When users are right

A few days ago I received an email from a user of Kdropbox saying the behaviour of the application when clicking on the the system tray icon was not the usual in KDE. As he said, if a window is opened when you click on the icon a second click should close it. It's funny but so many years using this desktop environment and I had not noticed. I checked and, it is true that not all programs fulfill it, but those that ship with KDE do it.