Support configuration on ActiveRecord::Model.

The problem: We need to be able to specify configuration in a way that
can be inherited to models that include ActiveRecord::Model. So it is
no longer sufficient to put 'top level' config on ActiveRecord::Base,
but we do want configuration specified on ActiveRecord::Base and
descendants to continue to work.

So we need something like class_attribute that can be defined on a
module but that is inherited when ActiveRecord::Model is included.

The solution: added ActiveModel::Configuration module which provides a
config_attribute macro. It's a bit specific hence I am not putting this
in Active Support or making it a 'public API' at present.

19 files changed, 190 insertions, 181 deletions

diff --git a/activerecord/lib/active_record.rb b/activerecord/lib/active_record.rb
index 4d143146d5..360b1218e6 100644
--- a/activerecord/lib/active_record.rb
+++ b/activerecord/lib/active_record.rb
@@ -57,7 +57,6 @@ module ActiveRecord
 
     autoload :Base
     autoload :Callbacks
-    autoload :Configuration
     autoload :Core
     autoload :CounterCache
     autoload :DynamicMatchers
diff --git a/activerecord/lib/active_record/attribute_methods/dirty.rb b/activerecord/lib/active_record/attribute_methods/dirty.rb
index f61e016f46..40e4a97e73 100644
--- a/activerecord/lib/active_record/attribute_methods/dirty.rb
+++ b/activerecord/lib/active_record/attribute_methods/dirty.rb
@@ -13,7 +13,7 @@ module ActiveRecord
           raise "You cannot include Dirty after Timestamp"
         end
 
-        class_attribute :partial_updates
+        config_attribute :partial_updates
         self.partial_updates = true
       end
 
diff --git a/activerecord/lib/active_record/attribute_methods/read.rb b/activerecord/lib/active_record/attribute_methods/read.rb
index 7d2d1db4b5..964c4123ef 100644
--- a/activerecord/lib/active_record/attribute_methods/read.rb
+++ b/activerecord/lib/active_record/attribute_methods/read.rb
@@ -5,7 +5,10 @@ module ActiveRecord
 
       ATTRIBUTE_TYPES_CACHED_BY_DEFAULT = [:datetime, :timestamp, :time, :date]
 
-      Configuration.define :attribute_types_cached_by_default, ATTRIBUTE_TYPES_CACHED_BY_DEFAULT
+      included do
+        config_attribute :attribute_types_cached_by_default, :global => true
+        self.attribute_types_cached_by_default = ATTRIBUTE_TYPES_CACHED_BY_DEFAULT
+      end
 
       module ClassMethods
         # +cache_attributes+ allows you to declare which converted attribute values should
diff --git a/activerecord/lib/active_record/attribute_methods/serialization.rb b/activerecord/lib/active_record/attribute_methods/serialization.rb
index 2ffd91f796..0c8e4e4b9a 100644
--- a/activerecord/lib/active_record/attribute_methods/serialization.rb
+++ b/activerecord/lib/active_record/attribute_methods/serialization.rb
@@ -6,7 +6,7 @@ module ActiveRecord
       included do
         # 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
+        config_attribute :serialized_attributes
         self.serialized_attributes = {}
       end
 
diff --git a/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb b/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
index 5e5392441b..2f86e32f41 100644
--- a/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
+++ b/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
@@ -6,10 +6,11 @@ module ActiveRecord
     module TimeZoneConversion
       extend ActiveSupport::Concern
 
-      Configuration.define :time_zone_aware_attributes, false
-
       included do
-        class_attribute :skip_time_zone_conversion_for_attributes, :instance_writer => false
+        config_attribute :time_zone_aware_attributes, :global => true
+        self.time_zone_aware_attributes = false
+
+        config_attribute :skip_time_zone_conversion_for_attributes
         self.skip_time_zone_conversion_for_attributes = []
       end
 
