'Test that a minus sign \'-\' at the front of a line ignores
any errors.'

def testIgnoredError(self):

    cmds = '-chown    0    missingFile\npwd\nexit\n'
    def _cbCheckResult(res):
        self.assertIn(self.testDir.asBytesMode().path, res)
    d = self._getBatchOutput(cmds)
    d.addCallback(_cbCheckResult)
    return d
