From e5f10b79578148500cf6139615f5a99a86aa4620 Mon Sep 17 00:00:00 2001
From: Eugene Pimenov <eugene@libc.st>
Date: Thu, 9 Feb 2012 11:40:37 +0100
Subject: [PATCH] Rails 2.2 and 2.3 does not have ActiveSupport::Concern.

---
 .../migration/multi_db_migrations.rb            | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/lib/db_charmer/active_record/migration/multi_db_migrations.rb b/lib/db_charmer/active_record/migration/multi_db_migrations.rb
index cf184ec..c0a6969 100644
--- a/lib/db_charmer/active_record/migration/multi_db_migrations.rb
+++ b/lib/db_charmer/active_record/migration/multi_db_migrations.rb
@@ -2,14 +2,19 @@ module DbCharmer
   module ActiveRecord
     module Migration
       module MultiDbMigrations
-        extend ActiveSupport::Concern
 
-        included do
-          if DbCharmer.rails31?
-            alias_method_chain :migrate, :db_wrapper
-          else
-            class << self
+        def self.append_features(base)
+          return false if base < self
+          super
+          base.extend const_get("ClassMethods") if const_defined?("ClassMethods")
+
+          base.class_eval do
+            if DbCharmer.rails31?
               alias_method_chain :migrate, :db_wrapper
+            else
+              class << self
+                alias_method_chain :migrate, :db_wrapper
+              end
             end
           end
         end