Fix fork choice (#10837)

* Fix fork choice:
`is_from_route_finalized` check before switching to parent

* Add tests for `tree_route` with finalization

* Fix Cargo dependencies

* Add comment on `tree_route` for finalization.
Refactor a test.

* Fix compilation error

* Checkout Cargo.lock from master

Cargo.lock

@@ -962,12 +962,14 @@ dependencies = [
  "parity-bytes 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-util-mem 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rayon 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rlp 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rlp_compress 0.1.0",
  "rlp_derive 0.1.0",
  "rustc-hex 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "tempdir 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "triehash-ethereum 0.2.0",
 ]
 
 [[package]]

ethcore/blockchain/Cargo.toml

@@ -13,21 +13,23 @@ blooms-db = { path = "../../util/blooms-db" }
 common-types = { path = "../types" }
 ethcore-db = { path = "../db" }
 ethereum-types = "0.6.0"
+keccak-hash = "0.2.0"
 parity-util-mem = "0.1"
 itertools = "0.5"
 kvdb = "0.1"
 log = "0.4"
 parity-bytes = "0.1"
 parking_lot = "0.8"
+rand = "0.6"
 rayon = "1.0"
 rlp = "0.4.0"
 rlp_compress = { path = "../../util/rlp-compress" }
 rlp_derive = { path = "../../util/rlp-derive" }
+triehash-ethereum = { version = "0.2",  path = "../../util/triehash-ethereum" }
 
 [dev-dependencies]
 env_logger = "0.5"
 ethkey = { path = "../../accounts/ethkey" }
-keccak-hash = "0.2.0"
 rustc-hex = "1.0"
 tempdir = "0.3"
 kvdb-memorydb = "0.1"

ethcore/blockchain/src/blockchain.rs

@@ -710,6 +710,10 @@ impl BlockChain {
 	///
 	/// If the tree route verges into pruned or unknown blocks,
 	/// `None` is returned.
+	///
+	/// `is_from_route_finalized` returns whether the `from` part of the
+	/// route contains a finalized block. This only holds if the two parts (from
+	/// and to) are on different branches, ie. on 2 different forks.
 	pub fn tree_route(&self, from: H256, to: H256) -> Option<TreeRoute> {
 		let mut from_branch = vec![];
 		let mut is_from_route_finalized = false;
@@ -723,9 +727,9 @@ impl BlockChain {
 		// reset from && to to the same level
 		while from_details.number > to_details.number {
 			from_branch.push(current_from);
+			is_from_route_finalized = is_from_route_finalized || from_details.is_finalized;
 			current_from = from_details.parent.clone();
 			from_details = self.block_details(&from_details.parent)?;
-			is_from_route_finalized = is_from_route_finalized || from_details.is_finalized;
 		}
 
 		while to_details.number > from_details.number {
@@ -739,9 +743,9 @@ impl BlockChain {
 		// move to shared parent
 		while current_from != current_to {
 			from_branch.push(current_from);
+			is_from_route_finalized = is_from_route_finalized || from_details.is_finalized;
 			current_from = from_details.parent.clone();
 			from_details = self.block_details(&from_details.parent)?;
-			is_from_route_finalized = is_from_route_finalized || from_details.is_finalized;
 
 			to_branch.push(current_to);
 			current_to = to_details.parent.clone();
@@ -2503,4 +2507,74 @@ mod tests {
 			assert_eq!(bc.epoch_transition_for(fork_hash).unwrap().block_number, 0);
 		}
 	}
+
+	#[test]
+	fn tree_rout_with_finalization() {
+		let genesis = BlockBuilder::genesis();
+		let a = genesis.add_block();
+		// First branch
+		let a1 = a.add_block_with_random_transactions();
+		let a2 = a1.add_block_with_random_transactions();
+		let a3 = a2.add_block_with_random_transactions();
+		// Second branch
+		let b1 = a.add_block_with_random_transactions();
+		let b2 = b1.add_block_with_random_transactions();
+
+		let a_hash = a.last().hash();
+		let a1_hash = a1.last().hash();
+		let a2_hash = a2.last().hash();
+		let a3_hash = a3.last().hash();
+		let b2_hash = b2.last().hash();
+
+		let bootstrap_chain = |blocks: Vec<&BlockBuilder>| {
+			let db = new_db();
+			let bc = new_chain(genesis.last().encoded(), db.clone());
+			let mut batch = db.key_value().transaction();
+			for block in blocks {
+				insert_block_batch(&mut batch, &bc, block.last().encoded(), vec![]);
+				bc.commit();
+			}
+			db.key_value().write(batch).unwrap();
+			(db, bc)
+		};
+
+		let mark_finalized = |block_hash: H256, db: &Arc<dyn BlockChainDB>, bc: &BlockChain| {
+			let mut batch = db.key_value().transaction();
+			bc.mark_finalized(&mut batch, block_hash).unwrap();
+			bc.commit();
+			db.key_value().write(batch).unwrap();
+		};
+
+		// Case 1: fork, with finalized common ancestor
+		{
+			let (db, bc) = bootstrap_chain(vec![&a, &a1, &a2, &a3, &b1, &b2]);
+			assert_eq!(bc.best_block_hash(), a3_hash);
+			assert_eq!(bc.block_hash(2).unwrap(), a1_hash);
+
+			mark_finalized(a_hash, &db, &bc);
+			assert!(!bc.tree_route(a3_hash, b2_hash).unwrap().is_from_route_finalized);
+			assert!(!bc.tree_route(b2_hash, a3_hash).unwrap().is_from_route_finalized);
+		}
+
+		// Case 2: fork with a finalized block on a branch
+		{
+			let (db, bc) = bootstrap_chain(vec![&a, &a1, &a2, &a3, &b1, &b2]);
+			assert_eq!(bc.best_block_hash(), a3_hash);
+			assert_eq!(bc.block_hash(2).unwrap(), a1_hash);
+
+			mark_finalized(a2_hash, &db, &bc);
+			assert!(bc.tree_route(a3_hash, b2_hash).unwrap().is_from_route_finalized);
+			assert!(!bc.tree_route(b2_hash, a3_hash).unwrap().is_from_route_finalized);
+		}
+
+		// Case 3: no-fork, with a finalized block
+		{
+			let (db, bc) = bootstrap_chain(vec![&a, &a1, &a2]);
+			assert_eq!(bc.best_block_hash(), a2_hash);
+
+			mark_finalized(a1_hash, &db, &bc);
+			assert!(!bc.tree_route(a1_hash, a2_hash).unwrap().is_from_route_finalized);
+			assert!(!bc.tree_route(a2_hash, a1_hash).unwrap().is_from_route_finalized);
+		}
+	}
 }

