libext2fs: fix bug in ext2fs_digest_encode()

The ext2fs_digest_encode() function was broken for any input which was
a multiple of 3.  Previously we never hit that case, so we never
noticed it was busted.  Also fix up the unit test so future problems
like this get noticed quickly.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2 files changed