bzr config fails to unquote non-string values

[Vincent Ladeuil]

With the recent support for proper quoting (so to speak ;) a new failure mode has been introduced leading to 'bzr config' crashing:

 bzr config
locations:
  [/home/vila/src/bzr]
  post_commit_to = <email address hidden>
  news_merge_files = doc/en/release-notes/bzr-2.5.txt
  mypush = lp:~vila/bzr/{basename}
branch:
  parent_location = bzr+ssh://bazaar.launchpad.net/+branch/bzr/
  gtk_global_commit_message = Bogus implementation passing smoke test
  gtk_file_commit_messages = de
  push_location = bzr+ssh://bazaar.launchpad.net/~vila/bzr/832046-globs-store-ordered/
bzr: ERROR: exceptions.KeyError: 0

Traceback (most recent call last):
  File "/home/vila/src/bzr/trunk/bzrlib/commands.py", line 919, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/home/vila/src/bzr/trunk/bzrlib/commands.py", line 1124, in run_bzr
    ret = run(*run_argv)
  File "/home/vila/src/bzr/trunk/bzrlib/commands.py", line 672, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/home/vila/src/bzr/trunk/bzrlib/commands.py", line 694, in run
    return self._operation.run_simple(*args, **kwargs)
  File "/home/vila/src/bzr/trunk/bzrlib/cleanup.py", line 136, in run_simple
    self.cleanups, self.func, *args, **kwargs)
  File "/home/vila/src/bzr/trunk/bzrlib/cleanup.py", line 166, in _do_with_cleanups
    result = func(*args, **kwargs)
  File "/home/vila/src/bzr/trunk/bzrlib/commands.py", line 1141, in ignore_pipe
    result = func(*args, **kwargs)
  File "/home/vila/src/bzr/trunk/bzrlib/config.py", line 3840, in run
    self._show_matching_options('.*', directory, scope)
  File "/home/vila/src/bzr/trunk/bzrlib/config.py", line 3928, in _show_matching_options
    value = store.unquote(value)
  File "/home/vila/src/bzr/trunk/bzrlib/config.py", line 3134, in unquote
    value = self._config_obj._unquote(value)
  File "/home/vila/src/bzr/trunk/bzrlib/util/configobj/configobj.py", line 1710, in _unquote
    if (value[0] == value[-1]) and (value[0] in ('"', "'")):
  File "/home/vila/src/bzr/trunk/bzrlib/util/configobj/configobj.py", line 587, in __getitem__
    val = dict.__getitem__(self, key)
KeyError: 0

bzr 2.5.0dev5 on python 2.7.2 (Linux-3.0.0-14-generic-x86_64-with-
    Ubuntu-11.10-oneiric)
arguments: ['/home/vila/bin/bzr', 'config']
plugins: bash_completion[2.5.0dev5], bisect[1.1.0dev], bookmarks[2.3.0dev],
    builddeb[2.7.0dev], builder[unknown], bzrtools[2.4.0],
    changelog_merge[2.5.0dev5], defaultToUrllib[unknown], diffstat[0.2.0],
    email[unknown], explorer[1.2.1], gardener[1.0.0dev], graph[1.0.0],
    grep[0.5.0dev], gtk[0.101.0dev], guess[unknown], hg[0.2.0dev],
    launchpad[2.5.0dev5], local_test_server[unknown], loom[2.2.1dev],
    netrc_credential_store[2.5.0dev5], news_merge[2.5.0dev5],
    po_merge[2.5.0dev5], pqm[1.4.0dev], qbzr[0.22.0dev], rewrite[0.6.2dev],
    stats[0.1.0dev], svn[1.1.2dev], tiplog[0.0.1dev],
    update_copyright[0.1.0dev], upload[1.0.1dev], weave_fmt[2.5.0dev5],
    webdav[1.12.3dev], wikkid[unknown], xmloutput[0.8.7]
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/bzr/+filebug
    including this traceback and a description of the problem.

Annoying but rather trivial to fix, the culprit being the very naive implementation of unquote in configobj