alternative for object.create under IE8 #727

packages/core-js/internals/object-create.js

@@ -10,8 +10,30 @@ var IE_PROTO = sharedKey('IE_PROTO');
 var PROTOTYPE = 'prototype';
 var EmptyConstructor = function () { /* empty */ };
 
+// Check for document.domain and active x support
+// No need to use active x approach when document.domain is not set
+// see https://github.com/es-shims/es5-shim/issues/150
+// variation of https://github.com/kitcambridge/es5-shim/commit/4f738ac066346
+var viaActiveX = function () {
+  try {
+    return document.domain && new ActiveXObject('htmlfile');
+  } catch (e) {
+    return false;
+  }
+};
+
+// Create object with fake `null` prototype: use ActiveX Object
+var NullProtoObjectViaActiveX = function () {
+  var activeXDocument = new ActiveXObject('htmlfile');
+  activeXDocument.write('<script><\/script>');
+  activeXDocument.close();
+  var empty = activeXDocument.parentWindow.Object.prototype;
+  activeXDocument = null;
+  return empty;
+};
+
 // Create object with fake `null` prototype: use iframe Object with cleared prototype
-var NullProtoObject = function () {
+var NullProtoObjectViaIFrame = function () {
   // Thrash, waste and sodomy: IE GC bug
   var iframe = documentCreateElement('iframe');
   var length = enumBugKeys.length;
@@ -28,9 +50,9 @@ var NullProtoObject = function () {
   iframeDocument.open();
   iframeDocument.write(LT + SCRIPT + GT + 'document.F=Object' + LT + '/' + SCRIPT + GT);
   iframeDocument.close();
-  NullProtoObject = iframeDocument.F;
-  while (length--) delete NullProtoObject[PROTOTYPE][enumBugKeys[length]];
-  return NullProtoObject();
+  NullProtoObjectViaIFrame = iframeDocument.F;
+  while (length--) delete NullProtoObjectViaIFrame[PROTOTYPE][enumBugKeys[length]];
+  return NullProtoObjectViaIFrame();
 };
 
 hiddenKeys[IE_PROTO] = true;
@@ -45,6 +67,6 @@ module.exports = Object.create || function create(O, Properties) {
     EmptyConstructor[PROTOTYPE] = null;
     // add "__proto__" for Object.getPrototypeOf polyfill
     result[IE_PROTO] = O;
-  } else result = NullProtoObject();
+  } else result = viaActiveX() ? NullProtoObjectViaActiveX() : NullProtoObjectViaIFrame();
   return Properties === undefined ? result : defineProperties(result, Properties);
 };