reject empty manifests

Author: ordian

polkadot/node/network/protocol/src/lib.rs

@@ -637,6 +637,12 @@ pub mod v2 {
 			}
 		}
 
+		/// Returns `true` if the filter consists of zeroes.
+		pub fn is_blank(&self) -> bool {
+			self.seconded_in_group.leading_zeros() == self.seconded_in_group.len() &&
+				self.validated_in_group.leading_zeros() == self.validated_in_group.len()
+		}
+
 		/// Whether the filter has a specific expected length, consistent across both
 		/// bitfields.
 		pub fn has_len(&self, len: usize) -> bool {

polkadot/node/network/statement-distribution/src/v2/requests.rs

@@ -788,6 +788,11 @@ fn validate_complete_response(
 			return invalid_candidate_output()
 		}
 
+		// If we filtered out all statements, the response is invalid.
+		if received_filter.is_blank() {
+			return invalid_candidate_output()
+		}
+
 		statements
 	};
 

polkadot/node/network/statement-distribution/src/v2/tests/requests.rs

@@ -1242,7 +1242,7 @@ fn peer_reported_for_providing_statement_from_disabled_validator() {
 			assert_matches!(
 				overseer.recv().await,
 				AllMessages::NetworkBridgeTx(NetworkBridgeTxMessage::ReportPeer(ReportPeerMessage::Single(p, r)))
-					if p == peer_b && r == BENEFIT_VALID_RESPONSE.into() => { }
+					if p == peer_b && r == COST_INVALID_RESPONSE.into() => { }
 			);
 
 			assert_matches!(