Allow existence of vote on root in saved tower

core/src/consensus.rs

@@ -921,11 +921,12 @@ impl Tower {
             }
 
             if let Some(checked_slot) = checked_slot {
-                // This is really special, only if tower is initialized (root = slot 0) for genesis and contains
-                // a vote (= slot 0) for the genesis, the slot 0 can repeat only once
-                let voting_from_genesis = *slot_in_tower == checked_slot && *slot_in_tower == 0;
+                // This is really special, only if tower is initialized and contains
+                // a vote for the root, the root slot can repeat only once
+                let voting_for_root =
+                    *slot_in_tower == checked_slot && *slot_in_tower == tower_root;
 
-                if !voting_from_genesis {
+                if !voting_for_root {
                     // Unless we're voting since genesis, slots_in_tower must always be older than last checked_slot
                     // including all vote slot and the root slot.
                     assert!(
@@ -3038,6 +3039,23 @@ pub mod test {
             .unwrap();
     }
 
+    #[test]
+    fn test_adjust_lockouts_after_replay_vote_on_root() {
+        let mut tower = Tower::new_for_tests(10, 0.9);
+        tower.lockouts.root_slot = Some(42);
+        tower.lockouts.votes.push_back(Lockout::new(42));
+        tower.lockouts.votes.push_back(Lockout::new(43));
+        tower.lockouts.votes.push_back(Lockout::new(44));
+        let vote = Vote::new(vec![44], Hash::default());
+        tower.last_vote = vote;
+
+        let mut slot_history = SlotHistory::default();
+        slot_history.add(42);
+
+        let tower = tower.adjust_lockouts_after_replay(42, &slot_history);
+        assert_eq!(tower.unwrap().voted_slots(), [43, 44]);
+    }
+
     #[test]
     fn test_adjust_lockouts_after_replay_vote_on_genesis() {
         let mut tower = Tower::new_for_tests(10, 0.9);