--- loncom/homework/rankresponse.pm	2011/09/16 22:23:54	1.67
+++ loncom/homework/rankresponse.pm	2012/10/12 12:45:46	1.68
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # rank style response
 #
-# $Id: rankresponse.pm,v 1.67 2011/09/16 22:23:54 raeburn Exp $
+# $Id: rankresponse.pm,v 1.68 2012/10/12 12:45:46 raeburn Exp $
 # Copyright Michigan State University Board of Trustees
 #
 # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
@@ -186,8 +186,11 @@ sub get_correct_order {
 
 sub displayanswers {
     my ($max,$randomize,$tol,@opt)=@_;
-    if (!defined(@{ $Apache::response::foilgroup{'names'} })) { return; }
-    my @names = @{ $Apache::response::foilgroup{'names'} };
+    my @names;
+    if (ref($Apache::response::foilgroup{'names'}) eq 'ARRAY') {
+        @names = @{ $Apache::response::foilgroup{'names'} };
+    }
+    return if (!@names);
     my @whichfoils = &whichfoils($max,$randomize);
     my @correctorder=&get_correct_order($tol,@whichfoils);
     my $result;