freebsd7 and mdconfig -l -u oddity

i've upgraded my server from 6 to 7 and mdconfig -l -u is behaving
in a weird (and incorrect) manner.

on freebsd 7, mdconfig -l -u returns exit code of 0 even for
non-existence md devices.

has anyone got the same problem or is it just me? this weirdness is
breaking the code to detect next available md device number in
ports/freebsd-snapshot.

e.g.

on freebsd6:

si1:~[512]# mdconfig -l -u 0 ; echo $?
md0     swap      2.0G
0
si1:~[513]# mdconfig -l -u 1 ; echo $?
mdconfig: ioctl(/dev/mdctl): No such file or directory
1

on freebsd7 beta3:

melati# uname -a
FreeBSD melati.hsins.com 7.0-BETA3 FreeBSD 7.0-BETA3 #0: Mon Nov 19 06:25:50 MYT 2007     ktsin_at_melati.hsins.com:/tmp/obj/usr/src/sys/MELATI  i386
melati# mdconfig -l -u 0 ; echo $?
md0     swap      2.0G
0
melati# mdconfig -l -u 1 ; echo $?
0

kt