From 9f4dcd86a73694e8f958b02a778c529275603abf Mon Sep 17 00:00:00 2001
From: Marc Labrecque <mlabre51@gmail.com>
Date: Sat, 15 Nov 2014 16:26:45 -0500
Subject: [PATCH] Fix isAlien to properly identify built-in functions.
 Partially fixes #18244

---
 _base/lang.js       |  2 +-
 tests/_base/lang.js | 17 +++++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/_base/lang.js b/_base/lang.js
index e544eabc4c..a1e332bc43 100644
--- a/_base/lang.js
+++ b/_base/lang.js
@@ -307,7 +307,7 @@ define(["./kernel", "../has", "../sniff"], function(dojo, has){
 			// summary:
 			//		Returns true if it is a built-in function or some other kind of
 			//		oddball that *should* report as a function but doesn't
-			return it && !lang.isFunction(it) && /\{\s*\[native code\]\s*\}/.test(String(it)); // Boolean
+			return !!it && lang.isFunction(it) && /\{\s*\[native code\]\s*\}/.test(String(it)); // Boolean
 		},
 
 		extend: function(ctor, props){
diff --git a/tests/_base/lang.js b/tests/_base/lang.js
index 2f47fc1464..4baf65cf80 100644
--- a/tests/_base/lang.js
+++ b/tests/_base/lang.js
@@ -356,6 +356,23 @@ define(["doh/main", "dojo/_base/array", "dojo/_base/lang", "dojo/_base/kernel"
 
 			var s4 = lang.replace("Hello, ${0} ${2}!", ["Robert", "X", "Cringely"], /\$\{([^\}]+)\}/g);
 			t.is("Hello, Robert Cringely!", s4);
+		},
+
+		function isAlien(t){
+			t.assertTrue(lang.isAlien(isNaN));
+			t.assertTrue(lang.isAlien({}.toString));
+			t.assertFalse(lang.isAlien(function() {}));
+			t.assertFalse(lang.isAlien(function() {/* [native code] */}));
+			t.assertFalse(lang.isAlien({}));
+			t.assertFalse(lang.isAlien(''));
+			t.assertFalse(lang.isAlien(0));
+			t.assertFalse(lang.isAlien(NaN));
+			t.assertFalse(lang.isAlien(null));
+			t.assertFalse(lang.isAlien(undefined));
+			if(typeof window != "undefined"){
+				t.assertTrue(lang.isAlien(window.atob));
+				t.assertFalse(lang.isAlien(window));
+			}
 		}
 	]
   );