another super wart

[Michele Simionato]

SOLVED!!

Finally, after quite a lot of thought, I have understood how does
it work. There is no bug, here, super is OK and also __new__ is OK. 
I was mislead by a wrong intuition.

The hierarchy I have used in my original posting is the following:

                                     
                                   5
                                 object
                                 /   |
                             2  A   type 4
                               /     |
                              /      |
                            1 B--.  Type 3
                               \  \ /
                                \  M  0
                                 \ :
                                   C

The colon in the graph denotes instantiation, i.e. C is an instance of M.
On the same time, C inherits from B and M inherits from B and Type.

The point is that C is both a subclass of B and an instance of M.
This generates an ambiguity in super with two possible interpretations
(and only one correct):

1. First interpretation (the wrong one!). 

super(B,C) is interpreted as "the superclass of B with respect to the
MRO of C". 

According to this interpretation, the superclass of B is A and therefore
super(B,C).__new__ calls A.__new__ which is object.__new__: but this is
not true!

2. Second interpretation (the correct one!)

super(B,C) is interpreted as "the superclass of B with respect to the
MRO of type(C)". Now the MRO of type(C)=M is

MRO[M]=[M B A Type type object]

therefore 

super(B,C).__new__ calls A.__new__ which is Type.__new__ and not
object.__new__! 

My example with a staticmethod called new defined both in A and in Type
was misleading, since the wrong interpretation was giving the same
result of the right one:

super(B,C).new calls A.new that overrides Type.new.

All the trouble came because I did not understand how super works, but
now I am happy ;)


                                 Michele