Merge commit 'rails/master'

26 files changed, 128 insertions, 55 deletions

diff --git a/activerecord/lib/active_record.rb b/activerecord/lib/active_record.rb
index 5942640c85..8a1aa50e24 100644
--- a/activerecord/lib/active_record.rb
+++ b/activerecord/lib/active_record.rb
@@ -111,10 +111,10 @@ module ActiveRecord
 
   autoload :TestCase
   autoload :TestFixtures, 'active_record/fixtures'
+end
 
-  base_hook do
-    Arel::Table.engine = Arel::Sql::Engine.new(self)
-  end
+ActiveSupport.on_load(:active_record) do
+  Arel::Table.engine = Arel::Sql::Engine.new(self)
 end
 
 I18n.load_path << File.dirname(__FILE__) + '/active_record/locale/en.yml'
\ No newline at end of file
diff --git a/activerecord/lib/active_record/association_preload.rb b/activerecord/lib/active_record/association_preload.rb
index 6725d4e88b..95bbaf00cf 100644
--- a/activerecord/lib/active_record/association_preload.rb
+++ b/activerecord/lib/active_record/association_preload.rb
@@ -159,6 +159,11 @@ module ActiveRecord
             association_proxy.__send__(:set_inverse_instance, associated_record, mapped_record)
           end
         end
+
+        id_to_record_map.each do |id, records|
+          next if seen_keys.include?(id.to_s)
+          records.each {|record| record.send("set_#{reflection_name}_target", nil) }            
+        end
       end
 
       # Given a collection of ActiveRecord objects, constructs a Hash which maps
@@ -324,7 +329,7 @@ module ActiveRecord
           klass = klass_name.constantize
 
           table_name = klass.quoted_table_name
-          primary_key = klass.primary_key
+          primary_key = reflection.options[:primary_key] || klass.primary_key
           column_type = klass.columns.detect{|c| c.name == primary_key}.type
 
           ids = id_map.keys.map do |id|
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index d623ddb915..7406daf837 100755
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -1,5 +1,6 @@
 require 'active_support/core_ext/module/delegation'
 require 'active_support/core_ext/enumerable'
+require 'active_support/core_ext/object/blank'
 
 module ActiveRecord
   class InverseOfAssociationNotFoundError < ActiveRecordError #:nodoc:
@@ -85,6 +86,15 @@ module ActiveRecord
     end
   end
 
+  # This error is raised when trying to destroy a parent instance in a N:1, 1:1 assosications
+  # (has_many, has_one) when there is at least 1 child assosociated instance.
+  # ex: if @project.tasks.size > 0, DeleteRestrictionError will be raised when trying to destroy @project
+  class DeleteRestrictionError < ActiveRecordError #:nodoc:
+    def initialize(reflection)
+      super("Cannot delete record because of dependent #{reflection.name}")
+    end
+  end
+
   # See ActiveRecord::Associations::ClassMethods for documentation.
   module Associations # :nodoc:
     extend ActiveSupport::Concern
@@ -830,6 +840,8 @@ module ActiveRecord
       #   objects are deleted *without* calling their +destroy+ method.  If set to <tt>:nullify</tt> all associated
       #   objects' foreign keys are set to +NULL+ *without* calling their +save+ callbacks. *Warning:* This option is ignored when also using
       #   the <tt>:through</tt> option.
+      #   the <tt>:through</tt> option. If set to <tt>:restrict</tt>
+      #   this object cannot be deleted if it has any associated object.
       # [:finder_sql]
       #   Specify a complete SQL statement to fetch the association. This is a good way to go for complex
       #   associations that depend on multiple tables. Note: When this option is used, +find_in_collection+ is _not_ added.
@@ -1468,9 +1480,15 @@ module ActiveRecord
 
