Merge branch 'master' of github.com:lifo/docrails

47 files changed, 862 insertions, 273 deletions

diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index 11eb47917d..a3e3051b96 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,32 @@
 *Rails 3.1.0 (unreleased)*
 
+* Migrations can be defined as reversible, meaning that the migration system
+will figure out how to reverse your migration.  To use reversible migrations,
+just define the "change" method.  For example:
+
+    class MyMigration < ActiveRecord::Migration
+      def change
+        create_table(:horses) do
+          t.column :content, :text
+          t.column :remind_at, :datetime
+        end
+      end
+    end
+
+Some things cannot be automatically reversed for you.  If you know how to
+reverse those things, you should define 'up' and 'down' in your migration.  If
+you define something in `change` that cannot be reversed, an
+IrreversibleMigration exception will be raised when going down.
+
+* Migrations should use instance methods rather than class methods:
+    class FooMigration < ActiveRecord::Migration
+      def up
+        ...
+      end
+    end
+
+  [Aaron Patterson]
+
 * has_one maintains the association with separate after_create/after_update instead
   of a single after_save. [fxn]
 
diff --git a/activerecord/lib/active_record/association_preload.rb b/activerecord/lib/active_record/association_preload.rb
index 911a5155fd..9743b1b4a7 100644
--- a/activerecord/lib/active_record/association_preload.rb
+++ b/activerecord/lib/active_record/association_preload.rb
@@ -193,13 +193,17 @@ module ActiveRecord
         conditions = "t0.#{reflection.primary_key_name} #{in_or_equals_for_ids(ids)}"
         conditions << append_conditions(reflection, preload_options)
 
-        associated_records = reflection.klass.unscoped.where([conditions, ids]).
+        associated_records_proxy = reflection.klass.unscoped.
             includes(options[:include]).
             joins("INNER JOIN #{connection.quote_table_name options[:join_table]} t0 ON #{reflection.klass.quoted_table_name}.#{reflection.klass.primary_key} = t0.#{reflection.association_foreign_key}").
             select("#{options[:select] || table_name+'.*'}, t0.#{reflection.primary_key_name} as the_parent_record_id").
-            order(options[:order]).to_a
+            order(options[:order])
 
-        set_association_collection_records(id_to_record_map, reflection.name, associated_records, 'the_parent_record_id')
+        all_associated_records = associated_records(ids) do |some_ids|
+          associated_records_proxy.where([conditions, ids]).to_a
+        end
+
+        set_association_collection_records(id_to_record_map, reflection.name, all_associated_records, 'the_parent_record_id')
       end
 
       def preload_has_one_association(records, reflection, preload_options={})
@@ -358,13 +362,14 @@ module ActiveRecord
         find_options = {
           :select => preload_options[:select] || options[:select] || Arel::SqlLiteral.new("#{table_name}.*"),
           :include => preload_options[:include] || options[:include],
-          :conditions => [conditions, ids],
           :joins => options[:joins],
           :group => preload_options[:group] || options[:group],
           :order => preload_options[:order] || options[:order]
         }
 
-        reflection.klass.scoped.apply_finder_options(find_options).to_a
+        associated_records(ids) do |some_ids|
+          reflection.klass.scoped.apply_finder_options(find_options.merge(:conditions => [conditions, some_ids])).to_a
+        end
       end
 
 
@@ -382,6 +387,17 @@ module ActiveRecord
       def in_or_equals_for_ids(ids)
         ids.size > 1 ? "IN (?)" : "= ?"
       end
+
+      # Some databases impose a limit on the number of ids in a list (in Oracle its 1000)
+      # Make several smaller queries if necessary or make one query if the adapter supports it
+      def associated_records(ids)
+        max_ids_in_a_list = connection.ids_in_list_limit || ids.size
+        records = []
+        ids.each_slice(max_ids_in_a_list) do |some_ids|
+          records += yield(some_ids)
+        end
+        records
+      end
     end
   end
 end
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index 08a4ebfd7e..7da38cd03f 100644
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -4,6 +4,7 @@ require 'active_support/core_ext/module/delegation'
 require 'active_support/core_ext/object/blank'
 require 'active_support/core_ext/string/conversions'
 require 'active_support/core_ext/module/remove_method'
+require 'active_support/core_ext/class/attribute'
 
 module ActiveRecord
   class InverseOfAssociationNotFoundError < ActiveRecordError #:nodoc:
@@ -1810,12 +1811,12 @@ module ActiveRecord
           callbacks.each do |callback_name|
             full_callback_name = "#{callback_name}_for_#{association_name}"
             defined_callbacks = options[callback_name.to_sym]
-            if options.has_key?(callback_name.to_sym)
-              class_inheritable_reader full_callback_name.to_sym
-              write_inheritable_attribute(full_callback_name.to_sym, [defined_callbacks].flatten)
-            else
-              write_inheritable_attribute(full_callback_name.to_sym, [])
-            end
+
+            full_callback_value = options.has_key?(callback_name.to_sym) ? [defined_callbacks].flatten : []
+
+            # TODO : why do i need method_defined? I think its because of the inheritance chain
+            class_attribute full_callback_name.to_sym unless method_defined?(full_callback_name)
+            self.send("#{full_callback_name}=", full_callback_value)
           end
         end
 
diff --git a/activerecord/lib/active_record/associations/association_collection.rb b/activerecord/lib/active_record/associations/association_collection.rb
index 5b34ac907c..774103342a 100644
--- a/activerecord/lib/active_record/associations/association_collection.rb
+++ b/activerecord/lib/active_record/associations/association_collection.rb
@@ -182,7 +182,7 @@ module ActiveRecord
           unless options.blank?
             raise ArgumentError, "If finder_sql/counter_sql is used then options cannot be passed"
           end
-          
+
           @reflection.klass.count_by_sql(custom_counter_sql)
         else
 
@@ -332,13 +332,10 @@ module ActiveRecord
       end
 
       def uniq(collection = self)
-        seen = Set.new
-        collection.map do |record|
-          unless seen.include?(record.id)
-            seen << record.id
-            record
-          end
-        end.compact
+        seen = {}
+        collection.find_all do |record|
+          seen[record.id] = true unless seen.key?(record.id)
+        end
       end
 
       # Replace this collection with +other_array+
@@ -375,14 +372,16 @@ module ActiveRecord
         def load_target
           if @owner.persisted? || foreign_key_present
             begin
-              if !loaded?
+              unless loaded?
                 if @target.is_a?(Array) && @target.any?
                   @target = find_target.map do |f|
                     i = @target.index(f)
                     if i
                       @target.delete_at(i).tap do |t|
                         keys = ["id"] + t.changes.keys + (f.attribute_names - t.attribute_names)
-                        t.attributes = f.attributes.except(*keys)
+                        f.attributes.except(*keys).each do |k,v|
+                          t.send("#{k}=", v)
+                        end
                       end
                     else
                       f
@@ -409,11 +408,7 @@ module ActiveRecord
           end
 
           if @target.respond_to?(method) || (!@reflection.klass.respond_to?(method) && Class.respond_to?(method))
-            if block_given?
-              super { |*block_args| yield(*block_args) }
-            else
-              super
-            end
+            super
           elsif @reflection.klass.scopes[method]
             @_named_scopes_cache ||= {}
             @_named_scopes_cache[method] ||= {}
@@ -436,10 +431,10 @@ module ActiveRecord
             # replace the SELECT clause with COUNT(*), preserving any hints within /* ... */
             counter_sql = @reflection.options[:finder_sql].sub(/SELECT\b(\/\*.*?\*\/ )?(.*)\bFROM\b/im) { "SELECT #{$1}COUNT(*) FROM" }
           end
-          
+
           interpolate_sql(counter_sql)
         end
-        
+
         def custom_finder_sql
           interpolate_sql(@reflection.options[:finder_sql])
         end
@@ -535,7 +530,7 @@ module ActiveRecord
 
         def callbacks_for(callback_name)
           full_callback_name = "#{callback_name}_for_#{@reflection.name}"
-          @owner.class.read_inheritable_attribute(full_callback_name.to_sym) || []
+          @owner.class.send(full_callback_name.to_sym) || []
         end
 
         def ensure_owner_is_not_new
diff --git a/activerecord/lib/active_record/associations/association_proxy.rb b/activerecord/lib/active_record/associations/association_proxy.rb
index 09bba213ce..7cd04a1ad5 100644
--- a/activerecord/lib/active_record/associations/association_proxy.rb
+++ b/activerecord/lib/active_record/associations/association_proxy.rb
@@ -211,12 +211,12 @@ module ActiveRecord
             :create => construct_create_scope
           }
         end
-        
+
         # Implemented by subclasses
         def construct_find_scope
           raise NotImplementedError
         end
-        
+
         # Implemented by (some) subclasses
         def construct_create_scope
           {}
diff --git a/activerecord/lib/active_record/attribute_methods/dirty.rb b/activerecord/lib/active_record/attribute_methods/dirty.rb
index 439880c1fa..c19a33faa8 100644
--- a/activerecord/lib/active_record/attribute_methods/dirty.rb
+++ b/activerecord/lib/active_record/attribute_methods/dirty.rb
@@ -1,3 +1,4 @@
+require 'active_support/core_ext/class/attribute'
 require 'active_support/core_ext/object/blank'
 
 module ActiveRecord
@@ -88,7 +89,7 @@ module ActiveRecord
       end
 
       def clone_with_time_zone_conversion_attribute?(attr, old)
-        old.class.name == "Time" && time_zone_aware_attributes && !skip_time_zone_conversion_for_attributes.include?(attr.to_sym)
+        old.class.name == "Time" && time_zone_aware_attributes && !self.skip_time_zone_conversion_for_attributes.include?(attr.to_sym)
       end
     end
   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 d640b26b74..dc2785b6bf 100644
--- a/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
+++ b/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
@@ -1,3 +1,5 @@
+require 'active_support/core_ext/class/attribute'
+
 module ActiveRecord
   module AttributeMethods
     module TimeZoneConversion
@@ -7,7 +9,7 @@ module ActiveRecord
         cattr_accessor :time_zone_aware_attributes, :instance_writer => false
         self.time_zone_aware_attributes = false
 
-        class_inheritable_accessor :skip_time_zone_conversion_for_attributes, :instance_writer => false
+        class_attribute :skip_time_zone_conversion_for_attributes, :instance_writer => false
         self.skip_time_zone_conversion_for_attributes = []
       end
 
