Hi, I am trapped in a discussion that is thrown back and forth between two groups of developers, and would hope to get a verdict from freedesktop.org. The bug, simplified, is this: 1. A window manager creates a _NET_WM_STATE property with _NET_WM_STATE_HIDDEN atom to tell an application window that it is no longer shown, and sends a notification. 2. The application window receives the notification and state change, and stops redrawing. 3. The window manager decides that the application is visible again, deletes the complete _NET_WM_STATE property (as _NET_WM_STATE_HIDDEN was the only atom in it), and sends a notification. 4. The application queries the property and receives something that is not actually a property, and treats this as an error, keeping its frozen state. The application developers claim that the WM must keep the property, even if it is empty. The WM developers claim that a non-existing property should be treated the same as an empty property, even if it existed at some time in the past. I found no part of the specification that enforces persistence of a property, or one that defines the identity between an empty but existing, and a non-existing property. Can you please clarify on this? Best regards, Christian