Object.getOwnPropertyNames should return string names for indexed properties....

src/v8natives.js

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 605 matching lines @@
 
   // Find all the indexed properties.
 
   // Get the local element names.
   var propertyNames = %GetLocalElementNames(obj);
 
   // Get names for indexed interceptor properties.
   if (%GetInterceptorInfo(obj) & 1) {
     var indexedInterceptorNames =
         %GetIndexedInterceptorElementNames(obj);
-    if (indexedInterceptorNames) {
+    if (indexedInterceptorNames)
       propertyNames = propertyNames.concat(indexedInterceptorNames);
-    }
   }
 
   // Find all the named properties.
 
   // Get the local property names.
   propertyNames = propertyNames.concat(%GetLocalPropertyNames(obj));
 
   // Get names for named interceptor properties if any.
 
   if (%GetInterceptorInfo(obj) & 2) {
     var namedInterceptorNames =
         %GetNamedInterceptorPropertyNames(obj);
     if (namedInterceptorNames) {
       propertyNames = propertyNames.concat(namedInterceptorNames);
     }
   }
 
+  // Property names are expected to be strings.
+  for (var i = 0; i < propertyNames.length; ++i)
+    propertyNames[i] = ToString(propertyNames[i]);
+
   return propertyNames;
 }
 
 
 // ES5 section 15.2.3.5.
 function ObjectCreate(proto, properties) {
   if (!IS_OBJECT(proto) && !IS_NULL(proto)) {
     throw MakeTypeError("proto_object_or_null", [proto]);
   }
   var obj = new $Object();
@@ skipping 333 matching lines @@
 
 // ----------------------------------------------------------------------------
 
 function SetupFunction() {
   InstallFunctions($Function.prototype, DONT_ENUM, $Array(
     "toString", FunctionToString
   ));
 }
 
 SetupFunction();