[Python-Dev] 2.1.1 maintenance branch

[Guido van Rossum]

> > I'n curious about abstract_isinstance -- is that what you checked in
> > last night?
> 
> Yes.
> 
> > I thought that was for 2.2 but I may have misunderstood
> > the issue (I have to admit I have no idea what abstract_isinstance
> > does any more :-( ).
> 
> No, abstract_isinstance has been broken for a long time, maybe forever.
> It is supposed to work for class-like objects like ExtensionClass
> instances as well as for standard classes and types.  One problem was
> that if you gave it a normal instance as the first argument but an
> ExtensionClass as the second argument it raised a type error.  It's
> annoying to us at the MEMS Exchange because we use ExtensionClasses and
> isinstance all the time (Greg likes type checking).  We ended up
> rewriting isinstance() and issubclass() in Python.  The average Python
> user doesn't care.

Then I'm not sure if this should be fixed in 2.1.2.  It's almost a new
feature that it doesn't bomb out. :-(

--Guido van Rossum (home page: http://www.python.org/~guido/)