fix BlockAttributes encoding (#6281)

substrate/client/network/src/light_client_handler.rs

@@ -27,9 +27,10 @@
 use bytes::Bytes;
 use codec::{self, Encode, Decode};
 use crate::{
+	block_requests::build_protobuf_block_request,
 	chain::Client,
 	config::ProtocolId,
-	protocol::message::BlockAttributes,
+	protocol::message::{BlockAttributes, Direction, FromBlock},
 	schema,
 };
 use futures::{channel::oneshot, future::BoxFuture, prelude::*, stream::FuturesUnordered};
@@ -1062,13 +1063,13 @@ fn retries<B: Block>(request: &Request<B>) -> usize {
 fn serialize_request<B: Block>(request: &Request<B>) -> Result<Vec<u8>, prost::EncodeError> {
 	let request = match request {
 		Request::Body { request, .. } => {
-			let rq = schema::v1::BlockRequest {
-				fields: u32::from(BlockAttributes::BODY.bits()),
-				from_block: Some(schema::v1::block_request::FromBlock::Hash(request.header.hash().encode())),
-				to_block: Vec::new(),
-				direction: schema::v1::Direction::Ascending as i32,
-				max_blocks: 1,
-			};
+			let rq = build_protobuf_block_request::<_, NumberFor<B>>(
+				BlockAttributes::BODY,
+				FromBlock::Hash(request.header.hash()),
+				None,
+				Direction::Ascending,
+				Some(1),
+			);
 			let mut buf = Vec::with_capacity(rq.encoded_len());
 			rq.encode(&mut buf)?;
 			return Ok(buf);
@@ -2036,4 +2037,22 @@ mod tests {
 		assert_eq!(vec![(100, 2)], task::block_on(chan.1).unwrap().unwrap());
 		//              ^--- from `DummyFetchChecker::check_changes_proof`
 	}
+
+	#[test]
+	fn body_request_fields_encoded_properly() {
+		let (sender, _) = oneshot::channel();
+		let serialized_request = serialize_request::<Block>(&Request::Body {
+			request: RemoteBodyRequest {
+				header: dummy_header(),
+				retry_count: None,
+			},
+			sender,
+		}).unwrap();
+		let deserialized_request = schema::v1::BlockRequest::decode(&serialized_request[..]).unwrap();
+		assert!(
+			BlockAttributes::from_be_u32(deserialized_request.fields)
+				.unwrap()
+				.contains(BlockAttributes::BODY)
+		);
+	}
 }