Running version-info fails when there is no work tree

Have some legacy tooling that need to run Bazaar like this on a shared repo without a worktree. Caveat for if I don't get the terminology quite right.

----
$ bzr version-info --all /path/to/shared/repo/without/worktree/
Traceback (most recent call last):
  File "/opt/breezy/lib64/python3.6/site-packages/breezy/commands.py", line 1017, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/opt/breezy/lib64/python3.6/site-packages/breezy/commands.py", line 1206, in run_bzr
    ret = run(*run_argv)
  File "/opt/breezy/lib64/python3.6/site-packages/breezy/commands.py", line 757, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/opt/breezy/lib64/python3.6/site-packages/breezy/commands.py", line 782, in run
    return class_run(*args, **kwargs)
  File "/opt/breezy/lib64/python3.6/site-packages/breezy/cmd_version_info.py", line 139, in run
    builder.generate(self.outf)
  File "/opt/breezy/lib64/python3.6/site-packages/breezy/version_info_formats/format_rio.py", line 61, in generate
    self._extract_file_revisions()
  File "/opt/breezy/lib64/python3.6/site-packages/breezy/version_info_formats/__init__.py", line 96, in _extract_file_revisions
    basis_tree = self._working_tree.basis_tree()
AttributeError: 'NoneType' object has no attribute 'basis_tree'

brz 3.2.2 on python 3.6.8 (Linux-4.18.0-425.10.1.el8_7.x86_64-x86_64-with-
    redhat-8.7-Ootpa)
arguments: ['/bin/bzr', 'version-info', '--all', '/path/to/shared/repo/without/worktree/']
plugins: bash_completion[3.2.2], changelog_merge[3.2.2],
    commitfromnews[3.2.2], cvs[3.2.2], darcs[3.2.2], email[3.2.2],
    fastimport[3.2.2], flake8[unknown], fossil[3.2.2], github[3.2.2],
    gitlab[3.2.2], hg[3.2.2], launchpad[3.2.2], mtn[3.2.2],
    netrc_credential_store[3.2.2], news_merge[3.2.2], po_merge[3.2.2],
    propose[3.2.2], pypi[3.2.2], quilt[unknown], repodebug[3.2.2],
    rewrite[unknown], stats[3.2.2], svn[3.2.2], upload[3.2.2],
    weave_fmt[3.2.2], zsh_completion[3.2.2]
encoding: 'utf-8', fsenc: 'utf-8', lang: 'en_US.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/brz/+filebug
    including this traceback and a description of the problem.
----

For now I'm using this patch, which seems to be working so far:

----
diff -Naru breezy-3.2.2.orig/breezy/version_info_formats/__init__.py breezy-3.2.2/breezy/version_info_formats/__init__.py
--- breezy-3.2.2.orig/breezy/version_info_formats/__init__.py 2021-12-07 02:24:26.000000000 +0000
+++ breezy-3.2.2/breezy/version_info_formats/__init__.py 2023-02-01 11:53:28.383389156 +0000
@@ -89,6 +89,9 @@
     def _extract_file_revisions(self):
         """Extract the working revisions for all files"""

+ if self._working_tree is None:
+ return None
+
         # Things seem clean if we never look :)
         self._clean = True

----

Submitting this here as a suggested change, as it seems to make sense that if there is no worktree, there is no need to inspect any files in it.