ComputeTile returns invalid number of tile

[j-hudecek]

I have a tiff with a directory with

td_imagelength 2560 td_imagewidth 3132 td_imagedepth 1 td_tiledepth 1 td_tilelength 512 td_tilewidth 512

Calling

_image.ComputeTile(0, 2560, 0, 0)

returns 35, But calling ReadEncodedTile with that prints out

35: Tile out of range, max 35

reads no data and returns -1. ComputeTile docs say "A valid tile number is always returned" so it looks like a bug - in my code and yours ;)