Index: openacs-4/packages/assessment/www/asm-admin/results-export.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/assessment/www/asm-admin/results-export.tcl,v
diff -u -r1.17 -r1.17.2.1
--- openacs-4/packages/assessment/www/asm-admin/results-export.tcl	29 Jun 2018 17:27:18 -0000	1.17
+++ openacs-4/packages/assessment/www/asm-admin/results-export.tcl	21 Nov 2019 18:54:20 -0000	1.17.2.1
@@ -113,15 +113,15 @@
 	    if {$mc_item_list ne ""} {
 		db_foreach mc_items {} {
 		    if {$text_value eq ""} {
-			if {[exists_and_not_null csv_${section_id}_${as_item_id}($session_id)]} {
+			if {[info exists csv_${section_id}_${as_item_id}($session_id)] && [set csv_${section_id}_${as_item_id}($session_id)] ne ""} {
 			    # append list of choices separated with comma
 			    append csv_${section_id}_${as_item_id}($session_id) ",[as::assessment::quote_export -text $title]"
 			} else {
 			    # just set the choice value
 			    set csv_${section_id}_${as_item_id}($session_id) [as::assessment::quote_export -text $title]
 			}
 		    } else {
-			if {[exists_and_not_null csv_${section_id}_${as_item_id}($session_id)]} {
+			if {[info exists csv_${section_id}_${as_item_id}($session_id)] && [set csv_${section_id}_${as_item_id}($session_id)] ne ""} {
 			    append csv_${section_id}_${as_item_id}($session_id) ",[as::assessment::quote_export -text $text_value]"
 			} else {
 			    set csv_${section_id}_${as_item_id}($session_id) [as::assessment::quote_export -text $text_value]
@@ -140,7 +140,7 @@
 
     foreach session_id $session_list {
 	foreach {section_id item_id} $item_list {
-	    if {[exists_and_not_null csv_${section_id}_${item_id}($session_id)]} {
+	    if {[info exists csv_${section_id}_${item_id}($session_id)] && [set csv_${section_id}_${item_id}($session_id)] ne ""} {
 		lappend csv_result_list($session_id) "\"[set csv_${section_id}_${item_id}($session_id)]\""
 	    } else {
 		lappend csv_result_list($session_id) ""