Merge branch 'master' into loofah

Conflicts:
	actionpack/CHANGELOG.md
	actionpack/test/controller/integration_test.rb
	actionview/CHANGELOG.md

20 files changed, 452 insertions, 327 deletions

diff --git a/guides/source/4_2_release_notes.md b/guides/source/4_2_release_notes.md
index 8c5abb54ea..a39dd9ace0 100644
--- a/guides/source/4_2_release_notes.md
+++ b/guides/source/4_2_release_notes.md
@@ -59,22 +59,35 @@ Please refer to the [Changelog][railties] for detailed changes.
 
 ### Removals
 
-* The `rails application` command has been removed without replacement.
-  ([Pull Request](https://github.com/rails/rails/pull/11616))
+*   The `rails application` command has been removed without replacement.
+    ([Pull Request](https://github.com/rails/rails/pull/11616))
+
+### Deprecations
+
+*   Deprecated `Rails::Rack::LogTailer` without replacement.
+    ([Commit](https://github.com/rails/rails/commit/84a13e019e93efaa8994b3f8303d635a7702dbce))
 
 ### Notable changes
 
-* Introduced `bin/setup` script to bootstrap an application.
-  ([Pull Request](https://github.com/rails/rails/pull/15189))
+*   Introduced `--skip-gems` option in the app generator to skip gems such as
+    `turbolinks` and `coffee-rails` that does not have their own specific flags.
+    ([Commit](https://github.com/rails/rails/commit/10565895805887d4faf004a6f71219da177f78b7))
+
+*   Introduced `bin/setup` script to bootstrap an application.
+    ([Pull Request](https://github.com/rails/rails/pull/15189))
+
+*   Changed default value for `config.assets.digest` to `true` in development.
+    ([Pull Request](https://github.com/rails/rails/pull/15155))
 
-* Changed default value for `config.assets.digest` to `true` in development.
-  ([Pull Request](https://github.com/rails/rails/pull/15155))
+*   Introduced an API to register new extensions for `rake notes`.
+    ([Pull Request](https://github.com/rails/rails/pull/14379))
 
-* Introduced an API to register new extensions for `rake notes`.
-  ([Pull Request](https://github.com/rails/rails/pull/14379))
+*   Introduced `Rails.gem_version` as a convenience method to return `Gem::Version.new(Rails.version)`.
+    ([Pull Request](https://github.com/rails/rails/pull/14101))
+
+*   Introduced an `after_bundle` callback in the Rails templates.
+    ([Pull Request](https://github.com/rails/rails/pull/16359))
 
-* Introduced `Rails.gem_version` as a convenience method to return `Gem::Version.new(Rails.version)`.
-  ([Pull Request](https://github.com/rails/rails/pull/14101))
 
 Action Pack
 -----------
@@ -83,8 +96,8 @@ Please refer to the [Changelog][action-pack] for detailed changes.
 
 ### Deprecations
 
-* Deprecated support for setting the `:to` option of a router to a symbol or a
-  string that does not contain a `#` character:
+*   Deprecated support for setting the `:to` option of a router to a symbol or a
+    string that does not contain a `#` character:
 
     ```ruby
     get '/posts', to: MyRackApp    => (No change necessary)
@@ -97,8 +110,17 @@ Please refer to the [Changelog][action-pack] for detailed changes.
 
 ### Notable changes
 
-* The `*_filter` family methods has been removed from the documentation. Their
-  usage are discouraged in favor of the `*_action` family methods:
+*   `render nothing: true` or rendering a `nil` body no longer add a single
+    space padding to the response body.
+    ([Pull Request](https://github.com/rails/rails/pull/14883))
+
+*   Introduced the `always_permitted_parameters` option to configure which
+    parameters are permitted globally. The default value of this configuration
+    is `['controller', 'action']`.
+    ([Pull Request](https://github.com/rails/rails/pull/15933))
+
+*   The `*_filter` family methods has been removed from the documentation. Their
+    usage are discouraged in favor of the `*_action` family methods:
 
     ```
     after_filter          => after_action
@@ -123,22 +145,21 @@ Please refer to the [Changelog][action-pack] for detailed changes.
     (Commit [1](https://github.com/rails/rails/commit/6c5f43bab8206747a8591435b2aa0ff7051ad3de),
     [2](https://github.com/rails/rails/commit/489a8f2a44dc9cea09154ee1ee2557d1f037c7d4))
 
