"""
For example, given input file:
foo
bar
baz
after shuffling the input file, foo will never end up back on the first line.
This came to light when I ran into a use-case where someone was selecting
a random line from a file using shuf | head -n 1, and the results on busybox
were showing a statistical anomaly (as in, the first line would never ever
be picked) vs the same process running on environments that had gnu coreutils
installed.
On line https://git.busybox.net/busybox/tree/coreutils/shuf.c#n56 it uses
r %= i, which will result in 0 <= r < i, while the algorithm specifies
0 <= r <= i.
"""
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>