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index 6085df7d9f..fbdb50f6b3 100644
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -328,7 +328,6 @@ module ActiveRecord #:nodoc:
   # instances in the current object space.
   class Base
     include ActiveRecord::Model
-    self.connection_handler = ConnectionAdapters::ConnectionHandler.new
   end
 end
 
diff --git a/activerecord/lib/active_record/callbacks.rb b/activerecord/lib/active_record/callbacks.rb
index a175bf003c..8b2fc69b00 100644
--- a/activerecord/lib/active_record/callbacks.rb
+++ b/activerecord/lib/active_record/callbacks.rb
@@ -25,7 +25,7 @@ module ActiveRecord
   # Check out <tt>ActiveRecord::Transactions</tt> for more details about <tt>after_commit</tt> and
   # <tt>after_rollback</tt>.
   #
-  # Lastly an <tt>after_find</tt> and <tt>after_initialize</tt> callback is triggered for each object that 
+  # Lastly an <tt>after_find</tt> and <tt>after_initialize</tt> callback is triggered for each object that
   # is found and instantiated by a finder, with <tt>after_initialize</tt> being triggered after new objects
   # are instantiated as well.
   #
@@ -215,24 +215,48 @@ module ActiveRecord
   # instead of quietly returning +false+.
   #
   # == Debugging callbacks
-  # 
-  # The callback chain is accessible via the <tt>_*_callbacks</tt> method on an object. ActiveModel Callbacks support 
+  #
+  # The callback chain is accessible via the <tt>_*_callbacks</tt> method on an object. ActiveModel Callbacks support
   # <tt>:before</tt>, <tt>:after</tt> and <tt>:around</tt> as values for the <tt>kind</tt> property. The <tt>kind</tt> property
   # defines what part of the chain the callback runs in.
-  # 
-  # To find all callbacks in the before_save callback chain: 
-  # 
+  #
+  # To find all callbacks in the before_save callback chain:
+  #
   #   Topic._save_callbacks.select { |cb| cb.kind.eql?(:before) }
-  # 
+  #
   # Returns an array of callback objects that form the before_save chain.
-  # 
+  #
   # To further check if the before_save chain contains a proc defined as <tt>rest_when_dead</tt> use the <tt>filter</tt> property of the callback object:
-  # 
+  #
   #   Topic._save_callbacks.select { |cb| cb.kind.eql?(:before) }.collect(&:filter).include?(:rest_when_dead)
-  # 
+  #
   # Returns true or false depending on whether the proc is contained in the before_save callback chain on a Topic model.
-  # 
+  #
   module Callbacks
+    # We can't define callbacks directly on ActiveRecord::Model because
+    # it is a module. So we queue up the definitions and execute them
+    # when ActiveRecord::Model is included.
+    module Register #:nodoc:
+      def self.extended(base)
+        base.config_attribute :_callbacks_register
+        base._callbacks_register = []
+      end
+
+      def self.setup(base)
+        base._callbacks_register.each do |item|
+          base.send(*item)
+        end
+      end
+
+      def define_callbacks(*args)
+        self._callbacks_register << [:define_callbacks, *args]
+      end
+
+      def define_model_callbacks(*args)
+        self._callbacks_register << [:define_model_callbacks, *args]
+      end
+    end
+
     extend ActiveSupport::Concern
 
     CALLBACKS = [
@@ -242,8 +266,11 @@ module ActiveRecord
       :before_destroy, :around_destroy, :after_destroy, :after_commit, :after_rollback
     ]
 
+    module ClassMethods
+      include ActiveModel::Callbacks
+    end
+
     included do
-      extend ActiveModel::Callbacks
       include ActiveModel::Validations::Callbacks
 
       define_model_callbacks :initialize, :find, :touch, :only => :after
diff --git a/activerecord/lib/active_record/configuration.rb b/activerecord/lib/active_record/configuration.rb
deleted file mode 100644
index d58ed82258..0000000000
--- a/activerecord/lib/active_record/configuration.rb
+++ /dev/null
@@ -1,36 +0,0 @@
-require 'active_support/concern'
-
-module ActiveRecord
-  # This module allows configuration options to be specified in a way such that
-  # ActiveRecord::Base and ActiveRecord::Model will have access to the same value,
-  # and will automatically get the appropriate readers and writers defined.
-  #
-  # In the future, we should probably move away from defining global config
-  # directly on ActiveRecord::Base / ActiveRecord::Model.
-  module Configuration #:nodoc:
-    extend ActiveSupport::Concern
-
-    module ClassMethods
-    end
-
-    def self.define(name, default = nil)
-      singleton_class.send(:attr_accessor, name)
-
-      [self, ClassMethods].each do |klass|
-        klass.class_eval <<-CODE, __FILE__, __LINE__
-          def #{name}
-            ActiveRecord::Configuration.#{name}
-          end
-        CODE
-      end
-
-      ClassMethods.class_eval <<-CODE, __FILE__, __LINE__
-        def #{name}=(val)
-          ActiveRecord::Configuration.#{name} = val
-        end
-      CODE
-
-      send("#{name}=", default) unless default.nil?
-    end
-  end
-end
diff --git a/activerecord/lib/active_record/core.rb b/activerecord/lib/active_record/core.rb
index 4f118e46a9..c29a0032bc 100644
--- a/activerecord/lib/active_record/core.rb
+++ b/activerecord/lib/active_record/core.rb
@@ -4,70 +4,75 @@ module ActiveRecord
   module Core
     extend ActiveSupport::Concern
 
