rebase-continue crashed and pruned my commit

[Julien Thewys]

Here is the workflow:
 commit changes in my branch (which is stacked on another one)
 rebase the parent branch but it failed (due to launchpad maintenance)
 commit new changes
 rebase failed due to lock
 break-lock
 rebase-continue -> crashed
 rebase-abort
 push -> my latest commit was lost

BazaarVersion: 2.1.0
PythonVersion: 2.6.4
Traceback:
 Traceback (most recent call last):
   File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 853, in exception_to_return_code
     return the_callable(*args, **kwargs)
   File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 1055, in run_bzr
     ret = run(*run_argv)
   File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 661, in run_argv_aliases
     return self.run_direct(**all_cmd_args)
   File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 665, in run_direct
     return self._operation.run_simple(*args, **kwargs)
   File "/usr/lib/python2.6/dist-packages/bzrlib/cleanup.py", line 122, in run_simple
     self.cleanups, self.func, *args, **kwargs)
   File "/usr/lib/python2.6/dist-packages/bzrlib/cleanup.py", line 156, in _do_with_cleanups
     result = func(*args, **kwargs)
   File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 1070, in ignore_pipe
     result = func(*args, **kwargs)
   File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/rebase/commands.py", line 274, in run
     workingtree_replay(wt, merge_type=merge_type))
   File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/rebase/rebase.py", line 318, in rebase
     replay_fn(repository, revid, newrevid, newparents)
   File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/rebase/rebase.py", line 507, in replay
     merge_type=merge_type)
   File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/rebase/rebase.py", line 478, in replay_delta_workingtree
     complete_revert(wt, [newparents[0]])
   File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/rebase/rebase.py", line 545, in complete_revert
     newtree = wt.branch.repository.revision_tree(newparents[0])
   File "/usr/lib/python2.6/dist-packages/bzrlib/decorators.py", line 140, in read_locked
     result = unbound(self, *args, **kwargs)
   File "/usr/lib/python2.6/dist-packages/bzrlib/repository.py", line 2579, in revision_tree
     inv = self.get_revision_inventory(revision_id)
   File "/usr/lib/python2.6/dist-packages/bzrlib/decorators.py", line 140, in read_locked
     result = unbound(self, *args, **kwargs)
   File "/usr/lib/python2.6/dist-packages/bzrlib/repository.py", line 2538, in get_revision_inventory
     return self.get_inventory(revision_id)
   File "/usr/lib/python2.6/dist-packages/bzrlib/decorators.py", line 140, in read_locked
     result = unbound(self, *args, **kwargs)
   File "/usr/lib/python2.6/dist-packages/bzrlib/repository.py", line 2367, in get_inventory
     return self.iter_inventories([revision_id]).next()
   File "/usr/lib/python2.6/dist-packages/bzrlib/repofmt/groupcompress_repo.py", line 900, in _iter_inventories
     raise errors.NoSuchRevision(self, record.key)
 NoSuchRevision: CHKInventoryRepository('file:///home ... ') has no revision (' ... ',)