From 3cb79c66deeb31fc820e177ffe5a9596f807bd64 Mon Sep 17 00:00:00 2001
From: Arsenii Kulikov <klkvrr@gmail.com>
Date: Mon, 21 Oct 2024 16:18:23 +0400
Subject: [PATCH 1/2] fix: always accept transactions with current nonce

---
 crates/transaction-pool/src/pool/txpool.rs | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/crates/transaction-pool/src/pool/txpool.rs b/crates/transaction-pool/src/pool/txpool.rs
index a85a9a1856b9..a2faf8905fc6 100644
--- a/crates/transaction-pool/src/pool/txpool.rs
+++ b/crates/transaction-pool/src/pool/txpool.rs
@@ -1424,11 +1424,15 @@ impl<T: PoolTransaction> AllTransactions<T> {
     fn ensure_valid(
         &self,
         transaction: ValidPoolTransaction<T>,
+        on_chain_nonce: u64,
     ) -> Result<ValidPoolTransaction<T>, InsertErr<T>> {
         if !self.local_transactions_config.is_local(transaction.origin, transaction.sender()) {
             let current_txs =
                 self.tx_counter.get(&transaction.sender_id()).copied().unwrap_or_default();
-            if current_txs >= self.max_account_slots {
+
+            // Reject transactions if sender's capacity is exceeded.
+            // If transaction's nonce matches on-chain nonce always let it through
+            if current_txs >= self.max_account_slots && transaction.nonce() > on_chain_nonce {
                 return Err(InsertErr::ExceededSenderTransactionsCapacity {
                     transaction: Arc::new(transaction),
                 })
@@ -1595,7 +1599,7 @@ impl<T: PoolTransaction> AllTransactions<T> {
     ) -> InsertResult<T> {
         assert!(on_chain_nonce <= transaction.nonce(), "Invalid transaction");
 
-        let mut transaction = self.ensure_valid(transaction)?;
+        let mut transaction = self.ensure_valid(transaction, on_chain_nonce)?;
 
         let inserted_tx_id = *transaction.id();
         let mut state = TxState::default();

From fcc3d322ec28f670409cdf073b87b251550e8dd1 Mon Sep 17 00:00:00 2001
From: Arsenii Kulikov <klkvrr@gmail.com>
Date: Mon, 21 Oct 2024 22:58:06 +0400
Subject: [PATCH 2/2] test

---
 crates/transaction-pool/src/pool/txpool.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/crates/transaction-pool/src/pool/txpool.rs b/crates/transaction-pool/src/pool/txpool.rs
index a2faf8905fc6..5a2afdf42001 100644
--- a/crates/transaction-pool/src/pool/txpool.rs
+++ b/crates/transaction-pool/src/pool/txpool.rs
@@ -2638,6 +2638,7 @@ mod tests {
         let mut pool = AllTransactions::default();
 
         let mut tx = MockTransaction::eip1559();
+        let unblocked_tx = tx.clone();
         for _ in 0..pool.max_account_slots {
             tx = tx.next();
             pool.insert_tx(f.validated(tx.clone()), on_chain_balance, on_chain_nonce).unwrap();
@@ -2651,6 +2652,10 @@ mod tests {
         let err =
             pool.insert_tx(f.validated(tx.next()), on_chain_balance, on_chain_nonce).unwrap_err();
         assert!(matches!(err, InsertErr::ExceededSenderTransactionsCapacity { .. }));
+
+        assert!(pool
+            .insert_tx(f.validated(unblocked_tx), on_chain_balance, on_chain_nonce)
+            .is_ok());
     }
 
     #[test]