fix(engine): is_fork header traversal

crates/engine/tree/src/tree/mod.rs

@@ -927,28 +927,31 @@ where
     ///   extension of the canonical chain.
     /// * walking back from the current head to verify that the target hash is not already part of
     ///   the canonical chain.
-    fn is_fork(&self, target_hash: B256, finalized_hash: Option<B256>) -> ProviderResult<bool> {
+    fn is_fork(&self, target_hash: B256, _finalized_hash: Option<B256>) -> ProviderResult<bool> {
         // verify that the given hash is not part of an extension of the canon chain.
+        let canonical_head = self.state.tree_state.canonical_head();
         let mut current_hash = target_hash;
         while let Some(current_block) = self.sealed_header_by_hash(current_hash)? {
-            if current_block.hash() == self.state.tree_state.canonical_block_hash() {
+            if current_block.hash() == canonical_head.hash {
                 return Ok(false)
             }
+            // We already passed the canonical head
+            if current_block.number <= canonical_head.number {
+                break
+            }
             current_hash = current_block.parent_hash;
         }
 
-        // verify that the given hash is not already part of the canon chain
-        current_hash = self.state.tree_state.canonical_block_hash();
-        while let Some(current_block) = self.sealed_header_by_hash(current_hash)? {
-            if Some(current_hash) == finalized_hash {
-                return Ok(true)
-            }
+        // verify that the given hash is not already part of canonical chain stored in memory
+        if self.canonical_in_memory_state.header_by_hash(target_hash).is_some() {
+            return Ok(false)
+        }
 
-            if current_block.hash() == target_hash {
-                return Ok(false)
-            }
-            current_hash = current_block.parent_hash;
+        // verify that the given hash is not already part of persisted canonical chain
+        if self.provider.block_number(target_hash)?.is_some() {
+            return Ok(false)
         }
+
         Ok(true)
     }