-    ##
-    # :singleton-method:
-    # Accepts a logger conforming to the interface of Log4r or the default Ruby 1.8+ Logger class,
-    # which is then passed on to any new database connections made and which can be retrieved on both
-    # a class and instance level by calling +logger+.
-    Configuration.define :logger
-
-    ##
-    # :singleton-method:
-    # Contains the database configuration - as is typically stored in config/database.yml -
-    # as a Hash.
-    #
-    # For example, the following database.yml...
-    #
-    #   development:
-    #     adapter: sqlite3
-    #     database: db/development.sqlite3
-    #
-    #   production:
-    #     adapter: sqlite3
-    #     database: db/production.sqlite3
-    #
-    # ...would result in ActiveRecord::Base.configurations to look like this:
-    #
-    #   {
-    #      'development' => {
-    #         'adapter'  => 'sqlite3',
-    #         'database' => 'db/development.sqlite3'
-    #      },
-    #      'production' => {
-    #         'adapter'  => 'sqlite3',
-    #         'database' => 'db/production.sqlite3'
-    #      }
-    #   }
-    Configuration.define :configurations, {}
-
-    ##
-    # :singleton-method:
-    # Determines whether to use Time.local (using :local) or Time.utc (using :utc) when pulling
-    # dates and times from the database. This is set to :local by default.
-    Configuration.define :default_timezone, :local
-
-    ##
-    # :singleton-method:
-    # Specifies the format to use when dumping the database schema with Rails'
-    # Rakefile. If :sql, the schema is dumped as (potentially database-
-    # specific) SQL statements. If :ruby, the schema is dumped as an
-    # ActiveRecord::Schema file which can be loaded into any database that
-    # supports migrations. Use :ruby if you want to have different database
-    # adapters for, e.g., your development and test environments.
-    Configuration.define :schema_format, :ruby
-
-    ##
-    # :singleton-method:
-    # Specify whether or not to use timestamps for migration versions
-    Configuration.define :timestamped_migrations, true
-
     included do
       ##
       # :singleton-method:
+      # Accepts a logger conforming to the interface of Log4r or the default Ruby 1.8+ Logger class,
+      # which is then passed on to any new database connections made and which can be retrieved on both
+      # a class and instance level by calling +logger+.
+      config_attribute :logger, :global => true
+
+      ##
+      # :singleton-method:
+      # Contains the database configuration - as is typically stored in config/database.yml -
+      # as a Hash.
+      #
+      # For example, the following database.yml...
+      #
+      #   development:
+      #     adapter: sqlite3
+      #     database: db/development.sqlite3
+      #
+      #   production:
+      #     adapter: sqlite3
+      #     database: db/production.sqlite3
+      #
+      # ...would result in ActiveRecord::Base.configurations to look like this:
+      #
+      #   {
+      #      'development' => {
+      #         'adapter'  => 'sqlite3',
+      #         'database' => 'db/development.sqlite3'
+      #      },
+      #      'production' => {
+      #         'adapter'  => 'sqlite3',
+      #         'database' => 'db/production.sqlite3'
+      #      }
+      #   }
+      config_attribute :configurations, :global => true
+      self.configurations = {}
+
+      ##
+      # :singleton-method:
+      # Determines whether to use Time.local (using :local) or Time.utc (using :utc) when pulling
+      # dates and times from the database. This is set to :local by default.
+      config_attribute :default_timezone, :global => true
+      self.default_timezone = :local
+
+      ##
+      # :singleton-method:
+      # Specifies the format to use when dumping the database schema with Rails'
+      # Rakefile. If :sql, the schema is dumped as (potentially database-
+      # specific) SQL statements. If :ruby, the schema is dumped as an
+      # ActiveRecord::Schema file which can be loaded into any database that
+      # supports migrations. Use :ruby if you want to have different database
+      # adapters for, e.g., your development and test environments.
+      config_attribute :schema_format, :global => true
+      self.schema_format = :ruby
+
+      ##
+      # :singleton-method:
+      # Specify whether or not to use timestamps for migration versions
+      config_attribute :timestamped_migrations, :global => true
+      self.timestamped_migrations = true
+
+      ##
+      # :singleton-method:
       # The connection handler
-      class_attribute :connection_handler, :instance_writer => false
+      config_attribute :connection_handler
+      self.connection_handler = ConnectionAdapters::ConnectionHandler.new
 