         # Creates before_destroy callback methods that nullify, delete or destroy
         # has_many associated objects, according to the defined :dependent rule.
+        # If the association is marked as :dependent => :restrict, create a callback
+        # that prevents deleting entirely.
         #
         # See HasManyAssociation#delete_records.  Dependent associations
         # delete children, otherwise foreign key is set to NULL.
+        # See HasManyAssociation#delete_records. Dependent associations
+        # delete children if the option is set to :destroy or :delete_all, set the
+        # foreign key to NULL if the option is set to :nullify, and do not touch the
+        # child records if the option is set to :restrict.
         #
         # The +extra_conditions+ parameter, which is not used within the main
         # Active Record codebase, is meant to allow plugins to define extra
@@ -1530,14 +1548,24 @@ module ActiveRecord
                       %@#{dependent_conditions}@)
                   end
                 CALLBACK
+                when :restrict
+                  method_name = "has_many_dependent_restrict_for_#{reflection.name}".to_sym
+                  define_method(method_name) do
+                    unless send(reflection.name).empty?
+                      raise DeleteRestrictionError.new(reflection)
+                    end
+                  end
+                  before_destroy method_name
               else
-                raise ArgumentError, "The :dependent option expects either :destroy, :delete_all, or :nullify (#{reflection.options[:dependent].inspect})"
+                raise ArgumentError, "The :dependent option expects either :destroy, :delete_all, :nullify or :restrict (#{reflection.options[:dependent].inspect})"
             end
           end
         end
 
         # Creates before_destroy callback methods that nullify, delete or destroy
         # has_one associated objects, according to the defined :dependent rule.
+        # If the association is marked as :dependent => :restrict, create a callback
+        # that prevents deleting entirely.
         def configure_dependency_for_has_one(reflection)
           if reflection.options.include?(:dependent)
             name = reflection.options[:dependent]
@@ -1558,8 +1586,16 @@ module ActiveRecord
                     association.update_attribute(#{reflection.primary_key_name.inspect}, nil) if association
                   end
                 eoruby
+              when :restrict
+                method_name = "has_one_dependent_restrict_for_#{reflection.name}".to_sym
+                define_method(method_name) do
+                  unless send(reflection.name).nil?
+                    raise DeleteRestrictionError.new(reflection)
+                  end
+                end
+                before_destroy method_name
               else
-                raise ArgumentError, "The :dependent option expects either :destroy, :delete or :nullify (#{reflection.options[:dependent].inspect})"
+                raise ArgumentError, "The :dependent option expects either :destroy, :delete, :nullify or :restrict (#{reflection.options[:dependent].inspect})"
             end
 
             before_destroy method_name
@@ -1995,7 +2031,7 @@ module ActiveRecord
                   [aliased_table[foreign_key].eq(parent_table[reflection.options[:primary_key] || parent.primary_key])]
                 end
               when :belongs_to
-                [aliased_table[reflection.klass.primary_key].eq(parent_table[options[:foreign_key] || reflection.primary_key_name])]
+                [aliased_table[options[:primary_key] || reflection.klass.primary_key].eq(parent_table[options[:foreign_key] || reflection.primary_key_name])]
               end
 
               unless klass.descends_from_active_record?
diff --git a/activerecord/lib/active_record/associations/has_many_through_association.rb b/activerecord/lib/active_record/associations/has_many_through_association.rb
index bd2acd4340..5338bb099d 100644
--- a/activerecord/lib/active_record/associations/has_many_through_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_through_association.rb
@@ -1,4 +1,5 @@
 require "active_record/associations/through_association_scope"
+require 'active_support/core_ext/object/blank'
 
 module ActiveRecord
   module Associations
diff --git a/activerecord/lib/active_record/attribute_methods/dirty.rb b/activerecord/lib/active_record/attribute_methods/dirty.rb
index a8698a2f5a..435aea9b09 100644
--- a/activerecord/lib/active_record/attribute_methods/dirty.rb
+++ b/activerecord/lib/active_record/attribute_methods/dirty.rb
@@ -1,3 +1,5 @@
+require 'active_support/core_ext/object/blank'
+
 module ActiveRecord
   module AttributeMethods
     module Dirty
diff --git a/activerecord/lib/active_record/attribute_methods/primary_key.rb b/activerecord/lib/active_record/attribute_methods/primary_key.rb
index 095814b635..411330dda2 100644
--- a/activerecord/lib/active_record/attribute_methods/primary_key.rb
+++ b/activerecord/lib/active_record/attribute_methods/primary_key.rb
@@ -3,6 +3,12 @@ module ActiveRecord
     module PrimaryKey
       extend ActiveSupport::Concern
 
