From 1aafb6c2c1756220e11ed922b56b88521a47370c Mon Sep 17 00:00:00 2001
From: John-David Dalton <john.david.dalton@gmail.com>
Date: Sat, 20 Sep 2014 11:47:34 -0700
Subject: [PATCH] Use type checks when checking for a `prototype` property.

---
 lodash.js    | 6 +++---
 test/test.js | 6 +++++-
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/lodash.js b/lodash.js
index ffc3f985e..c0e26360c 100644
--- a/lodash.js
+++ b/lodash.js
@@ -7627,7 +7627,7 @@
         var Ctor = object.constructor,
             length = object.length;
       }
-      if ((Ctor && Ctor.prototype === object) ||
+      if ((typeof Ctor == 'function' && Ctor.prototype === object) ||
           (typeof length == 'number' && length > 0) ||
           (support.enumPrototypes && typeof object == 'function')) {
         return shimKeys(object);
@@ -7670,7 +7670,7 @@
       var keyIndex,
           Ctor = object.constructor,
           index = -1,
-          isProto = Ctor && Ctor.prototype === object,
+          isProto = typeof Ctor == 'function' && Ctor.prototype === object,
           maxIndex = length - 1,
           result = Array(length),
           skipIndexes = length > 0,
@@ -7947,7 +7947,7 @@
           accumulator = [];
         } else if (isObject(object)) {
           var Ctor = object.constructor;
-          accumulator = baseCreate(Ctor && Ctor.prototype);
+          accumulator = baseCreate(typeof Ctor == 'function' && Ctor.prototype);
         } else {
           accumulator = {};
         }
diff --git a/test/test.js b/test/test.js
index b4e0e32c5..34a1a46d4 100644
--- a/test/test.js
+++ b/test/test.js
@@ -6818,7 +6818,7 @@
       deepEqual(func(Foo).sort(), expected);
     });
 
-    test('`_.' + methodName + '` skips the `constructor` property on prototype objects', 2, function() {
+    test('`_.' + methodName + '` skips the `constructor` property on prototype objects', 3, function() {
       function Foo() {}
       Foo.prototype.a = 1;
 
@@ -6827,6 +6827,10 @@
 
       Foo.prototype = { 'constructor': Foo, 'a': 1 };
       deepEqual(func(Foo.prototype), ['a']);
+
+      var Fake = { 'prototype': {} };
+      Fake.prototype.constructor = Fake;
+      deepEqual(func(Fake.prototype), ['constructor']);
     });
 
     test('`_.' + methodName + '` should ' + (isKeys ? 'not' : '') + ' include inherited properties', 1, function() {