From b6ffffb3a96705704d2877f17b69eb00dc1374e7 Mon Sep 17 00:00:00 2001
From: Brian Bland <brian.bland@coinbase.com>
Date: Fri, 23 Jan 2026 11:00:48 -0800
Subject: [PATCH] Return latest state root in Transaction.commit

---
 src/database.rs    | 5 ++++-
 src/meta/mod.rs    | 7 ++++++-
 src/transaction.rs | 8 ++++----
 3 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/src/database.rs b/src/database.rs
index 4c3efdbb..e163f07a 100644
--- a/src/database.rs
+++ b/src/database.rs
@@ -451,13 +451,16 @@ mod tests {
         let file_path = tmp_dir.path().join("test.db");
         let db = Database::create_new(&file_path).unwrap();
 
+        let tx = db.begin_rw().unwrap();
+        assert_eq!(tx.commit().unwrap(), EMPTY_ROOT_HASH);
+
         let address1 = address!("0xd8da6bf26964af9d7eed9e03e53415d37aa96045");
         let account1 = Account::new(1, U256::from(100), EMPTY_ROOT_HASH, KECCAK_EMPTY);
 
         let mut tx = db.begin_rw().unwrap();
         tx.set_account(AddressPath::for_address(address1), Some(account1.clone())).unwrap();
 
-        tx.commit().unwrap();
+        assert_ne!(tx.commit().unwrap(), EMPTY_ROOT_HASH);
         db.close().unwrap();
 
         let db = Database::open(&file_path).unwrap();
diff --git a/src/meta/mod.rs b/src/meta/mod.rs
index 488d9e45..ec59191a 100644
--- a/src/meta/mod.rs
+++ b/src/meta/mod.rs
@@ -69,6 +69,7 @@ use crate::{
     snapshot::SnapshotId,
 };
 use alloy_primitives::B256;
+use alloy_trie::EMPTY_ROOT_HASH;
 use memmap2::MmapMut;
 use std::{
     cmp::Ordering,
@@ -142,7 +143,11 @@ impl MetadataSlot {
     #[inline]
     #[must_use]
     pub fn root_node_hash(&self) -> B256 {
-        self.root_node_hash.into()
+        if self.root_node_hash == [0; 32] {
+            EMPTY_ROOT_HASH
+        } else {
+            self.root_node_hash.into()
+        }
     }
 
     /// Returns the ID of the page containing the root node.
diff --git a/src/transaction.rs b/src/transaction.rs
index aa7c4398..d0aa2c51 100644
--- a/src/transaction.rs
+++ b/src/transaction.rs
@@ -170,7 +170,7 @@ impl<DB: Deref<Target = Database>> Transaction<DB, RW> {
         Ok(())
     }
 
-    pub fn commit(mut self) -> Result<(), TransactionError> {
+    pub fn commit(mut self) -> Result<B256, TransactionError> {
         let mut changes = self.pending_changes.drain().collect::<Vec<_>>();
         if !changes.is_empty() {
             self.database.storage_engine.set_values(&mut self.context, changes.as_mut()).unwrap();
@@ -184,7 +184,7 @@ impl<DB: Deref<Target = Database>> Transaction<DB, RW> {
         transaction_manager.remove_tx(self.context.snapshot_id, true);
 
         self.committed = true;
-        Ok(())
+        Ok(self.context.root_node_hash)
     }
 
     pub fn rollback(mut self) -> Result<(), TransactionError> {
@@ -199,12 +199,12 @@ impl<DB: Deref<Target = Database>> Transaction<DB, RW> {
 }
 
 impl<DB: Deref<Target = Database>> Transaction<DB, RO> {
-    pub fn commit(mut self) -> Result<(), TransactionError> {
+    pub fn commit(mut self) -> Result<B256, TransactionError> {
         let mut transaction_manager = self.database.transaction_manager.lock();
         transaction_manager.remove_tx(self.context.snapshot_id, false);
 
         self.committed = true;
-        Ok(())
+        Ok(self.context.root_node_hash)
     }
 }