id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	field_blocks	field_dependson	field_seealso
585	AttributeError: 'NoneType' object has no attribute 'repository'	kobiburnley		"==== How to Reproduce ====

While doing a GET operation on `/changeset/current:/mainline`, Trac issued an internal error.

''(please provide additional details here)''

Request parameters:
{{{
{'format': u'zip',
 'new': u'current:',
 'new_path': u'/mainline',
 'old_path': u'/'}
}}}

User agent: `Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:28.0) Gecko/20100101 Firefox/28.0`

==== System Information ====
''System information not available''

==== Enabled Plugins ====
''Plugin information not available''

==== Python Traceback ====
{{{
Traceback (most recent call last):
  File ""/usr/lib/python2.7/site-packages/trac/web/main.py"", line 522, in _dispatch_request
    dispatcher.dispatch(req)
  File ""/usr/lib/python2.7/site-packages/trac/web/main.py"", line 243, in dispatch
    resp = chosen_handler.process_request(req)
  File ""/usr/lib/python2.7/site-packages/trac/versioncontrol/web_ui/changeset.py"", line 349, in process_request
    self._render_zip(req, filename, repos, data)
  File ""/usr/lib/python2.7/site-packages/trac/versioncontrol/web_ui/changeset.py"", line 768, in _render_zip
    old_path=data['old_path'], old_rev=data['old_rev']):
  File ""/usr/lib/python2.7/site-packages/tracbzr/backend.py"", line 744, in get_changes
    old_tree = old_branch.repository.revision_tree(old_revid)
AttributeError: 'NoneType' object has no attribute 'repository'
}}}"	defect	closed	major		helenos-web	mainline	duplicate