Resizable: The animate option breaks containment

[stackhasH]

First, I wrote the following code:

<div style="width: 400px; height: 500px;">        
 <div class="ui-widget-content" id="ejem" style="width: 300px; height: 200px;">
  LALALALALA
 </div>
            
 <script language="javascript">
  $(document).ready(function() {
   $('#ejem').resizable({containment: 'parent'});
  });
 </script>
        
</div>

ALL IS OK

But when I add the property "animate: true" and resize the div, visually the property 'containment' is not respected.

[watanabe]

See #4603.

[tj.vantoll]

Verified this is still an issue in 1.9.1 - ​http://jsfiddle.net/tj_vantoll/f5dmd/.