merge aborts with Tree transform is malformed [('unversioned executability', 'new-1')]

I haven't looked closely since the test is not exactly the one I wanted to write.

I think I hit this again:

mbp@grace% bzr import-upstream 2.1.0 ../Packaging/bzr-2.1.0.tar.gz ../bzr-2.1.0
bzr: ERROR: bzrlib.errors.MalformedTransform: Tree transform is malformed [('unversioned executability', 'new-896'), ('unversioned executability', 'new-684')]

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 "/home/mbp/.bazaar/plugins/builddeb/cmds.py", line 861, in run
    upstream_branch=upstream, upstream_revision=upstream_revid)
  File "/home/mbp/.bazaar/plugins/builddeb/import_dsc.py", line 1022, in import_upstream_tarball
    upstream_revision=upstream_revision)
  File "/home/mbp/.bazaar/plugins/builddeb/import_dsc.py", line 975, in import_upstream
    file_ids_from=upstream_trees + [self_tree])
  File "/home/mbp/.bazaar/plugins/builddeb/bzrtools_import.py", line 197, in import_dir
    import_archive(tree, dir_file, file_ids_from=file_ids_from)
  File "/home/mbp/.bazaar/plugins/builddeb/bzrtools_import.py", line 295, in import_archive
    for conflict in cook_conflicts(resolve_conflicts(tt), tt):
  File "/usr/lib/python2.6/dist-packages/bzrlib/transform.py", line 2769, in resolve_conflicts
    raise MalformedTransform(conflicts=conflicts)
MalformedTransform: Tree transform is malformed [('unversioned executability', 'new-896'), ('unversioned executability', 'new-684')]
bzr import-upstream 2.1.0 ../Packaging/bzr-2.1.0.tar.gz ../bzr-2.1.0 3.20s user 0.62s system 89% cpu 4.257 total