Make arguments and caller always be null on native functions (fixes issue 1548 and issue 1643).

src/v8natives.js

 // Copyright 2011 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 37 matching lines @@
 // Helper function used to install functions on objects.
 function InstallFunctions(object, attributes, functions) {
   if (functions.length >= 8) {
     %OptimizeObjectForAddingMultipleProperties(object, functions.length >> 1);
   }
   for (var i = 0; i < functions.length; i += 2) {
     var key = functions[i];
     var f = functions[i + 1];
     %FunctionSetName(f, key);
     %FunctionRemovePrototype(f);
+    %IgnoreAttributesAndSetProperty(f, "caller",

[Lasse Reichstein, 2011/09/01 08:23:49]

Add comment that we don't match Safari, but we do match Firefox (and possibly
IE).

+                                    null,
+                                    DONT_ENUM | DONT_DELETE);
+    %IgnoreAttributesAndSetProperty(f, "arguments",
+                                    null,
+                                    DONT_ENUM | DONT_DELETE);
+

[Lasse Reichstein, 2011/09/01 08:23:49]

Add a test that this works? E.g., 
[1].map(function() { assertEquals(null, [].map.caller); assertEquals(null,
[].map.arguments); }

     %SetProperty(object, key, f, attributes);
     %SetNativeFlag(f);
   }
   %ToFastProperties(object);
 }
 
 // Emulates JSC by installing functions on a hidden prototype that
 // lies above the current object/prototype.  This lets you override
 // functions on String.prototype etc. and then restore the old function
 // with delete.  See http://code.google.com/p/chromium/issues/detail?id=1717
@@ skipping 1455 matching lines @@
 // ----------------------------------------------------------------------------
 
 function SetupFunction() {
   InstallFunctions($Function.prototype, DONT_ENUM, $Array(
     "bind", FunctionBind,
     "toString", FunctionToString
   ));
 }
 
 SetupFunction();