Bazar crashes on lookup-revision for non-existant revno

[Aditya Kher]

foo@host:~/indiv-screenlets$ bzr lookup-revision 770
bzr: failed to report crash using apport:
     OSError(13, 'Permission denied')
bzr: ERROR: bzrlib.errors.NoSuchRevision: BzrBranch7(file:///home/foo/indiv-screenlets/) has no revision 770

Traceback (most recent call last):
  File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 912, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 1112, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 690, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 705, in run
    return self._operation.run_simple(*args, **kwargs)
  File "/usr/lib/python2.6/dist-packages/bzrlib/cleanup.py", line 135, in run_simple
    self.cleanups, self.func, *args, **kwargs)
  File "/usr/lib/python2.6/dist-packages/bzrlib/cleanup.py", line 165, in _do_with_cleanups
    result = func(*args, **kwargs)
  File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 1127, in ignore_pipe
    result = func(*args, **kwargs)
  File "/usr/lib/python2.6/dist-packages/bzrlib/builtins.py", line 2790, in run
    revid = WorkingTree.open_containing(directory)[0].branch.get_rev_id(revno)
  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/branch.py", line 3023, in get_rev_id
    raise errors.NoSuchRevision(self, revno)
NoSuchRevision: BzrBranch7(file:///home/foo/indiv-screenlets/) has no revision 770

bzr 2.2.1 on python 2.6.6 (Linux-2.6.35-22-generic-i686-with-Ubuntu-10.10-maverick)
arguments: ['/usr/bin/bzr', 'lookup-revision', '770']
encoding: 'UTF-8', fsenc: 'UTF-8', lang: 'en_US.UTF-8'
plugins:
  bash_completion /usr/lib/python2.6/dist-packages/bzrlib/plugins/bash_completion [2.2.1]
  bzrtools /usr/lib/python2.6/dist-packages/bzrlib/plugins/bzrtools [2.2.0]
  launchpad /usr/lib/python2.6/dist-packages/bzrlib/plugins/launchpad [2.2.1]
  netrc_credential_store /usr/lib/python2.6/dist-packages/bzrlib/plugins/netrc_credential_store [2.2.1]
  news_merge /usr/lib/python2.6/dist-packages/bzrlib/plugins/news_merge [2.2.1]

*** Bazaar has encountered an internal error. This probably indicates a
    bug in Bazaar. You can help us fix it by filing a bug report at
        https://bugs.launchpad.net/bzr/+filebug
    including this traceback and a description of the problem.

[Vincent Ladeuil (vila)]

lookup-revision is an hidden command and as such didn't receive much polish.

It shouldn't backtrace like this though.