# note: A RIFF size claiming more bytes than the file has.
# expect: reject
# anim: reject
# info: reject
# exercises: Where the demuxer parts company with the still decoder. It
#   computes partial = (buffer < riff_end) up front and, unless the caller
#   asked for partial parsing, refuses the file there and then -- before the
#   master chunk table is consulted, so none of the animation code runs at
#   all. container-riff-size-past-end is the same lie told to dwebp.
riff_size 4096
frame
frame_duration 100
lossless
width 16
height 16
argb 0xff800000 x256