ethcore/blockchain/src/generator.rs

@@ -21,11 +21,13 @@ use ethereum_types::{U256, H256, Bloom};
 
 use common_types::encoded;
 use common_types::header::Header;
-use common_types::transaction::SignedTransaction;
+use common_types::transaction::{SignedTransaction, Transaction, Action};
 use common_types::view;
 use common_types::views::BlockView;
+use keccak_hash::keccak;
 use rlp::encode;
 use rlp_derive::RlpEncodable;
+use triehash_ethereum::ordered_trie_root;
 
 /// Helper structure, used for encoding blocks.
 #[derive(Default, Clone, RlpEncodable)]
@@ -136,6 +138,29 @@ impl BlockBuilder {
 		})
 	}
 
+	/// Add a block with randomly generated transactions.
+	#[inline]
+	pub fn add_block_with_random_transactions(&self) -> Self {
+		// Maximum of ~50 transactions
+		let count = rand::random::<u8>() as usize / 5;
+		let transactions = std::iter::repeat_with(|| {
+			let data_len = rand::random::<u8>();
+			let data = std::iter::repeat_with(|| rand::random::<u8>())
+				.take(data_len as usize)
+				.collect::<Vec<_>>();
+			Transaction {
+				nonce: 0.into(),
+				gas_price: 0.into(),
+				gas: 100_000.into(),
+				action: Action::Create,
+				value: 100.into(),
+				data,
+			}.sign(&keccak("").into(), None)
+		}).take(count);
+
+		self.add_block_with_transactions(transactions)
+	}
+
 	/// Add a block with given transactions.
 	#[inline]
 	pub fn add_block_with_transactions<T>(&self, transactions: T) -> Self
@@ -166,11 +191,15 @@ impl BlockBuilder {
 			let mut block = Block::default();
 			let metadata = get_metadata();
 			let block_number = parent_number + 1;
+			let transactions = metadata.transactions;
+			let transactions_root = ordered_trie_root(transactions.iter().map(rlp::encode));
+
 			block.header.set_parent_hash(parent_hash);
 			block.header.set_number(block_number);
 			block.header.set_log_bloom(metadata.bloom);
 			block.header.set_difficulty(metadata.difficulty);
-			block.transactions = metadata.transactions;
+			block.header.set_transactions_root(transactions_root);
+			block.transactions = transactions;
 
 			parent_hash = block.hash();
 			parent_number = block_number;

ethcore/private-tx/src/lib.rs

@@ -288,7 +288,7 @@ impl Provider {
 		let mut state_buf = [0u8; 64];
 		state_buf[..32].clone_from_slice(state_hash.as_bytes());
 		state_buf[32..].clone_from_slice(nonce_h256.as_bytes());
-		keccak(&state_buf.as_ref())
+		keccak(AsRef::<[u8]>::as_ref(&state_buf[..]))
 	}
 
 	fn pool_client<'a>(&'a self, nonce_cache: &'a NonceCache, local_accounts: &'a HashSet<Address>) -> miner::pool_client::PoolClient<'a, Client> {

ethcore/src/machine.rs

@@ -463,7 +463,7 @@ mod tests {
 
 	#[test]
 	fn should_disallow_unsigned_transactions() {
-		let rlp = "ea80843b9aca0083015f90948921ebb5f79e9e3920abe571004d0b1d5119c154865af3107a400080038080".into();
+		let rlp = "ea80843b9aca0083015f90948921ebb5f79e9e3920abe571004d0b1d5119c154865af3107a400080038080";
 		let transaction: UnverifiedTransaction = ::rlp::decode(&::rustc_hex::FromHex::from_hex(rlp).unwrap()).unwrap();
 		let spec = ::ethereum::new_ropsten_test();
 		let ethparams = get_default_ethash_extensions();