Merge branch 'master' into joindep

* master: (44 commits)
  grammar fix (reverted in e9a1ecd)
  Revert "fixed a doc bug in the CHANGELOG.md s/does no longer depend on/no longer depends on/"
  Add missed require making `enable_warnings` available
  Prepare generated Gemfile for Capistrano 3
  Added --model-name option scaffold_controller_generator.
  read the association instead of sending
  we should have unique sponsorable ids in the fixtures at least
  simplify populating the ordering hash
  the preloader for the RHS has all the preloaded records, so ask it
  only calculate offset index once. #12537
  Remove size alias for length validation
  Fix `singleton_class?`
  Minor Refactoring to `NumberHelper#number_to_human`
  `$SAFE = 4;` has been removed with Ruby 2.1
  scope_chain should not be mutated for other reflections
  Remove `default_primary_key_type`  and extract contains of `native_database_types` to a constant since they aren't conditional now in SQLite3Adapter. Makes it more like other adapters.
  cleanup changelog entry format. [ci skip]
  Extract a function to determine if the default value is a function
  Push default_function to superclass to avoid method check
  Dump the default function when the primary key is uuid
  ...

Conflicts:
	activerecord/lib/active_record/relation/finder_methods.rb

56 files changed, 365 insertions, 203 deletions

diff --git a/actionview/lib/action_view/helpers/date_helper.rb b/actionview/lib/action_view/helpers/date_helper.rb
index 8e1aea50a9..d7e8e99200 100644
--- a/actionview/lib/action_view/helpers/date_helper.rb
+++ b/actionview/lib/action_view/helpers/date_helper.rb
@@ -531,7 +531,7 @@ module ActionView
       #   my_date = Time.now + 2.days
       #
       #   # Generates a select field for days that defaults to the day for the date in my_date.
-      #   select_day(my_time)
+      #   select_day(my_date)
       #
       #   # Generates a select field for days that defaults to the number given.
       #   select_day(5)
@@ -541,7 +541,7 @@ module ActionView
       #
       #   # Generates a select field for days that defaults to the day for the date in my_date
       #   # that is named 'due' rather than 'day'.
-      #   select_day(my_time, field_name: 'due')
+      #   select_day(my_date, field_name: 'due')
       #
       #   # Generates a select field for days with a custom prompt. Use <tt>prompt: true</tt> for a
       #   # generic prompt.
diff --git a/actionview/lib/action_view/helpers/url_helper.rb b/actionview/lib/action_view/helpers/url_helper.rb
index 8a4918a8c0..2f5246f42a 100644
--- a/actionview/lib/action_view/helpers/url_helper.rb
+++ b/actionview/lib/action_view/helpers/url_helper.rb
@@ -455,7 +455,7 @@ module ActionView
         html_options, name = name, nil if block_given?
         html_options = (html_options || {}).stringify_keys
 
-        extras = %w{ cc bcc body subject }.map { |item|
+        extras = %w{ cc bcc body subject }.map! { |item|
           option = html_options.delete(item) || next
           "#{item}=#{Rack::Utils.escape_path(option)}"
         }.compact
diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 83c94caa53..e1eb3e4113 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,47 @@
+*   `scope_chain` should not be mutated for other reflections.
+
+    Currently `scope_chain` uses same array for building different
+    `scope_chain` for different associations. During processing
+    these arrays are sometimes mutated and because of in-place
+    mutation the changed `scope_chain` impacts other reflections.
+
+    Fix is to dup the value before adding to the `scope_chain`.
+
+    Fixes #3882.
+
+    *Neeraj Singh*
+
+*   Prevent the inversed association from being reloaded on save.
+
+    Fixes #9499.
+
+    *Dmitry Polushkin*
+
+*   Generate subquery for `Relation` if it passed as array condition for `where`
+    method.
+
+    Example:
+
+        # Before
+        Blog.where('id in (?)', Blog.where(id: 1))
+        # =>  SELECT "blogs".* FROM "blogs"  WHERE "blogs"."id" = 1
+        # =>  SELECT "blogs".* FROM "blogs"  WHERE (id IN (1))
+
+        # After
+        Blog.where('id in (?)', Blog.where(id: 1).select(:id))
+        # =>  SELECT "blogs".* FROM "blogs"
+        #     WHERE "blogs"."id" IN (SELECT "blogs"."id" FROM "blogs"  WHERE "blogs"."id" = 1)
+
+    Fixes #12415.
+
+    *Paul Nikitochkin*
+
+*   For missed association exception message
+    which is raised in `ActiveRecord::Associations::Preloader` class
+    added owner record class name in order to simplify to find problem code.
+
+    *Paul Nikitochkin*
+
 *   `has_and_belongs_to_many` is now transparently implemented in terms of
     `has_many :through`.  Behavior should remain the same, if not, it is a bug.
 
@@ -199,6 +243,12 @@
 
     *Yves Senn*
 
+*   Fixes bug when using includes combined with select, the select statement was overwritten.
+
+    Fixes #11773
+
+    *Edo Balvers*
+
 *   Load fixtures from linked folders.
 
     *Kassio Borges*
@@ -538,7 +588,7 @@
 
     *Neeraj Singh*
 
-*   Fixture setup does no longer depend on `ActiveRecord::Base.configurations`.
+*   Fixture setup no longer depends on `ActiveRecord::Base.configurations`.
     This is relevant when `ENV["DATABASE_URL"]` is used in place of a `database.yml`.
 
     *Yves Senn*
diff --git a/activerecord/lib/active_record/associations/association.rb b/activerecord/lib/active_record/associations/association.rb
index 04c36d5740..e6a45487d0 100644
--- a/activerecord/lib/active_record/associations/association.rb
+++ b/activerecord/lib/active_record/associations/association.rb
@@ -17,6 +17,7 @@ module ActiveRecord
     #         HasManyThroughAssociation + ThroughAssociation
     class Association #:nodoc:
       attr_reader :owner, :target, :reflection
+      attr_accessor :inversed
 
       delegate :options, :to => :reflection
 
@@ -42,6 +43,7 @@ module ActiveRecord
         @loaded = false
         @target = nil
         @stale_state = nil
+        @inversed = false
       end
 
       # Reloads the \target and returns +self+ on success.
@@ -59,8 +61,9 @@ module ActiveRecord
 
       # Asserts the \target has been loaded setting the \loaded flag to +true+.
       def loaded!
-        @loaded      = true
+        @loaded = true
         @stale_state = stale_state
+        @inversed = false
       end
 
       # The target is stale if the target no longer points to the record(s) that the
@@ -70,7 +73,7 @@ module ActiveRecord
       #
       # Note that if the target has not been loaded, it is not considered stale.
       def stale_target?
-        loaded? && @stale_state != stale_state
+        !inversed && loaded? && @stale_state != stale_state
       end
 
       # Sets the target of this association to <tt>\target</tt>, and the \loaded flag to +true+.
@@ -104,6 +107,7 @@ module ActiveRecord
         if record && invertible_for?(record)
           inverse = record.association(inverse_reflection_for(record).name)
           inverse.target = owner
+          inverse.inversed = true
         end
       end
 
diff --git a/activerecord/lib/active_record/associations/collection_association.rb b/activerecord/lib/active_record/associations/collection_association.rb
index 75f8990cf0..6b06a5f7fd 100644
--- a/activerecord/lib/active_record/associations/collection_association.rb
+++ b/activerecord/lib/active_record/associations/collection_association.rb
@@ -195,9 +195,7 @@ module ActiveRecord
 
