IDL compiler: move EventHandler null check out of generated bindings

Source/bindings/v8/V8EventListenerList.h

 /*
  * Copyright (C) 2009 Google Inc. 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
@@ skipping 34 matching lines @@
     ListenerFindOnly,
     ListenerFindOrCreate,
 };
 
 // This is a container for V8EventListener objects that uses hidden properties of v8::Object to speed up lookups.
 class V8EventListenerList {
 public:
     static PassRefPtr<V8EventListener> findWrapper(v8::Local<v8::Value> value, bool isAttribute, v8::Isolate* isolate)
     {
         ASSERT(v8::Context::InContext());
+        // Non-callable input should be treated as null
+        if (!value->IsNull() && !value->IsFunction())
+            value = v8::Null(isolate);
         if (!value->IsObject())
             return 0;
 
         v8::Handle<v8::String> wrapperProperty = getHiddenProperty(isAttribute, isolate);
         return doFindWrapper(v8::Local<v8::Object>::Cast(value), wrapperProperty, isolate);
     }
 
     template<typename WrapperType>
     static PassRefPtr<V8EventListener> findOrCreateWrapper(v8::Local<v8::Value>, bool isAttribute, v8::Isolate*);
 
@@ skipping 19 matching lines @@
     static inline v8::Handle<v8::String> getHiddenProperty(bool isAttribute, v8::Isolate* isolate)
     {
         return isAttribute ? V8HiddenPropertyName::attributeListener(isolate) : V8HiddenPropertyName::listener(isolate);
     }
 };
 
 template<typename WrapperType>
 PassRefPtr<V8EventListener> V8EventListenerList::findOrCreateWrapper(v8::Local<v8::Value> value, bool isAttribute, v8::Isolate* isolate)
 {
     ASSERT(v8::Context::InContext());
+    // Non-callable attribute setter input should be treated as null
+    if (isAttribute && !value->IsNull() && !value->IsFunction())

[Nils Barth (inactive), 2013/10/22 07:29:29]

Note the isAttribute check.
isAttribute is true for setters (here),
but false for the other findOrCreateWrapper call,
via getEventListener, used in the IDL methods
addEventListener and removeEventListener.

See Perl CG, or the two places this occurs in EventTarget.idl,
code at V8EventTarget.cpp:
https://code.google.com/p/chromium/codesearch#chromium/src/out/Debug/gen/blin...

+        value = v8::Null(isolate);
     if (!value->IsObject())
         return 0;
 
     v8::Local<v8::Object> object = v8::Local<v8::Object>::Cast(value);
     v8::Handle<v8::String> wrapperProperty = getHiddenProperty(isAttribute, isolate);
 
     V8EventListener* wrapper = doFindWrapper(object, wrapperProperty, isolate);
     if (wrapper)
         return wrapper;
 
     RefPtr<V8EventListener> wrapperPtr = WrapperType::create(object, isAttribute, isolate);
     if (wrapperPtr)
         object->SetHiddenValue(wrapperProperty, v8::External::New(wrapperPtr.get()));
 
     return wrapperPtr;
 }
 
 } // namespace WebCore
 
 #endif // V8EventListenerList_h