[Python-Dev] new metaclass error condition checks

[Jean-Paul Calderone]

I just noticed r53997 (from some unit tests it broke), which disallowed things
like this:

    class X(object):
        def __repr__(self):
            return "blah"

    class Y(X, type):
        pass

    class Z:
        __metaclass__ = Y

Making X classic eliminates the TypeError, and is probably an acceptable fix
in a lot of cases (at least as long as classic classes are available).  I
wonder if the ability to override type special methods like this was considered
when the change was made, though?

Jean-Paul