sync/extra_requests.rs

@@ -138,7 +138,7 @@ impl<B: BlockT> ExtraRequests<B> {
 		}
 
 		if best_finalized_number > self.best_seen_finalized_number {
-			match self.tree.finalize_with_ancestors(
+			match self.tree.finalize(
 				best_finalized_hash,
 				best_finalized_number,
 				&is_descendent_of,