Perf fix - Use an instance variable instead of a class_attribute. Thanks @josevalim and @jhawthorn for the prompting.

1 files changed, 4 insertions, 8 deletions

diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index 08cccf1da2..6a5d282973 100644
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -428,10 +428,6 @@ module ActiveRecord #:nodoc:
     class_attribute :default_scopes, :instance_writer => false
     self.default_scopes = []
 
-    # Boolean flag to prevent infinite recursion when evaluating default scopes
-    class_attribute :apply_default_scope, :instance_writer => false
-    self.apply_default_scope = true
-
     # Returns a hash of all the attributes that have been specified for serialization as
     # keys and their class restriction as values.
     class_attribute :serialized_attributes
@@ -1265,11 +1261,11 @@ MSG
           self.default_scopes = default_scopes + [scope]
         end
 
-        # The apply_default_scope flag is used to prevent an infinite recursion situation where
+        # The @ignore_default_scope flag is used to prevent an infinite recursion situation where
         # a default scope references a scope which has a default scope which references a scope...
         def build_default_scope #:nodoc:
-          return unless apply_default_scope
-          self.apply_default_scope = false
+          return if defined?(@ignore_default_scope) && @ignore_default_scope
+          @ignore_default_scope = true
 
           if method(:default_scope).owner != Base.singleton_class
             default_scope
@@ -1285,7 +1281,7 @@ MSG
             end
           end
         ensure
-          self.apply_default_scope = true
+          @ignore_default_scope = false
         end
 
         # Returns the class type of the record using the current module as a prefix. So descendants of