Reproducible: always
0. Turn on JAWS
1. Download jar with accessibility test samples from https://wiki.se.oracle.com/download/attachments/46472587/Hello.jar
2. Execute combobox demo by java -cp Hello.jar hello.HelloComboBox
3. Focus on the first combobox (one with text "Prompting you here")
4. Open it with alt-down and try to collapse it with alt-up
Expected result: Popup menu is collapsed (as with non-empty comboboxes).
Actual result: Nothing happens, jaws says something unclear.