- 当前 Bug 的表现（可附上截图）

- 预期表现

- 复现路径

- 提供一个最简复现 Demo

h5 代码

<script src="http://cdn.bootcss.com/jquery/2.2.3/jquery.js"></script>
<div id="mouseMove">
  <span id="span" style="color: red"></span>
  <button id="movebtn" style="width: 100px;height: 100px;">拖动我</button>

</div>

<script>
  var num = 0;
  $().ready(function(){
    console.log('begin move')


    document.getElementById("movebtn").addEventListener("mousedown", function(e){
      document.getElementById("span").innerHTML = e.clientX + ',' + e.clientY
      drag(document.getElementById("movebtn"))
    });
  })

  /**
   * elementToDrag mousedown 事件的元素
   * @param elementToDrag
   * @param event
   */
  function drag(elementToDrag){
    document.addEventListener("mousemove", moveHandler, true);
    document.addEventListener("mouseup", upHandler, true);

    function moveHandler(e){
      num++;
      document.getElementById("span").innerHTML = e.clientX + ',' + e.clientY
      console.log(e.clientX + ',' + e.clientY)

      if(e.stopPropagation)
        e.stopPropagation();
      else
        e.cancelBubble = true;
    }

    function upHandler(e){
      document.removeEventListener("mousemove", moveHandler, true);
      document.removeEventListener("mouseup", upHandler, true);

      console.log(3);

      if(e.stopPropagation)
        e.stopPropagation();
      else
        e.cancelBubble = true;
    }
  }
</script>