@@ -54,7 +56,7 @@ module ActiveRecord
 
         private
           def create_time_zone_conversion_attribute?(name, column)
-            time_zone_aware_attributes && !skip_time_zone_conversion_for_attributes.include?(name.to_sym) && [:datetime, :timestamp].include?(column.type)
+            time_zone_aware_attributes && !self.skip_time_zone_conversion_for_attributes.include?(name.to_sym) && [:datetime, :timestamp].include?(column.type)
           end
       end
     end
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index f588475bbf..aee6f3a7eb 100644
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -7,7 +7,7 @@ require 'active_support/time'
 require 'active_support/core_ext/class/attribute'
 require 'active_support/core_ext/class/attribute_accessors'
 require 'active_support/core_ext/class/delegating_attributes'
-require 'active_support/core_ext/class/inheritable_attributes'
+require 'active_support/core_ext/class/attribute'
 require 'active_support/core_ext/array/extract_options'
 require 'active_support/core_ext/hash/deep_merge'
 require 'active_support/core_ext/hash/indifferent_access'
@@ -412,7 +412,7 @@ module ActiveRecord #:nodoc:
     self.store_full_sti_class = true
 
     # Stores the default scope for the class
-    class_inheritable_accessor :default_scoping, :instance_writer => false
+    class_attribute :default_scoping, :instance_writer => false
     self.default_scoping = []
 
     # Returns a hash of all the attributes that have been specified for serialization as
@@ -420,6 +420,9 @@ module ActiveRecord #:nodoc:
     class_attribute :serialized_attributes
     self.serialized_attributes = {}
 
+    class_attribute :_attr_readonly, :instance_writer => false
+    self._attr_readonly = []
+
     class << self # Class methods
       delegate :find, :first, :last, :all, :destroy, :destroy_all, :exists?, :delete, :delete_all, :update, :update_all, :to => :scoped
       delegate :find_each, :find_in_batches, :to => :scoped
@@ -504,12 +507,12 @@ module ActiveRecord #:nodoc:
       # Attributes listed as readonly will be used to create a new record but update operations will
       # ignore these fields.
       def attr_readonly(*attributes)
-        write_inheritable_attribute(:attr_readonly, Set.new(attributes.map { |a| a.to_s }) + (readonly_attributes || []))
+        self._attr_readonly = Set.new(attributes.map { |a| a.to_s }) + (self._attr_readonly || [])
       end
 
       # Returns an array of all the attributes that have been specified as readonly.
       def readonly_attributes
-        read_inheritable_attribute(:attr_readonly) || []
+        self._attr_readonly
       end
 
       # If you have an attribute that needs to be saved to the database as an object, and retrieved as the same object,
@@ -724,10 +727,6 @@ module ActiveRecord #:nodoc:
         @arel_engine = @relation = @arel_table = nil
       end
 
-      def reset_column_information_and_inheritable_attributes_for_all_subclasses#:nodoc:
-        descendants.each { |klass| klass.reset_inheritable_attributes; klass.reset_column_information }
-      end
-
       def attribute_method?(attribute)
         super || (table_exists? && column_names.include?(attribute.to_s.sub(/=$/, '')))
       end
@@ -736,15 +735,12 @@ module ActiveRecord #:nodoc:
       def lookup_ancestors #:nodoc:
         klass = self
         classes = [klass]
+        return classes if klass == ActiveRecord::Base
+
         while klass != klass.base_class
           classes << klass = klass.superclass
         end
         classes
-      rescue
-        # OPTIMIZE this rescue is to fix this test: ./test/cases/reflection_test.rb:56:in `test_human_name_for_column'
-        # Apparently the method base_class causes some trouble.
-        # It now works for sure.
-        [self]
       end
 
       # Set the i18n scope to overwrite ActiveModel.
@@ -1129,7 +1125,8 @@ MSG
         #   Article.create.published # => true
         def default_scope(options = {})
           reset_scoped_methods
-          self.default_scoping << construct_finder_arel(options, default_scoping.pop)
+          default_scoping = self.default_scoping.dup
+          self.default_scoping = default_scoping << construct_finder_arel(options, default_scoping.pop)
         end
 
         def current_scoped_methods #:nodoc:
@@ -1286,7 +1283,7 @@ MSG
         #   ["name='%s' and group_id='%s'", "foo'bar", 4]  returns  "name='foo''bar' and group_id='4'"
         def sanitize_sql_array(ary)
           statement, *values = ary
-          if values.first.is_a?(Hash) and statement =~ /:\w+/
+          if values.first.is_a?(Hash) && statement =~ /:\w+/
             replace_named_bind_variables(statement, values.first)
           elsif statement.include?('?')
             replace_bind_variables(statement, values)
@@ -1582,12 +1579,20 @@ MSG
         self.class.columns_hash[name.to_s]
       end
 
-      # Returns true if the +comparison_object+ is the same object, or is of the same type and has the same id.
+      # Returns true if +comparison_object+ is the same exact object, or +comparison_object+
+      # is of the same type and +self+ has an ID and it is equal to +comparison_object.id+.
+      #
+      # Note that new records are different from any other record by definition, unless the
+      # other record is the receiver itself. Besides, if you fetch existing records with
+      # +select+ and leave the ID out, you're on your own, this predicate will return false.
+      #
+      # Note also that destroying a record preserves its ID in the model instance, so deleted
+      # models are still comparable.
       def ==(comparison_object)
         comparison_object.equal?(self) ||
-          persisted? &&
-            (comparison_object.instance_of?(self.class) &&
-              comparison_object.id == id)
+          comparison_object.instance_of?(self.class) &&
+          id.present? &&
+          comparison_object.id == id
       end
 
       # Delegates to ==
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index f3fba9a3a9..ada1560ce2 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -91,6 +91,11 @@ module ActiveRecord
         false
       end
 
+      # Does this adapter restrict the number of ids you can use in a list. Oracle has a limit of 1000.
+      def ids_in_list_limit
+        nil
+      end
+
       # QUOTING ==================================================
 
       # Override to return the quoted table name. Defaults to column quoting.
diff --git a/activerecord/lib/active_record/migration.rb b/activerecord/lib/active_record/migration.rb
index a4c09b654a..f6321f1499 100644
--- a/activerecord/lib/active_record/migration.rb
+++ b/activerecord/lib/active_record/migration.rb
@@ -1,6 +1,3 @@
-require 'active_support/core_ext/kernel/singleton_class'
-require 'active_support/core_ext/module/aliasing'
-
 module ActiveRecord
   # Exception that can be raised to stop migrations from going backwards.
   class IrreversibleMigration < ActiveRecordError
@@ -43,11 +40,11 @@ module ActiveRecord
   # Example of a simple migration:
   #
   #   class AddSsl < ActiveRecord::Migration
-  #     def self.up
+  #     def up
   #       add_column :accounts, :ssl_enabled, :boolean, :default => 1
   #     end
   #
-  #     def self.down
+  #     def down
   #       remove_column :accounts, :ssl_enabled
   #     end
   #   end
@@ -63,7 +60,7 @@ module ActiveRecord
   # Example of a more complex migration that also needs to initialize data:
   #
   #   class AddSystemSettings < ActiveRecord::Migration
-  #     def self.up
+  #     def up
   #       create_table :system_settings do |t|
   #         t.string  :name
   #         t.string  :label
@@ -77,7 +74,7 @@ module ActiveRecord
   #                             :value => 1
   #     end
   #
-  #     def self.down
+  #     def down
   #       drop_table :system_settings
   #     end
   #   end
@@ -138,7 +135,7 @@ module ActiveRecord
   # in the <tt>db/migrate/</tt> directory where <tt>timestamp</tt> is the
   # UTC formatted date and time that the migration was generated.
   #
-  # You may then edit the <tt>self.up</tt> and <tt>self.down</tt> methods of
+  # You may then edit the <tt>up</tt> and <tt>down</tt> methods of
   # MyNewMigration.
   #
   # There is a special syntactic shortcut to generate migrations that add fields to a table.
@@ -147,11 +144,11 @@ module ActiveRecord
   #
   # This will generate the file <tt>timestamp_add_fieldname_to_tablename</tt>, which will look like this:
   #   class AddFieldnameToTablename < ActiveRecord::Migration
-  #     def self.up
+  #     def up
   #       add_column :tablenames, :fieldname, :string
   #     end
   #
-  #     def self.down
+  #     def down
   #       remove_column :tablenames, :fieldname
   #     end
   #   end
@@ -179,11 +176,11 @@ module ActiveRecord
   # Not all migrations change the schema. Some just fix the data:
   #
   #   class RemoveEmptyTags < ActiveRecord::Migration
-  #     def self.up
+  #     def up
   #       Tag.find(:all).each { |tag| tag.destroy if tag.pages.empty? }
   #     end
   #
-  #     def self.down
+  #     def down
   #       # not much we can do to restore deleted data
   #       raise ActiveRecord::IrreversibleMigration, "Can't recover the deleted tags"
   #     end
@@ -192,12 +189,12 @@ module ActiveRecord
   # Others remove columns when they migrate up instead of down:
   #
   #   class RemoveUnnecessaryItemAttributes < ActiveRecord::Migration
-  #     def self.up
+  #     def up
   #       remove_column :items, :incomplete_items_count
   #       remove_column :items, :completed_items_count
   #     end
   #
-  #     def self.down
+  #     def down
   #       add_column :items, :incomplete_items_count
   #       add_column :items, :completed_items_count
   #     end
@@ -206,11 +203,11 @@ module ActiveRecord
   # And sometimes you need to do something in SQL not abstracted directly by migrations:
   #
   #   class MakeJoinUnique < ActiveRecord::Migration
-  #     def self.up
+  #     def up
   #       execute "ALTER TABLE `pages_linked_pages` ADD UNIQUE `page_id_linked_page_id` (`page_id`,`linked_page_id`)"
   #     end
   #
-  #     def self.down
+  #     def down
   #       execute "ALTER TABLE `pages_linked_pages` DROP INDEX `page_id_linked_page_id`"
   #     end
   #   end
@@ -223,7 +220,7 @@ module ActiveRecord
   # latest column data from after the new column was added. Example:
   #
   #   class AddPeopleSalary < ActiveRecord::Migration
-  #     def self.up
+  #     def up
   #       add_column :people, :salary, :integer
   #       Person.reset_column_information
   #       Person.find(:all).each do |p|
@@ -243,7 +240,7 @@ module ActiveRecord
   # You can also insert your own messages and benchmarks by using the +say_with_time+
   # method:
   #
-  #   def self.up
+  #   def up
   #     ...
   #     say_with_time "Updating salaries..." do
   #       Person.find(:all).each do |p|
@@ -286,143 +283,201 @@ module ActiveRecord
   #
   # In application.rb.
   #
+  # == Reversible Migrations
+  #
+  # Starting with Rails 3.1, you will be able to define reversible migrations.
+  # Reversible migrations are migrations that know how to go +down+ for you.
+  # You simply supply the +up+ logic, and the Migration system will figure out
+  # how to execute the down commands for you.
+  #
+  # To define a reversible migration, define the +change+ method in your
+  # migration like this:
+  #
+  #   class TenderloveMigration < ActiveRecord::Migration
+  #     def change
+  #       create_table(:horses) do
+  #         t.column :content, :text
+  #         t.column :remind_at, :datetime
+  #       end
+  #     end
+  #   end
+  #
+  # This migration will create the horses table for you on the way up, and
+  # automatically figure out how to drop the table on the way down.
+  #
+  # Some commands like +remove_column+ cannot be reversed.  If you care to
+  # define how to move up and down in these cases, you should define the +up+
+  # and +down+ methods as before.
+  #
+  # If a command cannot be reversed, an
+  # <tt>ActiveRecord::IrreversibleMigration</tt> exception will be raised when
+  # the migration is moving down.
+  #
+  # For a list of commands that are reversible, please see
+  # <tt>ActiveRecord::Migration::CommandRecorder</tt>.
   class Migration
-    @@verbose = true
-    cattr_accessor :verbose
+    autoload :CommandRecorder, 'active_record/migration/command_recorder'
 
     class << self
-      def up_with_benchmarks #:nodoc:
-        migrate(:up)
-      end
+      attr_accessor :delegate # :nodoc:
+    end
 
