ethcore: use Machine::verify_transaction on parent block (#9900)

* ethcore: use Machine::verify_transaction on parent block

also fixes off-by-one activation of transaction permission contract

* ethcore: clarify call to verify_transaction

ethcore/src/machine.rs

@@ -371,11 +371,11 @@ impl EthereumMachine {
 	}
 
 	/// Does verification of the transaction against the parent state.
-	pub fn verify_transaction<C: BlockInfo + CallContract>(&self, t: &SignedTransaction, header: &Header, client: &C)
+	pub fn verify_transaction<C: BlockInfo + CallContract>(&self, t: &SignedTransaction, parent: &Header, client: &C)
 		-> Result<(), transaction::Error>
 	{
 		if let Some(ref filter) = self.tx_filter.as_ref() {
-			if !filter.transaction_allowed(header.parent_hash(), header.number(), t, client) {
+			if !filter.transaction_allowed(&parent.hash(), parent.number() + 1, t, client) {
 				return Err(transaction::Error::NotAllowed.into())
 			}
 		}

ethcore/src/verification/verification.rs

@@ -147,7 +147,9 @@ pub fn verify_block_family<C: BlockInfo + CallContract>(header: &Header, parent:
 	verify_uncles(params.block, params.block_provider, engine)?;
 
 	for tx in &params.block.transactions {
-		engine.machine().verify_transaction(tx, header, params.client)?;
+		// transactions are verified against the parent header since the current
+		// state wasn't available when the tx was created
+		engine.machine().verify_transaction(tx, parent, params.client)?;
 	}
 
 	Ok(())