       # Count all records using SQL.  Construct options and pass them with
       # scope to the target class's +count+.
-      def count(column_name = nil, count_options = {})
-        column_name, count_options = nil, column_name if column_name.is_a?(Hash)
-
+      def count(column_name = nil)
         relation = scope
         if association_scope.distinct_value
           # This is needed because 'SELECT count(DISTINCT *)..' is not valid SQL.
diff --git a/activerecord/lib/active_record/associations/collection_proxy.rb b/activerecord/lib/active_record/associations/collection_proxy.rb
index ea7f768a68..0b6cdf5217 100644
--- a/activerecord/lib/active_record/associations/collection_proxy.rb
+++ b/activerecord/lib/active_record/associations/collection_proxy.rb
@@ -669,8 +669,8 @@ module ActiveRecord
       #   #       #<Pet id: 2, name: "Spook", person_id: 1>,
       #   #       #<Pet id: 3, name: "Choo-Choo", person_id: 1>
       #   #    ]
-      def count(column_name = nil, options = {})
-        @association.count(column_name, options)
+      def count(column_name = nil)
+        @association.count(column_name)
       end
 
       # Returns the size of the collection. If the collection hasn't been loaded,
diff --git a/activerecord/lib/active_record/associations/preloader.rb b/activerecord/lib/active_record/associations/preloader.rb
index 713ff80d47..2393667ac8 100644
--- a/activerecord/lib/active_record/associations/preloader.rb
+++ b/activerecord/lib/active_record/associations/preloader.rb
@@ -153,13 +153,13 @@ module ActiveRecord
         records.group_by do |record|
           reflection = record.class.reflect_on_association(association)
 
-          reflection || raise_config_error(association)
+          reflection || raise_config_error(record, association)
         end
       end
 
-      def raise_config_error(association)
+      def raise_config_error(record, association)
         raise ActiveRecord::ConfigurationError,
-              "Association named '#{association}' was not found; " \
+              "Association named '#{association}' was not found on #{record.class.name}; " \
               "perhaps you misspelled it?"
       end
 
diff --git a/activerecord/lib/active_record/associations/preloader/through_association.rb b/activerecord/lib/active_record/associations/preloader/through_association.rb
index ea21836c65..2a8530af62 100644
--- a/activerecord/lib/active_record/associations/preloader/through_association.rb
+++ b/activerecord/lib/active_record/associations/preloader/through_association.rb
@@ -15,7 +15,7 @@ module ActiveRecord
                             through_reflection.name,
                             through_scope)
 
-          through_records = owners.map do |owner, h|
+          through_records = owners.map do |owner|
             association = owner.association through_reflection.name
 
             [owner, Array(association.reader)]
@@ -29,29 +29,30 @@ module ActiveRecord
                                          source_reflection.name,
                                          reflection_scope)
 
+          @preloaded_records = preloaders.flat_map(&:preloaded_records)
+
           middle_to_pl = preloaders.each_with_object({}) do |pl,h|
             pl.owners.each { |middle|
               h[middle] = pl
             }
           end
 
+          record_offset = {}
+          @preloaded_records.each_with_index do |record,i|
+            record_offset[record] = i
+          end
+
           through_records.each_with_object({}) { |(lhs,center),records_by_owner|
             pl_to_middle = center.group_by { |record| middle_to_pl[record] }
 
             records_by_owner[lhs] = pl_to_middle.flat_map do |pl, middles|
               rhs_records = middles.flat_map { |r|
-                r.send(source_reflection.name)
+                association = r.association source_reflection.name
+
+                association.reader
               }.compact
 
-              loaded_records = pl.preloaded_records
-              i = 0
-              record_index = loaded_records.each_with_object({}) { |r,indexes|
-                indexes[r] = i
-                i += 1
-              }
-              records = rhs_records.sort_by { |rhs| record_index[rhs] }
-              @preloaded_records.concat rhs_records
-              records
+              rhs_records.sort_by { |rhs| record_offset[rhs] }
             end
           }
         end
diff --git a/activerecord/lib/active_record/connection_adapters/column.rb b/activerecord/lib/active_record/connection_adapters/column.rb
index 2596c221bc..f2fbd5a8f2 100644
--- a/activerecord/lib/active_record/connection_adapters/column.rb
+++ b/activerecord/lib/active_record/connection_adapters/column.rb
@@ -13,7 +13,7 @@ module ActiveRecord
         ISO_DATETIME = /\A(\d{4})-(\d\d)-(\d\d) (\d\d):(\d\d):(\d\d)(\.\d+)?\z/
       end
 
-      attr_reader :name, :default, :type, :limit, :null, :sql_type, :precision, :scale
+      attr_reader :name, :default, :type, :limit, :null, :sql_type, :precision, :scale, :default_function
       attr_accessor :primary, :coder
 
       alias :encoded? :coder
@@ -27,16 +27,17 @@ module ActiveRecord
       # It will be mapped to one of the standard Rails SQL types in the <tt>type</tt> attribute.
       # +null+ determines if this column allows +NULL+ values.
       def initialize(name, default, sql_type = nil, null = true)
-        @name      = name
-        @sql_type  = sql_type
-        @null      = null
-        @limit     = extract_limit(sql_type)
-        @precision = extract_precision(sql_type)
-        @scale     = extract_scale(sql_type)
-        @type      = simplified_type(sql_type)
-        @default   = extract_default(default)
-        @primary   = nil
-        @coder     = nil
+        @name             = name
+        @sql_type         = sql_type
+        @null             = null
+        @limit            = extract_limit(sql_type)
+        @precision        = extract_precision(sql_type)
+        @scale            = extract_scale(sql_type)
+        @type             = simplified_type(sql_type)
+        @default          = extract_default(default)
+        @default_function = nil
+        @primary          = nil
+        @coder            = nil
       end
 
       # Returns +true+ if the column is either of type string or text.
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index 0c4d005e63..771a150eae 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -45,12 +45,12 @@ module ActiveRecord
   module ConnectionAdapters
     # PostgreSQL-specific extensions to column definitions in a table.
     class PostgreSQLColumn < Column #:nodoc:
-      attr_accessor :array, :default_function
+      attr_accessor :array
       # Instantiates a new PostgreSQL column definition in a table.
       def initialize(name, default, oid_type, sql_type = nil, null = true)
         @oid_type = oid_type
         default_value     = self.class.extract_value_from_default(default)
-        @default_function = default if !default_value && default && default =~ /.+\(.*\)/
+
         if sql_type =~ /\[\]$/
           @array = true
           super(name, default_value, sql_type[0..sql_type.length - 3], null)
@@ -58,6 +58,8 @@ module ActiveRecord
           @array = false
           super(name, default_value, sql_type, null)
         end
+
+        @default_function = default if has_default_function?(default_value, default)
       end
 
       # :stopdoc:
@@ -148,6 +150,10 @@ module ActiveRecord
 
       private
 
+        def has_default_function?(default_value, default)
+          !default_value && (%r{\w+(.*)} === default)
+        end
+
         def extract_limit(sql_type)
           case sql_type
           when /^bigint/i;    8
@@ -442,7 +448,7 @@ module ActiveRecord
       def prepare_column_options(column, types)
         spec = super
         spec[:array] = 'true' if column.respond_to?(:array) && column.array
-        spec[:default] = "\"#{column.default_function}\"" if column.respond_to?(:default_function) && column.default_function
+        spec[:default] = "\"#{column.default_function}\"" if column.default_function
         spec
       end
 