+      # Returns this record's primary key value wrapped in an Array
+      # or nil if the record is a new_record?
+      def to_key
+        new_record? ? nil : [ send(self.class.primary_key) ]
+      end
+
       module ClassMethods
         # Defines the primary key field -- can be overridden in subclasses. Overwriting will negate any effect of the
         # primary_key_prefix_type setting, though.
@@ -39,22 +45,6 @@ module ActiveRecord
         end
         alias :primary_key= :set_primary_key
       end
-
-      module InstanceMethods
-
-        # Returns this record's primary key value wrapped in an Array
-        # or nil if the record is a new_record?
-        # This is done to comply with the AMo interface that expects
-        # every AMo compliant object to respond_to?(:to_key) and return
-        # an Enumerable object from that call, or nil if new_record?
-        # This method also takes custom primary keys specified via
-        # the +set_primary_key+ into account.
-        def to_key
-          new_record? ? nil : [ self.primary_key ]
-        end
-
-      end
-
     end
   end
 end
diff --git a/activerecord/lib/active_record/attribute_methods/query.rb b/activerecord/lib/active_record/attribute_methods/query.rb
index a949d80120..948809c65a 100644
--- a/activerecord/lib/active_record/attribute_methods/query.rb
+++ b/activerecord/lib/active_record/attribute_methods/query.rb
@@ -1,3 +1,5 @@
+require 'active_support/core_ext/object/blank'
+
 module ActiveRecord
   module AttributeMethods
     module Query
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index 1c93346a52..37b379af9e 100755
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -13,6 +13,8 @@ require 'active_support/core_ext/hash/slice'
 require 'active_support/core_ext/string/behavior'
 require 'active_support/core_ext/object/singleton_class'
 require 'active_support/core_ext/module/delegation'
+require 'active_support/core_ext/object/duplicable'
+require 'active_support/core_ext/object/blank'
 require 'arel'
 require 'active_record/errors'
 
@@ -336,6 +338,9 @@ module ActiveRecord #:nodoc:
     # 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. By default, the prefix is the empty string.
+    #
+    # 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.
     cattr_accessor :table_name_prefix, :instance_writer => false
     @@table_name_prefix = ""
 
@@ -763,7 +768,7 @@ module ActiveRecord #:nodoc:
               contained = contained.singularize if parent.pluralize_table_names
               contained << '_'
             end
-            name = "#{table_name_prefix}#{contained}#{undecorated_table_name(base.name)}#{table_name_suffix}"
+            name = "#{full_table_name_prefix}#{contained}#{undecorated_table_name(base.name)}#{table_name_suffix}"
           end
 
         @quoted_table_name = nil
@@ -771,6 +776,10 @@ module ActiveRecord #:nodoc:
         name
       end
 
+      def full_table_name_prefix #:nodoc:
+        (parents.detect{ |p| p.respond_to?(:table_name_prefix) } || self).table_name_prefix
+      end
+
       # Defines the column name for use with single table inheritance
       # -- can be set in subclasses like so: self.inheritance_column = "type_id"
       def inheritance_column
@@ -1288,7 +1297,7 @@ module ActiveRecord #:nodoc:
         # <tt>options</tt> argument is the same as in find.
         #
         #   class Person < ActiveRecord::Base
-        #     default_scope :order => 'last_name, first_name'
+        #     default_scope order('last_name, first_name')
         #   end
         def default_scope(options = {})
           self.default_scoping << construct_finder_arel(options)
@@ -2214,6 +2223,7 @@ module ActiveRecord #:nodoc:
     extend QueryCache::ClassMethods
     extend ActiveSupport::Benchmarkable
 
+    include ActiveModel::Conversion
     include Validations
     include Locking::Optimistic, Locking::Pessimistic
     include AttributeMethods
@@ -2223,12 +2233,10 @@ module ActiveRecord #:nodoc:
     include AttributeMethods::Dirty
     include Callbacks, ActiveModel::Observing, Timestamp
     include Associations, AssociationPreload, NamedScope
-    include ActiveModel::Conversion
 
     # 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
 
     NilClass.add_whiner(self) if NilClass.respond_to?(:add_whiner)
@@ -2237,4 +2245,4 @@ end
 
 # TODO: Remove this and make it work with LAZY flag
 require 'active_record/connection_adapters/abstract_adapter'
-ActiveRecord.run_base_hooks(ActiveRecord::Base)
+ActiveSupport.run_load_hooks(:active_record, ActiveRecord::Base)
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb b/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb
index 020acbbe5a..1e095110f2 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb
@@ -1,3 +1,5 @@
+require 'active_support/core_ext/object/duplicable'
+
 module ActiveRecord
   module ConnectionAdapters # :nodoc:
     module QueryCache
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
index 64faaef4a0..046825d43f 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
@@ -1,3 +1,4 @@
+require 'active_support/core_ext/object/blank'
 require 'date'
 require 'set'
 require 'bigdecimal'
diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index 521bd810d0..55d9d20bb5 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
@@ -1,5 +1,6 @@
 require 'active_record/connection_adapters/abstract_adapter'
 require 'active_support/core_ext/kernel/requires'
+require 'active_support/core_ext/object/blank'
 require 'set'
 
