fixes #1109

app/models/pool.rb

@@ -141,6 +141,7 @@ class Pool < ActiveRecord::Base
 
   def add!(post)
     return if contains?(post.id)
+    return if is_deleted?
 
     update_attributes(:post_ids => add_number_to_string(post.id, post_ids), :post_count => post_count + 1)
     post.add_pool!(self)
@@ -149,6 +150,7 @@ class Pool < ActiveRecord::Base
 
   def remove!(post)
     return unless contains?(post.id)
+    return if is_deleted?
 
     update_attributes(:post_ids => remove_number_from_string(post.id, post_ids), :post_count => post_count - 1)
     post.remove_pool!(self)

app/models/post.rb

@@ -553,6 +553,7 @@ class Post < ActiveRecord::Base
 
     def add_pool!(pool)
       return if belongs_to_pool?(pool)
+      return if pool.is_deleted?
       self.pool_string = "#{pool_string} pool:#{pool.id}".strip
       update_column(:pool_string, pool_string) unless new_record?
       pool.add!(self)
@@ -560,6 +561,7 @@ class Post < ActiveRecord::Base
 
     def remove_pool!(pool)
       return unless belongs_to_pool?(pool)
+      return if pool.is_deleted?
       self.pool_string = pool_string.gsub(/(?:\A| )pool:#{pool.id}(?:\Z| )/, " ").strip
       update_column(:pool_string, pool_string) unless new_record?
       pool.remove!(self)