bzr branch-history fails on non-ascii committers

Running branch-history in a main branch of Emacs repository causes bzr to puke
thusly (happens in several other Emacs branches as well):

  bzr: ERROR: exceptions.UnicodeEncodeError: 'ascii' codec can't encode character u'\xec' in position 16: ordinal not in range(128)

  Traceback (most recent call last):
    File "bzrlib\commands.pyo", line 842, in exception_to_return_code
    File "bzrlib\commands.pyo", line 1037, in run_bzr
    File "C:/Program Files/Bazaar/plugins\bzrtools\command.py", line 13, in run_argv_aliases
    File "bzrlib\commands.pyo", line 654, in run_argv_aliases
    File "C:/Program Files/Bazaar/plugins\bzrtools\command_classes.py", line 361, in run
    File "C:/Program Files/Bazaar/plugins\bzrtools\branchhistory.py", line 20, in branch_history
    File "C:/Program Files/Bazaar/plugins\bzrtools\branchhistory.py", line 61, in print_info
  UnicodeEncodeError: 'ascii' codec can't encode character u'\xec' in position 16: ordinal not in range(128)

  bzr 2.0.2 on python 2.5.4 (Windows-XP-5.1.2600-SP2)
  arguments: ['bzr', 'branch-history']
  encoding: 'cp1255', fsenc: 'mbcs', lang: None
  plugins:
    bisect C:\Program Files\Bazaar\plugins\bisect [1.1.0.pre.0]
    bzrtools C:\Program Files\Bazaar\plugins\bzrtools [2.0.1]
    explorer C:\Program Files\Bazaar\plugins\explorer [0.8.3]
    launchpad C:\Program Files\Bazaar\plugins\launchpad [2.0.2]
    netrc_credential_store C:\Program Files\Bazaar\plugins\netrc_credential_store [2.0.2]
    qbzr C:\Program Files\Bazaar\plugins\qbzr [0.14.5]
    rebase C:\Program Files\Bazaar\plugins\rebase [0.5.4]
    svn C:\Program Files\Bazaar\plugins\svn [1.0.0]
    upload C:\Program Files\Bazaar\plugins\upload [1.0.0dev]
    xmloutput C:\Program Files\Bazaar\plugins\xmloutput [0.8.5]

  *** 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.