-      def down_with_benchmarks #:nodoc:
-        migrate(:down)
-      end
+    def self.method_missing(name, *args, &block) # :nodoc:
+      (delegate || superclass.delegate).send(name, *args, &block)
+    end
 
-      # Execute this migration in the named direction
-      def migrate(direction)
-        return unless respond_to?(direction)
+    cattr_accessor :verbose
 
-        case direction
-          when :up   then announce "migrating"
-          when :down then announce "reverting"
-        end
+    attr_accessor :name, :version
 
-        result = nil
-        time = Benchmark.measure { result = send("#{direction}_without_benchmarks") }
+    def initialize
+      @name       = self.class.name
+      @version    = nil
+      @connection = nil
+    end
 
-        case direction
-          when :up   then announce "migrated (%.4fs)" % time.real; write
-          when :down then announce "reverted (%.4fs)" % time.real; write
-        end
+    # instantiate the delegate object after initialize is defined
+    self.verbose  = true
+    self.delegate = new
 
-        result
-      end
+    def up
+      self.class.delegate = self
+      return unless self.class.respond_to?(:up)
+      self.class.up
+    end
+
+    def down
+      self.class.delegate = self
+      return unless self.class.respond_to?(:down)
+      self.class.down
+    end
 
-      # Because the method added may do an alias_method, it can be invoked
-      # recursively. We use @ignore_new_methods as a guard to indicate whether
-      # it is safe for the call to proceed.
-      def singleton_method_added(sym) #:nodoc:
-        return if defined?(@ignore_new_methods) && @ignore_new_methods
+    # Execute this migration in the named direction
+    def migrate(direction)
+      return unless respond_to?(direction)
 
-        begin
-          @ignore_new_methods = true
+      case direction
+      when :up   then announce "migrating"
+      when :down then announce "reverting"
+      end
 
-          case sym
-            when :up, :down
-              singleton_class.send(:alias_method_chain, sym, "benchmarks")
+      time   = nil
+      ActiveRecord::Base.connection_pool.with_connection do |conn|
+        @connection = conn
+        if respond_to?(:change)
+          if direction == :down
+            recorder = CommandRecorder.new(@connection)
+            suppress_messages do
+              @connection = recorder
+              change
+            end
+            @connection = conn
+            time = Benchmark.measure {
+              recorder.inverse.each do |cmd, args|
+                send(cmd, *args)
+              end
+            }
+          else
+            time = Benchmark.measure { change }
           end
-        ensure
-          @ignore_new_methods = false
+        else
+          time = Benchmark.measure { send(direction) }
         end
+        @connection = nil
       end
 
-      def write(text="")
-        puts(text) if verbose
+      case direction
+      when :up   then announce "migrated (%.4fs)" % time.real; write
+      when :down then announce "reverted (%.4fs)" % time.real; write
       end
+    end
 
-      def announce(message)
-        version = defined?(@version) ? @version : nil
+    def write(text="")
+      puts(text) if verbose
+    end
 
-        text = "#{version} #{name}: #{message}"
-        length = [0, 75 - text.length].max
-        write "== %s %s" % [text, "=" * length]
-      end
+    def announce(message)
+      text = "#{version} #{name}: #{message}"
+      length = [0, 75 - text.length].max
+      write "== %s %s" % [text, "=" * length]
+    end
 
-      def say(message, subitem=false)
-        write "#{subitem ? "   ->" : "--"} #{message}"
-      end
+    def say(message, subitem=false)
+      write "#{subitem ? "   ->" : "--"} #{message}"
+    end
 
-      def say_with_time(message)
-        say(message)
-        result = nil
-        time = Benchmark.measure { result = yield }
-        say "%.4fs" % time.real, :subitem
-        say("#{result} rows", :subitem) if result.is_a?(Integer)
-        result
-      end
+    def say_with_time(message)
+      say(message)
+      result = nil
+      time = Benchmark.measure { result = yield }
+      say "%.4fs" % time.real, :subitem
+      say("#{result} rows", :subitem) if result.is_a?(Integer)
+      result
+    end
 
-      def suppress_messages
-        save, self.verbose = verbose, false
-        yield
-      ensure
-        self.verbose = save
-      end
+    def suppress_messages
+      save, self.verbose = verbose, false
+      yield
+    ensure
+      self.verbose = save
+    end
 
-      def connection
-        ActiveRecord::Base.connection
-      end
+    def connection
+      @connection || ActiveRecord::Base.connection
+    end
 
-      def method_missing(method, *arguments, &block)
-        arg_list = arguments.map{ |a| a.inspect } * ', '
+    def method_missing(method, *arguments, &block)
+      arg_list = arguments.map{ |a| a.inspect } * ', '
 
-        say_with_time "#{method}(#{arg_list})" do
-          unless arguments.empty? || method == :execute
-            arguments[0] = Migrator.proper_table_name(arguments.first)
-          end
-          connection.send(method, *arguments, &block)
+      say_with_time "#{method}(#{arg_list})" do
+        unless arguments.empty? || method == :execute
+          arguments[0] = Migrator.proper_table_name(arguments.first)
         end
+        return super unless connection.respond_to?(method)
+        connection.send(method, *arguments, &block)
       end
+    end
 
-      def copy(destination, sources, options = {})
-        copied = []
-
-        destination_migrations = ActiveRecord::Migrator.migrations(destination)
-        last = destination_migrations.last
-        sources.each do |name, path|
-          source_migrations = ActiveRecord::Migrator.migrations(path)
+    def copy(destination, sources, options = {})
+      copied = []
 
-          source_migrations.each do |migration|
-            source = File.read(migration.filename)
-            source = "# This migration comes from #{name} (originally #{migration.version})\n#{source}"
+      FileUtils.mkdir_p(destination) unless File.exists?(destination)
 
-            if duplicate = destination_migrations.detect { |m| m.name == migration.name }
-              options[:on_skip].call(name, migration) if File.read(duplicate.filename) != source && options[:on_skip]
-              next
-            end
+      destination_migrations = ActiveRecord::Migrator.migrations(destination)
+      last = destination_migrations.last
+      sources.each do |name, path|
+        source_migrations = ActiveRecord::Migrator.migrations(path)
 
-            migration.version = next_migration_number(last ? last.version + 1 : 0).to_i
-            new_path = File.join(destination, "#{migration.version}_#{migration.name.underscore}.rb")
-            old_path, migration.filename = migration.filename, new_path
-            last = migration
+        source_migrations.each do |migration|
+          source = File.read(migration.filename)
+          source = "# This migration comes from #{name} (originally #{migration.version})\n#{source}"
 
-            FileUtils.cp(old_path, migration.filename)
-            copied << migration
-            options[:on_copy].call(name, migration, old_path) if options[:on_copy]
-            destination_migrations << migration
+          if duplicate = destination_migrations.detect { |m| m.name == migration.name }
+            options[:on_skip].call(name, migration) if File.read(duplicate.filename) != source && options[:on_skip]
+            next
           end
-        end
 
-        copied
-      end
+          migration.version = next_migration_number(last ? last.version + 1 : 0).to_i
+          new_path = File.join(destination, "#{migration.version}_#{migration.name.underscore}.rb")
+          old_path, migration.filename = migration.filename, new_path
+          last = migration
 
-      def next_migration_number(number)
-        if ActiveRecord::Base.timestamped_migrations
-          [Time.now.utc.strftime("%Y%m%d%H%M%S"), "%.14d" % number].max
-        else
-          "%.3d" % number
+          FileUtils.cp(old_path, migration.filename)
+          copied << migration
+          options[:on_copy].call(name, migration, old_path) if options[:on_copy]
+          destination_migrations << migration
         end
       end
+
+      copied
+    end
+
+    def next_migration_number(number)
+      if ActiveRecord::Base.timestamped_migrations
+        [Time.now.utc.strftime("%Y%m%d%H%M%S"), "%.14d" % number].max
+      else
+        "%.3d" % number
+      end
     end
   end
 
@@ -449,7 +504,7 @@ module ActiveRecord
 
       def load_migration
         require(File.expand_path(filename))
-        name.constantize
+        name.constantize.new
       end
 
   end
diff --git a/activerecord/lib/active_record/migration/command_recorder.rb b/activerecord/lib/active_record/migration/command_recorder.rb
new file mode 100644
index 0000000000..d7e481905a
--- /dev/null
+++ b/activerecord/lib/active_record/migration/command_recorder.rb
@@ -0,0 +1,91 @@
+module ActiveRecord
+  class Migration
+    # ActiveRecord::Migration::CommandRecorder records commands done during
+    # a migration and knows how to reverse those commands.  The CommandRecorder
+    # knows how to invert the following commands:
+    #
+    # * add_column
+    # * add_index
+    # * add_timestamp
+    # * create_table
+    # * remove_timestamps
+    # * rename_column
+    # * rename_index
+    # * rename_table
+    class CommandRecorder
+      attr_accessor :commands, :delegate
+
+      def initialize(delegate = nil)
+        @commands = []
+        @delegate = delegate
+      end
+
+      # record +command+.  +command+ should be a method name and arguments.
+      # For example:
+      #
+      #   recorder.record(:method_name, [:arg1, arg2])
+      def record(*command)
+        @commands << command
+      end
+
+      # Returns a list that represents commands that are the inverse of the
+      # commands stored in +commands+.  For example:
+      #
+      #   recorder.record(:rename_table, [:old, :new])
+      #   recorder.inverse # => [:rename_table, [:new, :old]]
+      #
+      # This method will raise an IrreversibleMigration exception if it cannot
+      # invert the +commands+.
+      def inverse
+        @commands.reverse.map { |name, args|
+          method = :"invert_#{name}"
+          raise IrreversibleMigration unless respond_to?(method, true)
+          __send__(method, args)
+        }
+      end
+
+      def respond_to?(*args) # :nodoc:
+        super || delegate.respond_to?(*args)
+      end
+
+      def send(method, *args) # :nodoc:
+        return super unless respond_to?(method)
+        record(method, args)
+      end
+
+      private
+      def invert_create_table(args)
+        [:drop_table, args]
+      end
+
+      def invert_rename_table(args)
+        [:rename_table, args.reverse]
+      end
+
+      def invert_add_column(args)
+        [:remove_column, args.first(2)]
+      end
+
+      def invert_rename_index(args)
+        [:rename_index, args.reverse]
+      end
+
+      def invert_rename_column(args)
+        [:rename_column, [args.first] + args.last(2).reverse]
+      end
+
+      def invert_add_index(args)
+        table, columns, _ = *args
+        [:remove_index, [table, {:column => columns}]]
+      end
+
+      def invert_remove_timestamps(args)
+        [:add_timestamps, args]
+      end
+
+      def invert_add_timestamps(args)
+        [:remove_timestamps, args]
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/named_scope.rb b/activerecord/lib/active_record/named_scope.rb
index 0b92ba5caa..0f421560f0 100644
--- a/activerecord/lib/active_record/named_scope.rb
+++ b/activerecord/lib/active_record/named_scope.rb
@@ -2,12 +2,18 @@ require 'active_support/core_ext/array'
 require 'active_support/core_ext/hash/except'
 require 'active_support/core_ext/kernel/singleton_class'
 require 'active_support/core_ext/object/blank'
+require 'active_support/core_ext/class/attribute'
 
 module ActiveRecord
   # = Active Record Named \Scopes
   module NamedScope
     extend ActiveSupport::Concern
 
