# note: An ALPH chunk holding its header byte and nothing else.
# expect: reject
# exercises: The "data_size <= ALPHA_HEADER_LEN" test at the top of
#   ALPHInit(), which is what stops the header byte itself from being read out
#   of an empty chunk.
chunks VP8X ALPH VP8
alpha 1
alph_data
width 16
height 16
yac_qi 30
macroblock
coeffs y2 -20
coeffs y[2] 1:5 -3