windowing: Set a new last active window when the last active window i…

…s closed

Fixes #565

Signed-off-by: Evan Maddock <maddock.evan@vivaldi.net>

src/windowing/window_group.vala

@@ -105,7 +105,10 @@ namespace Budgie.Windowing {
 			}
 
 			if (last_active_window == window) {
-				last_active_window = null;
+				// Set the last window before this one as the last active window.
+				// We do this so there should always be a valid window to focus
+				// when tasklist buttons are clicked.
+				last_active_window = get_next_window(window, true);
 			}
 
 			window_removed(window);