+    included do
+      class_attribute :scopes
+      self.scopes = {}
+    end
+
     module ClassMethods
       # Returns an anonymous \scope.
       #
@@ -33,10 +39,6 @@ module ActiveRecord
         end
       end
 
-      def scopes
-        read_inheritable_attribute(:scopes) || write_inheritable_attribute(:scopes, {})
-      end
-
       # Adds a class method for retrieving and querying objects. A \scope represents a narrowing of a database query,
       # such as <tt>where(:color => :red).select('shirts.*').includes(:washing_instructions)</tt>.
       #
diff --git a/activerecord/lib/active_record/nested_attributes.rb b/activerecord/lib/active_record/nested_attributes.rb
index 0c3392263a..f1d3eaed38 100644
--- a/activerecord/lib/active_record/nested_attributes.rb
+++ b/activerecord/lib/active_record/nested_attributes.rb
@@ -2,6 +2,7 @@ require 'active_support/core_ext/hash/except'
 require 'active_support/core_ext/object/try'
 require 'active_support/core_ext/object/blank'
 require 'active_support/core_ext/hash/indifferent_access'
+require 'active_support/core_ext/class/attribute'
 
 module ActiveRecord
   module NestedAttributes #:nodoc:
@@ -11,7 +12,7 @@ module ActiveRecord
     extend ActiveSupport::Concern
 
     included do
-      class_inheritable_accessor :nested_attributes_options, :instance_writer => false
+      class_attribute :nested_attributes_options, :instance_writer => false
       self.nested_attributes_options = {}
     end
 
@@ -268,7 +269,11 @@ module ActiveRecord
           if reflection = reflect_on_association(association_name)
             reflection.options[:autosave] = true
             add_autosave_association_callbacks(reflection)
+
+            nested_attributes_options = self.nested_attributes_options.dup
             nested_attributes_options[association_name.to_sym] = options
+            self.nested_attributes_options = nested_attributes_options
+
             type = (reflection.collection? ? :collection : :one_to_one)
 
             # def pirate_attributes=(attributes)
@@ -315,7 +320,7 @@ module ActiveRecord
     # update_only is true, and a <tt>:_destroy</tt> key set to a truthy value,
     # then the existing record will be marked for destruction.
     def assign_nested_attributes_for_one_to_one_association(association_name, attributes)
-      options = nested_attributes_options[association_name]
+      options = self.nested_attributes_options[association_name]
       attributes = attributes.with_indifferent_access
       check_existing_record = (options[:update_only] || !attributes['id'].blank?)
 
@@ -364,7 +369,7 @@ module ActiveRecord
     #     { :id => '2', :_destroy => true }
     #   ])
     def assign_nested_attributes_for_collection_association(association_name, attributes_collection)
-      options = nested_attributes_options[association_name]
+      options = self.nested_attributes_options[association_name]
 
       unless attributes_collection.is_a?(Hash) || attributes_collection.is_a?(Array)
         raise ArgumentError, "Hash or Array expected, got #{attributes_collection.class.name} (#{attributes_collection.inspect})"
@@ -433,7 +438,7 @@ module ActiveRecord
     end
 
     def call_reject_if(association_name, attributes)
-      case callback = nested_attributes_options[association_name][:reject_if]
+      case callback = self.nested_attributes_options[association_name][:reject_if]
       when Symbol
         method(callback).arity == 0 ? send(callback) : send(callback, attributes)
       when Proc
diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb
index a2260e9a19..a07c321960 100644
--- a/activerecord/lib/active_record/reflection.rb
+++ b/activerecord/lib/active_record/reflection.rb
@@ -1,8 +1,15 @@
+require 'active_support/core_ext/class/attribute'
+
 module ActiveRecord
   # = Active Record Reflection
   module Reflection # :nodoc:
     extend ActiveSupport::Concern
 
+    included do
+      class_attribute :reflections
+      self.reflections = {}
+    end
+
     # Reflection enables to interrogate Active Record classes and objects
     # about their associations and aggregations. This information can,
     # for example, be used in a form builder that takes an Active Record object
@@ -20,18 +27,9 @@ module ActiveRecord
           when :composed_of
             reflection = AggregateReflection.new(macro, name, options, active_record)
         end
-        write_inheritable_hash :reflections, name => reflection
-        reflection
-      end
 
-      # Returns a hash containing all AssociationReflection objects for the current class.
-      # Example:
-      #
-      #   Invoice.reflections
-      #   Account.reflections
-      #
-      def reflections
-        read_inheritable_attribute(:reflections) || write_inheritable_attribute(:reflections, {})
+        self.reflections = self.reflections.merge(name => reflection)
+        reflection
       end
 
       # Returns an array of AggregateReflection objects for all the aggregations in the class.
diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb
index 6bf698fe97..c8adaddfca 100644
--- a/activerecord/lib/active_record/relation/calculations.rb
+++ b/activerecord/lib/active_record/relation/calculations.rb
@@ -208,14 +208,16 @@ module ActiveRecord
     end
 
     def execute_grouped_calculation(operation, column_name, distinct) #:nodoc:
-      group_attr      = @group_values.first
-      association     = @klass.reflect_on_association(group_attr.to_sym)
-      associated      = association && association.macro == :belongs_to # only count belongs_to associations
-      group_field     = associated ? association.primary_key_name : group_attr
-      group_alias     = column_alias_for(group_field)
-      group_column    = column_for(group_field)
+      group_attr      = @group_values
+      association     = @klass.reflect_on_association(group_attr.first.to_sym)
+      associated      = group_attr.size == 1 && association && association.macro == :belongs_to # only count belongs_to associations
+      group_fields  = Array(associated ? association.primary_key_name : group_attr)
+      group_aliases = group_fields.map { |field| column_alias_for(field) }
+      group_columns = group_aliases.zip(group_fields).map { |aliaz,field|
+        [aliaz, column_for(field)]
+      }
 
-      group = @klass.connection.adapter_name == 'FrontBase' ? group_alias : group_field
+      group = @klass.connection.adapter_name == 'FrontBase' ? group_aliases : group_fields
 
       if operation == 'count' && column_name == :all
         aggregate_alias = 'count_all'
@@ -223,22 +225,33 @@ module ActiveRecord
         aggregate_alias = column_alias_for(operation, column_name)
       end
 
-      relation = except(:group).group(group)
-      relation.select_values = [
-        operation_over_aggregate_column(aggregate_column(column_name), operation, distinct).as(aggregate_alias),
-        "#{group_field} AS #{group_alias}"
+      select_values = [
+        operation_over_aggregate_column(
+          aggregate_column(column_name),
+          operation,
+          distinct).as(aggregate_alias)
       ]
 
+      select_values.concat group_fields.zip(group_aliases).map { |field,aliaz|
+        "#{field} AS #{aliaz}"
+      }
+
+      relation = except(:group).group(group.join(','))
+      relation.select_values = select_values
+
       calculated_data = @klass.connection.select_all(relation.to_sql)
 
       if association
-        key_ids     = calculated_data.collect { |row| row[group_alias] }
+        key_ids     = calculated_data.collect { |row| row[group_aliases.first] }
         key_records = association.klass.base_class.find(key_ids)
         key_records = Hash[key_records.map { |r| [r.id, r] }]
       end
 
       ActiveSupport::OrderedHash[calculated_data.map do |row|
-        key = type_cast_calculated_value(row[group_alias], group_column)
+        key   = group_columns.map { |aliaz, column|
+          type_cast_calculated_value(row[aliaz], column)
+        }
+        key   = key.first if key.size == 1
         key = key_records[key] if associated
         [key, type_cast_calculated_value(row[aggregate_alias], column_for(column_name), operation)]
       end]
diff --git a/activerecord/lib/active_record/relation/predicate_builder.rb b/activerecord/lib/active_record/relation/predicate_builder.rb
index c5428dccd6..32c7d08daa 100644
--- a/activerecord/lib/active_record/relation/predicate_builder.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder.rb
@@ -25,6 +25,11 @@ module ActiveRecord
             attribute.in(values)
           when Range, Arel::Relation
             attribute.in(value)
+          when ActiveRecord::Base
+            attribute.eq(value.quoted_id)
+          when Class
+            # FIXME: I think we need to deprecate this behavior
+            attribute.eq(value.name)
           else
             attribute.eq(value)
           end
diff --git a/activerecord/lib/active_record/relation/query_methods.rb b/activerecord/lib/active_record/relation/query_methods.rb
index 9c399d3333..9e7503a60d 100644
--- a/activerecord/lib/active_record/relation/query_methods.rb
+++ b/activerecord/lib/active_record/relation/query_methods.rb
@@ -141,7 +141,7 @@ module ActiveRecord
         "#{@klass.table_name}.#{@klass.primary_key} DESC" :
         reverse_sql_order(order_clause).join(', ')
 
-      except(:order).order(Arel::SqlLiteral.new(order))
+      except(:order).order(Arel.sql(order))
     end
 
     def arel
@@ -174,10 +174,7 @@ module ActiveRecord
 
       arel = build_joins(arel, @joins_values) unless @joins_values.empty?
 
-      (@where_values - ['']).uniq.each do |where|
-        where = Arel.sql(where) if String === where
-        arel = arel.where(Arel::Nodes::Grouping.new(where))
-      end
+      arel = collapse_wheres(arel, (@where_values - ['']).uniq)
 
       arel = arel.having(*@having_values.uniq.reject{|h| h.blank?}) unless @having_values.empty?
 
