'Regression test for https://github.com/astropy/astropy/issues/2363'

def test_compression_header_append_commentary(self):

    hdu = fits.CompImageHDU(np.array([0], dtype=np.int32))
    hdu.header['COMMENT'] = 'hello    world'
    assert (hdu.header['COMMENT'] == ['hello    world'])
    hdu.writeto(self.temp('test.fits'))
    with fits.open(self.temp('test.fits')) as hdul:
        assert (hdul[1].header['COMMENT'] == ['hello    world'])
