问如何为连接的排序器(部分由浮动/相对定位的父元素引起)修复错误定位的可拖式帮助程序？

$('.sortable').sortable({
  connectWith: '.sortable',
  revert: 600,
  forcePlaceholderSize: true,
  placeholder: 'ui-sortable-placeholder',
  tolerance: 'pointer'
}).disableSelection();

$('.draggable').draggable({
  connectToSortable: '.sortable',
  helper: 'clone',
  revert: true
}).disableSelection();

.sortable-container {
  display: inline-block;
  width: 100px;
  vertical-align: top;
}
.sortable {
  cursor: move;
  margin: 0;
  padding: 0;
  list-style-type: none;
  vertical-align: top;
  border: 1px solid #000;
}
.ui-sortable-placeholder {
  background: #ff0000;
}
#draggables {
  margin: 0;
  padding: 0;
  list-style-type: none;
}
.draggable {
  margin: 4px;
  cursor: move;
  color: #fff;
  background: #5dd1ff;
}

<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css" rel="stylesheet" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://code.jquery.com/ui/1.11.3/jquery-ui.min.js"></script>

<div class='container-fluid'>
  <div class="row">
    <div class="col-xs-3">
      <p>foo</p>
      <p>bar</p>
    </div>
    <div class="col-xs-3">
      <p>foo</p>
      <p>bar</p>
    </div>
    <div class="col-xs-6">
      <p>foo</p>
      <p>bar</p>
    </div>
  </div>
  <div class='row'>
    <div class='col-xs-6'>
      <div id='sortables'>
        <div class='sortable-container'>
          <ul class='sortable'>
            <li>sortable 1</li>
            <li>sortable 2</li>
            <li>sortable 3</li>
            <li>sortable 4</li>
            <li>sortable 5</li>
            <li>sortable 6</li>
          </ul>
        </div>
        <div class='sortable-container'>
          <ul class='sortable'>
            <li>sortable 1</li>
            <li>sortable 2</li>
            <li>sortable 3</li>
            <li>sortable 4</li>
            <li>sortable 5</li>
            <li>sortable 6</li>
          </ul>
        </div>
        <div class='sortable-container'>
          <ul class='sortable'>
            <li>sortable 1</li>
            <li>sortable 2</li>
            <li>sortable 3</li>
            <li>sortable 4</li>
            <li>sortable 5</li>
            <li>sortable 6</li>
          </ul>
        </div>
      </div>
    </div>

    <div class='col-xs-6'>
      <ul id='draggables'>
        <li class='draggable'>draggable 1</li>
        <li class='draggable'>draggable 2</li>
        <li class='draggable'>draggable 3</li>
      </ul>
    </div>
  </div>
</div>