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
index 997384daea..e5ad08b6b0 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
@@ -55,6 +55,21 @@ module ActiveRecord
     class SQLite3Adapter < AbstractAdapter
       include Savepoints
 
+      NATIVE_DATABASE_TYPES = {
+        primary_key:  'INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL',
+        string:       { name: "varchar", limit: 255 },
+        text:         { name: "text" },
+        integer:      { name: "integer" },
+        float:        { name: "float" },
+        decimal:      { name: "decimal" },
+        datetime:     { name: "datetime" },
+        timestamp:    { name: "datetime" },
+        time:         { name: "time" },
+        date:         { name: "date" },
+        binary:       { name: "blob" },
+        boolean:      { name: "boolean" }
+      }
+
       class Version
         include Comparable
 
@@ -183,11 +198,6 @@ module ActiveRecord
         true
       end
 
-      # Returns true
-      def supports_autoincrement? #:nodoc:
-        true
-      end
-
       def supports_index_sort_order?
         true
       end
@@ -200,20 +210,7 @@ module ActiveRecord
       end
 
       def native_database_types #:nodoc:
-        {
-          :primary_key => default_primary_key_type,
-          :string      => { :name => "varchar", :limit => 255 },
-          :text        => { :name => "text" },
-          :integer     => { :name => "integer" },
-          :float       => { :name => "float" },
-          :decimal     => { :name => "decimal" },
-          :datetime    => { :name => "datetime" },
-          :timestamp   => { :name => "datetime" },
-          :time        => { :name => "time" },
-          :date        => { :name => "date" },
-          :binary      => { :name => "blob" },
-          :boolean     => { :name => "boolean" }
-        }
+        NATIVE_DATABASE_TYPES
       end
 
       # Returns the current database encoding format as a string, eg: 'UTF-8'
@@ -596,14 +593,6 @@ module ActiveRecord
           @sqlite_version ||= SQLite3Adapter::Version.new(select_value('select sqlite_version(*)'))
         end
 
-        def default_primary_key_type
-          if supports_autoincrement?
-            'INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL'
-          else
-            'INTEGER PRIMARY KEY NOT NULL'
-          end
-        end
-
         def translate_exception(exception, message)
           case exception.message
           when /column(s)? .* (is|are) not unique/
diff --git a/activerecord/lib/active_record/null_relation.rb b/activerecord/lib/active_record/null_relation.rb
index 716020e7e7..1f3d377e53 100644
--- a/activerecord/lib/active_record/null_relation.rb
+++ b/activerecord/lib/active_record/null_relation.rb
@@ -50,7 +50,7 @@ module ActiveRecord
       0
     end
 
-    def calculate(_operation, _column_name, _options = {})
+    def calculate(_operation, _column_name)
       if _operation == :count
         0
       else
diff --git a/activerecord/lib/active_record/railties/databases.rake b/activerecord/lib/active_record/railties/databases.rake
index daccab762f..ecadb95a5d 100644
--- a/activerecord/lib/active_record/railties/databases.rake
+++ b/activerecord/lib/active_record/railties/databases.rake
@@ -287,6 +287,7 @@ db_namespace = namespace :db do
       if ActiveRecord::Base.connection.supports_migrations?
         File.open(filename, "a") do |f|
           f.puts ActiveRecord::Base.connection.dump_schema_information
+          f.print "\n"
         end
       end
       db_namespace['structure:dump'].reenable
diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb
index e88c5d17cb..bce7766501 100644
--- a/activerecord/lib/active_record/reflection.rb
+++ b/activerecord/lib/active_record/reflection.rb
@@ -574,7 +574,7 @@ module ActiveRecord
           # Add to it the scope from this reflection (if any)
           scope_chain.first << scope if scope
 
-          through_scope_chain = through_reflection.scope_chain
+          through_scope_chain = through_reflection.scope_chain.map(&:dup)
 
           if options[:source_type]
             through_scope_chain.first <<
diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb
index 27c04b0952..2d267183ce 100644
--- a/activerecord/lib/active_record/relation/calculations.rb
+++ b/activerecord/lib/active_record/relation/calculations.rb
@@ -19,17 +19,16 @@ module ActiveRecord
     #
     #   Person.group(:city).count
     #   # => { 'Rome' => 5, 'Paris' => 3 }
-    def count(column_name = nil, options = {})
-      column_name, options = nil, column_name if column_name.is_a?(Hash)
-      calculate(:count, column_name, options)
+    def count(column_name = nil)
+      calculate(:count, column_name)
     end
 
     # Calculates the average value on a given column. Returns +nil+ if there's
     # no row. See +calculate+ for examples with options.
     #
     #   Person.average(:age) # => 35.8
-    def average(column_name, options = {})
-      calculate(:average, column_name, options)
+    def average(column_name)
+      calculate(:average, column_name)
     end
 
     # Calculates the minimum value on a given column. The value is returned
@@ -37,8 +36,8 @@ module ActiveRecord
     # +calculate+ for examples with options.
     #
     #   Person.minimum(:age) # => 7
-    def minimum(column_name, options = {})
-      calculate(:minimum, column_name, options)
+    def minimum(column_name)
+      calculate(:minimum, column_name)
     end
 
     # Calculates the maximum value on a given column. The value is returned
@@ -46,8 +45,8 @@ module ActiveRecord
     # +calculate+ for examples with options.
     #
     #   Person.maximum(:age) # => 93
-    def maximum(column_name, options = {})
-      calculate(:maximum, column_name, options)
+    def maximum(column_name)
+      calculate(:maximum, column_name)
     end
 
     # Calculates the sum of values on a given column. The value is returned
@@ -90,15 +89,15 @@ module ActiveRecord
     #   Person.group(:last_name).having("min(age) > 17").minimum(:age)
     #
     #   Person.sum("2 * age")
-    def calculate(operation, column_name, options = {})
+    def calculate(operation, column_name)
       if column_name.is_a?(Symbol) && attribute_alias?(column_name)
         column_name = attribute_alias(column_name)
       end
 
       if has_include?(column_name)
-        construct_relation_for_association_calculations.calculate(operation, column_name, options)
+        construct_relation_for_association_calculations.calculate(operation, column_name)
       else
-        perform_calculation(operation, column_name, options)
+        perform_calculation(operation, column_name)
       end
     end
 
@@ -181,7 +180,7 @@ module ActiveRecord
       eager_loading? || (includes_values.present? && (column_name || references_eager_loaded_tables?))
     end
 
-    def perform_calculation(operation, column_name, options = {})
+    def perform_calculation(operation, column_name)
       operation = operation.to_s.downcase
 
