From 3a58b7bac63349b938c76a6c07ca5275d92bb0bd Mon Sep 17 00:00:00 2001
From: chrislu <chris.lu@gmail.com>
Date: Sat, 26 Feb 2022 03:23:06 -0800
Subject: [PATCH] a little safer

---
 weed/filer/filechunk_manifest.go | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/weed/filer/filechunk_manifest.go b/weed/filer/filechunk_manifest.go
index 2c9dc5e74..372901b7d 100644
--- a/weed/filer/filechunk_manifest.go
+++ b/weed/filer/filechunk_manifest.go
@@ -124,8 +124,10 @@ func retriedFetchChunkData(buffer []byte, urlStrings []string, cipherKey []byte,
 				urlString = url.PathEscape(urlString)
 			}
 			shouldRetry, err = util.ReadUrlAsStream(urlString+"?readDeleted=true", cipherKey, isGzipped, isFullChunk, offset, len(buffer), func(data []byte) {
-				x := copy(buffer[n:], data)
-				n += x
+				if n < len(buffer) {
+					x := copy(buffer[n:], data)
+					n += x
+				}
 			})
 			if !shouldRetry {
 				break