 module MysqlCompat #:nodoc:
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index 31d5266da8..a6042e1382 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -1,5 +1,6 @@
 require 'active_record/connection_adapters/abstract_adapter'
 require 'active_support/core_ext/kernel/requires'
+require 'active_support/core_ext/object/blank'
 
 begin
   require_library_or_gem 'pg'
@@ -299,7 +300,7 @@ module ActiveRecord
       # QUOTING ==================================================
 
       # Escapes binary strings for bytea input to the database.
-      def escape_bytea(value)
+      def escape_bytea(original_value)
         if @connection.respond_to?(:escape_bytea)
           self.class.instance_eval do
             define_method(:escape_bytea) do |value|
@@ -323,13 +324,13 @@ module ActiveRecord
             end
           end
         end
-        escape_bytea(value)
+        escape_bytea(original_value)
       end
 
       # Unescapes bytea output from a database to the binary string it represents.
       # NOTE: This is NOT an inverse of escape_bytea! This is only to be used
       #       on escaped binary output from database drive.
-      def unescape_bytea(value)
+      def unescape_bytea(original_value)
         # In each case, check if the value actually is escaped PostgreSQL bytea output
         # or an unescaped Active Record attribute that was just written.
         if PGconn.respond_to?(:unescape_bytea)
@@ -369,7 +370,7 @@ module ActiveRecord
             end
           end
         end
-        unescape_bytea(value)
+        unescape_bytea(original_value)
       end
 
       # Quotes PostgreSQL-specific data types for SQL input.
@@ -394,7 +395,7 @@ module ActiveRecord
       end
 
       # Quotes strings for use in SQL input in the postgres driver for better performance.
-      def quote_string(s) #:nodoc:
+      def quote_string(original_value) #:nodoc:
         if @connection.respond_to?(:escape)
           self.class.instance_eval do
             define_method(:quote_string) do |s|
@@ -414,7 +415,7 @@ module ActiveRecord
             remove_method(:quote_string)
           end
         end
-        quote_string(s)
+        quote_string(original_value)
       end
 
       # Checks the following cases:
diff --git a/activerecord/lib/active_record/fixtures.rb b/activerecord/lib/active_record/fixtures.rb
index 79f70f07cd..22f0e60083 100644
--- a/activerecord/lib/active_record/fixtures.rb
+++ b/activerecord/lib/active_record/fixtures.rb
@@ -4,6 +4,7 @@ require 'csv'
 require 'zlib'
 require 'active_support/dependencies'
 require 'active_support/core_ext/logger'
+require 'active_support/core_ext/object/blank'
 
 if RUBY_VERSION < '1.9'
   module YAML #:nodoc:
diff --git a/activerecord/lib/active_record/named_scope.rb b/activerecord/lib/active_record/named_scope.rb
index 394e1587e1..9abf979cd0 100644
--- a/activerecord/lib/active_record/named_scope.rb
+++ b/activerecord/lib/active_record/named_scope.rb
@@ -1,6 +1,7 @@
 require 'active_support/core_ext/array'
 require 'active_support/core_ext/hash/except'
 require 'active_support/core_ext/object/singleton_class'
+require 'active_support/core_ext/object/blank'
 
 module ActiveRecord
   module NamedScope
@@ -101,7 +102,8 @@ module ActiveRecord
         name = name.to_sym
 
         if !scopes[name] && respond_to?(name, true)
-          raise ArgumentError, "Cannot define scope :#{name} because #{self.name}.#{name} method already exists."
+          logger.warn "Creating scope :#{name}. " \
+                      "Overwriting existing method #{self.name}.#{name}."
         end
 
         scopes[name] = lambda do |parent_scope, *args|
@@ -165,7 +167,14 @@ module ActiveRecord
       end
 
       def ==(other)
-        other.respond_to?(:to_ary) ? to_a == other.to_a : false
+        case other
+        when Scope
+          to_sql == other.to_sql
+        when Relation
+          other == self
+        when Array
+          to_a == other.to_a
+        end
       end
 
