GeezerVison

cmp -l pads the byte offsets to the width of the largest offset it can print. That is the smaller file size, but the offsets count from the end of the skipped bytes, and the skips were not subtracted. GNU cmp subtracts them:

$ printf '0123456789abcdefghijklmnopqrstuvwxyz' > a; cp a b
$ LC_ALL=C cmp -l --ignore-initial=27:26 a b
cmp: EOF on 'a' after byte 9
 1 162 161        # GNU cmp 3.12: "1 162 161"
 2 163 162

cmp now subtracts each file's skip from its size (stopping at 0) before taking the smaller one. Without skips nothing changes.

Test cmp_verbose_offset_width_after_skip (fails on main). cargo test: 132 + 132 + 2 + 24 pass (23 cmp tests on main), cargo clippy -- -D warnings clean. Compared with GNU cmp 3.12 under LC_ALL=C for skips on one or both files, -i A:B, a skip past the end and no skip: same output.

#296 changes the quiet size check a few lines above; the two touch different lines.