jQuery UI 1.11.0 Resizable Containment Bug

Width calculation is wrong when containment element is "position: relative" . I think that it is this change cause https://github.com/jquery/jquery-ui/commit/c03cb8079c6984fb9286a64d980d367d86b9cd8b . However, because I am not familiar with the Javascript, I want to help someone.

HTML

<link rel="stylesheet" href="https://ajax.googleapis.com/ajax/libs/jqueryui/1.11.0/themes/base/jquery.ui.all.css">
<script src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.11.0/jquery-ui.min.js"></script>
<div id="container">
    <div id="parent">
        <div id="child"></div>
    </div>
</div>

CSS

#container {
    position: relative;
    width: 200px;
    height: 200px;
    margin: 30px 0 0 30px;
    border: 1px solid;
}
#parent {
    position: relative;
    width: 150px;
    height: 150px;
    background-color: blue;
}
#child {
    position: relative;
    width: 100px;
    height: 100px;
    border: 1px solid;
    background-color: white;
}

JavaScript

$(document).ready(function () {
    $("#child").resizable({
        containment: "#parent",
        resize: function (event, ui ){
            var h = ui.size.height;
            var t = ui.position.top;
            console.log(h,t);
        }
    });
});