node/service: Update finality target to fix disputes tests (#3732)

polkadot/node/service/src/relay_chain_selection.rs

@@ -415,7 +415,7 @@ where
 		let lag = initial_leaf_number.saturating_sub(subchain_number);
 		self.metrics.note_approval_checking_finality_lag(lag);
 
-		let lag = if cfg!(feature = "disputes") {
+		let (lag, subchain_head) = if cfg!(feature = "disputes") {
 			// Prevent sending flawed data to the dispute-coordinator.
 			if Some(subchain_block_descriptions.len() as _) !=
 				subchain_number.checked_sub(target_number)
@@ -441,7 +441,7 @@ where
 					std::any::type_name::<Self>(),
 				)
 				.await;
-			let (subchain_number, _subchain_head) = rx
+			let (subchain_number, subchain_head) = rx
 				.await
 				.map_err(Error::OverseerDisconnected)
 				.map_err(|e| ConsensusError::Other(Box::new(e)))?
@@ -450,9 +450,9 @@ where
 			// The the total lag accounting for disputes.
 			let lag_disputes = initial_leaf_number.saturating_sub(subchain_number);
 			self.metrics.note_disputes_finality_lag(lag_disputes);
-			lag_disputes
+			(lag_disputes, subchain_head)
 		} else {
-			lag
+			(lag, subchain_head)
 		};
 
 		// 4. Apply the maximum safeguard to the finality lag.