--- loncom/homework/caparesponse/caparesponse.c	2005/02/15 22:15:05	1.17
+++ loncom/homework/caparesponse/caparesponse.c	2005/11/07 23:37:39	1.18
@@ -1,6 +1,6 @@
 /* The LearningOnline Network with CAPA 
  * CAPA wrapper code
- * $Id: caparesponse.c,v 1.17 2005/02/15 22:15:05 albertel Exp $
+ * $Id: caparesponse.c,v 1.18 2005/11/07 23:37:39 albertel Exp $
  *
  * Copyright Michigan State University Board of Trustees
  *
@@ -34,7 +34,7 @@ PointsList_t * parse_pts_list (char *pts
   int done=0;
   /*fprintf(stderr,"ids %s\n",id_list);
     fprintf(stderr,"pts %s\n",pts_list);*/
-  while (!done) {
+  while (!done && pts_list) {
     int idx;
     /*fprintf(stderr,"pts; %s\n",idx_pts);*/
     new=gen_ptslist_str(idx_pts);
@@ -97,6 +97,9 @@ int caparesponse_capa_check_answer(char
   if (type == ANSWER_IS_FORMULA) {
     p.id_list=id_list;
     p.pts_list=parse_pts_list(pts_list);
+    if ( p.id_list == NULL || p.pts_list == NULL) {
+      return BAD_FORMULA;
+    }
   }
   p.ans_type   = type;
   p.answer     = correct;