       private
diff --git a/activerecord/lib/active_record/nested_attributes.rb b/activerecord/lib/active_record/nested_attributes.rb
index 76ec7eb681..ee2d420194 100644
--- a/activerecord/lib/active_record/nested_attributes.rb
+++ b/activerecord/lib/active_record/nested_attributes.rb
@@ -1,5 +1,6 @@
 require 'active_support/core_ext/hash/except'
 require 'active_support/core_ext/object/try'
+require 'active_support/core_ext/object/blank'
 
 module ActiveRecord
   module NestedAttributes #:nodoc:
diff --git a/activerecord/lib/active_record/query_cache.rb b/activerecord/lib/active_record/query_cache.rb
index eb92bc2545..093c6c1e55 100644
--- a/activerecord/lib/active_record/query_cache.rb
+++ b/activerecord/lib/active_record/query_cache.rb
@@ -1,3 +1,5 @@
+require 'active_support/core_ext/object/blank'
+
 module ActiveRecord
   class QueryCache
     module ClassMethods
diff --git a/activerecord/lib/active_record/railtie.rb b/activerecord/lib/active_record/railtie.rb
index de47461c73..04c4a9c153 100644
--- a/activerecord/lib/active_record/railtie.rb
+++ b/activerecord/lib/active_record/railtie.rb
@@ -23,18 +23,18 @@ module ActiveRecord
     log_subscriber :active_record, ActiveRecord::Railties::LogSubscriber.new
 
     initializer "active_record.initialize_timezone" do
-      ActiveRecord.base_hook do
+      ActiveSupport.on_load(:active_record) do
         self.time_zone_aware_attributes = true
         self.default_timezone = :utc
       end
     end
 
     initializer "active_record.logger" do
-      ActiveRecord.base_hook { self.logger ||= ::Rails.logger }
+      ActiveSupport.on_load(:active_record) { self.logger ||= ::Rails.logger }
     end
 
     initializer "active_record.set_configs" do |app|
-      ActiveRecord.base_hook do
+      ActiveSupport.on_load(:active_record) do
         app.config.active_record.each do |k,v|
           send "#{k}=", v
         end
@@ -44,7 +44,7 @@ module ActiveRecord
     # This sets the database configuration from Configuration#database_configuration
     # and then establishes the connection.
     initializer "active_record.initialize_database" do |app|
-      ActiveRecord.base_hook do
+      ActiveSupport.on_load(:active_record) do
         self.configurations = app.config.database_configuration
         establish_connection
       end
@@ -53,7 +53,7 @@ module ActiveRecord
     # Expose database runtime to controller for logging.
     initializer "active_record.log_runtime" do |app|
       require "active_record/railties/controller_runtime"
-      ActionController.base_hook do
+      ActiveSupport.on_load(:action_controller) do
         include ActiveRecord::Railties::ControllerRuntime
       end
     end
@@ -71,9 +71,9 @@ module ActiveRecord
     end
 
     initializer "active_record.load_observers" do
-      ActiveRecord.base_hook { instantiate_observers }
+      ActiveSupport.on_load(:active_record) { instantiate_observers }
 
-      ActiveRecord.base_hook do
+      ActiveSupport.on_load(:active_record) do
         ActionDispatch::Callbacks.to_prepare(:activerecord_instantiate_observers) do
           ActiveRecord::Base.instantiate_observers
         end
@@ -81,7 +81,7 @@ module ActiveRecord
     end
 
     initializer "active_record.set_dispatch_hooks", :before => :set_clear_dependencies_hook do |app|
-      ActiveRecord.base_hook do
+      ActiveSupport.on_load(:active_record) do
         unless app.config.cache_classes
           ActionDispatch::Callbacks.after do
             ActiveRecord::Base.reset_subclasses
diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb
index a20c152eeb..8577ec58f7 100644
--- a/activerecord/lib/active_record/relation.rb
+++ b/activerecord/lib/active_record/relation.rb
@@ -1,3 +1,5 @@
+require 'active_support/core_ext/object/blank'
+
 module ActiveRecord
   class Relation
     JoinOperation = Struct.new(:relation, :join_class, :on)
diff --git a/activerecord/lib/active_record/relation/batches.rb b/activerecord/lib/active_record/relation/batches.rb
index 4a260d4caa..1c61e7d450 100644
--- a/activerecord/lib/active_record/relation/batches.rb
+++ b/activerecord/lib/active_record/relation/batches.rb
@@ -1,3 +1,5 @@
+require 'active_support/core_ext/object/blank'
+
 module ActiveRecord
   module Batches # :nodoc:
     # Yields each record that was found by the find +options+. The find is
@@ -48,6 +50,10 @@ module ActiveRecord
     def find_in_batches(options = {})
       relation = self
 