       # If #count is used with #distinct / #uniq it is considered distinct. (eg. relation.distinct.count)
diff --git a/activerecord/lib/active_record/relation/finder_methods.rb b/activerecord/lib/active_record/relation/finder_methods.rb
index f7f60635d3..a2c18c5226 100644
--- a/activerecord/lib/active_record/relation/finder_methods.rb
+++ b/activerecord/lib/active_record/relation/finder_methods.rb
@@ -242,10 +242,9 @@ module ActiveRecord
 
     def find_with_associations
       join_dependency = construct_join_dependency
-      relation = except :select
 
       aliases  = join_dependency.aliases
-      relation = relation.select aliases.columns
+      relation = select aliases.columns
       relation = apply_join_dependency(relation, join_dependency)
 
       if block_given?
diff --git a/activerecord/lib/active_record/sanitization.rb b/activerecord/lib/active_record/sanitization.rb
index 0b87ab9926..cab8fd745a 100644
--- a/activerecord/lib/active_record/sanitization.rb
+++ b/activerecord/lib/active_record/sanitization.rb
@@ -127,7 +127,17 @@ module ActiveRecord
         raise_if_bind_arity_mismatch(statement, statement.count('?'), values.size)
         bound = values.dup
         c = connection
-        statement.gsub('?') { quote_bound_value(bound.shift, c) }
+        statement.gsub('?') do
+          replace_bind_variable(bound.shift, c)
+        end
+      end
+
+      def replace_bind_variable(value, c = connection) #:nodoc:
+        if ActiveRecord::Relation === value
+          value.to_sql
+        else
+          quote_bound_value(value, c)
+        end
       end
 
       def replace_named_bind_variables(statement, bind_vars) #:nodoc:
@@ -135,7 +145,7 @@ module ActiveRecord
           if $1 == ':' # skip postgresql casts
             $& # return the whole match
           elsif bind_vars.include?(match = $2.to_sym)
-            quote_bound_value(bind_vars[match])
+            replace_bind_variable(bind_vars[match])
           else
             raise PreparedStatementInvalid, "missing value for :#{match} in #{statement}"
           end
diff --git a/activerecord/lib/active_record/schema_dumper.rb b/activerecord/lib/active_record/schema_dumper.rb
index 8986d255cd..e055d571ab 100644
--- a/activerecord/lib/active_record/schema_dumper.rb
+++ b/activerecord/lib/active_record/schema_dumper.rb
@@ -123,6 +123,7 @@ HEADER
               tbl.print %Q(, primary_key: "#{pk}")
             elsif pkcol.sql_type == 'uuid'
               tbl.print ", id: :uuid"
+              tbl.print %Q(, default: "#{pkcol.default_function}") if pkcol.default_function
             end
           else
             tbl.print ", id: false"
diff --git a/activerecord/test/cases/adapters/postgresql/uuid_test.rb b/activerecord/test/cases/adapters/postgresql/uuid_test.rb
index 0cd5b420fc..a753a23c09 100644
--- a/activerecord/test/cases/adapters/postgresql/uuid_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/uuid_test.rb
@@ -24,7 +24,7 @@ class PostgresqlUUIDTest < ActiveRecord::TestCase
     @connection.reconnect!
 
     @connection.transaction do
-      @connection.create_table('pg_uuids', id: :uuid) do |t|
+      @connection.create_table('pg_uuids', id: :uuid, default: 'uuid_generate_v1()') do |t|
         t.string 'name'
         t.uuid 'other_uuid', default: 'uuid_generate_v4()'
       end
@@ -60,7 +60,7 @@ class PostgresqlUUIDTest < ActiveRecord::TestCase
   def test_schema_dumper_for_uuid_primary_key
     schema = StringIO.new
     ActiveRecord::SchemaDumper.dump(@connection, schema)
-    assert_match(/\bcreate_table "pg_uuids", id: :uuid\b/, schema.string)
+    assert_match(/\bcreate_table "pg_uuids", id: :uuid, default: "uuid_generate_v1\(\)"/, schema.string)
     assert_match(/t\.uuid   "other_uuid", default: "uuid_generate_v4\(\)"/, schema.string)
   end
 end
diff --git a/activerecord/test/cases/associations/inverse_associations_test.rb b/activerecord/test/cases/associations/inverse_associations_test.rb
index 8c81e00865..893030345f 100644
--- a/activerecord/test/cases/associations/inverse_associations_test.rb
+++ b/activerecord/test/cases/associations/inverse_associations_test.rb
@@ -603,6 +603,18 @@ class InversePolymorphicBelongsToTests < ActiveRecord::TestCase
     assert_equal face.description, new_man.polymorphic_face.description, "Description of face should be the same after changes to replaced-parent-owned instance"
   end
 
+  def test_inversed_instance_should_not_be_reloaded_after_stale_state_changed
+    new_man = Man.new
+    face = Face.new
+    new_man.face = face
+
+    old_inversed_man = face.man
+    new_man.save!
+    new_inversed_man = face.man
+
+    assert_equal old_inversed_man.object_id, new_inversed_man.object_id
+  end
+
   def test_should_not_try_to_set_inverse_instances_when_the_inverse_is_a_has_many
     i = interests(:llama_wrangling)
     m = i.polymorphic_man
diff --git a/activerecord/test/cases/fixtures_test.rb b/activerecord/test/cases/fixtures_test.rb
index e61deb1080..bffff07089 100644
--- a/activerecord/test/cases/fixtures_test.rb
+++ b/activerecord/test/cases/fixtures_test.rb
@@ -253,7 +253,8 @@ class FixturesTest < ActiveRecord::TestCase
   end
 
   def test_fixtures_are_set_up_with_database_env_variable
-    ENV.stubs(:[]).with("DATABASE_URL").returns("sqlite3:///:memory:")
+    db_url_tmp = ENV['DATABASE_URL']
+    ENV['DATABASE_URL'] = "sqlite3:///:memory:"
     ActiveRecord::Base.stubs(:configurations).returns({})
     test_case = Class.new(ActiveRecord::TestCase) do
       fixtures :accounts
@@ -266,6 +267,8 @@ class FixturesTest < ActiveRecord::TestCase
     result = test_case.new(:test_fixtures).run
 
     assert result.passed?, "Expected #{result.name} to pass:\n#{result}"
+  ensure
+    ENV['DATABASE_URL'] = db_url_tmp
   end
 end
 
diff --git a/activerecord/test/cases/reflection_test.rb b/activerecord/test/cases/reflection_test.rb
index 0e5c7df2cc..d7ad5ed29f 100644
--- a/activerecord/test/cases/reflection_test.rb
+++ b/activerecord/test/cases/reflection_test.rb
@@ -18,6 +18,11 @@ require 'models/subscription'
 require 'models/tag'
 require 'models/sponsor'
 require 'models/edge'
+require 'models/hotel'
+require 'models/chef'
+require 'models/department'
+require 'models/cake_designer'
+require 'models/drink_designer'
 
 class ReflectionTest < ActiveRecord::TestCase
   include ActiveRecord::Reflection
@@ -227,6 +232,17 @@ class ReflectionTest < ActiveRecord::TestCase
     assert_equal expected, actual
   end
 
