def png_invalid_bad_palette_reference():
"""Refer to a nonexistent palette entry."""
palette = ''.join([pngforge.rgb(i,i,i) for i in range(64)])
return (pngforge.sig() +
pngforge.ihdr(width=1, height=1,
color_type=pngforge.COLOR_INDEXED) +
pngforge.chunk('PLTE', palette) +
pngforge.idat(pngforge.scanline(0, chr(64))) +
pngforge.iend())
def png_invalid_short_palette():
"""Construct a palette that isn't a multiple of 3 bytes long."""
palette = ''.join([pngforge.rgb(i,i,i) for i in range(2)])[0:5]
return (pngforge.sig() +
pngforge.ihdr(width=1, height=1,
color_type=pngforge.COLOR_INDEXED) +
pngforge.chunk('PLTE', palette) +
pngforge.idat(pngforge.scanline(0, '\0')) +
pngforge.iend())
