gdkwindow-wayland: Don't post CONFIGURE events for the same size

The Wayland compositor is completely allowed to send us configure
events for the same size, and this validly happens if we're changing
states. Fizzle these out.

gdk/wayland/gdkwindow-wayland.c

@@ -596,11 +596,11 @@ gdk_wayland_window_configure (GdkWindow *window,
   GdkDisplay *display;
   GdkEvent *event;
 
+  if (window->width == width && window->height == height)
+    return;
+
   display = gdk_window_get_display (window);
 
-  /* TODO: Only generate a configure event if width/height/scale have actually
-   * changed?
-   */
   event = gdk_event_new (GDK_CONFIGURE);
   event->configure.window = window;
   event->configure.send_event = FALSE;