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

[Guido van Rossum]

> 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.

Works for me.

> 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?

Let's not mess with 2.3 semantics.

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