Index: openacs-4/packages/categories/tcl/category-trees-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/categories/tcl/category-trees-procs.tcl,v
diff -u -r1.16 -r1.17
--- openacs-4/packages/categories/tcl/category-trees-procs.tcl	13 Oct 2005 14:46:01 -0000	1.16
+++ openacs-4/packages/categories/tcl/category-trees-procs.tcl	27 Jun 2006 07:34:04 -0000	1.17
@@ -488,6 +488,7 @@
     {-tree_id {}}
     {-container_id {}}
     {-category_counts {}}
+    -append:boolean
     -datasource 
 } {
     get a multirow datasource for a given tree or for all trees mapped to a 
@@ -540,7 +541,13 @@
         array set counts [list]
     }
 
-    template::multirow create $datasource tree_id tree_name category_id category_name level pad deprecated_p count child_sum
+    # If we should append, then don't create the datasource if it already exists
+    if {$append_p && [template::multirow exists $datasource]} {
+	# do nothing
+    } else {
+	template::multirow create $datasource tree_id tree_name category_id category_name level pad deprecated_p count child_sum
+    }
+
     foreach mapped_tree $mapped_trees {
         foreach {tree_id tree_name subtree_id assign_single_p require_category_p} $mapped_tree { break }
         foreach category [category_tree::get_tree -subtree_id $subtree_id $tree_id] {