+  def test_scope_chain_does_not_interfere_with_hmt_with_polymorphic_case
+    @hotel = Hotel.create!
+    @department = @hotel.departments.create!
+    @department.chefs.create!(employable: CakeDesigner.create!)
+    @department.chefs.create!(employable: DrinkDesigner.create!)
+
+    assert_equal 1, @hotel.cake_designers.size
+    assert_equal 1, @hotel.drink_designers.size
+    assert_equal 2, @hotel.chefs.size
+  end
+
   def test_nested?
     assert !Author.reflect_on_association(:comments).nested?
     assert Author.reflect_on_association(:tags).nested?
diff --git a/activerecord/test/cases/relation/delegation_test.rb b/activerecord/test/cases/relation/delegation_test.rb
index 71ade0bcc2..c171c5e14e 100644
--- a/activerecord/test/cases/relation/delegation_test.rb
+++ b/activerecord/test/cases/relation/delegation_test.rb
@@ -9,10 +9,11 @@ module ActiveRecord
     def assert_responds(target, method)
       assert target.respond_to?(method)
       assert_nothing_raised do
-        case target.to_a.method(method).arity
-        when 0
+        method_arity = target.to_a.method(method).arity
+
+        if method_arity.zero?
           target.send(method)
-        when -1
+        elsif method_arity < 0
           if method == :shuffle!
             target.send(method)
           else
diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index f814947ab2..ec43ded690 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -295,7 +295,7 @@ class RelationTest < ActiveRecord::TestCase
   def test_null_relation_calculations_methods
     assert_no_queries do
       assert_equal 0, Developer.none.count
-      assert_equal 0, Developer.none.calculate(:count, nil, {})
+      assert_equal 0, Developer.none.calculate(:count, nil)
       assert_equal nil, Developer.none.calculate(:average, 'salary')
     end
   end
@@ -486,6 +486,14 @@ class RelationTest < ActiveRecord::TestCase
     assert_equal Developer.where(name: 'David').map(&:id).sort, developers
   end
 
+  def test_includes_with_select
+    query = Post.select('comments_count AS ranking').order('ranking').includes(:comments)
+      .where(comments: { id: 1 })
+
+    assert_equal ['comments_count AS ranking'], query.select_values
+    assert_equal 1, query.to_a.size
+  end
+
   def test_loading_with_one_association
     posts = Post.preload(:comments)
     post = posts.find { |p| p.id == 1 }
@@ -626,6 +634,11 @@ class RelationTest < ActiveRecord::TestCase
       relation = Author.where(:id => Author.where(:id => david.id))
       assert_equal [david], relation.to_a
     }
+
+    assert_queries(1) {
+      relation = Author.where('id in (?)', Author.where(id: david).select(:id))
+      assert_equal [david], relation.to_a
+    }
   end
 
   def test_find_all_using_where_with_relation_and_alternate_primary_key
diff --git a/activerecord/test/cases/sanitize_test.rb b/activerecord/test/cases/sanitize_test.rb
index 082570c55b..4c0762deca 100644
--- a/activerecord/test/cases/sanitize_test.rb
+++ b/activerecord/test/cases/sanitize_test.rb
@@ -31,4 +31,10 @@ class SanitizeTest < ActiveRecord::TestCase
     assert_equal "name=#{quoted_bambi_and_thumper}", Binary.send(:sanitize_sql_array, ["name=?", "Bambi\nand\nThumper"])
     assert_equal "name=#{quoted_bambi_and_thumper}", Binary.send(:sanitize_sql_array, ["name=?", "Bambi\nand\nThumper".mb_chars])
   end
+
+  def test_sanitize_sql_array_handles_relations
+    assert_match(/\(\bselect\b.*?\bwhere\b.*?\)/i,
+      Binary.send(:sanitize_sql_array, ["id in (?)", Binary.where(id: 1)]),
+      "should sanitize `Relation` as subquery")
+  end
 end
diff --git a/activerecord/test/cases/transactions_test.rb b/activerecord/test/cases/transactions_test.rb
index 17206ffe99..980981903a 100644
--- a/activerecord/test/cases/transactions_test.rb
+++ b/activerecord/test/cases/transactions_test.rb
@@ -421,7 +421,9 @@ class TransactionTest < ActiveRecord::TestCase
     topic = Topic.new(:title => 'test')
     topic.freeze
     e = assert_raise(RuntimeError) { topic.save }
-    assert_equal "can't modify frozen Hash", e.message
+    assert_match(/frozen/i, e.message) # Not good enough, but we can't do much
+                                       # about it since there is no specific error
+                                       # for frozen objects.
     assert !topic.persisted?, 'not persisted'
     assert_nil topic.id
     assert topic.frozen?, 'not frozen'
diff --git a/activerecord/test/fixtures/sponsors.yml b/activerecord/test/fixtures/sponsors.yml
index bfc6b238b1..2da541c539 100644
--- a/activerecord/test/fixtures/sponsors.yml
+++ b/activerecord/test/fixtures/sponsors.yml
@@ -8,5 +8,5 @@ boring_club_sponsor_for_groucho:
   sponsorable_type: Member
 crazy_club_sponsor_for_groucho:
   sponsor_club: crazy_club
-  sponsorable_id: 2
+  sponsorable_id: 3
   sponsorable_type: Member
diff --git a/activerecord/test/models/cake_designer.rb b/activerecord/test/models/cake_designer.rb
new file mode 100644
index 0000000000..9c57ef573a
--- /dev/null
+++ b/activerecord/test/models/cake_designer.rb
@@ -0,0 +1,3 @@
+class CakeDesigner < ActiveRecord::Base
+  has_one :chef, as: :employable
+end
diff --git a/activerecord/test/models/chef.rb b/activerecord/test/models/chef.rb
new file mode 100644
index 0000000000..67a4e54f06
--- /dev/null
+++ b/activerecord/test/models/chef.rb
@@ -0,0 +1,3 @@
+class Chef < ActiveRecord::Base
+  belongs_to :employable, polymorphic: true
+end
diff --git a/activerecord/test/models/department.rb b/activerecord/test/models/department.rb
new file mode 100644
index 0000000000..08004a0ed3
--- /dev/null
+++ b/activerecord/test/models/department.rb
@@ -0,0 +1,4 @@
+class Department < ActiveRecord::Base
+  has_many :chefs
+  belongs_to :hotel
+end
diff --git a/activerecord/test/models/drink_designer.rb b/activerecord/test/models/drink_designer.rb
new file mode 100644
index 0000000000..2db968ef11
--- /dev/null
+++ b/activerecord/test/models/drink_designer.rb
@@ -0,0 +1,3 @@
+class DrinkDesigner < ActiveRecord::Base
+  has_one :chef, as: :employable
+end
diff --git a/activerecord/test/models/hotel.rb b/activerecord/test/models/hotel.rb
new file mode 100644
index 0000000000..b352cd22f3
--- /dev/null
+++ b/activerecord/test/models/hotel.rb
@@ -0,0 +1,6 @@
+class Hotel < ActiveRecord::Base
+  has_many :departments
+  has_many :chefs, through: :departments
+  has_many :cake_designers, source_type: 'CakeDesigner', source: :employable, through: :chefs
+  has_many :drink_designers, source_type: 'DrinkDesigner', source: :employable, through: :chefs
+end
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index 75711673a7..88a686d436 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -787,6 +787,22 @@ ActiveRecord::Schema.define do
     t.string 'from'
   end
 
+  create_table :hotels, force: true do |t|
+  end
+  create_table :departments, force: true do |t|
+    t.integer :hotel_id
+  end
+  create_table :cake_designers, force: true do |t|
+  end
+  create_table :drink_designers, force: true do |t|
+  end
+  create_table :chefs, force: true do |t|
+    t.integer :employable_id
+    t.string :employable_type
+    t.integer :department_id
+  end
+
+
   except 'SQLite' do
     # fk_test_has_fk should be before fk_test_has_pk
     create_table :fk_test_has_fk, :force => true do |t|
diff --git a/activerecord/test/schema/sqlite_specific_schema.rb b/activerecord/test/schema/sqlite_specific_schema.rb
index e9ddeb32cf..b7aff4f47d 100644
--- a/activerecord/test/schema/sqlite_specific_schema.rb
+++ b/activerecord/test/schema/sqlite_specific_schema.rb
@@ -1,9 +1,6 @@
 ActiveRecord::Schema.define do
-  # For sqlite 3.1.0+, make a table with an autoincrement column
-  if supports_autoincrement?
-    create_table :table_with_autoincrement, :force => true do |t|
-      t.column :name, :string
-    end
+  create_table :table_with_autoincrement, :force => true do |t|
+    t.column :name, :string
   end
 
   execute "DROP TABLE fk_test_has_fk" rescue nil
diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index 478fef2baf..f1dd7c312d 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -1,10 +1,3 @@
-*   Add `flatten` and `flatten!` methods to Duration objects.
-
-    Example:
-         Date.today + (1.month + 1.month).flatten == Date.today + 2.months
-
-    *Ionatan Wiznia*
-
 *   `require_dependency` accepts objects that respond to `to_path`, in
     particular `Pathname` instances.
 
