From 6f584af7f58fd38054d7923525ea4143d24d68ba Mon Sep 17 00:00:00 2001
From: Benjamin Gruenbaum <inglor@gmail.com>
Date: Tue, 22 Mar 2016 15:40:36 +0200
Subject: [PATCH 1/2] dns: Use object without protoype for map

Currently we use `{}` for the `lookup` function to find the relevant
resolver to the dns.resolve function. It is preferable to use an
object without a Object.prototype, currently for example you can do
something like:

```js
dns.resolve("google.com", "toString", console.log);
```

And get `[Object undefined]` logged and the callback would never be
called. This is unexpected and strange behavior in my opinion.
In addition, if someone adds a property to `Object.prototype` might
also create unexpected results.

This pull request fixes it, with it an appropriate error is thrown.
---
 lib/dns.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/dns.js b/lib/dns.js
index e77542457b5cd1..e165b1bc0d2f05 100644
--- a/lib/dns.js
+++ b/lib/dns.js
@@ -243,7 +243,7 @@ function resolver(bindingName) {
 }
 
 
-var resolveMap = {};
+var resolveMap = Object.create(null);
 exports.resolve4 = resolveMap.A = resolver('queryA');
 exports.resolve6 = resolveMap.AAAA = resolver('queryAaaa');
 exports.resolveCname = resolveMap.CNAME = resolver('queryCname');

From 606fe5fef24205a1ed1ae9a12deadd49af038749 Mon Sep 17 00:00:00 2001
From: Benjamin Gruenbaum <inglor@gmail.com>
Date: Tue, 22 Mar 2016 17:15:37 +0200
Subject: [PATCH 2/2] add test

---
 test/parallel/test-c-ares.js | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/test/parallel/test-c-ares.js b/test/parallel/test-c-ares.js
index 8c2178ead6a93d..66ae0e0a4adf33 100644
--- a/test/parallel/test-c-ares.js
+++ b/test/parallel/test-c-ares.js
@@ -27,6 +27,11 @@ assert.throws(function() {
   dns.resolve('www.google.com', 'HI');
 }, /Unknown type/);
 
+// Try calling resolve with an unsupported type that's an object key
+assert.throws(function() {
+  dns.resolve('www.google.com', 'toString');
+}, /Unknown type/);
+
 // Windows doesn't usually have an entry for localhost 127.0.0.1 in
 // C:\Windows\System32\drivers\etc\hosts
 // so we disable this test on Windows.