Steps to Reproduce

1. run the page

    <combobox hflex="min">
        <comboitem label="Simple and Rich"/>
        <comboitem label="Cool!"/>
        <comboitem label="Ajax and RIA"/>
        <comboitem label="Ajax and RIA looooong looooooooong"/>
    </combobox>

2. click the button to open the drop-down 2 times

Current Result

combobox width grows longer each time

Expected Result

The width of combobox grows as the same width as the popup (since popup is the child)
Shouldn't grow longer each time

Debug Information

https://github.com/zkoss/zk/blob/v8.6.2/zk/src/archive/web/js/zk/widget.js#L3348
If the child is floating, the parent won't be the component itself.
It will keep calculating until there is no parent.