Index: openacs-4/packages/xowiki/tcl/category-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xowiki/tcl/category-procs.tcl,v
diff -u -r1.29 -r1.30
--- openacs-4/packages/xowiki/tcl/category-procs.tcl	25 Apr 2018 19:47:48 -0000	1.29
+++ openacs-4/packages/xowiki/tcl/category-procs.tcl	9 May 2018 15:33:34 -0000	1.30
@@ -24,7 +24,7 @@
     set mapped_trees [expr {$have_locale ?
                             [category_tree::get_mapped_trees $object_id $locale] :
                             [category_tree::get_mapped_trees $object_id]}]
-    set trees {}
+    set trees [list]
     foreach tree $mapped_trees {
       lassign $tree tree_id my_tree_name ...
 
@@ -50,7 +50,7 @@
       # Get the values from info in "tree" into separate variables given by output.
       # Note, that the order matters!
       lassign $tree {*}$output
-      set l {}
+      set l [list]
       foreach __var $output {lappend l [set $__var]}
       lappend trees $l
     }