Invalid control flow analysis for multiple except clauses.

[robertwb]

Consider

def unused_except_capture():
    """
    unused_except_capture()
    """
    try:
        raise ValueError
    except TypeError, s:
        raise TypeError
    except ValueError, s:
        raise TypeError

which tries to decref s (=NULL) in the second control block.

[vitja]

Fixed here  https://github.com/cython/cython/commit/314c25b5fd12ce7f0eedc13ff89ebfb67590a798