I'm seeing an ArrayIndexOutOfBoundsException in ScriptableObject.getIds(boolean, boolean) because the EmbeddedSlotMap iterator is returning one more result than its count, "map.size()", is returning.
Has anyone else seen this? I haven't found the cause yet so I can't make a test case, I only see the error after a lot of processing has happened so I don't yet know the sequence of events that causes this problem. However I tried removing EmbeddedSlotMap by having SlopMapContainer just make HashSlotMap and that "fixed" this issue.

This also might be caused by a fix I'm currently doing to allow Object.getOwnPropertyDescriptor("z", 0) and "z".propertyIsEnumerable(0) to work. I'll provide more information as I find it.