From 78b41da8fa28eb7db3ab4c94b22df468f545fd9b Mon Sep 17 00:00:00 2001
From: David Cai <davidcai1993@yahoo.com>
Date: Fri, 5 May 2017 22:26:19 +0800
Subject: [PATCH] buffer: fix isEncoding result for empty string

---
 lib/buffer.js                           | 1 +
 test/parallel/test-buffer-isencoding.js | 5 ++++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/buffer.js b/lib/buffer.js
index c30cbc2d8509a8..b735277357d9da 100644
--- a/lib/buffer.js
+++ b/lib/buffer.js
@@ -375,6 +375,7 @@ Buffer.compare = function compare(a, b) {
 
 Buffer.isEncoding = function(encoding) {
   return typeof encoding === 'string' &&
+         encoding.length > 0 &&
          typeof internalUtil.normalizeEncoding(encoding) === 'string';
 };
 Buffer[internalUtil.kIsEncodingSymbol] = Buffer.isEncoding;
diff --git a/test/parallel/test-buffer-isencoding.js b/test/parallel/test-buffer-isencoding.js
index 4ed380aae1ce69..72fdd7d4473ede 100644
--- a/test/parallel/test-buffer-isencoding.js
+++ b/test/parallel/test-buffer-isencoding.js
@@ -17,10 +17,13 @@ const assert = require('assert');
     assert.strictEqual(Buffer.isEncoding(enc), true);
   });
 
-[ 'utf9',
+[ '',
+  'utf9',
   'utf-7',
   'Unicode-FTW',
   'new gnu gun',
+  undefined,
+  null,
   false,
   NaN,
   {},