Issue 4804: Notify chain selection of concluded disputes directly

node/core/chain-selection/src/lib.rs

@@ -32,7 +32,6 @@ use parity_scale_codec::Error as CodecError;
 use std::{
 	sync::Arc,
 	time::{Duration, SystemTime, UNIX_EPOCH},
-	collections::HashSet,
 };
 
 use crate::backend::{Backend, BackendWriteOp, OverlayedBackend};
@@ -684,7 +683,8 @@ fn handle_approved_block(backend: &mut impl Backend, approved_block: Hash) -> Re
 }
 
 // Here we revert a provided group of blocks. The most common cause for this is that
-// the dispute coordinator has notified chain selection 
+// the dispute coordinator has notified chain selection of a dispute which concluded
+// against a candidate.
 fn handle_revert_blocks(
 	backend: &impl Backend,
 	blocks_to_revert: Vec<(BlockNumber, Hash)>,

node/core/chain-selection/src/tests.rs

@@ -2016,7 +2016,7 @@ fn stagnant_makes_childless_parent_leaf() {
 }
 
 #[test]
-fn dispute_concluded_against_message_triggers_proper_reversion() {
+fn revert_blocks_message_triggers_proper_reversion() {
 	test_harness(|backend, _, mut virtual_overseer| async move {
 		// Building mini chain with 1 finalized block and 3 unfinalized blocks
 		let finalized_number = 0;
@@ -2045,7 +2045,7 @@ fn dispute_concluded_against_message_triggers_proper_reversion() {
 		let (_, write_rx) = backend.await_next_write();
 		virtual_overseer
 			.send(FromOrchestra::Communication {
-				msg: ChainSelectionMessage::RevertBlocks(Vec::from({(2, block_2_hash)})),
+				msg: ChainSelectionMessage::RevertBlocks(Vec::from([(2, block_2_hash)])),
 			})
 			.await;
 
@@ -2080,7 +2080,7 @@ fn dispute_concluded_against_message_triggers_proper_reversion() {
 }
 
 #[test]
-fn dispute_reversion_against_finalized_is_ignored() {
+fn revert_blocks_against_finalized_is_ignored() {
 	test_harness(|backend, _, mut virtual_overseer| async move {
 		// Building mini chain with 1 finalized block and 3 unfinalized blocks
 		let finalized_number = 0;
@@ -2103,7 +2103,10 @@ fn dispute_reversion_against_finalized_is_ignored() {
 		// Sending dispute conculded against message
 		virtual_overseer
 			.send(FromOrchestra::Communication {
-				msg: ChainSelectionMessage::RevertBlocks(Vec::from({(finalized_number, finalized_hash)})),
+				msg: ChainSelectionMessage::RevertBlocks(Vec::from([(
+					finalized_number,
+					finalized_hash,
+				)])),
 			})
 			.await;
 

node/core/chain-selection/src/tree.rs

@@ -176,6 +176,7 @@ fn propagate_viability_update(
 				*viability_pivots.entry(new_entry.parent_hash).or_insert(0) += 1;
 			}
 		}
+
 		backend.write_block_entry(new_entry);
 
 		tree_frontier

node/core/dispute-coordinator/src/initialized.rs

@@ -1036,11 +1036,11 @@ impl Initialized {
 				ctx.send_message(ChainSelectionMessage::RevertBlocks(blocks_to_revert.clone()))
 					.await;
 			} else {
-				gum::error!(
+				gum::trace!(
 					target: LOG_TARGET,
 					?candidate_hash,
 					?session,
-					"Could not find parent block info for concluded candidate!"
+					"Could not find an including block for candidate against which a dispute has concluded."
 				);
 			}
 		}

node/core/dispute-coordinator/src/scraping/mod.rs

@@ -71,7 +71,7 @@ impl ScrapedUpdates {
 
 /// A structure meant to facilitate chain reversions in the event of a dispute
 /// concluding against a candidate. Each candidate hash maps to a vector of block
-/// numbers and hashes for all blocks which included the candidate. The entries
+/// number + hash pairs for all blocks which included the candidate. The entries
 /// in each vector are ordered by decreasing parent block number to facilitate
 /// minimal cost pruning.
 pub struct InclusionsPerCandidate {