@@ -198,6 +195,27 @@ module ActiveRecord
 
     private
 
+    def collapse_wheres(arel, wheres)
+      equalities = wheres.grep(Arel::Nodes::Equality)
+
+      groups = equalities.group_by do |equality|
+        equality.left
+      end
+
+      groups.each do |_, eqls|
+        test = eqls.inject(eqls.shift) do |memo, expr|
+          memo.or(expr)
+        end
+        arel = arel.where(test)
+      end
+
+      (wheres - equalities).each do |where|
+        where = Arel.sql(where) if String === where
+        arel = arel.where(Arel::Nodes::Grouping.new(where))
+      end
+      arel
+    end
+
     def build_where(opts, other = [])
       case opts
       when String, Array
diff --git a/activerecord/lib/active_record/schema.rb b/activerecord/lib/active_record/schema.rb
index c1bc3214ea..c6bb5c1961 100644
--- a/activerecord/lib/active_record/schema.rb
+++ b/activerecord/lib/active_record/schema.rb
@@ -30,9 +30,7 @@ module ActiveRecord
   # ActiveRecord::Schema is only supported by database adapters that also
   # support migrations, the two features being very similar.
   class Schema < Migration
-    private_class_method :new
-
-    def self.migrations_path
+    def migrations_path
       ActiveRecord::Migrator.migrations_path
     end
 
@@ -48,11 +46,12 @@ module ActiveRecord
     #     ...
     #   end
     def self.define(info={}, &block)
-      instance_eval(&block)
+      schema = new
+      schema.instance_eval(&block)
 
       unless info[:version].blank?
         initialize_schema_migrations_table
-        assume_migrated_upto_version(info[:version], migrations_path)
+        assume_migrated_upto_version(info[:version], schema.migrations_path)
       end
     end
   end
diff --git a/activerecord/lib/active_record/timestamp.rb b/activerecord/lib/active_record/timestamp.rb
index 230adf6b2b..2ecbd906bd 100644
--- a/activerecord/lib/active_record/timestamp.rb
+++ b/activerecord/lib/active_record/timestamp.rb
@@ -1,3 +1,5 @@
+require 'active_support/core_ext/class/attribute'
+
 module ActiveRecord
   # = Active Record Timestamp
   #
@@ -29,14 +31,14 @@ module ActiveRecord
     extend ActiveSupport::Concern
 
     included do
-      class_inheritable_accessor :record_timestamps, :instance_writer => false
+      class_attribute :record_timestamps, :instance_writer => false
       self.record_timestamps = true
     end
 
   private
 
     def create #:nodoc:
-      if record_timestamps
+      if self.record_timestamps
         current_time = current_time_from_proper_timezone
 
         all_timestamp_attributes.each do |column|
@@ -61,7 +63,7 @@ module ActiveRecord
     end
 
     def should_record_timestamps?
-      record_timestamps && (!partial_updates? || changed? || (attributes.keys & self.class.serialized_attributes.keys).present?)
+      self.record_timestamps && (!partial_updates? || changed? || (attributes.keys & self.class.serialized_attributes.keys).present?)
     end
 
     def timestamp_attributes_for_update_in_model
diff --git a/activerecord/lib/active_record/version.rb b/activerecord/lib/active_record/version.rb
index 89eba15be1..0667be7d23 100644
--- a/activerecord/lib/active_record/version.rb
+++ b/activerecord/lib/active_record/version.rb
@@ -3,8 +3,8 @@ module ActiveRecord
     MAJOR = 3
     MINOR = 1
     TINY  = 0
-    BUILD = "beta"
+    PRE   = "beta"
 
-    STRING = [MAJOR, MINOR, TINY, BUILD].join('.')
+    STRING = [MAJOR, MINOR, TINY, PRE].compact.join('.')
   end
 end
diff --git a/activerecord/lib/rails/generators/active_record/migration/templates/migration.rb b/activerecord/lib/rails/generators/active_record/migration/templates/migration.rb
index 8ac21c1410..126b6f434b 100644
--- a/activerecord/lib/rails/generators/active_record/migration/templates/migration.rb
+++ b/activerecord/lib/rails/generators/active_record/migration/templates/migration.rb
@@ -1,5 +1,5 @@
 class <%= migration_class_name %> < ActiveRecord::Migration
-  def self.up
+  def up
 <% attributes.each do |attribute| -%>
   <%- if migration_action -%>
     <%= migration_action %>_column :<%= table_name %>, :<%= attribute.name %><% if migration_action == 'add' %>, :<%= attribute.type %><% end %>
@@ -7,7 +7,7 @@ class <%= migration_class_name %> < ActiveRecord::Migration
 <%- end -%>
   end
 
-  def self.down
+  def down
 <% attributes.reverse.each do |attribute| -%>
   <%- if migration_action -%>
     <%= migration_action == 'add' ? 'remove' : 'add' %>_column :<%= table_name %>, :<%= attribute.name %><% if migration_action == 'remove' %>, :<%= attribute.type %><% end %>
diff --git a/activerecord/lib/rails/generators/active_record/model/templates/migration.rb b/activerecord/lib/rails/generators/active_record/model/templates/migration.rb
index 1f68487304..70e064be21 100644
--- a/activerecord/lib/rails/generators/active_record/model/templates/migration.rb
+++ b/activerecord/lib/rails/generators/active_record/model/templates/migration.rb
@@ -1,5 +1,5 @@
 class <%= migration_class_name %> < ActiveRecord::Migration
-  def self.up
+  def up
     create_table :<%= table_name %> do |t|
 <% for attribute in attributes -%>
       t.<%= attribute.type %> :<%= attribute.name %>
@@ -10,7 +10,7 @@ class <%= migration_class_name %> < ActiveRecord::Migration
     end
   end
 
-  def self.down
+  def down
     drop_table :<%= table_name %>
   end
 end
diff --git a/activerecord/lib/rails/generators/active_record/session_migration/templates/migration.rb b/activerecord/lib/rails/generators/active_record/session_migration/templates/migration.rb
index 919822af7b..8f0bf1ef0d 100644
--- a/activerecord/lib/rails/generators/active_record/session_migration/templates/migration.rb
+++ b/activerecord/lib/rails/generators/active_record/session_migration/templates/migration.rb
@@ -1,5 +1,5 @@
 class <%= migration_class_name %> < ActiveRecord::Migration
-  def self.up
+  def up
     create_table :<%= session_table_name %> do |t|
       t.string :session_id, :null => false
       t.text :data
@@ -10,7 +10,7 @@ class <%= migration_class_name %> < ActiveRecord::Migration
     add_index :<%= session_table_name %>, :updated_at
   end
 
-  def self.down
+  def down
     drop_table :<%= session_table_name %>
   end
 end
diff --git a/activerecord/test/cases/associations/cascaded_eager_loading_test.rb b/activerecord/test/cases/associations/cascaded_eager_loading_test.rb
index 37c6f354a8..0742e311d9 100644
--- a/activerecord/test/cases/associations/cascaded_eager_loading_test.rb
+++ b/activerecord/test/cases/associations/cascaded_eager_loading_test.rb
@@ -10,7 +10,8 @@ require 'models/reply'
 require 'models/person'
 
 class CascadedEagerLoadingTest < ActiveRecord::TestCase
-  fixtures :authors, :mixins, :companies, :posts, :topics, :accounts, :comments, :categorizations, :people
+  fixtures :authors, :mixins, :companies, :posts, :topics, :accounts, :comments,
+           :categorizations, :people, :categories
 
   def test_eager_association_loading_with_cascaded_two_levels
     authors = Author.find(:all, :include=>{:posts=>:comments}, :order=>"authors.id")
diff --git a/activerecord/test/cases/associations/eager_test.rb b/activerecord/test/cases/associations/eager_test.rb
index 66fb5ac1e1..c00b8a1cde 100644
--- a/activerecord/test/cases/associations/eager_test.rb
+++ b/activerecord/test/cases/associations/eager_test.rb
@@ -79,6 +79,58 @@ class EagerAssociationTest < ActiveRecord::TestCase
     end
   end
 
+  def test_preloading_has_many_in_multiple_queries_with_more_ids_than_database_can_handle
+    Post.connection.expects(:ids_in_list_limit).at_least_once.returns(5)
+    posts = Post.find(:all, :include=>:comments)
+    assert_equal 7, posts.size
+  end
+
+  def test_preloading_has_many_in_one_queries_when_database_has_no_limit_on_ids_it_can_handle
+    Post.connection.expects(:ids_in_list_limit).at_least_once.returns(nil)
+    posts = Post.find(:all, :include=>:comments)
+    assert_equal 7, posts.size
+  end
+
+  def test_preloading_habtm_in_multiple_queries_with_more_ids_than_database_can_handle
+    Post.connection.expects(:ids_in_list_limit).at_least_once.returns(5)
+    posts = Post.find(:all, :include=>:categories)
+    assert_equal 7, posts.size
+  end
+
+  def test_preloading_habtm_in_one_queries_when_database_has_no_limit_on_ids_it_can_handle
+    Post.connection.expects(:ids_in_list_limit).at_least_once.returns(nil)
+    posts = Post.find(:all, :include=>:categories)
+    assert_equal 7, posts.size
+  end
+
+  def test_load_associated_records_in_one_query_when_adapter_has_no_limit
+    Post.connection.expects(:ids_in_list_limit).at_least_once.returns(nil)
+    Post.expects(:i_was_called).with([1,2,3,4,5,6,7]).returns([1])
+    associated_records = Post.send(:associated_records, [1,2,3,4,5,6,7]) do |some_ids|
+      Post.i_was_called(some_ids)
+    end
+    assert_equal [1], associated_records
+  end
+
+  def test_load_associated_records_in_several_queries_when_many_ids_passed
+    Post.connection.expects(:ids_in_list_limit).at_least_once.returns(5)
+    Post.expects(:i_was_called).with([1,2,3,4,5]).returns([1])
+    Post.expects(:i_was_called).with([6,7]).returns([6])
+    associated_records = Post.send(:associated_records, [1,2,3,4,5,6,7]) do |some_ids|
+      Post.i_was_called(some_ids)
+    end
+    assert_equal [1,6], associated_records
+  end
+
+  def test_load_associated_records_in_one_query_when_a_few_ids_passed
+    Post.connection.expects(:ids_in_list_limit).at_least_once.returns(5)
+    Post.expects(:i_was_called).with([1,2,3]).returns([1])
+    associated_records = Post.send(:associated_records, [1,2,3]) do |some_ids|
+      Post.i_was_called(some_ids)
+    end
+    assert_equal [1], associated_records
+  end
+
   def test_including_duplicate_objects_from_belongs_to
     popular_post = Post.create!(:title => 'foo', :body => "I like cars!")
     comment = popular_post.comments.create!(:body => "lol")
diff --git a/activerecord/test/cases/associations/has_many_associations_test.rb b/activerecord/test/cases/associations/has_many_associations_test.rb
index ecfc769f3a..33c53e695b 100644
--- a/activerecord/test/cases/associations/has_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_associations_test.rb
@@ -1282,4 +1282,25 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
     comment = post.comments.build
     assert post.comments.include?(comment)
   end
+
+  def test_load_target_respects_protected_attributes
+    topic = Topic.create!
+    reply = topic.replies.create(:title => "reply 1")
+    reply.approved = false
+    reply.save!
+
+    # Save with a different object instance, so the instance that's still held
+    # in topic.relies doesn't know about the changed attribute.
+    reply2 = Reply.find(reply.id)
+    reply2.approved = true
+    reply2.save!
+
+    # Force loading the collection from the db. This will merge the existing
+    # object (reply) with what gets loaded from the db (which includes the
+    # changed approved attribute). approved is a protected attribute, so if mass
+    # assignment is used, it won't get updated and will still be false.
+    first = topic.replies.to_a.first
+    assert_equal reply.id, first.id
+    assert_equal true, first.approved?
+  end
 end
diff --git a/activerecord/test/cases/associations/inverse_associations_test.rb b/activerecord/test/cases/associations/inverse_associations_test.rb
index fa5c2e49df..081583038f 100644
--- a/activerecord/test/cases/associations/inverse_associations_test.rb
+++ b/activerecord/test/cases/associations/inverse_associations_test.rb
@@ -551,8 +551,8 @@ class InverseMultipleHasManyInversesForSameModel < ActiveRecord::TestCase
   def test_that_we_can_load_associations_that_have_the_same_reciprocal_name_from_different_models
     assert_nothing_raised(ActiveRecord::AssociationTypeMismatch) do
       i = Interest.find(:first)
-      z = i.zine
-      m = i.man
+      i.zine
+      i.man
     end
   end
 
