bug: 'bzr shelf show'

[Mátyás János]

If no patches on the shelf, the result of 'bzr shelf show' is:

---------------------------------

bzr: ERROR: exceptions.TypeError: coercing to Unicode: need string or
buffer, NoneType found

Traceback (most recent call last):
  File "/usr/lib/python2.4/site-packages/bzrlib/commands.py", line 729,
in run_bzr_catch_errors return run_bzr(argv)
  File "/usr/lib/python2.4/site-packages/bzrlib/commands.py", line 691,
in run_bzr ret = run(*run_argv)
  File "/usr/lib/python2.4/site-packages/bzrlib/commands.py", line 389,
in run_argv_aliases return self.run(**all_cmd_args)
  File
"/usr/lib/python2.4/site-packages/bzrlib/plugins/bzrtools/__init__.py",
line 329, in run return cmd.run_argv_aliases(args_list) File
"/usr/lib/python2.4/site-packages/bzrlib/commands.py", line 389, in
run_argv_aliases return self.run(**all_cmd_args) File
"/usr/lib/python2.4/site-packages/bzrlib/plugins/bzrtools/__init__.py",
line 300, in run self.shelf.display(patch) File
"/usr/lib/python2.4/site-packages/bzrlib/plugins/bzrtools/shelf.py",
line 65, in display sys.stdout.write(open(path).read()) TypeError:
coercing to Unicode: need string or buffer, NoneType found

bzr 0.18.0 on python 2.4.4.final.0 (linux2)
arguments: ['/usr/bin/bzr', 'shelf', 'show']