From 1a5394f4afdf2eeadd91b5b0ff5ad199c9dc93b0 Mon Sep 17 00:00:00 2001
From: Aaron Patterson <aaron.patterson@gmail.com>
Date: Tue, 2 Jul 2013 15:44:58 -0700
Subject: lock around mutating the generated methods module

---
 activerecord/lib/active_record/attribute_methods.rb | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/activerecord/lib/active_record/attribute_methods.rb b/activerecord/lib/active_record/attribute_methods.rb
index ff93640814..5e990955ab 100644
--- a/activerecord/lib/active_record/attribute_methods.rb
+++ b/activerecord/lib/active_record/attribute_methods.rb
@@ -46,8 +46,10 @@ module ActiveRecord
       end
 
       def undefine_attribute_methods # :nodoc:
-        super if @attribute_methods_generated
-        @attribute_methods_generated = false
+        generated_attribute_methods.synchronize do
+          super if @attribute_methods_generated
+          @attribute_methods_generated = false
+        end
       end
 
       # Raises a <tt>ActiveRecord::DangerousAttributeError</tt> exception when an
-- 
cgit v1.2.3