On Sep 29, 1:48 am, Marc Guillemot <[EMAIL PROTECTED]> wrote:
> Norris Boyd wrote:
> > On Sep 13, 8:22 pm, wolffiex <[EMAIL PROTECTED]> wrote:
> >> Hi everyone,
> >> I found a little surprising behavior today with Rhino. I don't know if
> >> this is a bug; I'm hoping someone will weigh in. It appears that
> >> instanceof doesn't work on objects from a foreign scope. I assume this
> >> is because instanceof just looks up the prototype chain, but I wonder
> >> if that is the correct implementation, given the fact that you can
> >> pass objects from one scope to another using Rhino and Java. Here's my
> >> little testcase:
>
> >> import org.junit.Test;
> >> import org.mozilla.javascript.ContextFactory;
> >> import org.mozilla.javascript.Context;
> >> import org.mozilla.javascript.Scriptable;
> >> import org.mozilla.javascript.ScriptableObject;
>
> >> public class ObjectSurprise {
> >> @Test
> >> public void showBug(){
> >> ContextFactory factory = new ContextFactory();
> >> Context cx1 = factory.enterContext();
> >> Context cx2 = factory.enterContext();
> >> final Scriptable scope1 = cx1.initStandardObjects();
>
> >> cx1.evaluateString(scope1,
> >> "tryMe = function(){return {};}",
> >> "tryMe", 1, null);
>
> >> Scriptable result = (Scriptable)
> >> ScriptableObject.callMethod(scope1, "tryMe", new Object[]
> >> {});
>
> >> String throwIfNotObject =
> >> "isObject = function(obj){ if( !(obj instanceof
> >> Object)) throw('not an object');}";
>
> >> cx1.evaluateString(scope1, throwIfNotObject, "isObject", 1,
> >> null);
> >> Object [] arg = { result };
>
> >> //doesn't throw, as expected
> >> ScriptableObject.callMethod(scope1, "isObject", arg);
> >> Context.exit();
>
> >> final Scriptable scope2 = cx2.initStandardObjects();
> >> cx2.evaluateString(scope2, throwIfNotObject, "isObject", 1,
> >> null);
>
> >> //throws -- unexpected
> >> ScriptableObject.callMethod(scope2, "isObject", arg);
> >> Context.exit();
> >> }
>
> >> }
>
> > You're right: instanceof just walks up the prototype chain looking for
> > the object. Mixing objects from two separate initStandardObject calls
> > is problematic in general; why do you need to do this?
>
> we didn't hurt this problem until now, but in the case of HtmlUnit,
> mixing objects of two separate initStandardObject calls is natural as
> each Window is a top scope and windows have access to child and parent
> windows.
>
> Cheers,
> Marc.
> --
> Web:http://www.efficient-webtesting.com
> Blog:http://mguillem.wordpress.com
I just saw a post about this bug:
https://bugzilla.mozilla.org/show_bug.cgi?id=374918
Seems like it's related, huh?
A
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