Index: trunk/src/obj_pstk_proto.c
===================================================================
--- trunk/src/obj_pstk_proto.c	(revision 31565)
+++ trunk/src/obj_pstk_proto.c	(revision 31566)
@@ -1374,9 +1374,11 @@
 
 	if (undoable) {
 		undo_shape_geo_t *g = pstk_shape_geo_undo_init(proto, tridx, shpidx);
-		g->clr = shp->clearance;
-		g->clr_valid = 1;
-		pcb_undo_inc_serial();
+		if (g != NULL) {
+			g->clr = shp->clearance;
+			g->clr_valid = 1;
+			pcb_undo_inc_serial();
+		}
 	}
 	pcb_pstk_shape_clr_grow_(shp, is_absolute, val);
 }
@@ -1388,9 +1390,11 @@
 
 	if (undoable) {
 		undo_shape_geo_t *g = pstk_shape_geo_undo_init(proto, tridx, shpidx);
-		pcb_pstk_shape_copy(&g->shp, shp);
-		g->shp_valid = 1;
-		pcb_undo_inc_serial();
+		if (g != NULL) {
+			pcb_pstk_shape_copy(&g->shp, shp);
+			g->shp_valid = 1;
+			pcb_undo_inc_serial();
+		}
 	}
 
 	pcb_pstk_shape_grow_(shp, is_absolute, val);
@@ -1403,9 +1407,11 @@
 
 	if (undoable) {
 		undo_shape_geo_t *g = pstk_shape_geo_undo_init(proto, tridx, shpidx);
-		pcb_pstk_shape_copy(&g->shp, shp);
-		g->shp_valid = 1;
-		pcb_undo_inc_serial();
+		if (g != NULL) {
+			pcb_pstk_shape_copy(&g->shp, shp);
+			g->shp_valid = 1;
+			pcb_undo_inc_serial();
+		}
 	}
 
 	pcb_pstk_shape_scale_(shp, sx, sy);