can't get selected item correctly

Steps to Reproduce

1. run the attached code
2. click "load" button
3. select 1 in the first combobox

Current Result

don't see any item in the 2nd combobox

Expected Result

the 2nd combobox should contain 1

Debug Information

• ZK calls setSelectedRootItem() twice, the 2nd time passed a null value
• ZK calls getAvailableRoots() when selecting an item in the first combobox, this is unexpected

  [6642]NOTIFY_CHANGE
  [6642] *[notify-change] [[email protected]][availableChildren] <hbox uuid="wMwP0" id="" /> Size=2
  [6642] + LOAD_BINDING
  [6642] *[load:prop-load] vm.availableChildren > model [2] <combobox uuid="wMwP2" id="childCombo" />
  [6642] + LOAD_BINDING
  [6642] *[load:prop-load] vm.availableRoots > model [1, 2] <combobox uuid="wMwP1" id="rootCombo" />

Workaround

t5799-2.zul