FIX: You shouldn't be able to add a parent to Uncategorized

db/migrate/20140715190552_remove_uncategorized_parents.rb

@@ -0,0 +1,11 @@
+class RemoveUncategorizedParents < ActiveRecord::Migration
+  def up
+    uncat = execute("SELECT value FROM site_settings WHERE name = 'uncategorized_category_id'")
+    if uncat && uncat[0] && uncat[0]['value']
+      execute "UPDATE categories SET parent_category_id = NULL where id = #{uncat[0]['value'].to_i}"
+    end
+  end
+
+  def down
+  end
+end