[GROOVY-4720] Method overriding with ExpandoMetaClass is partially broken

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Fix Version/s: 1.8-rc-4, 1.9-beta-1, 1.7.11
• Assignee: Guillaume Sauthier
• Reporter: Graeme Rocher
• Created: 11/Mar/11 04:57
• Updated: 13/Apr/11 14:33
• Resolved: 24/Mar/11 09:31

Description

There is a regression whereby you cannot override methods using ExpandoMetaClass.

The reason is that ClosureMetaMethod.createMethodList creates an anonymous inner class of type MetaMethod and adds it to the returned List<MetaMethod> that are to be registered

Later the isNonRealMethod(MetaMethod) check in MetaMethodIndex does this check:

    private boolean isNonRealMethod(MetaMethod method) {
        return method instanceof NewInstanceMetaMethod ||
                method instanceof NewStaticMetaMethod ||
                method instanceof ClosureMetaMethod ||
                method instanceof GeneratedMetaMethod ||
                method instanceof ClosureStaticMetaMethod ||
                method instanceof MixinInstanceMetaMethod;
    }

Since the anonymous inner MetaMethod defined in ClosureMetaMethod is not an instance of any of these types then the method is never registered in the MetaMethodIndex:

                    if (methodC == matchC) {
                        if (isNonRealMethod(method)) {
                            list.set(found, method);
                        }