Documentation / diff-heuristic-options.txton commit packed_ref_iterator_begin(): iterate using `mmapped_ref_iterator` (d1cf155)
   1--indent-heuristic::
   2--no-indent-heuristic::
   3        These are to help debugging and tuning experimental heuristics
   4        (which are off by default) that shift diff hunk boundaries to
   5        make patches easier to read.