Index: openacs-4/packages/xotcl-core/xotcl-core.info
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xotcl-core/xotcl-core.info,v
diff -u -r1.106.2.34 -r1.106.2.35
--- openacs-4/packages/xotcl-core/xotcl-core.info	20 Dec 2021 17:42:31 -0000	1.106.2.34
+++ openacs-4/packages/xotcl-core/xotcl-core.info	8 Jan 2022 15:18:10 -0000	1.106.2.35
@@ -10,7 +10,7 @@
     <inherit-templates-p>t</inherit-templates-p>
     <auto-mount>xotcl</auto-mount>
 
-    <version name="5.10.1d2" url="http://media.wu-wien.ac.at/download/xotcl-core-5.10.1d2.apm">
+    <version name="5.10.1d3" url="http://media.wu-wien.ac.at/download/xotcl-core-5.10.1d3.apm">
 	<owner url="mailto:neumann@wu-wien.ac.at">Gustaf Neumann</owner>
 	<summary>XOTcl library functionality (e.g. thread handling, online documentation, Generic Form and List Classes)</summary>
 	<release-date>2021-09-16</release-date>
@@ -42,7 +42,7 @@
 	<license>BSD-Style</license>
 	<maturity>2</maturity>
 
-	<provides url="xotcl-core" version="5.10.1d2"/>
+	<provides url="xotcl-core" version="5.10.1d3"/>
 	<requires url="acs-kernel" version="5.10.0"/>
 	<requires url="acs-templating" version="5.10.0"/>
 	<requires url="acs-api-browser" version="5.10.0"/>
Index: openacs-4/packages/xotcl-core/tcl/cr-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xotcl-core/tcl/cr-procs.tcl,v
diff -u -r1.76.2.53 -r1.76.2.54
--- openacs-4/packages/xotcl-core/tcl/cr-procs.tcl	30 Dec 2021 15:26:37 -0000	1.76.2.53
+++ openacs-4/packages/xotcl-core/tcl/cr-procs.tcl	8 Jan 2022 15:18:10 -0000	1.76.2.54
@@ -89,15 +89,33 @@
     @return fully qualified object containing the attributes of the CrItem
   } {
     set object ::[expr {$revision_id ? $revision_id : $item_id}]
+    if {$object eq "::0"} {
+      set msg "get_instance_from_db must be called with either item_id or revision_id different from 0"
+      ad_log error $msg
+      error $msg
+    }
     if {![::nsf::is object $object]} {
       set object_type [:get_object_type -item_id $item_id -revision_id $revision_id]
       set class [::xo::db::Class object_type_to_class $object_type]
       set object [$class get_instance_from_db -item_id $item_id -revision_id $revision_id -initialize $initialize]
     }
     return $object
   }
-  #{4.544836 microseconds per iteration}
-  #{1.310991 microseconds per iteration}
+
+  CrClass ad_proc ensure_item_ids_instantiated {
+    {-initialize:boolean true}
+    {-item_ids:required}
+  } {
+    
+    Make sure, the objects all of the provided items_ids are
+    instantiated initialized (i.e. the same-named objects do exist as
+    executable commands in the current thread).
+
+  } {
+    foreach item_id $item_ids {
+      :get_instance_from_db -item_id $item_id -initialize $initialize
+    }
+  }
   
   CrClass ad_proc get_parent_id {
     -item_id:required