Message 186386 - Python tracker

As I wrote in issue17589, there are some extension modules (pytables) that which assume that Py_INCREF is an expression:
  return Py_INCREF(x), x;
and Py_RETURN_NONE is also defined with a comma expression.

Oh, and Cython:
#define __Pyx_PyBool_FromLong(b) ((b) ? (Py_INCREF(Py_True), Py_True) : (Py_INCREF(Py_False), Py_False))