phosh: Fix crash when an unmapped surface is selected when switching

Unmapped surfaces have no app_id and no title, so comparisons are not possible.

rootston/phosh.c

@@ -70,14 +70,16 @@ static void xdg_switcher_handle_raise_xdg_surfaces(struct wl_client *client,
 	wl_list_for_each(view, &desktop->views, link) {
 		switch (view->type) {
 		case ROOTS_XDG_SHELL_VIEW:
-			if (view->xdg_surface->role != WLR_XDG_SURFACE_ROLE_TOPLEVEL)
+			if (view->xdg_surface->role != WLR_XDG_SURFACE_ROLE_TOPLEVEL
+					|| !view->xdg_surface->mapped)
 				continue;
 			if (!strcmp(app_id, view->xdg_surface->toplevel->app_id) &&
 				!strcmp(title, view->xdg_surface->toplevel->title))
 				found_view = view;
 			break;
 		case ROOTS_XDG_SHELL_V6_VIEW:
-			if (view->xdg_surface_v6->role != WLR_XDG_SURFACE_V6_ROLE_TOPLEVEL)
+			if (view->xdg_surface_v6->role != WLR_XDG_SURFACE_V6_ROLE_TOPLEVEL
+					|| !view->xdg_surface_v6->mapped)
 				continue;
 			if (!strcmp(app_id, view->xdg_surface_v6->toplevel->app_id) &&
 				!strcmp(title, view->xdg_surface_v6->toplevel->title))