diff --git a/activerecord/test/cases/associations_test.rb b/activerecord/test/cases/associations_test.rb
index dd8152b219..83c605d2bb 100644
--- a/activerecord/test/cases/associations_test.rb
+++ b/activerecord/test/cases/associations_test.rb
@@ -120,7 +120,7 @@ class AssociationsTest < ActiveRecord::TestCase
 
   def test_force_reload_is_uncached
     firm = Firm.create!("name" => "A New Firm, Inc")
-    client = Client.create!("name" => "TheClient.com", :firm => firm)
+    Client.create!("name" => "TheClient.com", :firm => firm)
     ActiveRecord::Base.cache do
       firm.clients.each {}
       assert_queries(0) { assert_not_nil firm.clients.each {} }
@@ -270,17 +270,17 @@ class OverridingAssociationsTest < ActiveRecord::TestCase
 
   def test_habtm_association_redefinition_callbacks_should_differ_and_not_inherited
     # redeclared association on AR descendant should not inherit callbacks from superclass
-    callbacks = PeopleList.read_inheritable_attribute(:before_add_for_has_and_belongs_to_many)
+    callbacks = PeopleList.before_add_for_has_and_belongs_to_many
     assert_equal([:enlist], callbacks)
-    callbacks = DifferentPeopleList.read_inheritable_attribute(:before_add_for_has_and_belongs_to_many)
+    callbacks = DifferentPeopleList.before_add_for_has_and_belongs_to_many
     assert_equal([], callbacks)
   end
 
   def test_has_many_association_redefinition_callbacks_should_differ_and_not_inherited
     # redeclared association on AR descendant should not inherit callbacks from superclass
-    callbacks = PeopleList.read_inheritable_attribute(:before_add_for_has_many)
+    callbacks = PeopleList.before_add_for_has_many
     assert_equal([:enlist], callbacks)
-    callbacks = DifferentPeopleList.read_inheritable_attribute(:before_add_for_has_many)
+    callbacks = DifferentPeopleList.before_add_for_has_many
     assert_equal([], callbacks)
   end
 
diff --git a/activerecord/test/cases/attribute_methods_test.rb b/activerecord/test/cases/attribute_methods_test.rb
index ab9a65944f..bb0166a60c 100644
--- a/activerecord/test/cases/attribute_methods_test.rb
+++ b/activerecord/test/cases/attribute_methods_test.rb
@@ -568,7 +568,7 @@ class AttributeMethodsTest < ActiveRecord::TestCase
   def test_bulk_update_respects_access_control
     privatize("title=(value)")
 
-    assert_raise(ActiveRecord::UnknownAttributeError) { topic = @target.new(:title => "Rants about pants") }
+    assert_raise(ActiveRecord::UnknownAttributeError) { @target.new(:title => "Rants about pants") }
     assert_raise(ActiveRecord::UnknownAttributeError) { @target.new.attributes = { :title => "Ants in pants" } }
   end
 
diff --git a/activerecord/test/cases/autosave_association_test.rb b/activerecord/test/cases/autosave_association_test.rb
index 459f9fa55c..b13cb2d7a2 100644
--- a/activerecord/test/cases/autosave_association_test.rb
+++ b/activerecord/test/cases/autosave_association_test.rb
@@ -355,8 +355,6 @@ class TestDefaultAutosaveAssociationOnAHasManyAssociation < ActiveRecord::TestCa
   end
 
   def test_invalid_adding_before_save
-    no_of_firms = Firm.count
-    no_of_clients = Client.count
     new_firm = Firm.new("name" => "A New Firm, Inc")
     new_firm.clients_of_firm.concat([c = Client.new, Client.new("name" => "Apple")])
     assert !c.persisted?
@@ -461,7 +459,7 @@ class TestDefaultAutosaveAssociationOnAHasManyAssociation < ActiveRecord::TestCa
 
   def test_build_many_before_save
     company = companies(:first_firm)
-    new_clients = assert_no_queries { company.clients_of_firm.build([{"name" => "Another Client"}, {"name" => "Another Client II"}]) }
+    assert_no_queries { company.clients_of_firm.build([{"name" => "Another Client"}, {"name" => "Another Client II"}]) }
 
     company.name += '-changed'
     assert_queries(3) { assert company.save }
@@ -481,7 +479,7 @@ class TestDefaultAutosaveAssociationOnAHasManyAssociation < ActiveRecord::TestCa
 
   def test_build_many_via_block_before_save
     company = companies(:first_firm)
-    new_clients = assert_no_queries do
+    assert_no_queries do
       company.clients_of_firm.build([{"name" => "Another Client"}, {"name" => "Another Client II"}]) do |client|
         client.name = "changed"
       end
diff --git a/activerecord/test/cases/base_test.rb b/activerecord/test/cases/base_test.rb
index 9f2b0c9c86..26f388ca46 100644
--- a/activerecord/test/cases/base_test.rb
+++ b/activerecord/test/cases/base_test.rb
@@ -182,7 +182,7 @@ class BasicsTest < ActiveRecord::TestCase
 
   def test_initialize_with_invalid_attribute
     begin
-      topic = Topic.new({ "title" => "test",
+      Topic.new({ "title" => "test",
         "last_read(1i)" => "2005", "last_read(2i)" => "2", "last_read(3i)" => "31"})
     rescue ActiveRecord::MultiparameterAssignmentErrors => ex
       assert_equal(1, ex.errors.size)
@@ -397,6 +397,15 @@ class BasicsTest < ActiveRecord::TestCase
     assert_not_equal Topic.new, Topic.new
   end
 
+  def test_equality_of_destroyed_records
+    topic_1 = Topic.new(:title => 'test_1')
+    topic_1.save
+    topic_2 = Topic.find(topic_1.id)
+    topic_1.destroy
+    assert_equal topic_1, topic_2
+    assert_equal topic_2, topic_1
+  end
+
   def test_hashing
     assert_equal [ Topic.find(1) ], [ Topic.find(2).topic ] & [ Topic.find(1) ]
   end
@@ -963,7 +972,6 @@ class BasicsTest < ActiveRecord::TestCase
   end
 
   def test_nil_serialized_attribute_with_class_constraint
-    myobj = MyObject.new('value1', 'value2')
     topic = Topic.new
     assert_nil topic.content
   end
diff --git a/activerecord/test/cases/calculations_test.rb b/activerecord/test/cases/calculations_test.rb
index 61fbf01a50..5cb8485b4b 100644
--- a/activerecord/test/cases/calculations_test.rb
+++ b/activerecord/test/cases/calculations_test.rb
@@ -54,6 +54,19 @@ class CalculationsTest < ActiveRecord::TestCase
     c = Account.sum(:credit_limit, :group => :firm_id)
     [1,6,2].each { |firm_id| assert c.keys.include?(firm_id) }
   end
+  
+  def test_should_group_by_multiple_fields
+    c = Account.count(:all, :group => ['firm_id', :credit_limit])
+    [ [nil, 50], [1, 50], [6, 50], [6, 55], [9, 53], [2, 60] ].each { |firm_and_limit| assert c.keys.include?(firm_and_limit) }
+  end
+
+  def test_should_group_by_multiple_fields_having_functions
+    c = Topic.group(:author_name, 'COALESCE(type, title)').count(:all)
+    assert_equal 1, c[["Carl", "The Third Topic of the day"]]
+    assert_equal 1, c[["Mary", "Reply"]]
+    assert_equal 1, c[["David", "The First Topic"]]
+    assert_equal 1, c[["Carl", "Reply"]]
+  end
 
   def test_should_group_by_summed_field
     c = Account.sum(:credit_limit, :group => :firm_id)
diff --git a/activerecord/test/cases/finder_test.rb b/activerecord/test/cases/finder_test.rb
index 39ce47d9d6..31e4981a1d 100644
--- a/activerecord/test/cases/finder_test.rb
+++ b/activerecord/test/cases/finder_test.rb
@@ -949,7 +949,7 @@ class FinderTest < ActiveRecord::TestCase
 
   # http://dev.rubyonrails.org/ticket/6778
   def test_find_ignores_previously_inserted_record
-    post = Post.create!(:title => 'test', :body => 'it out')
+    Post.create!(:title => 'test', :body => 'it out')
     assert_equal [], Post.find_all_by_id(nil)
   end
 
diff --git a/activerecord/test/cases/fixtures_test.rb b/activerecord/test/cases/fixtures_test.rb
index d5ef30e137..9ce163a00f 100644
--- a/activerecord/test/cases/fixtures_test.rb
+++ b/activerecord/test/cases/fixtures_test.rb
@@ -58,7 +58,7 @@ class FixturesTest < ActiveRecord::TestCase
   end
 
   def test_inserts
-    topics = create_fixtures("topics")
+    create_fixtures("topics")
     first_row = ActiveRecord::Base.connection.select_one("SELECT * FROM topics WHERE author_name = 'David'")
     assert_equal("The First Topic", first_row["title"])
 
@@ -114,7 +114,7 @@ class FixturesTest < ActiveRecord::TestCase
   end
 
   def test_insert_with_datetime
-    topics = create_fixtures("tasks")
+    create_fixtures("tasks")
     first = Task.find(1)
     assert first
   end
@@ -240,7 +240,7 @@ if Account.connection.respond_to?(:reset_pk_sequence!)
 
