From 8e4d67fcd1f32b23af00cf5b52753e1a52f8c603 Mon Sep 17 00:00:00 2001
From: prathamesh0 <prathamesh.musale0@gmail.com>
Date: Thu, 15 Dec 2022 16:02:15 +0530
Subject: [PATCH] Skip undesired nodes from stem and head iterators

---
 pkg/eth/backend.go | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/pkg/eth/backend.go b/pkg/eth/backend.go
index 6f7e9385..a3eb6ea8 100644
--- a/pkg/eth/backend.go
+++ b/pkg/eth/backend.go
@@ -17,6 +17,7 @@
 package eth
 
 import (
+	"bytes"
 	"context"
 	"database/sql"
 	"errors"
@@ -932,6 +933,11 @@ func (b *Backend) getSliceStem(headPath []byte, t state.Trie, response *GetSlice
 		it, timeTaken := getIteratorAtPath(t, startPath)
 		metaData.trieLoadingTime += timeTaken
 
+		// Skip if iterator not at required path (might happen if node not present at given path)
+		if !bytes.Equal(it.Path(), startPath) {
+			continue
+		}
+
 		sliceNodeMetrics, err := fillSliceNodeData(b.EthDB, b.StateDatabase.TrieDB(), response.TrieNodes.Stem, response.Leaves, it, storage)
 		if err != nil {
 			return err
@@ -956,6 +962,11 @@ func (b *Backend) getSliceHead(headPath []byte, t state.Trie, response *GetSlice
 	it, timeTaken := getIteratorAtPath(t, headPath)
 	metaData.trieLoadingTime += timeTaken
 
+	// Skip if iterator not at required path (might happen if node not present at given path)
+	if !bytes.Equal(it.Path(), headPath) {
+		return nil
+	}
+
 	sliceNodeMetrics, err := fillSliceNodeData(b.EthDB, b.StateDatabase.TrieDB(), response.TrieNodes.Head, response.Leaves, it, storage)
 	if err != nil {
 		return err