Function rebaseHist

static/editor.md/lib/codemirror/lib/codemirror.js:7872–7876

(hist, change)

  }

  function rebaseHist(hist, change) {
    var from = change.from.line, to = change.to.line, diff = change.text.length - (to - from) - 1;
    rebaseHistArray(hist.done, from, to, diff);
    rebaseHistArray(hist.undone, from, to, diff);
  }

  // EVENT UTILITIES