Index: trunk/src/layer_grp.c
===================================================================
--- trunk/src/layer_grp.c	(revision 22775)
+++ trunk/src/layer_grp.c	(revision 22776)
@@ -243,6 +243,9 @@
 static void pcb_layergrp_free_fields(pcb_layergrp_t *g)
 {
 	free(g->name);
+	free(g->purpose);
+	g->name = g->purpose = NULL;
+	g->purpi = -1;
 }