     def test_create_fixtures_resets_sequences_when_not_cached
       @instances.each do |instance|
-        max_id = create_fixtures(instance.class.table_name).inject(0) do |_max_id, (name, fixture)|
+        max_id = create_fixtures(instance.class.table_name).inject(0) do |_max_id, (_, fixture)|
           fixture_id = fixture['id'].to_i
           fixture_id > _max_id ? fixture_id : _max_id
         end
diff --git a/activerecord/test/cases/helper.rb b/activerecord/test/cases/helper.rb
index 52f26b71f5..f9bbc5299b 100644
--- a/activerecord/test/cases/helper.rb
+++ b/activerecord/test/cases/helper.rb
@@ -13,11 +13,6 @@ require 'active_record'
 require 'active_support/dependencies'
 require 'connection'
 
-begin
-  require 'ruby-debug'
-rescue LoadError
-end
-
 # Show backtraces for deprecated behavior for quicker cleanup.
 ActiveSupport::Deprecation.debug = true
 
diff --git a/activerecord/test/cases/invertible_migration_test.rb b/activerecord/test/cases/invertible_migration_test.rb
new file mode 100644
index 0000000000..afec64750e
--- /dev/null
+++ b/activerecord/test/cases/invertible_migration_test.rb
@@ -0,0 +1,57 @@
+require "cases/helper"
+
+module ActiveRecord
+  class InvertibleMigrationTest < ActiveRecord::TestCase
+    class SilentMigration < ActiveRecord::Migration
+      def write(text = '')
+        # sssshhhhh!!
+      end
+    end
+
+    class InvertibleMigration < SilentMigration
+      def change
+        create_table("horses") do |t|
+          t.column :content, :text
+          t.column :remind_at, :datetime
+        end
+      end
+    end
+
+    class NonInvertibleMigration < SilentMigration
+      def change
+        create_table("horses") do |t|
+          t.column :content, :text
+          t.column :remind_at, :datetime
+        end
+        remove_column "horses", :content
+      end
+    end
+
+    def teardown
+      if ActiveRecord::Base.connection.table_exists?("horses")
+        ActiveRecord::Base.connection.drop_table("horses")
+      end
+    end
+
+    def test_no_reverse
+      migration = NonInvertibleMigration.new
+      migration.migrate(:up)
+      assert_raises(IrreversibleMigration) do
+        migration.migrate(:down)
+      end
+    end
+
+    def test_up
+      migration = InvertibleMigration.new
+      migration.migrate(:up)
+      assert migration.connection.table_exists?("horses"), "horses should exist"
+    end
+
+    def test_down
+      migration = InvertibleMigration.new
+      migration.migrate :up
+      migration.migrate :down
+      assert !migration.connection.table_exists?("horses")
+    end
+  end
+end
diff --git a/activerecord/test/cases/migration/command_recorder_test.rb b/activerecord/test/cases/migration/command_recorder_test.rb
new file mode 100644
index 0000000000..ea2292dda5
--- /dev/null
+++ b/activerecord/test/cases/migration/command_recorder_test.rb
@@ -0,0 +1,108 @@
+require "cases/helper"
+
+module ActiveRecord
+  class Migration
+    class CommandRecorderTest < ActiveRecord::TestCase
+      def setup
+        @recorder = CommandRecorder.new
+      end
+
+      def test_respond_to_delegates
+        recorder = CommandRecorder.new(Class.new {
+          def america; end
+        }.new)
+        assert recorder.respond_to?(:america)
+      end
+
+      def test_send_calls_super
+        assert_raises(NoMethodError) do
+          @recorder.send(:create_table, :horses)
+        end
+      end
+
+      def test_send_delegates_to_record
+        recorder = CommandRecorder.new(Class.new {
+          def create_table(name); end
+        }.new)
+        assert recorder.respond_to?(:create_table), 'respond_to? create_table'
+        recorder.send(:create_table, :horses)
+        assert_equal [[:create_table, [:horses]]], recorder.commands
+      end
+
+      def test_unknown_commands_raise_exception
+        @recorder.record :execute, ['some sql']
+        assert_raises(ActiveRecord::IrreversibleMigration) do
+          @recorder.inverse
+        end
+      end
+
+      def test_record
+        @recorder.record :create_table, [:system_settings]
+        assert_equal 1, @recorder.commands.length
+      end
+
+      def test_inverse
+        @recorder.record :create_table, [:system_settings]
+        assert_equal 1, @recorder.inverse.length
+
+        @recorder.record :rename_table, [:old, :new]
+        assert_equal 2, @recorder.inverse.length
+      end
+
+      def test_inverted_commands_are_reveresed
+        @recorder.record :create_table, [:hello]
+        @recorder.record :create_table, [:world]
+        tables = @recorder.inverse.map(&:last)
+        assert_equal [[:world], [:hello]], tables
+      end
+
+      def test_invert_create_table
+        @recorder.record :create_table, [:system_settings]
+        drop_table = @recorder.inverse.first
+        assert_equal [:drop_table, [:system_settings]], drop_table
+      end
+
+      def test_invert_rename_table
+        @recorder.record :rename_table, [:old, :new]
+        rename = @recorder.inverse.first
+        assert_equal [:rename_table, [:new, :old]], rename
+      end
+
+      def test_invert_add_column
+        @recorder.record :add_column, [:table, :column, :type, {}]
+        remove = @recorder.inverse.first
+        assert_equal [:remove_column, [:table, :column]], remove
+      end
+
+      def test_invert_rename_column
+        @recorder.record :rename_column, [:table, :old, :new]
+        rename = @recorder.inverse.first
+        assert_equal [:rename_column, [:table, :new, :old]], rename
+      end
+
+      def test_invert_add_index
+        @recorder.record :add_index, [:table, [:one, :two], {:options => true}]
+        remove = @recorder.inverse.first
+        assert_equal [:remove_index, [:table, {:column => [:one, :two]}]], remove
+      end
+
+      def test_invert_rename_index
+        @recorder.record :rename_index, [:old, :new]
+        rename = @recorder.inverse.first
+        assert_equal [:rename_index, [:new, :old]], rename
+      end
+
+      def test_invert_add_timestamps
+        @recorder.record :add_timestamps, [:table]
+        remove = @recorder.inverse.first
+        assert_equal [:remove_timestamps, [:table]], remove
+      end
+
+      def test_invert_remove_timestamps
+        @recorder.record :remove_timestamps, [:table]
+        add = @recorder.inverse.first
+        assert_equal [:add_timestamps, [:table]], add
+      end
+    end
+  end
+end
diff --git a/activerecord/test/cases/migration_test.rb b/activerecord/test/cases/migration_test.rb
index e6eef805cf..3037d73a1b 100644
--- a/activerecord/test/cases/migration_test.rb
+++ b/activerecord/test/cases/migration_test.rb
@@ -18,10 +18,11 @@ if ActiveRecord::Base.connection.supports_migrations?
   class ActiveRecord::Migration
     class <<self
       attr_accessor :message_count
-      def puts(text="")
-        self.message_count ||= 0
-        self.message_count += 1
-      end
+    end
+
+    def puts(text="")
+      self.class.message_count ||= 0
+      self.class.message_count += 1
     end
   end
 
@@ -1165,6 +1166,44 @@ if ActiveRecord::Base.connection.supports_migrations?
       assert_raise(ActiveRecord::StatementInvalid) { Reminder.find(:first) }
     end
 
+    class MockMigration < ActiveRecord::Migration
+      attr_reader :went_up, :went_down
+      def initialize
+        @went_up   = false
+        @went_down = false
+      end
+
+      def up
+        @went_up = true
+        super
+      end
+
+      def down
+        @went_down = true
+        super
+      end
+    end
+
+    def test_instance_based_migration_up
+      migration = MockMigration.new
+      assert !migration.went_up, 'have not gone up'
+      assert !migration.went_down, 'have not gone down'
+
+      migration.migrate :up
+      assert migration.went_up, 'have gone up'
+      assert !migration.went_down, 'have not gone down'
+    end
+
+    def test_instance_based_migration_down
+      migration = MockMigration.new
+      assert !migration.went_up, 'have not gone up'
+      assert !migration.went_down, 'have not gone down'
+
+      migration.migrate :down
+      assert !migration.went_up, 'have gone up'
+      assert migration.went_down, 'have not gone down'
+    end
+
     def test_migrator_one_up
       assert !Person.column_methods_hash.include?(:last_name)
       assert !Reminder.table_exists?
@@ -1312,20 +1351,20 @@ if ActiveRecord::Base.connection.supports_migrations?
 
     def test_migrator_verbosity
       ActiveRecord::Migrator.up(MIGRATIONS_ROOT + "/valid", 1)
-      assert PeopleHaveLastNames.message_count > 0
+      assert_operator PeopleHaveLastNames.message_count, :>, 0
       PeopleHaveLastNames.message_count = 0
 
       ActiveRecord::Migrator.down(MIGRATIONS_ROOT + "/valid", 0)
-      assert PeopleHaveLastNames.message_count > 0
+      assert_operator PeopleHaveLastNames.message_count, :>, 0
       PeopleHaveLastNames.message_count = 0
     end
 
     def test_migrator_verbosity_off
       PeopleHaveLastNames.verbose = false
       ActiveRecord::Migrator.up(MIGRATIONS_ROOT + "/valid", 1)
-      assert PeopleHaveLastNames.message_count.zero?
+      assert_equal 0, PeopleHaveLastNames.message_count
       ActiveRecord::Migrator.down(MIGRATIONS_ROOT + "/valid", 0)
-      assert PeopleHaveLastNames.message_count.zero?
+      assert_equal 0, PeopleHaveLastNames.message_count
     end
 
     def test_migrator_going_down_due_to_version_target
@@ -1947,7 +1986,7 @@ if ActiveRecord::Base.connection.supports_migrations?
       @migrations_path = MIGRATIONS_ROOT + "/valid_with_timestamps"
       @existing_migrations = Dir[@migrations_path + "/*.rb"]
 
-      Time.travel_to(created_at = Time.utc(2010, 7, 26, 10, 10, 10)) do
+      Time.travel_to(Time.utc(2010, 7, 26, 10, 10, 10)) do
         copied = ActiveRecord::Migration.copy(@migrations_path, {:bukkits => MIGRATIONS_ROOT + "/to_copy_with_timestamps"})
         assert File.exists?(@migrations_path + "/20100726101010_people_have_hobbies.rb")
         assert File.exists?(@migrations_path + "/20100726101011_people_have_descriptions.rb")
@@ -1972,7 +2011,7 @@ if ActiveRecord::Base.connection.supports_migrations?
       sources[:bukkits] = MIGRATIONS_ROOT + "/to_copy_with_timestamps"
       sources[:omg]     = MIGRATIONS_ROOT + "/to_copy_with_timestamps2"
 
