Index: openacs-4/packages/calendar/www/view-list-display.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/calendar/www/view-list-display.tcl,v
diff -u -r1.33 -r1.34
--- openacs-4/packages/calendar/www/view-list-display.tcl	16 Jul 2009 11:31:56 -0000	1.33
+++ openacs-4/packages/calendar/www/view-list-display.tcl	27 Oct 2014 16:41:08 -0000	1.34
@@ -11,25 +11,25 @@
 if { ![info exists show_calendar_name_p] } {
     set show_calendar_name_p 1
 }
-if { ![exists_and_not_null sort_by] } {
+if { (![info exists sort_by] || $sort_by eq "") } {
     set sort_by "start_date"
 }
 
-if { ![exists_and_not_null start_date] } {
+if { (![info exists start_date] || $start_date eq "") } {
     set start_date [clock format [clock seconds] -format "%Y-%m-%d 00:00"]
 }
 
-if { ![exists_and_not_null end_date] } {
+if { (![info exists end_date] || $end_date eq "") } {
     set end_date [clock format [clock scan "+30 days" -base [clock scan $start_date]] -format "%Y-%m-%d 00:00"]
 }
 
-if {[exists_and_not_null calendar_id_list]} {
+if {([info exists calendar_id_list] && $calendar_id_list ne "")} {
     set calendars_clause [db_map dbqd.calendar.www.views.openacs_in_portal_calendar] 
 } else {
     set calendars_clause [db_map dbqd.calendar.www.views.openacs_calendar] 
 }
 
-#if { ![exists_and_not_null period_days] } {
+#if { (![info exists period_days] || $period_days eq "") } {
 #    set period_days [parameter::get -parameter ListView_DefaultPeriodDays -default 31]
 #}  else {
 #    set end_date [clock format [clock scan "+${period_days} days" -base [clock scan $start_date]] -format "%Y-%m-%d 00:00"]
@@ -40,19 +40,19 @@
 set user_id [ad_conn user_id]
 
 # The title
-if {[empty_string_p $start_date] && [empty_string_p $end_date]} {
+if {$start_date eq "" && $end_date eq ""} {
     set title ""
 }
 
-if {[empty_string_p $start_date] && ![empty_string_p $end_date]} {
+if {$start_date eq "" && $end_date ne ""} {
     set title "[_ acs-datetime.to] [lc_time_fmt $end_date "%q"]"
 }
 
-if {![empty_string_p $start_date] && [empty_string_p $end_date]} {
+if {$start_date ne "" && $end_date eq ""} {
     set title "[_ acs-datetime.Items_from] [lc_time_fmt $start_date "%q"]"
 }
 
-if {![empty_string_p $start_date] && ![empty_string_p $end_date]} {
+if {$start_date ne "" && $end_date ne ""} {
     set title "[_ acs-datetime.Items_from] [lc_time_fmt $start_date "%q"] [_ acs-datetime.to] [lc_time_fmt $end_date "%q"]"
 }
 
@@ -84,7 +84,7 @@
 set interval_limitation_clause [db_map dbqd.calendar.www.views.list_interval_limitation]
 set order_by_clause " order by $sort_by"
 set additional_limitations_clause ""
-if { [exists_and_not_null cal_system_type] } {
+if { ([info exists cal_system_type] && $cal_system_type ne "") } {
     append additional_limitations_clause " and system_type = :cal_system_type "
 }
 
@@ -118,15 +118,15 @@
         set pretty_end_time "--"
     }
 
-    if {[string equal $pretty_start_time "00:00"]} {
+    if {$pretty_start_time eq "00:00"} {
         set pretty_start_time "--"
     }
 
-    if {[string equal $pretty_end_time "00:00"]} {
+    if {$pretty_end_time eq "00:00"} {
         set pretty_end_time "--"
     }
 
-    if {![string equal $pretty_start_date $last_pretty_start_date]} {
+    if {$pretty_start_date ne $last_pretty_start_date } {
         set last_pretty_start_date $pretty_start_date
     }
 
@@ -205,7 +205,7 @@
     set period_url_$i "[export_vars -base $self_url -url -entire_form {{period_days $i}}]\#calendar"
 }
 
-if { [info exists export] && [string equal $export print] } {
+if { [info exists export] && $export eq "print" } {
     set print_html [template::adp_parse [acs_root_dir]/packages/calendar/www/view-print-display [list &items items show_calendar_name_p $show_calendar_name_p]]
     ns_return 200 text/html $print_html
     ad_script_abort
@@ -216,7 +216,7 @@
 
 
     set the_form [ns_getform]
-    if { ![empty_string_p $the_form] } {
+    if { $the_form ne "" } {
 	for { set i 0 } { $i < [ns_set size $the_form] } { incr i } {
 	    set varname [ns_set key $the_form $i]
 	    set varvalue [ns_set value $the_form $i]