1457                     # give it one last try against prev.

  1457                     # give it one last try against prev.

  1458                     if drev != prev and not self._isgooddelta(delta, textlen):

  1458                     if drev != prev and not self._isgooddelta(delta, textlen):

  1459                         delta = builddelta(prev)

  1459                         delta = builddelta(prev)

  1460             else:

  1460             else:

  1461                 delta = builddelta(prev)

  1461                 delta = builddelta(prev)

  1462             dist, l, data, base, chainbase, chainlen, compresseddeltalen = delta

  1463             dist, l, data, base, chainbase, chainlen, compresseddeltalen = delta

  1463 

  1464 

  1464         if not self._isgooddelta(delta, textlen):

  1465         if not self._isgooddelta(delta, textlen):

  1465             text = buildtext()

  1466             text = buildtext()

  1466             data = self.compress(text)

  1467             data = self.compress(text)