+*   Added HTTP method `MKCALENDAR` from RFC-4791
+    ([Pull Request](https://github.com/rails/rails/pull/15121))
 
-* Added HTTP method `MKCALENDAR` from RFC-4791
-  ([Pull Request](https://github.com/rails/rails/pull/15121))
+*   `*_fragment.action_controller` notifications now include the controller and action name
+    in the payload.
+    ([Pull Request](https://github.com/rails/rails/pull/14137))
 
-* `*_fragment.action_controller` notifications now include the controller and action name
-  in the payload.
-  ([Pull Request](https://github.com/rails/rails/pull/14137))
+*   Segments that are passed into URL helpers are now automatically escaped.
+    ([Commit](https://github.com/rails/rails/commit/5460591f0226a9d248b7b4f89186bd5553e7768f))
 
-* Segments that are passed into URL helpers are now automatically escaped.
-  ([Commit](https://github.com/rails/rails/commit/5460591f0226a9d248b7b4f89186bd5553e7768f))
+*   Improved Routing Error page with fuzzy matching for route search.
+    ([Pull Request](https://github.com/rails/rails/pull/14619))
 
-* Improved Routing Error page with fuzzy matching for route search.
-  ([Pull Request](https://github.com/rails/rails/pull/14619))
-
-* Added option to disable logging of CSRF failures.
-  ([Pull Request](https://github.com/rails/rails/pull/14280))
+*   Added option to disable logging of CSRF failures.
+    ([Pull Request](https://github.com/rails/rails/pull/14280))
 
 
 Action View
@@ -148,17 +169,21 @@ Please refer to the [Changelog][action-view] for detailed changes.
 
 ### Deprecations
 
-* Deprecated `AbstractController::Base.parent_prefixes`.
-  Override `AbstractController::Base.local_prefixes` when you want to change
-  where to find views.
-  ([Pull Request](https://github.com/rails/rails/pull/15026))
+*   Deprecated `AbstractController::Base.parent_prefixes`.
+    Override `AbstractController::Base.local_prefixes` when you want to change
+    where to find views.
+    ([Pull Request](https://github.com/rails/rails/pull/15026))
 
-* Deprecated `ActionView::Digestor#digest(name, format, finder, options = {})`,
-  arguments should be passed as a hash instead.
-  ([Pull Request](https://github.com/rails/rails/pull/14243))
+*   Deprecated `ActionView::Digestor#digest(name, format, finder, options = {})`,
+    arguments should be passed as a hash instead.
+    ([Pull Request](https://github.com/rails/rails/pull/14243))
 
 ### Notable changes
 
+*   The form helpers no longer generate a `<div>` element with inline CSS around
+    the hidden fields.
+    ([Pull Request](https://github.com/rails/rails/pull/14738))
+
 
 Action Mailer
 -------------
@@ -167,6 +192,10 @@ Please refer to the [Changelog][action-mailer] for detailed changes.
 
 ### Notable changes
 
+*   Added the `show_previews` configuration option for enabling mailer previews
+    outside of the development environment.
+    ([Pull Request](https://github.com/rails/rails/pull/15970))
+
 
 Active Record
 -------------
@@ -177,91 +206,114 @@ for detailed changes.
 
 ### Removals
 
-* Removed deprecated method `ActiveRecord::Base.quoted_locking_column`.
-  ([Pull Request](https://github.com/rails/rails/pull/15612))
+*   Removed `cache_attributes` and friends. All attributes are cached.
+    ([Pull Request](https://github.com/rails/rails/pull/15429))
 
-* Removed deprecated `ActiveRecord::Migrator.proper_table_name`. Use the
-  `proper_table_name` instance method on `ActiveRecord::Migration` instead.
-  ([Pull Request](https://github.com/rails/rails/pull/15512))
+*   Removed deprecated method `ActiveRecord::Base.quoted_locking_column`.
+    ([Pull Request](https://github.com/rails/rails/pull/15612))
 
-* Removed `cache_attributes` and friends. All attributes are cached.
-  ([Pull Request](https://github.com/rails/rails/pull/15429))
+*   Removed deprecated `ActiveRecord::Migrator.proper_table_name`. Use the
+    `proper_table_name` instance method on `ActiveRecord::Migration` instead.
+    ([Pull Request](https://github.com/rails/rails/pull/15512))
 
