Steps to reproduce

1.  In a dialog, browse the category tree.
2.  Expand a category with sub-category children and see the children displayed.
3. Expand a category without sub-category children.

Expected results

1. The category does not expand in any way and the UI remains usable. ie other categories can be opened and closed.

Actual results

1. The UI inside the chooser dialog no longer responds. Categories cannot be expanded or closed.

Workaround

1. The dialog must be closed and re-opened.

Development notes