Invalid arguments to rebase cause internal error

[Graham Markall]

Creating a repo with two branches and attempting to rebase with an invalid argument causes an error. To replicate, the following commands were run:

bzr init-repo repo
cd repo
bzr init trunk
cd trunk/
vi file.txt # Create a new file
bzr add file.txt
bzr commit -m "Add file"
cd ..
bzr branch trunk branch1
cd branch1
vi file.txt # Edit file.txt
bzr commit -m "Edit file"
cd ../trunk
vi file.txt # Edit file in a different way
bzr commit -m "Edit file (add Line 2)"
cd ../branch1
bzr rebase -r -2:.. ../trunk/

The output and traceback are as follows:

bzr: ERROR: exceptions.AssertionError: invalid start revid('<email address hidden>'), todo_set(set(['<email address hidden>']))

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 920, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 1131, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 673, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 695, in run
    return self._operation.run_simple(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/cleanup.py", line 136, in run_simple
    self.cleanups, self.func, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/cleanup.py", line 166, in _do_with_cleanups
    result = func(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 1148, in ignore_pipe
    result = func(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/plugins/rewrite/commands.py", line 212, in run
    not always_rebase_merges
  File "/usr/lib/python2.7/dist-packages/bzrlib/plugins/rewrite/rebase.py", line 217, in generate_simple_plan
    "invalid start revid(%r), todo_set(%r)" % (start_revid, todo_set)
AssertionError: invalid start revid('<email address hidden>'), todo_set(set(['<email address hidden>']))

bzr 2.5.0dev7 on python 2.7.3 (Linux-3.2.0-2-amd64-x86_64-with-debian-wheezy-
    sid)
arguments: ['/usr/bin/bzr', 'rebase', '-r', '-2:..', '../trunk/']
plugins: bash_completion[2.5.0dev7], bzrtools[2.5.0],
    changelog_merge[2.5.0dev7], dbus[0.1.0dev], fastimport[0.14.0dev],
    git[0.6.9], gtk[0.101.0dev], launchpad[2.5.0dev7],
    netrc_credential_store[2.5.0dev7], news_merge[2.5.0dev7], pager[unknown],
    po_merge[2.5.0dev7], qbzr[0.22.0], rewrite[0.6.4dev], weave_fmt[2.5.0dev7]
encoding: 'utf-8', fsenc: 'UTF-8', lang: 'en_GB.UTF-8'

*** 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.

Details from the end of .bzr.log are as follows:

Fri 2012-11-09 07:53:57 +0000
0.033 bazaar version: 2.5.0dev7
0.033 bzr arguments: [u'rebase', u'-r', u'-2:..', u'../trunk/']
0.034 looking for plugins in /home/graham/.bazaar/plugins
0.034 looking for plugins in /usr/lib/python2.7/dist-packages/bzrlib/plugins
0.056 encoding stdout as sys.stdout encoding 'UTF-8'
0.071 opening working tree '/home/graham/tmp/repo/branch1'
0.079 Returning RevisionSpec._match_on: None
0.082 Started 2 unique searchers for 2 unique revisions
0.082 Transferred: 0kB (0.0kB/s r:0kB w:0kB)
0.083 Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 920, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 1131, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 673, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 695, in run
    return self._operation.run_simple(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/cleanup.py", line 136, in run_simple
    self.cleanups, self.func, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/cleanup.py", line 166, in _do_with_cleanups
    result = func(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 1148, in ignore_pipe
    result = func(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/plugins/rewrite/commands.py", line 212, in run
    not always_rebase_merges
  File "/usr/lib/python2.7/dist-packages/bzrlib/plugins/rewrite/rebase.py", line 217, in generate_simple_plan
    "invalid start revid(%r), todo_set(%r)" % (start_revid, todo_set)
AssertionError: invalid start revid('<email address hidden>'), todo_set(set(['<email address hidden>']))

0.084 couldn't find apport bug-reporting library: No module named apport
0.101 return code 4