[Python-Dev] Changing semantics of issubclass when accepting a tuple

[Brett]

Bug #858016 shows how issubclass can segfault if you pass a deeply 
nested tuple as issubclass' second argument.  I would like to propose 
changing the semantics so that it only accepts a flat tuple; when a 
tuple is passed in to do a quick check that each item is a class and if 
it is pass that to issubclass.

But this is a change in semantics.  Tim said I should clear it here 
first so that is what I am doing.  Anyone have issues if I do this?  And 
if so, any objections of backporting to 2.3?

-Brett