fixed edge case for pool creation

app/models/post.rb

@@ -440,7 +440,7 @@ class Post < ActiveRecord::Base
           if pool.nil?
             pool = Pool.create(:name => $1, :description => "This pool was automatically generated")
           end
-          add_pool!(pool)
+          add_pool!(pool) if pool
 
         when /^rating:([qse])/i
           self.rating = $1.downcase

app/models/tag_implication.rb

@@ -28,7 +28,7 @@ class TagImplication < ActiveRecord::Base
             all.concat(children)
             children = self.class.where(["antecedent_name IN (?)", children]).all.map(&:consequent_name)
           end
-        end.sort
+        end.sort.uniq
       end
     end