From 7d0be24267ef2d2911c997bd6f8c5047dc296b6f Mon Sep 17 00:00:00 2001
From: rizkyikiw42 <rizzikwann@gmail.com>
Date: Tue, 2 Dec 2025 17:05:38 +0800
Subject: [PATCH] eth/downloader: optimize fetch result concatenation

---
 eth/downloader/downloader.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/eth/downloader/downloader.go b/eth/downloader/downloader.go
index 09837a3045..074fb3cb23 100644
--- a/eth/downloader/downloader.go
+++ b/eth/downloader/downloader.go
@@ -940,7 +940,11 @@ func (d *Downloader) processSnapSyncContent() error {
 				}
 			}
 		} else { // results already piled up, consume before handling pivot move
-			results = append(append([]*fetchResult{oldPivot}, oldTail...), results...)
+			newResults := make([]*fetchResult, 1+len(oldTail)+len(results))
+			newResults[0] = oldPivot
+			copy(newResults[1:], oldTail)
+			copy(newResults[1+len(oldTail):], results)
+			results = newResults
 		}
 		// Split around the pivot block and process the two sides via snap/full sync
 		if !d.committed.Load() {