steps to reproduce

1. run the zul in osx 10.12 sierra, firefox 51
2. type 'abab' in the combobox

current result

the label show aba, 1 character missing

expected result

show complete value

debug info

• Can't reproduce in Chrome. Neither with firefox 51 under osx 10.10 (Yosemite), 10.11 (El Capitan)
• root cause: when onKeyDown event happens, the event handler only can get the value before users change the value (http://stackoverflow.com/questions/1338483/detecting-value-of-input-text-field-after-a-keydown-event-in-the-text-field). Need to wait a moment to get the value.
• another possible solution is to handle it in onKeyUp

workaround

please see the attached zul