--- loncom/homework/default_homework.lcpm	2010/10/14 19:54:56	1.149
+++ loncom/homework/default_homework.lcpm	2010/10/18 19:47:31	1.150
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA 
 # used by lonxml::xmlparse() as input variable $safeinit to Apache::run::run()
 #
-# $Id: default_homework.lcpm,v 1.149 2010/10/14 19:54:56 raeburn Exp $
+# $Id: default_homework.lcpm,v 1.150 2010/10/18 19:47:31 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -357,6 +357,17 @@ sub caparesponse_check_list {
 	}
     }
 
+    my $allow_control_char = 0;
+    my $control_chars_removed = 0;
+    if ($type eq 'cs' || $type eq 'ci') {
+        if (ref($LONCAPA::CAPAresponse_answer->{'answers'}) eq 'ARRAY') {
+            foreach my $strans (@{$LONCAPA::CAPAresponse_answer->{'answers'}}) {
+                if ($strans =~ /[\000-\037]/) {
+                    $allow_control_char = 1;
+                }
+            }
+        }
+    }
 
 #    &LONCAPA_INTERNAL_DEBUG(&LONCAPA_INTERNAL_Dumper($responses));
     my %memoized;
@@ -366,7 +377,15 @@ sub caparesponse_check_list {
 	    my $response = $responses->[$i];
 	    my $key = "$answer\0$response";
 	    my (@awards,@msgs);
-	    for (my $j=0; $j<scalar(@$response); $j++) { 
+	    for (my $j=0; $j<scalar(@$response); $j++) {
+                if ($type eq 'cs' || $type eq 'ci') {
+                    unless ($allow_control_char) {
+                        if ($response->[$j] =~ /[\000-\037]/) { 
+                            $response->[$j] =~ s/[\000-\037]//g;
+                            $control_chars_removed = 1;
+                        }  
+                    }
+                }
 		my ($award,$msg) = &caparesponse_check($answer->[$j],
 						       $response->[$j]);
                 if ($type eq 'cs' || $type eq 'ci') {
@@ -397,6 +416,14 @@ sub caparesponse_check_list {
 		} else {
 		    my (@awards,@msgs);
 		    for (my $j=0; $j<scalar(@$response); $j++) {
+                        if ($type eq 'cs' || $type eq 'ci') {
+                            unless ($allow_control_char) {
+                                if ($response->[$j] =~ /[\000-\037]/) {
+                                    $response->[$j] =~ s/[\000-\037]//g;
+                                    $control_chars_removed = 1;
+                                }
+                            }
+                        }
 			my ($award,$msg) = &caparesponse_check($answer->[$j],
 							       $response->[$j]);
                         if ($type eq 'cs' || $type eq 'ci') {
@@ -449,7 +476,7 @@ sub caparesponse_check_list {
     &LONCAPA_INTERNAL_DEBUG(" all final_awards ".join(':',@final_awards));
     my ($final_award,$final_msg) = 
 	&LONCAPA_INTERNAL_FINALIZEAWARDS(\@final_awards,\@final_msg,undef,1);
-    return ($final_award,$final_msg,$error);
+    return ($final_award,$final_msg,$error,$control_chars_removed);
 }
 
 sub verify_stringresponse {