diff --git a/activesupport/lib/active_support/core_ext/class/attribute.rb b/activesupport/lib/active_support/core_ext/class/attribute.rb
index 83038f9da5..f2a221c396 100644
--- a/activesupport/lib/active_support/core_ext/class/attribute.rb
+++ b/activesupport/lib/active_support/core_ext/class/attribute.rb
@@ -118,7 +118,10 @@ class Class
   end
 
   private
-    def singleton_class?
-      ancestors.first != self
+
+    unless respond_to?(:singleton_class?)
+      def singleton_class?
+        ancestors.first != self
+      end
     end
 end
diff --git a/activesupport/lib/active_support/dependencies.rb b/activesupport/lib/active_support/dependencies.rb
index df13fef0a4..19d4ff51d7 100644
--- a/activesupport/lib/active_support/dependencies.rb
+++ b/activesupport/lib/active_support/dependencies.rb
@@ -8,6 +8,7 @@ require 'active_support/core_ext/module/introspection'
 require 'active_support/core_ext/module/anonymous'
 require 'active_support/core_ext/module/qualified_const'
 require 'active_support/core_ext/object/blank'
+require 'active_support/core_ext/kernel/reporting'
 require 'active_support/core_ext/load_error'
 require 'active_support/core_ext/name_error'
 require 'active_support/core_ext/string/starts_ends_with'
diff --git a/activesupport/lib/active_support/duration.rb b/activesupport/lib/active_support/duration.rb
index 1db0ca51ae..87b6407038 100644
--- a/activesupport/lib/active_support/duration.rb
+++ b/activesupport/lib/active_support/duration.rb
@@ -81,18 +81,6 @@ module ActiveSupport
       to_i
     end
 
-    # Flattens all the +parts+ of the duration, and returns a
-    # new duration object.
-    def flatten
-      Duration.new(@value, flatten_parts)
-    end
-
-    # Flattens all the +parts+ of this duration.
-    def flatten!
-      @parts = flatten_parts
-      self
-    end
-
     protected
 
       def sum(sign, time = ::Time.current) #:nodoc:
@@ -109,14 +97,6 @@ module ActiveSupport
         end
       end
 
-      def flatten_parts
-        @parts.inject({}) do |result, (name, value)|
-          result[name] ||= 0
-          result[name] += value
-          result
-        end.to_a
-      end
-
     private
 
       def method_missing(method, *args, &block) #:nodoc:
diff --git a/activesupport/lib/active_support/number_helper.rb b/activesupport/lib/active_support/number_helper.rb
index c9c0eff2bf..e0151baa36 100644
--- a/activesupport/lib/active_support/number_helper.rb
+++ b/activesupport/lib/active_support/number_helper.rb
@@ -108,7 +108,7 @@ module ActiveSupport
 
     DECIMAL_UNITS = { 0 => :unit, 1 => :ten, 2 => :hundred, 3 => :thousand, 6 => :million, 9 => :billion, 12 => :trillion, 15 => :quadrillion,
       -1 => :deci, -2 => :centi, -3 => :mili, -6 => :micro, -9 => :nano, -12 => :pico, -15 => :femto }
-
+    INVERTED_DECIMAL_UNITS = DECIMAL_UNITS.invert
     STORAGE_UNITS = [:byte, :kb, :mb, :gb, :tb]
 
     # Formats a +number+ into a US phone number (e.g., (555)
@@ -561,8 +561,6 @@ module ActiveSupport
       #for backwards compatibility with those that didn't add strip_insignificant_zeros to their locale files
       options[:strip_insignificant_zeros] = true if not options.key?(:strip_insignificant_zeros)
 
-      inverted_du = DECIMAL_UNITS.invert
-
       units = options.delete :units
       unit_exponents = case units
       when Hash
@@ -573,7 +571,7 @@ module ActiveSupport
         translate_number_value_with_default("human.decimal_units.units", :locale => options[:locale], :raise => true)
       else
         raise ArgumentError, ":units must be a Hash or String translation scope."
-      end.keys.map{|e_name| inverted_du[e_name] }.sort_by{|e| -e}
+      end.keys.map!{|e_name| INVERTED_DECIMAL_UNITS[e_name] }.sort_by!{|e| -e}
 
       number_exponent = number != 0 ? Math.log10(number.abs).floor : 0
       display_exponent = unit_exponents.find{ |e| number_exponent >= e } || 0
diff --git a/activesupport/test/core_ext/duration_test.rb b/activesupport/test/core_ext/duration_test.rb
index cc24d7c74c..ed267cf4b9 100644
--- a/activesupport/test/core_ext/duration_test.rb
+++ b/activesupport/test/core_ext/duration_test.rb
@@ -145,21 +145,6 @@ class DurationTest < ActiveSupport::TestCase
     assert_equal '172800', 2.days.to_json
   end
 
-  def test_flatten
-    a = 2.months
-    b = (1.month + 1.month).flatten
-
-    assert_equal a.parts, b.parts
-  end
-
-  def test_flatten!
-    a = (1.month + 1.month)
-    b = a.flatten
-    a.flatten!
-
-    assert_equal a.parts, b.parts
-  end
-
   protected
     def with_env_tz(new_tz = 'US/Eastern')
       old_tz, ENV['TZ'] = ENV['TZ'], new_tz
diff --git a/activesupport/test/core_ext/thread_test.rb b/activesupport/test/core_ext/thread_test.rb
index 54d2dcd8dd..6a7c6e0604 100644
--- a/activesupport/test/core_ext/thread_test.rb
+++ b/activesupport/test/core_ext/thread_test.rb
@@ -72,17 +72,4 @@ class ThreadExt < ActiveSupport::TestCase
     end
   end
 
-  def test_thread_variable_security
-    rubinius_skip "$SAFE is not supported on Rubinius."
-
-    t = Thread.new { sleep }
-
-    assert_raises(SecurityError) do
-      Thread.new { $SAFE = 4; t.thread_variable_get(:foo) }.join
-    end
-
-    assert_raises(SecurityError) do
-      Thread.new { $SAFE = 4; t.thread_variable_set(:foo, :baz) }.join
-    end
-  end
 end
diff --git a/guides/source/action_controller_overview.md b/guides/source/action_controller_overview.md
index 8dfecd0190..cd4a1a0792 100644
--- a/guides/source/action_controller_overview.md
+++ b/guides/source/action_controller_overview.md
@@ -209,7 +209,7 @@ class PeopleController < ActionController::Base
   # Request reply.
   def update
     person = current_account.people.find(params[:id])
-    person.update_attributes!(person_params)
+    person.update!(person_params)
     redirect_to person
   end
 
diff --git a/guides/source/action_view_overview.md b/guides/source/action_view_overview.md
index 94aa0f8502..d19dd11181 100644
--- a/guides/source/action_view_overview.md
+++ b/guides/source/action_view_overview.md
@@ -269,7 +269,7 @@ Rails will render the `_product_ruler` partial (with no data passed to it) betwe
 
