Index: work/polydev/test.c
===================================================================
--- work/polydev/test.c	(revision 8192)
+++ work/polydev/test.c	(revision 8193)
@@ -77,6 +77,11 @@
 			return;
 		}
 		drw[cnt] = a - 'A';
+		if ((pa[drw[cnt]] == NULL) || (pa[drw[cnt]]->contours == NULL)) {
+			fprintf(stderr, "Error: invalid index in draw: '%c': empty poly \n", a);
+			return;
+		}
+
 		update_bbox(pa[drw[cnt]]->contours, &minx, &miny, &maxx, &maxy);
 		cnt++;
 		arg++;
@@ -251,7 +256,7 @@
 		if (strcmp(cmd, "polygon") == 0) {
 			get_idx();
 			pa[idx] = ply_parse(arg);
-			if (pa[idx] == NULL)
+			if ((pa[idx] == NULL) || (pa[idx]->contours == NULL))
 				fprintf(stderr, "poly parse error\n");
 		}
 		else if (strcmp(cmd, "draw") == 0)