From 83c17c7026a61bac82503152f7172db06a634a18 Mon Sep 17 00:00:00 2001
From: Juhyung Park <jh@codechain.io>
Date: Wed, 25 Sep 2019 12:13:38 +0900
Subject: [PATCH 1/2] Remove unused `on_verified_proposal` in consensus

---
 core/src/client/importer.rs | 5 -----
 core/src/consensus/mod.rs   | 5 -----
 2 files changed, 10 deletions(-)

diff --git a/core/src/client/importer.rs b/core/src/client/importer.rs
index d039b36e22..b00e992e8f 100644
--- a/core/src/client/importer.rs
+++ b/core/src/client/importer.rs
@@ -30,7 +30,6 @@ use super::{BlockChainTrait, Client, ClientConfig};
 use crate::block::{enact, IsBlock, LockedBlock};
 use crate::blockchain::{BodyProvider, HeaderProvider, ImportRoute};
 use crate::consensus::CodeChainEngine;
-use crate::encoded;
 use crate::error::Error;
 use crate::miner::{Miner, MinerService};
 use crate::service::ClientIoMessage;
@@ -117,10 +116,6 @@ impl Importer {
                     continue
                 }
                 if let Ok(closed_block) = self.check_and_close_block(&block, client) {
-                    if self.engine.is_proposal(&block.header) {
-                        self.engine.on_verified_proposal(encoded::Block::new(block.bytes.clone()))
-                    }
-
                     imported_blocks.push(header.hash());
                     let route = self.commit_block(&closed_block, &header, &block.bytes, client);
                     import_results.push(route);
diff --git a/core/src/consensus/mod.rs b/core/src/consensus/mod.rs
index bf92051d3b..37deaec6f0 100644
--- a/core/src/consensus/mod.rs
+++ b/core/src/consensus/mod.rs
@@ -54,7 +54,6 @@ use crate::account_provider::AccountProvider;
 use crate::block::{ExecutedBlock, SealedBlock};
 use crate::client::ConsensusClient;
 use crate::codechain_machine::CodeChainMachine;
-use crate::encoded;
 use crate::error::Error;
 use crate::transaction::UnverifiedTransaction;
 use crate::views::HeaderView;
@@ -243,10 +242,6 @@ pub trait ConsensusEngine: Sync + Send {
         false
     }
 
-    /// Called when proposal block is verified.
-    /// Consensus many hold the verified proposal block until it should be imported.
-    fn on_verified_proposal(&self, _verified_block_data: encoded::Block) {}
-
     /// Register an account which signs consensus messages.
     fn set_signer(&self, _ap: Arc<AccountProvider>, _address: Address) {}
 

From 4afb73d0110e64c05ebfc1b77ac2284200a49c1d Mon Sep 17 00:00:00 2001
From: Juhyung Park <jh@codechain.io>
Date: Thu, 26 Sep 2019 15:39:41 +0900
Subject: [PATCH 2/2] Do not panic when height, view or step is changed while
 creating a block

---
 core/src/consensus/tendermint/worker.rs | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/core/src/consensus/tendermint/worker.rs b/core/src/consensus/tendermint/worker.rs
index ea6c94a361..4a466bfee9 100644
--- a/core/src/consensus/tendermint/worker.rs
+++ b/core/src/consensus/tendermint/worker.rs
@@ -1102,6 +1102,24 @@ impl Worker {
     }
 
     fn proposal_generated(&mut self, sealed_block: &SealedBlock) {
+        let proposal_height = sealed_block.header().number();
+        let proposal_seal = sealed_block.header().seal();
+        let proposal_view = TendermintSealView::new(proposal_seal)
+            .consensus_view()
+            .expect("Generated proposal should have a valid seal");
+        assert!(proposal_height <= self.height, "A proposal cannot be generated on the future height");
+        if proposal_height < self.height || (proposal_height == self.height && proposal_view != self.view) {
+            ctrace!(
+                ENGINE,
+                "Proposal is generated on the height {} and view {}. Current height is {} and view is {}",
+                proposal_height,
+                proposal_view,
+                self.height,
+                self.view,
+            );
+            return
+        }
+
         let header = sealed_block.header();
         let hash = header.hash();
         let parent_hash = header.parent_hash();
@@ -1116,7 +1134,12 @@ impl Worker {
                 parent_hash, expected_parent_hash
             );
         } else {
-            panic!("Block is generated at unexpected step {:?}", self.step);
+            ctrace!(
+                ENGINE,
+                "Proposal is generated after step is changed. Expected step is ProposeWaitBlockGeneration but current step is {:?}",
+                self.step,
+            );
+            return
         }
         let prev_proposer_idx = self.block_proposer_idx(*parent_hash).expect("Prev block must exists");