There needs to be a Lisp-level way to get the frame associated with a window configuration.

If a window configuration is saved and the frame from which it was saved is deleted, then when a set-window-configuration call is made on another frame, internally that call will check that the frame doesn't match and may do next to nothing. But the caller is not informed of the non-effectiveness or partial effectiveness of the call. In order to write robust code, there needs to be a `window-configuration-frame' type call which returns the frame with which the configuration is associated, so that callers may check it before trying to invoke set-window-configuration. It also wouldn't be a bad idea if set-window-configuration returned t when a full configuration restore is performed and nil otherwise. Regards, Bob