Index: openacs-4/packages/calendar/www/mini-calendar.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/calendar/www/mini-calendar.tcl,v
diff -u -r1.20.2.4 -r1.20.2.5
--- openacs-4/packages/calendar/www/mini-calendar.tcl	9 Sep 2013 16:44:26 -0000	1.20.2.4
+++ openacs-4/packages/calendar/www/mini-calendar.tcl	3 Oct 2013 07:39:46 -0000	1.20.2.5
@@ -1,8 +1,8 @@
-if {![exists_and_not_null base_url]} {
+if {(![info exists base_url] || $base_url eq "")} {
     set base_url [ad_conn url]
 }
 
-if {![exists_and_not_null date]} {
+if {(![info exists date] || $date eq "")} {
     set date [dt_sysdate]
 }
 
@@ -20,7 +20,7 @@
 } -on_submit {}
 
 
-if {[exists_and_not_null page_num]} {
+if {([info exists page_num] && $page_num ne "")} {
     set page_num_formvar [export_vars -form {page_num}]
     set page_num "&page_num=$page_num"
 } else {
@@ -29,8 +29,10 @@
 }
 
 # Determine whether we need to pass on the period_days variable from the list view
-if {[string equal $view list]} {
-    if {![exists_and_not_null period_days] || [string equal $period_days [parameter::get -parameter ListView_DefaultPeriodDays -default 31]]} {
+if {$view eq "list"} {
+    if {(![info exists period_days] || $period_days eq "") 
+	|| $period_days eq [parameter::get -parameter ListView_DefaultPeriodDays -default 31]
+    } {
 	set url_stub_period_days ""
     } else {
 	set url_stub_period_days "&period_days=${period_days}"
@@ -49,12 +51,12 @@
 # Create row with existing views
 multirow create views name text active_p url
 foreach viewname {list day week month} {
-    if { [string equal $viewname $view] } {
+    if {$viewname eq $view} {
         set active_p t
     } else {
         set active_p f
     }
-    if {[string equal $viewname list]} {
+    if {$viewname eq "list"} {
 	multirow append views [lang::util::localize $message_key_array($viewname)] $viewname $active_p \
 	    "[export_vars -base $base_url {date {view $viewname}}]${page_num}${url_stub_period_days}"
     } else {
@@ -88,7 +90,7 @@
 
 set today [lc_time_fmt [dt_sysdate] "%q"]
 
-if [string equal $view month] {
+if {$view eq "month"} {
     set prev_year [clock format [clock scan "1 year ago" -base $now] -format "%Y-%m-%d"]
     set next_year [clock format [clock scan "1 year" -base $now] -format "%Y-%m-%d"]
     set prev_year_url "$base_url?view=$view&date=[ad_urlencode $prev_year]${page_num}${url_stub_period_days}"
@@ -104,8 +106,8 @@
 
         # show 3 months in a row
 
-        set new_row_p [expr $i / 3]
-#         if {($i != 0) && ([expr $i % 3] == 0)} {
+        set new_row_p [expr {$i / 3}]
+#         if {($i != 0) && ($i % 3 == 0)} {
 #             set new_row_p t
 #         } else {
 #             set new_row_p f
@@ -117,7 +119,7 @@
             set current_month_p f
         }
         set target_date [clock format \
-                             [clock scan "[expr $i-$curr_month_idx] month" -base $now] -format "%Y-%m-%d"]
+                             [clock scan "[expr {$i-$curr_month_idx}] month" -base $now] -format "%Y-%m-%d"]
         multirow append months $month $current_month_p $new_row_p  \
             "[export_vars -base $base_url {{date $target_date} view}]${page_num}${url_stub_period_days}"
         
@@ -134,7 +136,7 @@
     multirow create days_of_week day_short day_num
     for {set i 0} {$i < 7} {incr i} {
         multirow append days_of_week \
-            [lindex $week_days [expr [expr $i + $first_day_of_week] % 7]] \
+            [lindex $week_days [expr {[expr {$i + $first_day_of_week}] % 7}]] \
             $i
     }
 
@@ -143,14 +145,14 @@
     set day_of_week 1
 
     # Calculate number of active days
-    set active_days_before_month [expr [expr [dt_first_day_of_month $year $month]] -1 ]
-    set active_days_before_month [expr [expr $active_days_before_month + 7 - $first_day_of_week] % 7]
+    set active_days_before_month [expr {[dt_first_day_of_month $year $month] - 1} ]
+    set active_days_before_month [expr {($active_days_before_month + 7 - $first_day_of_week) % 7}]
 
-    set calendar_starts_with_julian_date [expr $first_julian_date_of_month - $active_days_before_month]
-    set day_number [expr $days_in_last_month - $active_days_before_month + 1]
+    set calendar_starts_with_julian_date [expr {$first_julian_date_of_month - $active_days_before_month}]
+    set day_number [expr {$days_in_last_month - $active_days_before_month + 1}]
 
-    for {set julian_date $calendar_starts_with_julian_date} {$julian_date <= [expr $last_julian_date + 7]} {incr julian_date} {
-        if {$julian_date > $last_julian_date_in_month && [string equal $end_of_week_p t] } {
+    for {set julian_date $calendar_starts_with_julian_date} {$julian_date <= $last_julian_date + 7} {incr julian_date} {
+        if {$julian_date > $last_julian_date_in_month && $end_of_week_p eq "t" } {
             break
         }
         set today_p f
@@ -166,7 +168,7 @@
         
         if {$julian_date == $first_julian_date_of_month} {
             set day_number 1
-        } elseif {$julian_date == [expr $last_julian_date_in_month +1]} {
+        } elseif {$julian_date == $last_julian_date_in_month + 1} {
             set day_number 1
         }
 
@@ -203,7 +205,7 @@
 
 set today_url "$base_url?view=day&date=[ad_urlencode [dt_sysdate]]${page_num}${url_stub_period_days}"
 
-if { $view == "day" && [dt_sysdate] == $date } {
+if { $view eq "day" && [dt_sysdate] == $date } {
     set today_p t
 } else {
     set today_p f