+       if orders.present? || taken.present?
+         ActiveRecord::Base.logger.warn("Scoped order and limit are ignored, it's forced to be batch order and batch size")
+       end
+
       if (finder_options = options.except(:start, :batch_size)).present?
         raise "You can't specify an order, it's forced to be #{batch_order}" if options[:order].present?
         raise "You can't specify a limit, it's forced to be the batch_size"  if options[:limit].present?
@@ -75,4 +81,4 @@ module ActiveRecord
       "#{@klass.table_name}.#{@klass.primary_key} ASC"
     end
   end
-end
\ No newline at end of file
+end
diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb
index e77424a64b..a5ea6e7e3a 100644
--- a/activerecord/lib/active_record/relation/calculations.rb
+++ b/activerecord/lib/active_record/relation/calculations.rb
@@ -1,3 +1,5 @@
+require 'active_support/core_ext/object/blank'
+
 module ActiveRecord
   module Calculations
     # Count operates using three different approaches.
diff --git a/activerecord/lib/active_record/relation/finder_methods.rb b/activerecord/lib/active_record/relation/finder_methods.rb
index c1cce679b6..37aaac0894 100644
--- a/activerecord/lib/active_record/relation/finder_methods.rb
+++ b/activerecord/lib/active_record/relation/finder_methods.rb
@@ -1,3 +1,5 @@
+require 'active_support/core_ext/object/blank'
+
 module ActiveRecord
   module FinderMethods
     # Find operates with four different retrieval approaches:
diff --git a/activerecord/lib/active_record/relation/predicate_builder.rb b/activerecord/lib/active_record/relation/predicate_builder.rb
index 7e83eccbb5..711df16bf1 100644
--- a/activerecord/lib/active_record/relation/predicate_builder.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder.rb
@@ -27,12 +27,7 @@ module ActiveRecord
             values = value.to_a
             attribute.in(values)
           when Range
-            # TODO : Arel should handle ranges with excluded end.
-            if value.exclude_end?
-              [attribute.gteq(value.begin), attribute.lt(value.end)]
-            else
-              attribute.in(value)
-            end
+            attribute.in(value)
           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 0250e739b8..e224781016 100644
--- a/activerecord/lib/active_record/relation/query_methods.rb
+++ b/activerecord/lib/active_record/relation/query_methods.rb
@@ -1,3 +1,5 @@
+require 'active_support/core_ext/object/blank'
+
 module ActiveRecord
   module QueryMethods
     extend ActiveSupport::Concern
diff --git a/activerecord/lib/active_record/relation/spawn_methods.rb b/activerecord/lib/active_record/relation/spawn_methods.rb
index 2841ff1239..a17de1bdbb 100644
--- a/activerecord/lib/active_record/relation/spawn_methods.rb
+++ b/activerecord/lib/active_record/relation/spawn_methods.rb
@@ -1,3 +1,5 @@
+require 'active_support/core_ext/object/blank'
+
 module ActiveRecord
   module SpawnMethods
     def merge(r)
diff --git a/activerecord/lib/active_record/schema.rb b/activerecord/lib/active_record/schema.rb
index a996a0ebac..a833356d15 100644
--- a/activerecord/lib/active_record/schema.rb
+++ b/activerecord/lib/active_record/schema.rb
@@ -1,3 +1,5 @@
+require 'active_support/core_ext/object/blank'
+
 module ActiveRecord
   # Allows programmers to programmatically define a schema in a portable
   # DSL. This means you can define tables, indexes, etc. without using SQL
diff --git a/activerecord/lib/active_record/validations/uniqueness.rb b/activerecord/lib/active_record/validations/uniqueness.rb
index e28808df98..4806fa0ecc 100644
--- a/activerecord/lib/active_record/validations/uniqueness.rb
+++ b/activerecord/lib/active_record/validations/uniqueness.rb
@@ -67,13 +67,11 @@ module ActiveRecord
 
         if value.nil? || (options[:case_sensitive] || !column.text?)
           sql = "#{sql_attribute} #{operator}"
-          params = [value]
         else
-          sql = "LOWER(#{sql_attribute}) #{operator}"
-          params = [value.mb_chars.downcase]
+          sql = "LOWER(#{sql_attribute}) = LOWER(?)"
         end
 
-        [sql, params]
+        [sql, [value]]
       end
     end