3472         def _cacheabletip(self):

  3473             q = self.mq

  3474             cl = self.changelog

  3475             qbase = None

  3476             if not q.applied:

  3477                 if getattr(self, '_committingpatch', False):

  3478                     # Committing a new patch, must be tip

  3479                     qbase = len(cl) - 1

  3480             else:

  3481                 qbasenode = q.applied[0].node

  3482                 try:

  3483                     qbase = self.unfiltered().changelog.rev(qbasenode)

  3484                 except error.LookupError:

  3485                     self.ui.warn(_('mq status file refers to unknown node %s\n')

  3486                                  % short(qbasenode))

  3487             ret = super(mqrepo, self)._cacheabletip()

  3488             if qbase is not None:

  3489                 ret = min(qbase - 1, ret)

  3490             return ret

  3491