Function drag_

static/editor.md/lib/codemirror/lib/codemirror.js:3379–3381

(e)

    on(d.wrapper, "scroll", function() { d.wrapper.scrollTop = d.wrapper.scrollLeft = 0; });

    function drag_(e) {
      if (!signalDOMEvent(cm, e)) e_stop(e);
    }
    if (cm.options.dragDrop) {
      on(d.scroller, "dragstart", function(e){onDragStart(cm, e);});
      on(d.scroller, "dragenter", drag_);