add subtree reference should not traceback on non-subtree formats

[zurgutt]

I tried to have part of working tree in two repositories, like this:

zrg@aivas:~$ mkdir webroot
zrg@aivas:~$ mkdir webroot/subsite

zrg@aivas:~$ cd webroot/subsite
zrg@aivas:~/webroot/subsite$ bzr init --rich-root-pack
zrg@aivas:~/webroot/subsite$ echo "v1" > subsite_file.txt
zrg@aivas:~/webroot/subsite$ bzr add
added subsite_file.txt
zrg@aivas:~/webroot/subsite$ bzr commit -m "Subsite initial, v1"
Committing to: /home/zrg/webroot/subsite/
added subsite_file.txt
Committed revision 1.

zrg@aivas:~/webroot/subsite$ cd ..
zrg@aivas:~/webroot$ bzr init --rich-root-pack
zrg@aivas:~/webroot$ bzr join subsite --reference
zrg@aivas:~/webroot$ bzr add

bzr: ERROR: exceptions.AssertionError: repository of <WorkingTree4 of /home/zrg/webroot> doesn't support tree references required by entry 'subsite'

Traceback (most recent call last):
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 806, in run_bzr_catch_errors
    return run_bzr(argv)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 762, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 492, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/python2.5/site-packages/bzrlib/builtins.py", line 384, in run
    no_recurse, action=action, save=not dry_run)
  File "/usr/lib/python2.5/site-packages/bzrlib/mutabletree.py", line 51, in tree_write_locked
    return unbound(self, *args, **kwargs)
  File "/usr/lib/python2.5/site-packages/bzrlib/mutabletree.py", line 284, in smart_add
    inv = self.inventory
  File "/usr/lib/python2.5/site-packages/bzrlib/workingtree_4.py", line 425, in _get_inventory
    self._generate_inventory()
  File "/usr/lib/python2.5/site-packages/bzrlib/workingtree_4.py", line 363, in _generate_inventory
    % (self, name)
AssertionError: repository of <WorkingTree4 of /home/zrg/webroot> doesn't support tree references required by entry 'subsite'

[James Westby (james-w)]

Hi,

The error is trying to tell you that the format you are using does not
support subtrees. Admittedly this is a bit cryptic, and it would
be good to have a sensible error here.

You should bzr upgrade --pack-0.92-subtree to enable
support.

This option is hidden as subtree support is still experimental.

Thanks,

James