Index: layer.h
===================================================================
--- layer.h	(revision 19122)
+++ layer.h	(revision 19123)
@@ -95,6 +95,7 @@
 
 #define PCB_LAYER_IS_ASSY(lyt, purpi) (((lyt) & PCB_LYT_VIRTUAL) && ((purpi) == F_assy))
 #define PCB_LAYER_IS_FAB(lyt, purpi) (((lyt) & PCB_LYT_VIRTUAL) && ((purpi) == F_fab))
+#define PCB_LAYER_IS_CSECT(lyt, purpi) (((lyt) & PCB_LYT_VIRTUAL) && ((purpi) == F_csect))
 
 #include "globalconst.h"
 #include "global_typedefs.h"
@@ -248,10 +249,14 @@
     - the number of layers copied into res if res is not NULL
    The plain version require exact match (look for a specific layer),
    the  _any version allows partial match so work with PCB_LYT_ANY*.
+   The version that ends in 'p' also matches purpose if purpi is not -1
+   and/or purpose is not NULL.
 */
 int pcb_layer_list(pcb_board_t *pcb, pcb_layer_type_t mask, pcb_layer_id_t *res, int res_len);
 int pcb_layer_list_any(pcb_board_t *pcb, pcb_layer_type_t mask, pcb_layer_id_t *res, int res_len);
+int pcb_layer_listp(pcb_board_t *pcb, pcb_layer_type_t mask, pcb_layer_id_t *res, int res_len, int purpi, const char *purpose);
 
+
 /**** layer creation (for load/import code) ****/
 
 /* Reset layers to the bare minimum (double sided board) */