9e7c7598aa
lower_fullscreen_surface() was removing fullscreen surfaces from the fullscreen layer and inserting them in the normal workspace layer. However, those fullscreen surfaces were never put back in the fullscreen layer, causing bugs such as unrelated surfaces being drawn between a fullscreen surface and its black view. Change the lower_fullscreen_surface() logic so that it lowers fullscreen surfaces to the workspace layer *and* hides the black views. Make this reversible by re-configuring the lowered fullscreen surface: when it is re-configured, the black view will be shown again and the surface will be restacked in the fullscreen layer. https://bugs.freedesktop.org/show_bug.cgi?id=73575 https://bugs.freedesktop.org/show_bug.cgi?id=74221 https://bugs.freedesktop.org/show_bug.cgi?id=74222