Another fix for leaking error objects. User code can overwrite

test/cctest/test-api.cc

 // Copyright 2007-2009 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 2365 matching lines @@
   v8::HandleScope scope;
   v8::V8::AddMessageListener(check_reference_error_message);
   LocalContext context;
   CompileRun("ReferenceError.prototype.toString ="
              "  function() { return 'Whoops' }");
   CompileRun("asdf;");
   CompileRun("ReferenceError.prototype.constructor.name = void 0;");
   CompileRun("asdf;");
   CompileRun("ReferenceError.prototype.constructor = void 0;");
   CompileRun("asdf;");
+  CompileRun("ReferenceError.prototype.__proto__ = new Object();");
+  CompileRun("asdf;");
+  CompileRun("ReferenceError.prototype = new Object();");
+  CompileRun("asdf;");
   v8::Handle<Value> string = CompileRun("try { asdf; } catch(e) { e + ''; }");
   CHECK(string->Equals(v8_str("Whoops")));
   v8::V8::RemoveMessageListeners(check_message);
 }
 
 
 static void receive_message(v8::Handle<v8::Message> message,
                             v8::Handle<v8::Value> data) {
   message->Get();
   message_received = true;
@@ skipping 9805 matching lines @@
   v8::Context::Scope context_scope(context.local());
 
   v8::Handle<v8::ObjectTemplate> tmpl = v8::ObjectTemplate::New();
   tmpl->SetNamedPropertyHandler(Getter, NULL, NULL, NULL, Enumerator);
   context->Global()->Set(v8_str("o"), tmpl->NewInstance());
   v8::Handle<v8::Array> result = v8::Handle<v8::Array>::Cast(CompileRun(
         "var result = []; for (var k in o) result.push(k); result"));
   CHECK_EQ(1, result->Length());
   CHECK_EQ(v8_str("universalAnswer"), result->Get(0));
 }