    def test_tofile_sep(self):
        x = np.array([1.51, 2, 3.51, 4], dtype=float)
        f = open(self.filename, 'w')
        x.tofile(f, sep=',')
        f.close()
        f = open(self.filename, 'r')
        s = f.read()
        f.close()
        assert_equal(s, '1.51,2.0,3.51,4.0')
        os.unlink(self.filename)
The software attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.