Index: obj_pstk.h
===================================================================
--- obj_pstk.h	(revision 20388)
+++ obj_pstk.h	(revision 20389)
@@ -172,7 +172,9 @@
 void pcb_pstk_shape_update_pa(pcb_pstk_poly_t *poly);
 
 /* Insert proto into the cache of data; if it's already in, return the existing
-   ID, else dup it and insert it. */
+   ID, else dup it and insert it. WARNING: make sure
+   pcb_pstk_proto_update() was called on proto some point in time before this
+   call, esle the hash is invalid */
 pcb_cardinal_t pcb_pstk_proto_insert_dup(pcb_data_t *data, const pcb_pstk_proto_t *proto, int quiet);
 
 /* Change the non-NULL hole properties of a padstack proto; undoable.