does anyone know if the function /sys/src/cmd/snap/take.c:/^sumr can return 0 for a buffer that is not all zeros?
i think it can not, since for sum&1, the next sum at least has 0x8000 set and otherwise if (sum&1) == 0, then either sum == 0 or sum>>1 != 0. fletcher-16 seems similar except for the extra sum. does anyone know of any writeups on this algorithm? or at least an example that shows that sum can return 0 for a non-zeroed buffer? - erik
