Index: openacs-4/packages/xotcl-core/tcl/03-doc-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xotcl-core/tcl/03-doc-procs.tcl,v
diff -u -N -r1.16 -r1.17
--- openacs-4/packages/xotcl-core/tcl/03-doc-procs.tcl	17 May 2018 14:24:34 -0000	1.16
+++ openacs-4/packages/xotcl-core/tcl/03-doc-procs.tcl	11 Jun 2018 20:51:50 -0000	1.17
@@ -511,6 +511,10 @@
   }
 
   :public object method get_object_source {scope obj} {
+    if {![nsf::is object $obj]} {
+      ns_log warning "get_object_source: argument passed as obj is not an object: $obj"
+      return ""
+    }
     set init_block [:get_init_block $scope $obj]
     if {$init_block ne ""} {
       set dummy [:get_doc_block $init_block body]