Index: layer_grp.h
===================================================================
--- layer_grp.h	(revision 29691)
+++ layer_grp.h	(revision 29692)
@@ -121,7 +121,7 @@
 
 /* Duplicate a layer group (with no layers); if auto_substrate is set, insert
    a substrate layer automatically if needed */
-pcb_layergrp_id_t pcb_layergrp_dup(pcb_board_t *pcb, pcb_layergrp_id_t gid, int auto_substrate);
+pcb_layergrp_id_t pcb_layergrp_dup(pcb_board_t *pcb, pcb_layergrp_id_t gid, int auto_substrate, pcb_bool undoable);
 
 /* Move gfrom to to_before and shift the stack as necessary. Return -1 on range error */
 int pcb_layergrp_move(pcb_board_t *pcb, pcb_layergrp_id_t gfrom, pcb_layergrp_id_t to_before);
@@ -197,7 +197,10 @@
    copper groups. */
 void pcb_layergrp_create_missing_substrate(pcb_board_t *pcb);
 
+/* Call this after creating grp to add the creation to the undo list */
+void pcb_layergrp_undoable_create(pcb_layergrp_t *grp);
 
+
 /********* OBSOLETE functions, do not use in new code *********/
 /* parses the group definition string which is a colon separated list of
    comma separated layer numbers (1,2,b:4,6,8,t); oldfmt is 0 or 1