-      initialize_generated_modules unless self == Base
+      #
     end
 
     module ClassMethods
diff --git a/activerecord/lib/active_record/explain.rb b/activerecord/lib/active_record/explain.rb
index b5a67afd88..e502d7e52b 100644
--- a/activerecord/lib/active_record/explain.rb
+++ b/activerecord/lib/active_record/explain.rb
@@ -2,9 +2,11 @@ require 'active_support/core_ext/class/attribute'
 
 module ActiveRecord
   module Explain
-    # If a query takes longer than these many seconds we log its query plan
-    # automatically. nil disables this feature.
-    Configuration.define :auto_explain_threshold_in_seconds
+    def self.extended(base)
+      # If a query takes longer than these many seconds we log its query plan
+      # automatically. nil disables this feature.
+      base.config_attribute :auto_explain_threshold_in_seconds, :global => true
+    end
 
     # If auto explain is enabled, this method triggers EXPLAIN logging for the
     # queries triggered by the block if it takes more than the threshold as a
diff --git a/activerecord/lib/active_record/inheritance.rb b/activerecord/lib/active_record/inheritance.rb
index ec57151d40..0e92b7cf41 100644
--- a/activerecord/lib/active_record/inheritance.rb
+++ b/activerecord/lib/active_record/inheritance.rb
@@ -6,7 +6,7 @@ module ActiveRecord
 
     included do
       # Determine whether to store the full constant name including namespace when using STI
-      class_attribute :store_full_sti_class
+      config_attribute :store_full_sti_class
       self.store_full_sti_class = true
     end
 
@@ -88,7 +88,7 @@ module ActiveRecord
       #
       # Mainly for internal use.
       def active_record_super #:nodoc:
-        if self == Base || superclass && superclass < Model::Tag
+        if self == Base || superclass && superclass < Model
           superclass
         else
           Base
@@ -100,7 +100,7 @@ module ActiveRecord
       # Returns the class descending directly from ActiveRecord::Base or an
       # abstract class, if any, in the inheritance hierarchy.
       def class_of_active_record_descendant(klass)
-        unless klass < Model::Tag
+        unless klass < Model
           raise ActiveRecordError, "#{name} doesn't belong in a hierarchy descending from ActiveRecord"
         end
 
diff --git a/activerecord/lib/active_record/locking/optimistic.rb b/activerecord/lib/active_record/locking/optimistic.rb
index b80d01db81..e643c0d437 100644
--- a/activerecord/lib/active_record/locking/optimistic.rb
+++ b/activerecord/lib/active_record/locking/optimistic.rb
@@ -48,7 +48,10 @@ module ActiveRecord
     module Optimistic
       extend ActiveSupport::Concern
 
-      Configuration.define :lock_optimistically, true
+      included do
+        config_attribute :lock_optimistically, :global => true
+        self.lock_optimistically = true
+      end
 
       def locking_enabled? #:nodoc:
         self.class.locking_enabled?
diff --git a/activerecord/lib/active_record/model.rb b/activerecord/lib/active_record/model.rb
index f87be257db..86c4d18534 100644
--- a/activerecord/lib/active_record/model.rb
+++ b/activerecord/lib/active_record/model.rb
@@ -1,4 +1,5 @@
 require 'active_support/deprecation'
+require 'active_support/concern'
 
