new_contents: """Fixes nodes with two copies of the files and wiki addons attached.
  
  This script must be run from the OSF root directory for the imports to work.
  """
  
  
  from pymongo import MongoClient
  
  from website.app import init_app
  from website.project.model import Node
  
  from website.addons.wiki.model import AddonWikiNodeSettings
  from website.addons.osffiles.model import AddonFilesNodeSettings
  
  app = init_app()
  
  from website.settings import DB_USER, DB_PASS
  
  client = MongoClient('localhost', 20771)
  client.osf20130903.authenticate(DB_USER, DB_PASS)
  db = client.osf20130903
  
  for addon_class in (AddonWikiNodeSettings, AddonFilesNodeSettings):
      print('Processing ' + addon_class.__name__)
      query = db['node'].find({
          '.'.join(
              ('__backrefs',
                    'addons',
                    addon_class.__name__.lower(),
                   'owner'
              )
          ): {'$size': 2}
      })
  
      for node in (Node.load(node['_id']) for node in query):
          print('- ' + node._id)
          keep, discard = [x for x in node.addons if isinstance(x, addon_class)]
          addon_class.remove_one(discard)
  
      print('')
  
  print('-----\nDone.')
  
subject: Add script to fix file and wiki migration bug