When comparing a directory to an mtree file NetBSD mtree has output like
this:
xxx: size (4, 5)
md5digest (0x6de9439834c9147569741d3c9c9fc010, 0xa5d119ab8edcda0ef7f381da8=
f52f92f)
=2E/yyy missing
FreeBSD's historical behavior is this:
xxx changed
size expected 4 found 5
md5digest expected 6de9439834c9147569741d3c9c9fc010 found a5d119ab8edcda0e=
f7f381da8f52f92f
=2E/yyy missing
FreeBSD's mergemaster -U command depends on the latter behavior so
the following patch alters the freebsd9 mode of mtree to output
that format. I don't think programs should rely on this output one way
or another since it's clearly meant for humans, but this seems like the
easiest short term fix.