Support for subforums (#3831).

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@10142 e93f8b46-1217-0410-a6f0-8f06a7374b81

lib/plugins/acts_as_tree/lib/active_record/acts/tree.rb

@@ -74,7 +74,7 @@ module ActiveRecord
         #
         #   root.descendants # => [child1, subchild1, subchild2]
         def descendants
-          children + children.collect(&:children).flatten
+          children + children.collect(&:descendants).flatten
         end
 
         # Returns list of descendants and a reference to the current node.