steps to reproduce

run the attached example
A) drag the splitter left then right again
B) collapse and expand the splitter

actual result

A) the splitter only resizes properly when dragged to the left
B) the tabbox does not resize after the splitter is expanded
--> causes a horizontal scrollbar

expected result

the tabbox should not stop the splitter from resizing

debug info

the tabbox defines a fixed width at one of its child elements interfering with the resizing of the splitter.

<div id="pKCQ6" class="z-tabs" style="width: 1725px;">...</div>

when this width is removed manually the splitter can be dragged to the right again and the tabbox shrinks accordingly (but resetting the fixed width at the z-tabs element)

root cause

splitter requires a <hbox> component which uses a <table> layout.
It seems fixed widths conflict with the table column sizing algorithm

Workaround

use a <borderlayout> with a collapsible <west> and a <center> element