lxc-clone makes unbootable clone when using lvm backing store

*******************************
1. Impact: lxc-clone for lvm-backed containers is broken
2. Development fix: saucy fixed the use of wrong pathnames in the
 lxc-clone script.
3. Stable fix: same as development fix
4. Test case:
 * Create an lvm backed container, clone it, and try to start the
 clones. (note this requires a LVM vg called 'lxc')
 sudo lxc-create -t ubuntu -B lvm -n c1
 sudo lxc-clone -s -o c1 -n c2
 sudo lxc-clone -o c1 -n c3
 sudo lxc-start -n c2
 sudo lxc-start -n c3
5. Regression potential: none, only the lxc-clone script is updated.
*******************************

Container clones made by lxc-clone is not bootable.
New container config misses lxc.rootfs.
lxc.network.hwaddr is the same as in original container.

# lsb_release -rd
Description: Ubuntu 13.04
Release: 13.04

# apt-cache policy lxc
lxc:
  Installed: 0.9.0-0ubuntu3
  Candidate: 0.9.0-0ubuntu3
  Version table:
 *** 0.9.0-0ubuntu3 0
        500 http://ru.archive.ubuntu.com/ubuntu/ raring/universe amd64 Packages
        100 /var/lib/dpkg/status

Steps to reproduce:
root@lxc-host:~# lxc-create -n ubuntu -t ubuntu -B lvm --fssize 5gb

lxc-create: No config file specified, using the default config /etc/lxc/default.conf
  Logical volume "ubuntu" created
mke2fs 1.42.5 (29-Jul-2012)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
327680 inodes, 1310720 blocks
65536 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=1342177280
40 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
 32768, 98304, 163840, 229376, 294912, 819200, 884736

Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

Checking cache download in /var/cache/lxc/raring/rootfs-amd64 ...
Copy /var/cache/lxc/raring/rootfs-amd64 to /var/lib/lxc/ubuntu/rootfs ...
Copying rootfs to /var/lib/lxc/ubuntu/rootfs ...
Generating locales...
  en_US.UTF-8... up-to-date
Generation complete.

##
# The default user is 'ubuntu' with password 'ubuntu'!
# Use the 'sudo' command to run tasks as root in the container.
##

'ubuntu' template installed
Unmounting LVM
'ubuntu' created
root@lxc-host:~#
root@lxc-host:~# lxc-clone -o ubuntu -n ubuntu_clone
Tweaking configuration
Copying rootfs...
  Logical volume "ubuntu_clone_snapshot" created
mkdir: cannot create directory ‘/dev/lxc/ubuntu_clone_snapshot’: File exists

root@lxc-host:~# diff /var/lib/lxc/ubuntu/config /var/lib/lxc/ubuntu_clone/config
9d8
< lxc.mount = /var/lib/lxc/ubuntu/fstab
16d14
< lxc.utsname = ubuntu
52c50,51
< lxc.rootfs = /dev/lxc/ubuntu
---
> lxc.utsname = ubuntu_clone
> lxc.mount = /var/lib/lxc/ubuntu_clone/fstab

If I manually add lxc.rootfs=/dev/lxc/ubuntu_clone_snapshot to /var/lib/lxc/ubuntu_clone/config, container starts normally.