QML ComboBox closes on escape/back key release, not press

In the documentation for the close policy of a QML Popup type, Popup.CloseOnEscape  will close when the escape key is pressed while the Popup has active focus.

QML ComboBox owns a Popup type, with a default close policy of Popup.CloseOnEscape | Popup.CloseOnPressOutsideParent. This suggests that the Popup will close when Escape is pressed. This is not currently the case.  The Popup will close when Escape is released.