Index: openacs-4/packages/caldav/tcl/caldav-interface-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/caldav/tcl/caldav-interface-procs.tcl,v
diff -u -r1.1.2.6 -r1.1.2.7
--- openacs-4/packages/caldav/tcl/caldav-interface-procs.tcl	11 Jul 2022 12:45:57 -0000	1.1.2.6
+++ openacs-4/packages/caldav/tcl/caldav-interface-procs.tcl	22 Dec 2022 02:51:37 -0000	1.1.2.7
@@ -119,7 +119,7 @@
         } else {
             set calclause "= :calendar_ids"
         }
-        set e_clause [expr {[string is integer $uid] ? " or e.activity_id = :uid" : ""}]
+        set e_clause [expr {[nsf::is integer $uid] ? " or e.activity_id = :uid" : ""}]
 
         return [::xo::dc list get_cal_item_from_uid [subst {
             select cal_item_id
@@ -166,7 +166,7 @@
             limit 1
         }]
 
-        # set e_clause [expr {[string is integer $uid] ? " or e.activity_id = :uid" : ""}]
+        # set e_clause [expr {[nsf::is integer $uid] ? " or e.activity_id = :uid" : ""}]
         #
         # - we could pass-in a calendar-clause, would save a query in
         #   the PUT case