From d3cfe9cf0f275467fec56ef1498b272e4839a71f Mon Sep 17 00:00:00 2001
From: buffalu <85544055+buffalu@users.noreply.github.com>
Date: Sun, 12 Nov 2023 21:04:32 -0600
Subject: [PATCH] Don't unlock accounts in TransactionBatches used during
 simulation (#449)

---
 runtime/src/bank.rs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/runtime/src/bank.rs b/runtime/src/bank.rs
index 9b359c50f1..bbc780e8f0 100644
--- a/runtime/src/bank.rs
+++ b/runtime/src/bank.rs
@@ -3696,7 +3696,12 @@ impl Bank {
         let mut account_locks = AccountLocks::default();
         let lock_results =
             Accounts::lock_accounts_sequential(&mut account_locks, tx_account_locks_results);
-        TransactionBatch::new(lock_results, self, Cow::Borrowed(transactions))
+        let mut batch = TransactionBatch::new(lock_results, self, Cow::Borrowed(transactions));
+        // this is required to ensure that accounts aren't unlocked accidentally, which can be problematic during replay.
+        // more specifically, during process_entries, if the lock counts are accidentally decremented,
+        // one might end up replaying a block incorrectly
+        batch.set_needs_unlock(false);
+        batch
     }
 
     /// Prepare a transaction batch without locking accounts for transaction simulation.