Recover TendermintState when empty the proposal timer is fired in a wrong time

core/src/consensus/tendermint/types.rs

@@ -76,6 +76,15 @@ impl TendermintState {
         }
     }
 
+    pub fn is_propose_wait_empty_block_timer(&self) -> bool {
+        match self {
+            TendermintState::ProposeWaitEmptyBlockTimer {
+                ..
+            } => true,
+            _ => false,
+        }
+    }
+
     pub fn is_commit(&self) -> bool {
         match self {
             TendermintState::Commit {

core/src/consensus/tendermint/worker.rs

@@ -949,7 +949,9 @@ impl Worker {
                     block,
                 } => {
                     if !block.transactions().is_empty() {
-                        self.submit_proposal_block(&block);
+                        cinfo!(ENGINE, "Submitting proposal block {}", block.header().hash());
+                        self.move_to_step(TendermintState::Prevote, false);
+                        self.broadcast_proposal_block(self.view, encoded::Block::new(block.rlp_bytes()));
                     } else {
                         ctrace!(ENGINE, "Empty proposal is generated, set timer");
                         self.step = TendermintState::ProposeWaitEmptyBlockTimer {
@@ -986,12 +988,6 @@ impl Worker {
         }
     }
 
-    fn submit_proposal_block(&mut self, sealed_block: &SealedBlock) {
-        cinfo!(ENGINE, "Submitting proposal block {}", sealed_block.header().hash());
-        self.move_to_step(TendermintState::Prevote, false);
-        self.broadcast_proposal_block(self.view, encoded::Block::new(sealed_block.rlp_bytes()));
-    }
-
     fn backup(&self) {
         backup(self.client().get_kvdb().as_ref(), BackupView {
             height: &self.height,
@@ -1214,25 +1210,30 @@ impl Worker {
     fn on_timeout(&mut self, token: usize) {
         // Timeout from empty block generation
         if token == ENGINE_TIMEOUT_EMPTY_PROPOSAL {
-            let prev_step = mem::replace(&mut self.step, TendermintState::Propose);
-            match prev_step {
-                TendermintState::ProposeWaitEmptyBlockTimer {
-                    block,
-                } => {
-                    if self.height == block.header().number() {
-                        cdebug!(
-                            ENGINE,
-                            "Empty proposal timer is finished, go to the prevote step and broadcast the block"
-                        );
-                        self.submit_proposal_block(block.as_ref());
-                    } else {
-                        cwarn!(ENGINE, "Empty proposal timer was for previous height.");
-                    }
-                }
-                _ => {
-                    cwarn!(ENGINE, "Empty proposal timer was not cleared.");
+            let block = if self.step.is_propose_wait_empty_block_timer() {
+                let previous = mem::replace(&mut self.step, TendermintState::Propose);
+                match previous {
+                    TendermintState::ProposeWaitEmptyBlockTimer {
+                        block,
+                    } => block,
+                    _ => unreachable!(),
                 }
+            } else {
+                cwarn!(ENGINE, "Empty proposal timer was not cleared.");
+                return
+            };
+
+            // When self.height != block.header().number() && "propose timeout" is already called,
+            // the state is stuck and can't move to Prevote. We should change the step to Prevote.
+            self.move_to_step(TendermintState::Prevote, false);
+            if self.height == block.header().number() {
+                cdebug!(ENGINE, "Empty proposal timer is finished, go to the prevote step and broadcast the block");
+                cinfo!(ENGINE, "Submitting proposal block {}", block.header().hash());
+                self.broadcast_proposal_block(self.view, encoded::Block::new(block.rlp_bytes()));
+            } else {
+                cwarn!(ENGINE, "Empty proposal timer was for previous height.");
             }
+
             return
         }