IDL: Treat undefined as missing for optional arguments with defaults

Source/bindings/tests/results/V8TestInterfaceConstructor2.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 "V8TestInterfaceConstructor2.h"
 
 #include "bindings/core/v8/Dictionary.h"
@@ skipping 75 matching lines @@
     V8StringResource<> defaultUndefinedOptionalStringArg;
     V8StringResource<> defaultNullStringOptionalStringArg;
     Dictionary defaultUndefinedOptionalDictionaryArg;
     V8StringResource<> optionalStringArg;
     {
         v8::TryCatch block;
         V8RethrowTryCatchScope rethrow(block);
         TONATIVE_VOID_INTERNAL(testInterfaceEmptyArg, V8TestInterfaceEmpty::toNativeWithTypeCheck(info.GetIsolate(), info[0]));
         TONATIVE_VOID_EXCEPTIONSTATE_INTERNAL(longArg, toInt32(info[1], exceptionState), exceptionState);
         TOSTRING_VOID_INTERNAL(defaultUndefinedOptionalStringArg, info[2]);
-        if (info.Length() > 3) {
+        if (!info[3]->IsUndefined()) {
             TOSTRING_VOID_INTERNAL(defaultNullStringOptionalStringArg, info[3]);
         } else {
             defaultNullStringOptionalStringArg = nullptr;
         }
         TONATIVE_VOID_INTERNAL(defaultUndefinedOptionalDictionaryArg, Dictionary(info[4], info.GetIsolate()));
         if (!defaultUndefinedOptionalDictionaryArg.isUndefinedOrNull() && !defaultUndefinedOptionalDictionaryArg.isObject()) {
             exceptionState.throwTypeError("parameter 5 ('defaultUndefinedOptionalDictionaryArg') is not an object.");
             exceptionState.throwIfNeeded();
             return;
         }
@@ skipping 155 matching lines @@
     fromInternalPointer(object)->deref();
 }
 
 template<>
 v8::Handle<v8::Value> toV8NoInline(TestInterfaceConstructor2* impl, v8::Handle<v8::Object> creationContext, v8::Isolate* isolate)
 {
     return toV8(impl, creationContext, isolate);
 }
 
 } // namespace WebCore