Does parameter type matter for GC_unref()?

[Stefan_Salewski]

Yes, I think this was really a bug in the bindings, and it may have been only a 
lucky incident that it worked all the years. Ref object and and RootRef is very 
different.

So I have to use
    
    
    Surface* = ref object of RootRef
    
    
    Run

I think that was initially intented to allow subclassing.

I am still not sure is this is the same as
    
    
    Surface* = ref object of RootObj
    
    
    Run

I guess it is the same?