Index: openacs-4/packages/file-storage/tcl/file-storage-procs-postgresql.xql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/file-storage/tcl/file-storage-procs-postgresql.xql,v
diff -u -r1.47 -r1.48
--- openacs-4/packages/file-storage/tcl/file-storage-procs-postgresql.xql	7 Aug 2017 23:48:11 -0000	1.47
+++ openacs-4/packages/file-storage/tcl/file-storage-procs-postgresql.xql	15 Sep 2017 20:03:12 -0000	1.48
@@ -223,17 +223,14 @@
 
   <fullquery name="fs::get_folder_package_and_root.select_package_and_root">
     <querytext>
-      select r.package_id,
-             r.folder_id as root_folder_id
-      from fs_root_folders r,
-           (select parent.item_id as folder_id
-            from cr_items parent,
-                 cr_items children
-            where children.item_id = :folder_id
-              and children.tree_sortkey
-                between parent.tree_sortkey
-                and tree_right(parent.tree_sortkey)) t
-      where r.folder_id = t.folder_id
+      With RECURSIVE items AS (
+        select cr.item_id from cr_items cr where cr.item_id = :folder_id
+      UNION ALL
+        select cr.parent_id from cr_items cr, items where items.item_id = cr.item_id
+      )
+      select r.package_id, r.folder_id as root_folder_id
+      from   items i, fs_root_folders r
+      where  r.folder_id = i.item_id
     </querytext>
   </fullquery>