Steps to Reproduce

http://zkfiddle.org/sample/3djug99/7-Hidden-selected-tree-nodes-ignored-in-onSelect
1. click "select all"
2. unselect any level 1 node (e.g. "2")
3. observe the logs

Current Result

previous: [1.1, 1.2, 1, 2.1, 2.2, 2.3, 2, 3.1, 3]
current from event: [3, 1]
unselected from event: [2]
current from model: [1.1, 1.2, 1, 2.1, 2.2, 2.3, 3.1, 3]

Expected Result

previous: [1.1, 1.2, 1, 2.1, 2.2, 2.3, 2, 3.1, 3]
current from event: [1.1, 2.3, 2.2, 2.1, 1.2, 3.1, 3, 1]
unselected from event: [2]
current from model: [1.1, 1.2, 1, 2.1, 2.2, 2.3, 3.1, 3]

Debug Info

getSelectedObjects returns objects based on the currently rendered treeitems
getPreviousSelectedObjects returns objects based on the actual model

this is inconsistent and confusing

Workaround

instead of calling selectEvent.getSelectedObjects() call treeModel.getSelection() (which is synchronized correctly)