Fix #183

substrate/tendermint/machine/src/block.rs

@@ -14,7 +14,7 @@ use crate::{
 pub(crate) struct BlockData<N: Network> {
   pub(crate) number: BlockNumber,
   pub(crate) validator_id: Option<N::ValidatorId>,
-  pub(crate) proposal: N::Block,
+  pub(crate) proposal: Option<N::Block>,
 
   pub(crate) log: MessageLog<N>,
   pub(crate) slashes: HashSet<N::ValidatorId>,
@@ -35,7 +35,7 @@ impl<N: Network> BlockData<N> {
     weights: Arc<N::Weights>,
     number: BlockNumber,
     validator_id: Option<N::ValidatorId>,
-    proposal: N::Block,
+    proposal: Option<N::Block>,
   ) -> BlockData<N> {
     BlockData {
       number,
@@ -106,12 +106,8 @@ impl<N: Network> BlockData<N> {
 
     // 14-21
     if Some(proposer) == self.validator_id {
-      let (round, block) = if let Some((round, block)) = &self.valid {
-        (Some(*round), block.clone())
-      } else {
-        (None, self.proposal.clone())
-      };
-      Some(Data::Proposal(round, block))
+      let (round, block) = self.valid.clone().unzip();
+      block.or_else(|| self.proposal.clone()).map(|block| Data::Proposal(round, block))
     } else {
       self.round_mut().set_timeout(Step::Propose);
       None

substrate/tendermint/machine/src/ext.rs

@@ -270,5 +270,5 @@ pub trait Network: Send + Sync {
     &mut self,
     block: Self::Block,
     commit: Commit<Self::SignatureScheme>,
-  ) -> Self::Block;
+  ) -> Option<Self::Block>;
 }

substrate/tendermint/machine/src/lib.rs

@@ -135,7 +135,8 @@ pub struct TendermintMachine<N: Network> {
 
   queue: VecDeque<MessageFor<N>>,
   msg_recv: mpsc::UnboundedReceiver<SignedMessageFor<N>>,
-  step_recv: mpsc::UnboundedReceiver<(BlockNumber, Commit<N::SignatureScheme>, N::Block)>,
+  #[allow(clippy::type_complexity)]
+  step_recv: mpsc::UnboundedReceiver<(BlockNumber, Commit<N::SignatureScheme>, Option<N::Block>)>,
 
   block: BlockData<N>,
 }
@@ -143,7 +144,7 @@ pub struct TendermintMachine<N: Network> {
 pub type StepSender<N> = mpsc::UnboundedSender<(
   BlockNumber,
   Commit<<N as Network>::SignatureScheme>,
-  <N as Network>::Block,
+  Option<<N as Network>::Block>,
 )>;
 
 pub type MessageSender<N> = mpsc::UnboundedSender<SignedMessageFor<N>>;
@@ -186,7 +187,7 @@ impl<N: Network + 'static> TendermintMachine<N> {
   }
 
   // 53-54
-  async fn reset(&mut self, end_round: RoundNumber, proposal: N::Block) {
+  async fn reset(&mut self, end_round: RoundNumber, proposal: Option<N::Block>) {
     // Ensure we have the end time data for the last round
     self.block.populate_end_time(end_round);
 
@@ -209,7 +210,11 @@ impl<N: Network + 'static> TendermintMachine<N> {
     self.round(RoundNumber(0), Some(round_end));
   }
 
-  async fn reset_by_commit(&mut self, commit: Commit<N::SignatureScheme>, proposal: N::Block) {
+  async fn reset_by_commit(
+    &mut self,
+    commit: Commit<N::SignatureScheme>,
+    proposal: Option<N::Block>,
+  ) {
     let mut round = self.block.round().number;
     // If this commit is for a round we don't have, jump up to it
     while self.block.end_time[&round].canonical() < commit.end_time {
@@ -271,7 +276,12 @@ impl<N: Network + 'static> TendermintMachine<N> {
           msg_recv,
           step_recv,
 
-          block: BlockData::new(weights, BlockNumber(last_block.0 + 1), validator_id, proposal),
+          block: BlockData::new(
+            weights,
+            BlockNumber(last_block.0 + 1),
+            validator_id,
+            Some(proposal),
+          ),
         };
 
         // The end time of the last block is the start time for this one

substrate/tendermint/machine/tests/ext.rs

@@ -140,11 +140,11 @@ impl Network for TestNetwork {
     &mut self,
     block: TestBlock,
     commit: Commit<TestSignatureScheme>,
-  ) -> TestBlock {
+  ) -> Option<TestBlock> {
     dbg!("Adding ", &block);
     assert!(block.valid.is_ok());
     assert!(self.verify_commit(block.id(), &commit));
-    TestBlock { id: (u32::from_le_bytes(block.id) + 1).to_le_bytes(), valid: Ok(()) }
+    Some(TestBlock { id: (u32::from_le_bytes(block.id) + 1).to_le_bytes(), valid: Ok(()) })
   }
 }