 ### Layouts
 
-Layouts can be used to render a common view template around the results of Rails controller actions. Typically, every Rails has a couple of overall layouts that most pages are rendered within. For example, a site might have a layout for a logged in user, and a layout for the marketing or sales side of the site. The logged in user layout might include top-level navigation that should be present across many controller actions. The sales layout for a SaaS app might include top-level navigation for things like "Pricing" and "Contact Us." You would expect each layout to have a different look and feel. You can read more details about Layouts in the [Layouts and Rendering in Rails](layouts_and_rendering.html) guide.
+Layouts can be used to render a common view template around the results of Rails controller actions. Typically, every Rails application has a couple of overall layouts that most pages are rendered within. For example, a site might have a layout for a logged in user, and a layout for the marketing or sales side of the site. The logged in user layout might include top-level navigation that should be present across many controller actions. The sales layout for a SaaS app might include top-level navigation for things like "Pricing" and "Contact Us." You would expect each layout to have a different look and feel. You can read more details about Layouts in the [Layouts and Rendering in Rails](layouts_and_rendering.html) guide.
 
 Partial Layouts
 ---------------
diff --git a/guides/source/active_record_basics.md b/guides/source/active_record_basics.md
index 34baae509b..a184f0753d 100644
--- a/guides/source/active_record_basics.md
+++ b/guides/source/active_record_basics.md
@@ -116,7 +116,7 @@ to Active Record instances:
   locking](http://api.rubyonrails.org/classes/ActiveRecord/Locking.html) to
   a model.
 * `type` - Specifies that the model uses [Single Table
-  Inheritance](http://api.rubyonrails.org/classes/ActiveRecord/Base.html).
+  Inheritance](http://api.rubyonrails.org/classes/ActiveRecord/Base.html#label-Single+table+inheritance).
 * `(association_name)_type` - Stores the type for
   [polymorphic associations](association_basics.html#polymorphic-associations).
 * `(table_name)_count` - Used to cache the number of belonging objects on
diff --git a/guides/source/active_record_validations.md b/guides/source/active_record_validations.md
index 339612ebc5..0df52a655f 100644
--- a/guides/source/active_record_validations.md
+++ b/guides/source/active_record_validations.md
@@ -438,8 +438,6 @@ provide a personalized message or use `presence: true` instead. When
 `:in` or `:within` have a lower limit of 1, you should either provide a
 personalized message or call `presence` prior to `length`.
 
-The `size` helper is an alias for `length`.
-
 ### `numericality`
 
 This helper validates that your attributes have only numeric values. By
@@ -528,7 +526,7 @@ If you validate the presence of an object associated via a `has_one` or
 Since `false.blank?` is true, if you want to validate the presence of a boolean
 field you should use `validates :field_name, inclusion: { in: [true, false] }`.
 
-The default error message is _"can't be empty"_.
+The default error message is _"can't be blank"_.
 
 ### `absence`
 
diff --git a/guides/source/active_support_core_extensions.md b/guides/source/active_support_core_extensions.md
index d11c17117e..d3f49b19fa 100644
--- a/guides/source/active_support_core_extensions.md
+++ b/guides/source/active_support_core_extensions.md
@@ -3699,21 +3699,6 @@ Time.utc(1582, 10, 3) + 5.days
 # => Mon Oct 18 00:00:00 UTC 1582
 ```
 
-When addinng or substracting durations, the resulting duration will be equivalent to subsequent calls to since or advance, so:
-
-```ruby
-Date.new(2013,1,28) + 1.month + 1.month
-# => Thu, 28 Mar 2013
-```
-
-If you want to add durations and then use them as just one call to since or advance, you can use the flatten or flatten! method:
-
-```ruby
-Date.new(2013,1,31) + (1.month + 1.month).flatten
-# => Sun, 31 Mar 2013
-```
-
-
 Extensions to `File`
 --------------------
 
diff --git a/guides/source/getting_started.md b/guides/source/getting_started.md
index bb2e8e906f..2f322d15da 100644
--- a/guides/source/getting_started.md
+++ b/guides/source/getting_started.md
@@ -1490,8 +1490,8 @@ So first, we'll wire up the Post show template
   </p>
 <% end %>
 
-<%= link_to 'Edit Post', edit_post_path(@post) %> |
-<%= link_to 'Back to Posts', posts_path %>
+<%= link_to 'Back', posts_path %>
+| <%= link_to 'Edit', edit_post_path(@post) %>
 ```
 
 This adds a form on the `Post` show page that creates a new comment by
diff --git a/railties/CHANGELOG.md b/railties/CHANGELOG.md
index 4e6bf899af..8a0e0ff3f6 100644
--- a/railties/CHANGELOG.md
+++ b/railties/CHANGELOG.md
@@ -1,3 +1,7 @@
+*   Added `--model-name` scaffld\_controller\_generator option.
+
+    *yalab*
+
 *   Expose MiddlewareStack#unshift to environment configuration.
 
     *Ben Pickles*
diff --git a/railties/lib/rails/commands/server.rb b/railties/lib/rails/commands/server.rb
index 485bd1eb09..4201dac42f 100644
--- a/railties/lib/rails/commands/server.rb
+++ b/railties/lib/rails/commands/server.rb
@@ -1,6 +1,7 @@
 require 'fileutils'
 require 'optparse'
 require 'action_dispatch'
+require 'rails'
 
 module Rails
   class Server < ::Rack::Server
@@ -32,7 +33,7 @@ module Rails
 
         opt_parser.parse! args
 
-        options[:log_stdout] = options[:daemonize].blank? && options[:environment] == "development"
+        options[:log_stdout] = options[:daemonize].blank? && (options[:environment] || Rails.env) == "development"
         options[:server]     = args.shift
         options
       end
diff --git a/railties/lib/rails/generators/rails/app/templates/Gemfile b/railties/lib/rails/generators/rails/app/templates/Gemfile
index edc76e6c34..4048930c8d 100644
--- a/railties/lib/rails/generators/rails/app/templates/Gemfile
+++ b/railties/lib/rails/generators/rails/app/templates/Gemfile
@@ -25,7 +25,7 @@ end
 # gem 'unicorn'
 
 # Use Capistrano for deployment
-# gem 'capistrano', group: :development
+# gem 'capistrano-rails', group: :development
 
 <% unless defined?(JRUBY_VERSION) -%>
 # Use debugger
diff --git a/railties/lib/rails/generators/rails/scaffold_controller/scaffold_controller_generator.rb b/railties/lib/rails/generators/rails/scaffold_controller/scaffold_controller_generator.rb
index 4f36b612ae..6bf0a33a5f 100644
--- a/railties/lib/rails/generators/rails/scaffold_controller/scaffold_controller_generator.rb
+++ b/railties/lib/rails/generators/rails/scaffold_controller/scaffold_controller_generator.rb
@@ -13,7 +13,7 @@ module Rails
       argument :attributes, type: :array, default: [], banner: "field:type field:type"
 
       def create_controller_files
-        template "controller.rb", File.join('app/controllers', class_path, "#{controller_file_name}_controller.rb")
+        template "controller.rb", File.join('app/controllers', controller_class_path, "#{controller_file_name}_controller.rb")
       end
 
       hook_for :template_engine, :test_framework, as: :scaffold
diff --git a/railties/lib/rails/generators/resource_helpers.rb b/railties/lib/rails/generators/resource_helpers.rb
index 7fd5c00768..a01eb57651 100644
--- a/railties/lib/rails/generators/resource_helpers.rb
+++ b/railties/lib/rails/generators/resource_helpers.rb
@@ -9,11 +9,19 @@ module Rails
 
       def self.included(base) #:nodoc:
         base.class_option :force_plural, type: :boolean, desc: "Forces the use of a plural ModelName"
+        base.class_option :model_name, type: :string, desc: "ModelName to be used"
       end
 