-* Removed unused `:timestamp` type. Transparently alias it to `:datetime`
-  in all cases. Fixes inconsistencies when column types are sent outside of
-  `ActiveRecord`, such as for XML Serialization.
-  ([Pull Request](https://github.com/rails/rails/pull/15184))
+*   Removed unused `:timestamp` type. Transparently alias it to `:datetime`
+    in all cases. Fixes inconsistencies when column types are sent outside of
+    `ActiveRecord`, such as for XML Serialization.
+    ([Pull Request](https://github.com/rails/rails/pull/15184))
 
 ### Deprecations
 
-* Deprecated returning `nil` from `column_for_attribute` when no column exists.
-  It will return a null object in Rails 5.0
-  ([Pull Request](https://github.com/rails/rails/pull/15878))
+*   Deprecated broken support for automatic detection of counter caches on
+    `has_many :through` associations. You should instead manually specify the
+    counter cache on the `has_many` and `belongs_to` associations for the
+    through records.
+    ([Pull Request](https://github.com/rails/rails/pull/15754))
+
+*   Deprecated `serialized_attributes` without replacement.
+    ([Pull Request](https://github.com/rails/rails/pull/15704))
 
-* Deprecated `serialized_attributes` without replacement.
-  ([Pull Request](https://github.com/rails/rails/pull/15704))
+*   Deprecated returning `nil` from `column_for_attribute` when no column
+    exists. It will return a null object in Rails 5.0
+    ([Pull Request](https://github.com/rails/rails/pull/15878))
 
-* Deprecated using `.joins`, `.preload` and `.eager_load` with associations that
-  depends on the instance state (i.e. those defined with a scope that takes an
-  argument) without replacement.
-  ([Commit](https://github.com/rails/rails/commit/ed56e596a0467390011bc9d56d462539776adac1))
+*   Deprecated using `.joins`, `.preload` and `.eager_load` with associations
+    that depends on the instance state (i.e. those defined with a scope that
+    takes an argument) without replacement.
+    ([Commit](https://github.com/rails/rails/commit/ed56e596a0467390011bc9d56d462539776adac1))
 
-* Deprecated passing Active Record objects to `.find` or `.exists?`. Call `#id`
-  on the objects first.
-  (Commit [1](https://github.com/rails/rails/commit/d92ae6ccca3bcfd73546d612efaea011270bd270),
-  [2](https://github.com/rails/rails/commit/d35f0033c7dec2b8d8b52058fb8db495d49596f7))
+*   Deprecated passing Active Record objects to `.find` or `.exists?`. Call
+    `#id` on the objects first.
+    (Commit [1](https://github.com/rails/rails/commit/d92ae6ccca3bcfd73546d612efaea011270bd270),
+    [2](https://github.com/rails/rails/commit/d35f0033c7dec2b8d8b52058fb8db495d49596f7))
 
-* Deprecated half-baked support for PostgreSQL range values with excluding
-  beginnings. We currently map PostgreSQL ranges to Ruby ranges. This conversion
-  is not fully possible because the Ruby range does not support excluded
-  beginnings.
+*   Deprecated half-baked support for PostgreSQL range values with excluding
+    beginnings. We currently map PostgreSQL ranges to Ruby ranges. This conversion
+    is not fully possible because the Ruby range does not support excluded
+    beginnings.
 
     The current solution of incrementing the beginning is not correct
     and is now deprecated. For subtypes where we don't know how to increment
-    (e.g. `#succ` is not defined) it will raise an `ArgumentError` for ranges with
-    excluding beginnings.
+    (e.g. `#succ` is not defined) it will raise an `ArgumentError` for ranges
+    with excluding beginnings.
 
     ([Commit](https://github.com/rails/rails/commit/91949e48cf41af9f3e4ffba3e5eecf9b0a08bfc3))
 
-* Deprecated broken support for automatic detection of counter caches on
-  `has_many :through` associations. You should instead manually specify the
-  counter cache on the `has_many` and `belongs_to` associations for the through
-  records.
-  ([Pull Request](https://github.com/rails/rails/pull/15754))
-
 ### Notable changes
 
-* Added support for `#pretty_print` in `ActiveRecord::Base` objects.
-  ([Pull Request](https://github.com/rails/rails/pull/15172))
+*   Added a `:required` option to singular associations, which defines a
+    presence validation on the association.
+    ([Pull Request](https://github.com/rails/rails/pull/16056))
+
+*   Introduced `ActiveRecord::Base#validate!` that raises `RecordInvalid` if the
+    record is invalid.
+    ([Pull Request](https://github.com/rails/rails/pull/8639))
+
+*   `ActiveRecord::Base#reload` now behaves the same as `m = Model.find(m.id)`,
+    meaning that it no longer retains the extra attributes from custom
+    `select`s.
+    ([Pull Request](https://github.com/rails/rails/pull/15866))
 