 module ActiveRecord
   # <tt>ActiveRecord::Model</tt> can be included into a class to add Active Record persistence.
@@ -9,57 +10,61 @@ module ActiveRecord
   #     end
   #
   module Model
-    # So we can recognise an AR class even while self.included is being
-    # executed. (At that time, klass < Model == false.)
-    module Tag #:nodoc:
+    module ClassMethods #:nodoc:
+      include ActiveSupport::Callbacks::ClassMethods
+      include ActiveModel::Naming
+      include QueryCache::ClassMethods
+      include ActiveSupport::Benchmarkable
+      include ActiveSupport::DescendantsTracker
+
+      include Querying
+      include Translation
+      include DynamicMatchers
+      include CounterCache
+      include Explain
     end
 
     def self.included(base)
-      return if base < Tag
+      return if base.singleton_class < ClassMethods
 
       base.class_eval do
-        include Tag
-
-        include Configuration
-
-        include ActiveRecord::Persistence
-        extend ActiveModel::Naming
-        extend QueryCache::ClassMethods
-        extend ActiveSupport::Benchmarkable
-        extend ActiveSupport::DescendantsTracker
-
-        extend Querying
-        include ReadonlyAttributes
-        include ModelSchema
-        extend Translation
-        include Inheritance
-        include Scoping
-        extend DynamicMatchers
-        include Sanitization
-        include Integration
-        include AttributeAssignment
-        include ActiveModel::Conversion
-        include Validations
-        extend CounterCache
-        include Locking::Optimistic, Locking::Pessimistic
-        include AttributeMethods
-        include Callbacks, ActiveModel::Observing, Timestamp
-        include Associations
-        include IdentityMap
-        include ActiveModel::SecurePassword
-        extend Explain
-
-        # AutosaveAssociation needs to be included before Transactions, because we want
-        # #save_with_autosave_associations to be wrapped inside a transaction.
-        include AutosaveAssociation, NestedAttributes
-        include Aggregations, Transactions, Reflection, Serialization, Store
+        extend ClassMethods
+        Callbacks::Register.setup(self)
+        initialize_generated_modules unless self == Base
+      end
+    end
 
-        include Core
+    extend ActiveModel::Configuration
+    extend ActiveModel::Callbacks
+    extend ActiveModel::MassAssignmentSecurity::ClassMethods
+    extend ActiveModel::AttributeMethods::ClassMethods
+    extend Callbacks::Register
+    extend Explain
 
-        self.connection_handler = Base.connection_handler
-      end
+    def self.extend(*modules)
+      ClassMethods.send(:include, *modules)
     end
 
+    include Persistence
+    include ReadonlyAttributes
+    include ModelSchema
+    include Inheritance
+    include Scoping
+    include Sanitization
+    include Integration
+    include AttributeAssignment
+    include ActiveModel::Conversion
+    include Validations
+    include Locking::Optimistic, Locking::Pessimistic
+    include AttributeMethods
+    include Callbacks, ActiveModel::Observing, Timestamp
+    include Associations
+    include IdentityMap
+    include ActiveModel::SecurePassword
+    include AutosaveAssociation, NestedAttributes
+    include Aggregations, Transactions, Reflection, Serialization, Store
+    include Core
+
     module DeprecationProxy #:nodoc:
       class << self
         instance_methods.each { |m| undef_method m unless m =~ /^__|^object_id$|^instance_eval$/ }
diff --git a/activerecord/lib/active_record/model_schema.rb b/activerecord/lib/active_record/model_schema.rb
index adf85c6436..d9d18a9752 100644
--- a/activerecord/lib/active_record/model_schema.rb
+++ b/activerecord/lib/active_record/model_schema.rb
@@ -5,18 +5,18 @@ module ActiveRecord
   module ModelSchema
     extend ActiveSupport::Concern
 
