av-store: write meta for unknown finalized blocks (#6452)

* av-store: write meta for unknown finalized blocks

* fix test

polkadot/node/core/av-store/src/lib.rs

@@ -570,6 +570,14 @@ async fn run_iteration<Context>(
 				FromOrchestra::Signal(OverseerSignal::BlockFinalized(hash, number)) => {
 					let _timer = subsystem.metrics.time_process_block_finalized();
 
+					if !subsystem.known_blocks.is_known(&hash) {
+						// If we haven't processed this block yet,
+						// make sure we write the metadata about the
+						// candidates backed in this finalized block.
+						// Otherwise, we won't be able to store our chunk
+						// for these candidates.
+						process_block_activated(ctx, subsystem, hash).await?;
+					}
 					subsystem.finalized_number = Some(number);
 					subsystem.known_blocks.prune_finalized(number);
 					process_block_finalized(

polkadot/node/core/av-store/src/tests.rs

@@ -732,8 +732,49 @@ fn we_dont_miss_anything_if_import_notifications_are_missed() {
 	let test_state = TestState::default();
 
 	test_harness(test_state.clone(), store.clone(), |mut virtual_overseer| async move {
-		overseer_signal(&mut virtual_overseer, OverseerSignal::BlockFinalized(Hash::zero(), 1))
-			.await;
+		let block_hash = Hash::repeat_byte(1);
+		overseer_signal(&mut virtual_overseer, OverseerSignal::BlockFinalized(block_hash, 1)).await;
+
+		let header = Header {
+			parent_hash: Hash::repeat_byte(0),
+			number: 1,
+			state_root: Hash::zero(),
+			extrinsics_root: Hash::zero(),
+			digest: Default::default(),
+		};
+
+		assert_matches!(
+			overseer_recv(&mut virtual_overseer).await,
+			AllMessages::ChainApi(ChainApiMessage::BlockHeader(
+				relay_parent,
+				tx,
+			)) => {
+				assert_eq!(relay_parent, block_hash);
+				tx.send(Ok(Some(header))).unwrap();
+			}
+		);
+
+		assert_matches!(
+			overseer_recv(&mut virtual_overseer).await,
+			AllMessages::RuntimeApi(RuntimeApiMessage::Request(
+				relay_parent,
+				RuntimeApiRequest::CandidateEvents(tx),
+			)) => {
+				assert_eq!(relay_parent, block_hash);
+				tx.send(Ok(Vec::new())).unwrap();
+			}
+		);
+
+		assert_matches!(
+			overseer_recv(&mut virtual_overseer).await,
+			AllMessages::RuntimeApi(RuntimeApiMessage::Request(
+				relay_parent,
+				RuntimeApiRequest::Validators(tx),
+			)) => {
+				assert_eq!(relay_parent, Hash::zero());
+				tx.send(Ok(Vec::new())).unwrap();
+			}
+		);
 
 		let header = Header {
 			parent_hash: Hash::repeat_byte(3),