Index: layer_grp.h
===================================================================
--- layer_grp.h	(revision 31751)
+++ layer_grp.h	(revision 31752)
@@ -232,8 +232,9 @@
 pcb_layergrp_t *pcb_get_grp_new_intern(pcb_board_t *pcb, int intern_id);
 pcb_layergrp_t *pcb_get_grp_new_misc(pcb_board_t *pcb);
 
-/* append a layer group without any smart side effects - use only from io loaders */
-pcb_layergrp_t *pcb_get_grp_new_raw(pcb_board_t *pcb);
+/* prepend or append a layer group without any smart side effects - used
+   from io loaders */
+pcb_layergrp_t *pcb_get_grp_new_raw(pcb_board_t *pcb, rnd_bool prepend);
 
 /* ugly hack: remove the extra substrate we added after the outline layer */
 void pcb_layergrp_fix_old_outline(pcb_board_t *pcb);