binding: Retires ExceptionState::throwIfNeeded().

third_party/WebKit/Source/bindings/core/v8/custom/V8DocumentCustom.cpp

 /*
  * Copyright (C) 2007, 2008, 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 69 matching lines @@
         std::unique_ptr<v8::Local<v8::Value>[]> params = wrapArrayUnique(new v8::Local<v8::Value>[info.Length()]);
         for (int i = 0; i < info.Length(); i++)
             params[i] = info[i];
 
         v8SetReturnValue(info, V8ScriptRunner::callFunction(v8::Local<v8::Function>::Cast(function), frame->document(), global, info.Length(), params.get(), info.GetIsolate()));
         return;
     }
 
     ExceptionState exceptionState(ExceptionState::ExecutionContext, "open", "Document", info.Holder(), info.GetIsolate());
     document->open(enteredDOMWindow(info.GetIsolate())->document(), exceptionState);
-    if (exceptionState.throwIfNeeded())

[haraken, 2016/08/24 13:33:02]

Don't you need to change this to:

  if (exceptionState.hadException())
    return;

?

Otherwise info.Holder() will be set to the return value when an exception is
thrown.

The same comment for other files in this CL.

[Yuki, 2016/08/24 13:36:20]

Exactly speaking, info.GetReturnValue() will be set to the return value,
however, since an exception will be thrown, user script never observes the
return value.  So practically it's okay.

In general, when an exception is thrown, a return value is just ignored.

-        return;
 
     v8SetReturnValue(info, info.Holder());
 }
 
 } // namespace blink