'Test for https://aeon.stsci.edu/ssb/trac/pyfits/ticket/152
Ignore blank cards.'

def test_ignore_blank_cards(self):

    ha = Header([('A', 1), ('B', 2), ('C', 3)])
    hb = Header([('A', 1), ('', ''), ('B', 2), ('', ''), ('C', 3)])
    hc = ha.copy()
    hc.append()
    hc.append()
    assert HeaderDiff(ha, hb).identical
    assert HeaderDiff(ha, hc).identical
    assert HeaderDiff(hb, hc).identical
    assert (not HeaderDiff(ha, hb, ignore_blank_cards=False).identical)
    assert (not HeaderDiff(ha, hc, ignore_blank_cards=False).identical)
    assert HeaderDiff(hb, hc, ignore_blank_cards=False).identical
    hc.append()
    assert (not HeaderDiff(hb, hc, ignore_blank_cards=False).identical)
