Documentation / diff-heuristic-options.txton commit refs: convert dwim_ref and expand_ref to struct object_id (cca5fa6)
   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.