Bump to v4.7.0.

isPlainObject.js

@@ -1,4 +1,5 @@
-var isHostObject = require('./_isHostObject'),
+var getPrototype = require('./_getPrototype'),
+    isHostObject = require('./_isHostObject'),
     isObjectLike = require('./isObjectLike');
 
 /** `Object#toString` result references. */
@@ -10,6 +11,9 @@ var objectProto = Object.prototype;
 /** Used to resolve the decompiled source of functions. */
 var funcToString = Function.prototype.toString;
 
+/** Used to check objects for own properties. */
+var hasOwnProperty = objectProto.hasOwnProperty;
+
 /** Used to infer the `Object` constructor. */
 var objectCtorString = funcToString.call(Object);
 
@@ -19,18 +23,17 @@ var objectCtorString = funcToString.call(Object);
  */
 var objectToString = objectProto.toString;
 
-/** Built-in value references. */
-var getPrototypeOf = Object.getPrototypeOf;
-
 /**
  * Checks if `value` is a plain object, that is, an object created by the
  * `Object` constructor or one with a `[[Prototype]]` of `null`.
  *
  * @static
  * @memberOf _
+ * @since 0.8.0
  * @category Lang
  * @param {*} value The value to check.
- * @returns {boolean} Returns `true` if `value` is a plain object, else `false`.
+ * @returns {boolean} Returns `true` if `value` is a plain object,
+ *  else `false`.
  * @example
  *
  * function Foo() {
@@ -54,11 +57,11 @@ function isPlainObject(value) {
       objectToString.call(value) != objectTag || isHostObject(value)) {
     return false;
   }
-  var proto = getPrototypeOf(value);
+  var proto = getPrototype(value);
   if (proto === null) {
     return true;
   }
-  var Ctor = proto.constructor;
+  var Ctor = hasOwnProperty.call(proto, 'constructor') && proto.constructor;
   return (typeof Ctor == 'function' &&
     Ctor instanceof Ctor && funcToString.call(Ctor) == objectCtorString);
 }