Issue1382

I get an ArrayStoreException while doing a __cmp__ operation. It occurs
in PyType.java at 1073:

                    where[0] = t;

While the 'where' parameter is declared as a PyObject[], over in
PyObjectDerived at line 770 it is created as an array of PyType[] and
passed to lookup_where on the following line.

        PyType[]where_type=new PyType[1];
        PyObject impl=self_type.lookup_where("__cmp__",where_type);

The exception indicates that the actual type being assigned is PyClass.
PyClass is a PyObject, but not a PyType which appears to be the cause of
the exception.

Please provide a short test or at least a snippet of code that reproduces 
the problem. A formal test for this probably belongs in test.test_cmp_jy

I tried to produce a simple example that recreates the problem. That, of
course, didn't work.

I assume the issue is that lookup_where is not allowed to return an
object of type PyClass?

If lookup_where is allowed to return any type other than a PyType or one
of its descendants (and it's typed as PyObject so it could easily do
so), then I believe that the code is incorrect by inspection. The array
definition should be PyObject instead of PyType.

If, however, by convention lookup_where is only allowed to return
descendants of PyType (even though the type is PyObject) then the bug
lies elsewhere in something that's causing it to violate the convention.

If I can produce a simple example, I'll send it in.

I agree there's a bug from what you described, but it needs a test to be 
fixed

I get error for:

import UserDict
class Configuration(object, UserDict.DictMixin):
    def __init__(self):
        pass
x = Configuration()
print x != None

thanks for the example Simon, fixed in r6769/r6770