-    ##
-    # :singleton-method:
-    # Accessor for the prefix type that will be prepended to every primary key column name.
-    # The options are :table_name and :table_name_with_underscore. If the first is specified,
-    # the Product class will look for "productid" instead of "id" as the primary column. If the
-    # latter is specified, the Product class will look for "product_id" instead of "id". Remember
-    # that this is a global setting for all Active Records.
-    Configuration.define :primary_key_prefix_type
-
     included do
       ##
       # :singleton-method:
+      # Accessor for the prefix type that will be prepended to every primary key column name.
+      # The options are :table_name and :table_name_with_underscore. If the first is specified,
+      # the Product class will look for "productid" instead of "id" as the primary column. If the
+      # latter is specified, the Product class will look for "product_id" instead of "id". Remember
+      # that this is a global setting for all Active Records.
+      config_attribute :primary_key_prefix_type, :global => true
+
+      ##
+      # :singleton-method:
       # Accessor for the name of the prefix string to prepend to every table name. So if set
       # to "basecamp_", all table names will be named like "basecamp_projects", "basecamp_people",
       # etc. This is a convenient way of creating a namespace for tables in a shared database.
@@ -25,14 +25,14 @@ module ActiveRecord
       # If you are organising your models within modules you can add a prefix to the models within
       # a namespace by defining a singleton method in the parent module called table_name_prefix which
       # returns your chosen prefix.
-      class_attribute :table_name_prefix, :instance_writer => false
+      config_attribute :table_name_prefix
       self.table_name_prefix = ""
 
       ##
       # :singleton-method:
       # Works like +table_name_prefix+, but appends instead of prepends (set to "_basecamp" gives "projects_basecamp",
       # "people_basecamp"). By default, the suffix is the empty string.
-      class_attribute :table_name_suffix, :instance_writer => false
+      config_attribute :table_name_suffix
       self.table_name_suffix = ""
 
       ##
@@ -40,7 +40,7 @@ module ActiveRecord
       # Indicates whether table names should be the pluralized versions of the corresponding class names.
       # If true, the default table name for a Product class will be +products+. If false, it would just be +product+.
       # See table_name for the full rules on table/class naming. This is true, by default.
-      class_attribute :pluralize_table_names, :instance_writer => false
+      config_attribute :pluralize_table_names
       self.pluralize_table_names = true
     end
 
diff --git a/activerecord/lib/active_record/nested_attributes.rb b/activerecord/lib/active_record/nested_attributes.rb
index d2065d701f..a8ee43b598 100644
--- a/activerecord/lib/active_record/nested_attributes.rb
+++ b/activerecord/lib/active_record/nested_attributes.rb
@@ -12,7 +12,7 @@ module ActiveRecord
     extend ActiveSupport::Concern
 
     included do
-      class_attribute :nested_attributes_options, :instance_writer => false
+      config_attribute :nested_attributes_options
       self.nested_attributes_options = {}
     end
 
diff --git a/activerecord/lib/active_record/readonly_attributes.rb b/activerecord/lib/active_record/readonly_attributes.rb
index bf37ab5f14..836b15e2ce 100644
--- a/activerecord/lib/active_record/readonly_attributes.rb
+++ b/activerecord/lib/active_record/readonly_attributes.rb
@@ -6,7 +6,7 @@ module ActiveRecord
     extend ActiveSupport::Concern
 
     included do
-      class_attribute :_attr_readonly, :instance_writer => false
+      config_attribute :_attr_readonly
       self._attr_readonly = []
     end
 
diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb
index 794a0526fb..60b73e9fe5 100644
--- a/activerecord/lib/active_record/reflection.rb
+++ b/activerecord/lib/active_record/reflection.rb
@@ -7,7 +7,8 @@ module ActiveRecord
     extend ActiveSupport::Concern
 
     included do
-      class_attribute :reflections
+      extend ActiveModel::Configuration
+      config_attribute :reflections
       self.reflections = {}
     end
 
diff --git a/activerecord/lib/active_record/scoping/default.rb b/activerecord/lib/active_record/scoping/default.rb
index 6b5070808a..5f05d146f2 100644
--- a/activerecord/lib/active_record/scoping/default.rb
+++ b/activerecord/lib/active_record/scoping/default.rb
@@ -7,7 +7,7 @@ module ActiveRecord
 
       included do
         # Stores the default scope for the class
-        class_attribute :default_scopes, :instance_writer => false
+        config_attribute :default_scopes
         self.default_scopes = []
       end
 
diff --git a/activerecord/lib/active_record/timestamp.rb b/activerecord/lib/active_record/timestamp.rb
index 0c760e9850..c717fdea47 100644
--- a/activerecord/lib/active_record/timestamp.rb
+++ b/activerecord/lib/active_record/timestamp.rb
@@ -33,7 +33,7 @@ module ActiveRecord
     extend ActiveSupport::Concern
 
     included do
-      class_attribute :record_timestamps
+      config_attribute :record_timestamps, :instance_writer => true
       self.record_timestamps = true
     end