xwayland: Correct input for undecorated clients

We were correctly handling decorated and fullscreen clients, but left
uninitialized values in the input region for undecorated clients. Fix
this behavi-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

xwayland/window-manager.c

@@ -1039,14 +1039,14 @@ weston_wm_window_draw_decoration(void *data)
 
 		pixman_region32_fini(&window->surface->pending.input);
 
-		if (window->fullscreen) {
-			input_x = 0;
-			input_y = 0;
-			input_w = window->width;
-			input_h = window->height;
-		} else if (window->decorate) {
+		if (window->decorate && !window->fullscreen) {
 			frame_input_rect(window->frame, &input_x, &input_y,
 					 &input_w, &input_h);
+		} else {
+			input_x = x;
+			input_y = y;
+			input_w = width;
+			input_h = height;
 		}
 
 		pixman_region32_init_rect(&window->surface->pending.input,