Index: openacs-4/packages/calendar/tcl/calendar-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/calendar/tcl/calendar-procs.tcl,v
diff -u -r1.39.2.19 -r1.39.2.20
--- openacs-4/packages/calendar/tcl/calendar-procs.tcl	14 Apr 2023 14:03:39 -0000	1.39.2.19
+++ openacs-4/packages/calendar/tcl/calendar-procs.tcl	6 Jun 2023 13:25:31 -0000	1.39.2.20
@@ -183,6 +183,11 @@
         return -1
     }
 
+    #
+    # Cleanup empty strings from the id list
+    #
+    set calendar_id_list [lsearch -all -inline -not -exact $calendar_id_list {}]
+
     if { [llength $calendar_id_list] > 0 } {
         set result [db_string get_calendar_info_calendar_id_list {} -default 0]
     } else {