Documentation / diff-heuristic-options.txton commit refs: convert update_ref and refs_update_ref to use struct object_id (ae07777)
   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.