       # Set controller variables on initialization.
       def initialize(*args) #:nodoc:
         super
+        if options[:model_name]
+          controller_name = name
+          self.name = options[:model_name]
+          assign_names!(self.name)
+        else
+          controller_name = name
+        end
 
         if name == name.pluralize && name.singularize != name.pluralize && !options[:force_plural]
           unless ResourceHelpers.skip_warn
@@ -24,19 +32,26 @@ module Rails
           assign_names!(name)
         end
 
-        @controller_name = name.pluralize
+        assign_controller_names!(controller_name.pluralize)
       end
 
       protected
 
-        attr_reader :controller_name
+        attr_reader :controller_name, :controller_file_name
 
         def controller_class_path
-          class_path
+          if options[:model_name]
+            @controller_class_path
+          else
+            class_path
+          end
         end
 
-        def controller_file_name
-          @controller_file_name ||= file_name.pluralize
+        def assign_controller_names!(name)
+          @controller_name = name
+          @controller_class_path = name.include?('/') ? name.split('/') : name.split('::')
+          @controller_class_path.map! { |m| m.underscore }
+          @controller_file_name = @controller_class_path.pop
         end
 
         def controller_file_path
diff --git a/railties/test/commands/server_test.rb b/railties/test/commands/server_test.rb
index 20afca2618..ba688f1e9e 100644
--- a/railties/test/commands/server_test.rb
+++ b/railties/test/commands/server_test.rb
@@ -27,26 +27,62 @@ class Rails::ServerTest < ActiveSupport::TestCase
   end
 
   def test_environment_with_rails_env
-    with_rails_env 'production' do
-      server = Rails::Server.new
-      assert_equal 'production', server.options[:environment]
+    with_rack_env nil do
+      with_rails_env 'production' do
+        server = Rails::Server.new
+        assert_equal 'production', server.options[:environment]
+      end
     end
   end
 
   def test_environment_with_rack_env
-    with_rack_env 'production' do
-      server = Rails::Server.new
-      assert_equal 'production', server.options[:environment]
+    with_rails_env nil do
+      with_rack_env 'production' do
+        server = Rails::Server.new
+        assert_equal 'production', server.options[:environment]
+      end
     end
   end
 
   def test_log_stdout
-    args    = ["-e", "development"]
-    options = Rails::Server::Options.new.parse!(args)
-    assert_equal true, options[:log_stdout]
+    with_rack_env nil do
+      with_rails_env nil do
+        args    = []
+        options = Rails::Server::Options.new.parse!(args)
+        assert_equal true, options[:log_stdout]
 
-    args    = ["-e", "production"]
-    options = Rails::Server::Options.new.parse!(args)
-    assert_equal false, options[:log_stdout]
+        args    = ["-e", "development"]
+        options = Rails::Server::Options.new.parse!(args)
+        assert_equal true, options[:log_stdout]
+
+        args    = ["-e", "production"]
+        options = Rails::Server::Options.new.parse!(args)
+        assert_equal false, options[:log_stdout]
+
+        with_rack_env 'development' do
+          args    = []
+          options = Rails::Server::Options.new.parse!(args)
+          assert_equal true, options[:log_stdout]
+        end
+
+        with_rack_env 'production' do
+          args    = []
+          options = Rails::Server::Options.new.parse!(args)
+          assert_equal false, options[:log_stdout]
+        end
+
+        with_rails_env 'development' do
+          args    = []
+          options = Rails::Server::Options.new.parse!(args)
+          assert_equal true, options[:log_stdout]
+        end
+
+        with_rails_env 'production' do
+          args    = []
+          options = Rails::Server::Options.new.parse!(args)
+          assert_equal false, options[:log_stdout]
+        end
+      end
+    end
   end
 end
diff --git a/railties/test/env_helpers.rb b/railties/test/env_helpers.rb
index 6223c85bbf..330fe150ca 100644
--- a/railties/test/env_helpers.rb
+++ b/railties/test/env_helpers.rb
@@ -1,7 +1,10 @@
+require 'rails'
+
 module EnvHelpers
   private
 
   def with_rails_env(env)
+    Rails.instance_variable_set :@_env, nil
     switch_env 'RAILS_ENV', env do
       switch_env 'RACK_ENV', nil do
         yield
@@ -10,6 +13,7 @@ module EnvHelpers
   end
 
   def with_rack_env(env)
+    Rails.instance_variable_set :@_env, nil
     switch_env 'RACK_ENV', env do
       switch_env 'RAILS_ENV', nil do
         yield
diff --git a/railties/test/generators/named_base_test.rb b/railties/test/generators/named_base_test.rb
index 2bc2c33a72..ac5cfff229 100644
--- a/railties/test/generators/named_base_test.rb
+++ b/railties/test/generators/named_base_test.rb
@@ -117,6 +117,25 @@ class NamedBaseTest < Rails::Generators::TestCase
     assert Rails::Generators.hidden_namespaces.include?('hidden')
   end
 
+  def test_scaffold_plural_names_with_model_name_option
+    g = generator ['Admin::Foo'], model_name: 'User'
+    assert_name g, 'user',        :singular_name
+    assert_name g, 'User',        :name
+    assert_name g, 'user',        :file_path
+    assert_name g, 'User',        :class_name
+    assert_name g, 'user',        :file_name
+    assert_name g, 'User',        :human_name
+    assert_name g, 'users',       :plural_name
+    assert_name g, 'user',        :i18n_scope
+    assert_name g, 'users',       :table_name
+    assert_name g, 'Admin::Foos', :controller_name
+    assert_name g, %w(admin),     :controller_class_path
+    assert_name g, 'Admin::Foos', :controller_class_name
+    assert_name g, 'admin/foos',  :controller_file_path
+    assert_name g, 'foos',        :controller_file_name
+    assert_name g, 'admin.foos',  :controller_i18n_scope
+  end
+
   protected
 
     def assert_name(generator, value, method)
diff --git a/railties/test/generators/scaffold_controller_generator_test.rb b/railties/test/generators/scaffold_controller_generator_test.rb
index 013cb78252..26e56a162c 100644
--- a/railties/test/generators/scaffold_controller_generator_test.rb
+++ b/railties/test/generators/scaffold_controller_generator_test.rb
@@ -166,4 +166,13 @@ class ScaffoldControllerGeneratorTest < Rails::Generators::TestCase
       assert_match(/render action: 'new'/, content)
     end
   end
+
+  def test_model_name_option
+    run_generator ["Admin::User", "--model-name=User"]
+    assert_file "app/controllers/admin/users_controller.rb" do |content|
+      assert_instance_method :index, content do |m|
+        assert_match("@users = User.all", m)
+      end
+    end
+  end
 end