-      Time.travel_to(created_at = Time.utc(2010, 7, 26, 10, 10, 10)) do
+      Time.travel_to(Time.utc(2010, 7, 26, 10, 10, 10)) do
         copied = ActiveRecord::Migration.copy(@migrations_path, sources)
         assert File.exists?(@migrations_path + "/20100726101010_people_have_hobbies.rb")
         assert File.exists?(@migrations_path + "/20100726101011_people_have_descriptions.rb")
@@ -1992,7 +2031,7 @@ if ActiveRecord::Base.connection.supports_migrations?
       @migrations_path = MIGRATIONS_ROOT + "/valid_with_timestamps"
       @existing_migrations = Dir[@migrations_path + "/*.rb"]
 
-      Time.travel_to(created_at = Time.utc(2010, 2, 20, 10, 10, 10)) do
+      Time.travel_to(Time.utc(2010, 2, 20, 10, 10, 10)) do
         ActiveRecord::Migration.copy(@migrations_path, {:bukkits => MIGRATIONS_ROOT + "/to_copy_with_timestamps"})
         assert File.exists?(@migrations_path + "/20100301010102_people_have_hobbies.rb")
         assert File.exists?(@migrations_path + "/20100301010103_people_have_descriptions.rb")
@@ -2024,11 +2063,26 @@ if ActiveRecord::Base.connection.supports_migrations?
       clear
     end
 
+    def test_copying_migrations_to_non_existing_directory
+      @migrations_path = MIGRATIONS_ROOT + "/non_existing"
+      @existing_migrations = []
+
+      Time.travel_to(Time.utc(2010, 7, 26, 10, 10, 10)) do
+        copied = ActiveRecord::Migration.copy(@migrations_path, {:bukkits => MIGRATIONS_ROOT + "/to_copy_with_timestamps"})
+        assert File.exists?(@migrations_path + "/20100726101010_people_have_hobbies.rb")
+        assert File.exists?(@migrations_path + "/20100726101011_people_have_descriptions.rb")
+        assert_equal 2, copied.length
+      end
+    ensure
+      clear
+      Dir.delete(@migrations_path)
+    end
+
     def test_copying_migrations_to_empty_directory
       @migrations_path = MIGRATIONS_ROOT + "/empty"
       @existing_migrations = []
 
-      Time.travel_to(created_at = Time.utc(2010, 7, 26, 10, 10, 10)) do
+      Time.travel_to(Time.utc(2010, 7, 26, 10, 10, 10)) do
         copied = ActiveRecord::Migration.copy(@migrations_path, {:bukkits => MIGRATIONS_ROOT + "/to_copy_with_timestamps"})
         assert File.exists?(@migrations_path + "/20100726101010_people_have_hobbies.rb")
         assert File.exists?(@migrations_path + "/20100726101011_people_have_descriptions.rb")
diff --git a/activerecord/test/cases/named_scope_test.rb b/activerecord/test/cases/named_scope_test.rb
index fb24c65fff..6ac3e3fc56 100644
--- a/activerecord/test/cases/named_scope_test.rb
+++ b/activerecord/test/cases/named_scope_test.rb
@@ -122,7 +122,7 @@ class NamedScopeTest < ActiveRecord::TestCase
       :joins => 'JOIN authors ON authors.id = posts.author_id',
       :conditions => [ 'authors.author_address_id = ?', address.id ]
     )
-    assert_equal posts_with_authors_at_address_titles, Post.with_authors_at_address(address).find(:all, :select => 'title')
+    assert_equal posts_with_authors_at_address_titles.map(&:title), Post.with_authors_at_address(address).find(:all, :select => 'title').map(&:title)
   end
 
   def test_scope_with_object
diff --git a/activerecord/test/cases/persistence_test.rb b/activerecord/test/cases/persistence_test.rb
index 07262f56be..8ca9d626d1 100644
--- a/activerecord/test/cases/persistence_test.rb
+++ b/activerecord/test/cases/persistence_test.rb
@@ -192,7 +192,6 @@ class PersistencesTest < ActiveRecord::TestCase
     topic = Topic.create("title" => "New Topic") do |t|
       t.author_name = "David"
     end
-    topicReloaded = Topic.find(topic.id)
     assert_equal("New Topic", topic.title)
     assert_equal("David", topic.author_name)
   end
@@ -270,7 +269,7 @@ class PersistencesTest < ActiveRecord::TestCase
   end
 
   def test_record_not_found_exception
-    assert_raise(ActiveRecord::RecordNotFound) { topicReloaded = Topic.find(99999) }
+    assert_raise(ActiveRecord::RecordNotFound) { Topic.find(99999) }
   end
 
   def test_update_all
diff --git a/activerecord/test/cases/query_cache_test.rb b/activerecord/test/cases/query_cache_test.rb
index 5bb21a54bd..33916c4e46 100644
--- a/activerecord/test/cases/query_cache_test.rb
+++ b/activerecord/test/cases/query_cache_test.rb
@@ -133,7 +133,6 @@ class QueryCacheExpiryTest < ActiveRecord::TestCase
   def test_cache_is_expired_by_habtm_delete
     ActiveRecord::Base.connection.expects(:clear_query_cache).times(2)
     ActiveRecord::Base.cache do
-      c = Category.find(1)
       p = Post.find(1)
       assert p.categories.any?
       p.categories.delete_all
diff --git a/activerecord/test/cases/relation_scoping_test.rb b/activerecord/test/cases/relation_scoping_test.rb
index a27e2e72cd..dae9721a63 100644
--- a/activerecord/test/cases/relation_scoping_test.rb
+++ b/activerecord/test/cases/relation_scoping_test.rb
@@ -254,13 +254,11 @@ class HasManyScopingTest< ActiveRecord::TestCase
   end
 
   def test_should_maintain_default_scope_on_associations
-    person = people(:michael)
     magician = BadReference.find(1)
     assert_equal [magician], people(:michael).bad_references
   end
 
   def test_should_default_scope_on_associations_is_overriden_by_association_conditions
-    person = people(:michael)
     assert_equal [], people(:michael).fixed_bad_references
   end
 
diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index b44c716db8..535bcd4396 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -426,6 +426,52 @@ class RelationTest < ActiveRecord::TestCase
     assert_blank authors.all
   end
 
+  def test_where_with_ar_object
+    author = Author.first
+    authors = Author.scoped.where(:id => author)
+    assert_equal 1, authors.all.length
+  end
+
+  def test_find_with_list_of_ar
+    author = Author.first
+    authors = Author.find([author])
+    assert_equal author, authors.first
+  end
+
+  class Mary < Author; end
+
+  def test_find_by_classname
+    Author.create!(:name => Mary.name)
+    assert_equal 1, Author.where(:name => Mary).size
+  end
+
+  def test_find_by_id_with_list_of_ar
+    author = Author.first
+    authors = Author.find_by_id([author])
+    assert_equal author, authors
+  end
+
+  def test_find_all_using_where_twice_should_or_the_relation
+    david = authors(:david)
+    relation = Author.unscoped
+    relation = relation.where(:name => david.name)
+    relation = relation.where(:name => 'Santiago')
+    relation = relation.where(:id => david.id)
+    assert_equal [david], relation.all
+  end
+
+  def test_find_all_with_multiple_ors
+    david = authors(:david)
+    relation = [
+      { :name => david.name },
+      { :name => 'Santiago' },
+      { :name => 'tenderlove' },
+    ].inject(Author.unscoped) do |memo, param|
+      memo.where(param)
+    end
+    assert_equal [david], relation.all
+  end
+
   def test_exists
     davids = Author.where(:name => 'David')
     assert davids.exists?
diff --git a/activerecord/test/cases/timestamp_test.rb b/activerecord/test/cases/timestamp_test.rb
index eb93761fb2..70c098bc6d 100644
--- a/activerecord/test/cases/timestamp_test.rb
+++ b/activerecord/test/cases/timestamp_test.rb
@@ -113,7 +113,7 @@ class TimestampTest < ActiveRecord::TestCase
 
     pet = Pet.first
     owner = pet.owner
-    owner.update_attribute(:happy_at, (time = 3.days.ago))
+    owner.update_attribute(:happy_at, 3.days.ago)
     previously_owner_updated_at = owner.updated_at
 
     pet.name = "I'm a parrot"
diff --git a/activerecord/test/cases/transactions_test.rb b/activerecord/test/cases/transactions_test.rb
index dd9de3510b..b0ccd71836 100644
--- a/activerecord/test/cases/transactions_test.rb
+++ b/activerecord/test/cases/transactions_test.rb
@@ -163,7 +163,7 @@ class TransactionTest < ActiveRecord::TestCase
         @first.author_name += '_this_should_not_end_up_in_the_db'
         @first.save!
         flunk
-      rescue => e
+      rescue
         assert_equal original_author_name, @first.reload.author_name
         assert_equal nbooks_before_save, Book.count
       ensure
diff --git a/activerecord/test/cases/validations/association_validation_test.rb b/activerecord/test/cases/validations/association_validation_test.rb
index 1246dd4276..56e345990f 100644
--- a/activerecord/test/cases/validations/association_validation_test.rb
+++ b/activerecord/test/cases/validations/association_validation_test.rb
@@ -17,7 +17,7 @@ class AssociationValidationTest < ActiveRecord::TestCase
     o = Owner.new('name' => 'nopets')
     assert !o.save
     assert o.errors[:pets].any?
-    pet = o.pets.build('name' => 'apet')
+    o.pets.build('name' => 'apet')
     assert o.valid?
   end
 
@@ -27,7 +27,7 @@ class AssociationValidationTest < ActiveRecord::TestCase
     assert !o.save
     assert o.errors[:pets].any?
 
-    pet = o.pets.build('name' => 'apet')
+    o.pets.build('name' => 'apet')
     assert o.valid?
 
     2.times { o.pets.build('name' => 'apet') }
diff --git a/activerecord/test/cases/validations/uniqueness_validation_test.rb b/activerecord/test/cases/validations/uniqueness_validation_test.rb
index 9a863c25a8..679d67553b 100644
--- a/activerecord/test/cases/validations/uniqueness_validation_test.rb
+++ b/activerecord/test/cases/validations/uniqueness_validation_test.rb
@@ -60,7 +60,7 @@ class UniquenessValidationTest < ActiveRecord::TestCase
 
   def test_validates_uniqueness_with_validates
     Topic.validates :title, :uniqueness => true
-    t = Topic.create!('title' => 'abc')
+    Topic.create!('title' => 'abc')
 
     t2 = Topic.new('title' => 'abc')
     assert !t2.valid?
@@ -201,7 +201,7 @@ class UniquenessValidationTest < ActiveRecord::TestCase
 
   def test_validate_case_sensitive_uniqueness_with_attribute_passed_as_integer
     Topic.validates_uniqueness_of(:title, :case_sensitve => true)
-    t = Topic.create!('title' => 101)
+    Topic.create!('title' => 101)
 
     t2 = Topic.new('title' => 101)
     assert !t2.valid?