#1020 Fail to reinsert the new region of borderlayout

[Jumper Chen]

<zk>
<borderlayout id="b" height="300px">
<west maxsize="600" size="30%" flex="true" border="0" splittable="true">
<div style="background:#E6D92C">
<label value="30%"
style="color:white;font-size:50px" />
</div>
</west>
<center id="c">
<label value="Here is a border"
style="color:gray;font-size:30px" />
</center>
<east size="30%" flex="true" border="0" collapsible="true">
<div style="background:#B8D335">
<label value="30%"
style="color:white;font-size:50px" />
</div>
</east>
</borderlayout>
<button label="It doesn't show any error after Click the button">
<attribute name="onClick">
c.detach();
new Center().setParent(b);
</attribute>
</button>
</zk>

[Jumper Chen]

Logged In: YES
user_id=1684431
Originator: YES

Fixed since 6/10.