IDL: Treat undefined as missing for optional arguments with defaults

Source/bindings/tests/results/V8TestInterfaceNamedConstructor.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file has been auto-generated by code_generator_v8.py. DO NOT MODIFY!
 
 #include "config.h"
 #include "V8TestInterfaceNamedConstructor.h"
 
 #include "bindings/core/v8/ExceptionState.h"
@@ skipping 84 matching lines @@
     V8StringResource<> defaultUndefinedOptionalStringArg;
     V8StringResource<> defaultNullStringOptionalstringArg;
     V8StringResource<> optionalStringArg;
     {
         v8::TryCatch block;
         V8RethrowTryCatchScope rethrow(block);
         TOSTRING_VOID_INTERNAL(stringArg, info[0]);
         TONATIVE_VOID_INTERNAL(defaultUndefinedOptionalBooleanArg, info[1]->BooleanValue());
         TONATIVE_VOID_EXCEPTIONSTATE_INTERNAL(defaultUndefinedOptionalLongArg, toInt32(info[2], exceptionState), exceptionState);
         TOSTRING_VOID_INTERNAL(defaultUndefinedOptionalStringArg, info[3]);
-        if (info.Length() > 4) {
+        if (!info[4]->IsUndefined()) {
             TOSTRING_VOID_INTERNAL(defaultNullStringOptionalstringArg, info[4]);
         } else {
             defaultNullStringOptionalstringArg = nullptr;
         }
         if (UNLIKELY(info.Length() <= 5)) {
             Document& document = *toDocument(currentExecutionContext(info.GetIsolate()));
             RefPtr<TestInterfaceNamedConstructor> impl = TestInterfaceNamedConstructor::createForJSConstructor(document, stringArg, defaultUndefinedOptionalBooleanArg, defaultUndefinedOptionalLongArg, defaultUndefinedOptionalStringArg, defaultNullStringOptionalstringArg, exceptionState);
             if (exceptionState.hadException()) {
                 exceptionState.throwIfNeeded();
                 return;
@@ skipping 108 matching lines @@
     fromInternalPointer(object)->deref();
 }
 
 template<>
 v8::Handle<v8::Value> toV8NoInline(TestInterfaceNamedConstructor* impl, v8::Handle<v8::Object> creationContext, v8::Isolate* isolate)
 {
     return toV8(impl, creationContext, isolate);
 }
 
 } // namespace WebCore