Index: openacs-4/packages/acs-content-repository/sql/postgresql/upgrade/upgrade-5.1.2d6-5.1.2d7.sql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-content-repository/sql/postgresql/upgrade/upgrade-5.1.2d6-5.1.2d7.sql,v
diff -u -r1.1.2.1 -r1.1.2.2
--- openacs-4/packages/acs-content-repository/sql/postgresql/upgrade/upgrade-5.1.2d6-5.1.2d7.sql	2 Sep 2004 20:18:52 -0000	1.1.2.1
+++ openacs-4/packages/acs-content-repository/sql/postgresql/upgrade/upgrade-5.1.2d6-5.1.2d7.sql	21 Sep 2004 00:00:14 -0000	1.1.2.2
@@ -7,4 +7,119 @@
 -- @cvs-id $Id$
 --
 
-create index cr_items_name on cr_items(name);
\ No newline at end of file
+create index cr_items_name on cr_items(name);
+
+drop trigger cr_items_tree_insert_tr on cr_items;
+
+drop function cr_items_tree_insert_tr ();
+
+create function cr_items_tree_insert_tr () returns opaque as '
+declare
+    v_parent_sk      varbit default null;
+    v_max_value      integer;
+    v_parent_id      integer;
+begin
+    -- Lars: If the parent is not a cr_item, we treat it as if it was null.
+    select item_id
+    into   v_parent_id
+    from   cr_items
+    where  item_id = new.parent_id;
+
+    if v_parent_id is null then 
+
+        -- Lars: Treat all items with a non-cr_item parent as one big pool wrt tree_sortkeys
+        -- The old algorithm had tree_sortkeys start from zero for each different parent
+
+        select max(tree_leaf_key_to_int(child.tree_sortkey)) into v_max_value 
+          from cr_items child
+         where not exists (select 1 from cr_items where child.parent_id = item_id);
+    else 
+        select max(tree_leaf_key_to_int(tree_sortkey)) into v_max_value 
+          from cr_items 
+         where parent_id = new.parent_id;
+
+        select tree_sortkey into v_parent_sk 
+          from cr_items 
+         where item_id = new.parent_id;
+    end if;
+
+    new.tree_sortkey := tree_next_key(v_parent_sk, v_max_value);
+
+    return new;
+end;' language 'plpgsql';
+
+create trigger cr_items_tree_insert_tr before insert 
+on cr_items for each row 
+execute procedure cr_items_tree_insert_tr ();
+
+drop trigger cr_items_tree_update_tr on cr_items;
+
+drop function cr_items_tree_update_tr ();
+
+create function cr_items_tree_update_tr () returns opaque as '
+declare
+        v_parent_sk     varbit default null;
+        v_max_value     integer;
+        p_id            integer;
+        v_rec           record;
+        clr_keys_p      boolean default ''t'';
+begin
+        if new.item_id = old.item_id and 
+           ((new.parent_id = old.parent_id) or
+            (new.parent_id is null and old.parent_id is null)) then
+
+           return new;
+
+        end if;
+
+        for v_rec in select item_id
+                       from cr_items 
+                      where tree_sortkey between new.tree_sortkey and tree_right(new.tree_sortkey)
+                   order by tree_sortkey
+        LOOP
+            if clr_keys_p then
+               update cr_items set tree_sortkey = null
+               where tree_sortkey between new.tree_sortkey and tree_right(new.tree_sortkey);
+               clr_keys_p := ''f'';
+            end if;
+            
+            -- Lars: If the parent is not a cr_item, we treat it as if it was null.
+            select parent.item_id 
+              into p_id
+              from cr_items parent, 
+                   cr_items child
+             where child.item_id = v_rec.item_id
+             and   parent.item_id = child.parent_id;
+
+            if p_id is null then 
+
+                -- Lars: Treat all items with a non-cr_item parent as one big pool wrt tree_sortkeys
+                -- The old algorithm had tree_sortkeys start from zero for each different parent
+
+                select max(tree_leaf_key_to_int(tree_sortkey)) into v_max_value
+                  from cr_items child
+                 where not exists (select 1 from cr_items where child.parent_id = item_id);
+            else 
+                select max(tree_leaf_key_to_int(tree_sortkey)) into v_max_value
+                  from cr_items 
+                 where parent_id = p_id;
+
+                select tree_sortkey into v_parent_sk 
+                  from cr_items 
+                 where item_id = p_id;
+            end if;
+
+            update cr_items 
+               set tree_sortkey = tree_next_key(v_parent_sk, v_max_value)
+             where item_id = v_rec.item_id;
+
+        end LOOP;
+
+        return new;
+
+end;' language 'plpgsql';
+
+create trigger cr_items_tree_update_tr after update 
+on cr_items
+for each row 
+execute procedure cr_items_tree_update_tr ();