From 00da2ac0f8268b1feab5b1dc62ed18f31169efc9 Mon Sep 17 00:00:00 2001
From: Gareth Ellis <gareth.ellis@uk.ibm.com>
Date: Mon, 21 Mar 2016 09:46:42 +0000
Subject: [PATCH] buffer: changing let in for loops back to var

Using let in for loops showed a regression in 4.4.0. @ofrobots
suggested that we avoid using let in for loops until TurboFan becomes
the default optimiser.

The regression that was detected was when looking at how long it took
to create a new buffer from an array of data.

When using `for (let i=0; i<length; i++) ` we saw the operation take
almost 40% longer compared to `var i=0`.

Ref: http://github.com/nodejs/benchmarking/issues/38
---
 lib/buffer.js | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/lib/buffer.js b/lib/buffer.js
index 01a8f303e1b92c..b138552ef965a8 100644
--- a/lib/buffer.js
+++ b/lib/buffer.js
@@ -185,7 +185,7 @@ function fromString(string, encoding) {
 function fromArrayLike(obj) {
   const length = obj.length;
   const b = allocate(length);
-  for (let i = 0; i < length; i++)
+  for (var i = 0; i < length; i++)
     b[i] = obj[i] & 255;
   return b;
 }
@@ -276,6 +276,7 @@ Buffer.isEncoding = function(encoding) {
 
 
 Buffer.concat = function(list, length) {
+  var i;
   if (!Array.isArray(list))
     throw new TypeError('"list" argument must be an Array of Buffers');
 
@@ -284,7 +285,7 @@ Buffer.concat = function(list, length) {
 
   if (length === undefined) {
     length = 0;
-    for (let i = 0; i < list.length; i++)
+    for (i = 0; i < list.length; i++)
       length += list[i].length;
   } else {
     length = length >>> 0;
@@ -292,7 +293,7 @@ Buffer.concat = function(list, length) {
 
   var buffer = Buffer.allocUnsafe(length);
   var pos = 0;
-  for (let i = 0; i < list.length; i++) {
+  for (i = 0; i < list.length; i++) {
     var buf = list[i];
     if (!Buffer.isBuffer(buf))
       throw new TypeError('"list" argument must be an Array of Buffers');