+
+ layer_t top = regions.size() - 1;
+
+ if (region->layer() >= top) {
+ /* already on the top */
+ return;
+ }
+
+ move_region_to_layer (top, region, 1);
+ /* mark the region's last_layer_op as now, so that it remains on top when
+ doing future relayers (until something else takes over)
+ */
+ timestamp_layer_op (region);