Remove position from an issue when it is changed from a story into a task

db/migrate/015_order_tasks_using_tree.rb

@@ -1,4 +1,4 @@
-class RemoveTaskPosition < ActiveRecord::Migration
+class OrderTasksUsingTree < ActiveRecord::Migration
   def self.up
     last_task = {}
     ActiveRecord::Base.transaction do

db/migrate/016_remove_task_position.rb

@@ -0,0 +1,13 @@
+class RemoveTaskPosition < ActiveRecord::Migration
+  def self.up
+    ActiveRecord::Base.transaction do
+      Task.find(:all, :conditions => "id <> root_id and not position is null").each do |t|
+        t.remove_from_list
+      end
+    end
+  end
+
+  def self.down
+    raise ActiveRecord::IrreversibleMigration
+  end
+end

lib/backlogs_issue_patch.rb

@@ -161,9 +161,13 @@ module Backlogs
           touched_sprint.touch_burndown
         end
 
-        if ! self.in_list? && self.is_story?
-          self.insert_at
-          self.move_to_bottom
+        if self.in_list?
+          self.remove_from_list if self.is_task?
+        else
+          if self.is_story?
+            self.insert_at
+            self.move_to_bottom
+          end
         end
       end