From a16103143d39d4a737d719cc3fda60a0453fc577 Mon Sep 17 00:00:00 2001
From: Mathias Buus <mathiasbuus@gmail.com>
Date: Sat, 2 Jan 2016 17:16:19 +0100
Subject: [PATCH] buffer: throw if both length and enc are passed
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PR-URL: https://github.com/nodejs/node/pull/4514
Reviewed-By: Rod Vagg <rod@vagg.org>
Reviewed-By: Vladimir Kurchatkin <vladimir.kurchatkin@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Trevor Norris <trev.norris@gmail.com>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>
---
 lib/buffer.js                               |  5 +++++
 test/sequential/test-buffer-bad-overload.js | 15 +++++++++++++++
 2 files changed, 20 insertions(+)
 create mode 100644 test/sequential/test-buffer-bad-overload.js

diff --git a/lib/buffer.js b/lib/buffer.js
index 9bc9090697a780..00be048d4a6e0b 100644
--- a/lib/buffer.js
+++ b/lib/buffer.js
@@ -47,6 +47,11 @@ function alignPool() {
 function Buffer(arg, encoding) {
   // Common case.
   if (typeof arg === 'number') {
+    if (typeof encoding === 'string') {
+      throw new Error(
+        'If encoding is specified then the first argument must be a string'
+      );
+    }
     // If less than zero, or NaN.
     if (arg < 0 || arg !== arg)
       arg = 0;
diff --git a/test/sequential/test-buffer-bad-overload.js b/test/sequential/test-buffer-bad-overload.js
new file mode 100644
index 00000000000000..2102c1f9a71d59
--- /dev/null
+++ b/test/sequential/test-buffer-bad-overload.js
@@ -0,0 +1,15 @@
+'use strict';
+require('../common');
+const assert = require('assert');
+
+assert.doesNotThrow(function() {
+  new Buffer(10);
+});
+
+assert.throws(function() {
+  new Buffer(10, 'hex');
+});
+
+assert.doesNotThrow(function() {
+  new Buffer('deadbeaf', 'hex');
+});