From cae2051b832d6f836d6ab9bc5752113fc01fc0c8 Mon Sep 17 00:00:00 2001
From: Nikolai Vavilov <vvnicholas@gmail.com>
Date: Sat, 2 May 2020 20:30:44 +0300
Subject: [PATCH] buffer: improve copy() performance

There is no need to create a slice when sourceEnd is out of bounds.

PR-URL: https://github.com/nodejs/node/pull/33214
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Zeyu Yang <himself65@outlook.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
---
 lib/buffer.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/buffer.js b/lib/buffer.js
index 874227f0d44051..a818f41a26ed5b 100644
--- a/lib/buffer.js
+++ b/lib/buffer.js
@@ -257,7 +257,7 @@ function _copyActual(source, target, targetStart, sourceStart, sourceEnd) {
   if (nb > sourceLen)
     nb = sourceLen;
 
-  if (sourceStart !== 0 || sourceEnd !== source.length)
+  if (sourceStart !== 0 || sourceEnd < source.length)
     source = new Uint8Array(source.buffer, source.byteOffset + sourceStart, nb);
 
   target.set(source, targetStart);