fix(nits)

ethcore/src/block.rs

@@ -497,7 +497,7 @@ pub(crate) fn enact(
  last_hashes,
  // Engine such as Clique will calculate author from extra_data.
  // this is only important for executing contracts as the 'executive_author'.
- engine.executive_author(&header),
+ engine.executive_author(&header)?,
  (3141562.into(), 31415620.into()),
  vec![],
  is_epoch_begin,

ethcore/src/engines/clique/mod.rs

@@ -153,7 +153,7 @@ impl VoteType {
 }
 
 /// Clique Engine implementation
-/// block_state_by_hash -> block state indexed by header hash.
+// block_state_by_hash -> block state indexed by header hash.
 #[cfg(not(test))]
 pub struct Clique {
  epoch_length: u64,
@@ -688,7 +688,6 @@ impl Engine<EthereumMachine> for Clique {
  }
 
  // Our task here is to set difficulty
- // TODO:(niklasad1): Return `Result<(), Error>` here instead
  fn populate_from_parent(&self, header: &mut Header, parent: &Header) {
  // TODO(https://github.com/paritytech/parity-ethereum/issues/10410): this is a horrible hack,
  // it is due to the fact that enact and miner both use OpenBlock::new() which will both call
@@ -742,6 +741,8 @@ impl Engine<EthereumMachine> for Clique {
  fn stop(&mut self) {
  if let Some(mut s) = self.step_service.as_mut() {
  Arc::get_mut(&mut s).map(|x| x.stop());
+ } else {
+ warn!(target: "engine", "Stopping `CliqueStepService` failed requires mutable access");
  }
  }
 
@@ -759,8 +760,7 @@ impl Engine<EthereumMachine> for Clique {
  super::total_difficulty_fork_choice(new, current)
  }
 
- fn executive_author(&self, header: &Header) -> Address {
- // Should have been verified now.
- recover_creator(header).expect("Unable to extract creator.")
+ fn executive_author(&self, header: &Header) -> Result<Address, Error> {
+ recover_creator(header)
  }
 }

ethcore/src/engines/mod.rs

@@ -135,7 +135,7 @@ impl fmt::Display for EngineError {
  FailedSystemCall(ref msg) => format!("Failed to make system call: {}", msg),
  MalformedMessage(ref msg) => format!("Received malformed consensus message: {}", msg),
  RequiresClient => format!("Call requires client but none registered"),
- RequiresSigner => format!("Call requires client but none registered"),
+ RequiresSigner => format!("Call requires signer but none registered"),
  InvalidEngine => format!("Invalid engine specification or implementation"),
  };
 
@@ -462,7 +462,9 @@ pub trait Engine<M: Machine>: Sync + Send {
  fn fork_choice(&self, new: &ExtendedHeader, best: &ExtendedHeader) -> ForkChoice;
 
  /// Returns author should used when executing tx's for this block.
- fn executive_author(&self, header: &Header) -> Address { *header.author() }
+ fn executive_author(&self, header: &Header) -> Result<Address, Error> {
+ Ok(*header.author())
+ }
 }
 
 /// Check whether a given block is the best block based on the default total difficulty rule.

json/src/spec/engine.rs

@@ -136,7 +136,7 @@ mod tests {
  let s = r#"{
  "clique": {
  "params": {
- "peorid" : 15,
+ "period": 15,
  "epoch": 30000
  }
  }