This permits imple- mentation of window manager facilities that aid debugging. A client can set its close-down mode to RetainTemporary . If the client then crashes, its windows would not be destroyed. The programmer can then inspect the application's window tree and use the window manager to destroy the zombie win- dows. XKillClient can generate a BadValue error.
Some numeric value falls outside the range of values accepted by the request.
Unless a specific range is specified for an argument, the full range defined by the argument's type is accepted. Any argument defined as a set of alternatives can gen- erate this error.