'Save the current SIGCHLD handler as reported by L{signal.signal} and
the current file descriptor registered with L{installHandler}.'

def setUp(self):

    handler = signal.getsignal(signal.SIGCHLD)
    if (handler != signal.SIG_DFL):
        self.signalModuleHandler = handler
        signal.signal(signal.SIGCHLD, signal.SIG_DFL)
    else:
        self.signalModuleHandler = None
    self.oldFD = installHandler((-1))
    if ((self.signalModuleHandler is not None) and (self.oldFD != (-1))):
        msg(("Previous    test    didn't    clean    up    after    its    SIGCHLD    setup:    %r    %r" % (self.signalModuleHandler, self.oldFD)))
