Filter vote accounts with no delegate from being selected in Rotation

core/src/staking_utils.rs

@@ -63,12 +63,21 @@ fn node_staked_accounts_at_epoch(
     epoch_height: u64,
 ) -> Option<impl Iterator<Item = (&Pubkey, u64, &Account)>> {
     bank.epoch_vote_accounts(epoch_height).map(|epoch_state| {
-        epoch_state.into_iter().filter_map(|(account_id, account)| {
-            filter_zero_balances(account).map(|stake| (account_id, stake, account))
-        })
+        epoch_state
+            .into_iter()
+            .filter_map(|(account_id, account)| {
+                filter_zero_balances(account).map(|stake| (account_id, stake, account))
+            })
+            .filter(|(account_id, _, account)| filter_no_delegate(account_id, account))
     })
 }
 
+fn filter_no_delegate(account_id: &Pubkey, account: &Account) -> bool {
+    VoteState::deserialize(&account.userdata)
+        .map(|vote_state| vote_state.delegate_id != *account_id)
+        .unwrap_or(false)
+}
+
 fn filter_zero_balances(account: &Account) -> Option<u64> {
     let balance = Bank::read_balance(&account);
     if balance > 0 {
@@ -189,7 +198,13 @@ mod tests {
 
         // Make a mint vote account. Because the mint has nonzero stake, this
         // should show up in the active set
-        voting_keypair_tests::new_vote_account_with_vote(&mint_keypair, &bank_voter, &bank, 499, 0);
+        voting_keypair_tests::new_vote_account_with_delegate(
+            &mint_keypair,
+            &bank_voter,
+            &mint_keypair.pubkey(),
+            &bank,
+            499,
+        );
 
         // soonest slot that could be a new epoch is 1
         let mut slot = 1;

core/src/voting_keypair.rs

@@ -120,6 +120,25 @@ pub mod tests {
         bank.process_transaction(&tx).unwrap();
     }
 
+    pub fn new_vote_account_with_delegate(
+        from_keypair: &Keypair,
+        voting_keypair: &Keypair,
+        delegate: &Pubkey,
+        bank: &Bank,
+        lamports: u64,
+    ) {
+        let blockhash = bank.last_blockhash();
+        let tx = VoteTransaction::new_account_with_delegate(
+            from_keypair,
+            voting_keypair,
+            delegate,
+            blockhash,
+            lamports,
+            0,
+        );
+        bank.process_transaction(&tx).unwrap();
+    }
+
     pub fn push_vote<T: KeypairUtil>(voting_keypair: &T, bank: &Bank, slot: u64) {
         let blockhash = bank.last_blockhash();
         let tx =