Bump to v4.16.5.

isPlainObject.js

@@ -1,4 +1,5 @@
-var getPrototype = require('./_getPrototype'),
+var baseGetTag = require('./_baseGetTag'),
+    getPrototype = require('./_getPrototype'),
     isObjectLike = require('./isObjectLike');
 
 /** `Object#toString` result references. */
@@ -17,13 +18,6 @@ var hasOwnProperty = objectProto.hasOwnProperty;
 /** Used to infer the `Object` constructor. */
 var objectCtorString = funcToString.call(Object);
 
-/**
- * Used to resolve the
- * [`toStringTag`](http://ecma-international.org/ecma-262/7.0/#sec-object.prototype.tostring)
- * of values.
- */
-var objectToString = objectProto.toString;
-
 /**
  * Checks if `value` is a plain object, that is, an object created by the
  * `Object` constructor or one with a `[[Prototype]]` of `null`.
@@ -53,7 +47,7 @@ var objectToString = objectProto.toString;
  * // => true
  */
 function isPlainObject(value) {
-  if (!isObjectLike(value) || objectToString.call(value) != objectTag) {
+  if (!isObjectLike(value) || baseGetTag(value) != objectTag) {
     return false;
   }
   var proto = getPrototype(value);
@@ -61,8 +55,8 @@ function isPlainObject(value) {
     return true;
   }
   var Ctor = hasOwnProperty.call(proto, 'constructor') && proto.constructor;
-  return (typeof Ctor == 'function' &&
-    Ctor instanceof Ctor && funcToString.call(Ctor) == objectCtorString);
+  return typeof Ctor == 'function' && Ctor instanceof Ctor &&
+    funcToString.call(Ctor) == objectCtorString;
 }
 
 module.exports = isPlainObject;