-* PostgreSQL and SQLite adapters no longer add a default limit of 255 characters
-  on string columns.
-  ([Pull Request](https://github.com/rails/rails/pull/14579))
+*   Introduced the `bin/rake db:purge` task to empty the database for the
+    current environment.
+    ([Commit](https://github.com/rails/rails/commit/e2f232aba15937a4b9d14bd91e0392c6d55be58d))
 
-* `sqlite3:///some/path` now resolves to the absolute system path `/some/path`.
-  For relative paths, use `sqlite3:some/path` instead. (Previously, `sqlite3:///some/path`
-  resolved to the relative path `some/path`. This behaviour was deprecated on
-  Rails 4.1.)
-  ([Pull Request](https://github.com/rails/rails/pull/14569))
+*   `ActiveRecord::Dirty` now detects in-place changes to mutable values.
+    Serialized attributes on ActiveRecord models will no longer save when
+    unchanged. This also works with other types such as string columns and json
+    columns on PostgreSQL.
+    (Pull Requests [1](https://github.com/rails/rails/pull/15674),
+    [2](https://github.com/rails/rails/pull/15786),
+    [3](https://github.com/rails/rails/pull/15788))
 
-* Introduced `#validate` as an alias for `#valid?`.
-  ([Pull Request](https://github.com/rails/rails/pull/14456))
+*   Added support for `#pretty_print` in `ActiveRecord::Base` objects.
+    ([Pull Request](https://github.com/rails/rails/pull/15172))
 
-* `#touch` now accepts multiple attributes to be touched at once.
-  ([Pull Request](https://github.com/rails/rails/pull/14423))
+*   PostgreSQL and SQLite adapters no longer add a default limit of 255
+    characters on string columns.
+    ([Pull Request](https://github.com/rails/rails/pull/14579))
 
-* Added support for fractional seconds for MySQL 5.6 and above.
-  (Pull Request [1](https://github.com/rails/rails/pull/8240), [2](https://github.com/rails/rails/pull/14359))
+*   `sqlite3:///some/path` now resolves to the absolute system path
+    `/some/path`. For relative paths, use `sqlite3:some/path` instead.
+    (Previously, `sqlite3:///some/path` resolved to the relative path
+    `some/path`. This behaviour was deprecated on Rails 4.1.)
+    ([Pull Request](https://github.com/rails/rails/pull/14569))
 
-* Added support for the `citext` column type in PostgreSQL adapter.
-  ([Pull Request](https://github.com/rails/rails/pull/12523))
+*   Introduced `#validate` as an alias for `#valid?`.
+    ([Pull Request](https://github.com/rails/rails/pull/14456))
 
-* Added support for user-created range types in PostgreSQL adapter.
-  ([Commit](https://github.com/rails/rails/commit/4cb47167e747e8f9dc12b0ddaf82bdb68c03e032))
+*   `#touch` now accepts multiple attributes to be touched at once.
+    ([Pull Request](https://github.com/rails/rails/pull/14423))
+
+*   Added support for fractional seconds for MySQL 5.6 and above.
+    (Pull Request [1](https://github.com/rails/rails/pull/8240),
+    [2](https://github.com/rails/rails/pull/14359))
+
+*   Added support for the `citext` column type in PostgreSQL adapter.
+    ([Pull Request](https://github.com/rails/rails/pull/12523))
+
+*   Added support for user-created range types in PostgreSQL adapter.
+    ([Commit](https://github.com/rails/rails/commit/4cb47167e747e8f9dc12b0ddaf82bdb68c03e032))
 
-* Added a `:required` option to singular associations, which defines a
-  presence validation on the association.
-  ([Pull Request](https://github.com/rails/rails/pull/16056))
 
 Active Model
 ------------
@@ -270,13 +322,21 @@ Please refer to the [Changelog][active-model] for detailed changes.
 
 ### Removals
 
-* Removed deprecated `Validator#setup` without replacement.
-  ([Pull Request](https://github.com/rails/rails/pull/15617))
+*   Removed deprecated `Validator#setup` without replacement.
+    ([Pull Request](https://github.com/rails/rails/pull/15617))
 
 ### Notable changes
 
-* Introduced `#validate` as an alias for `#valid?`.
-  ([Pull Request](https://github.com/rails/rails/pull/14456))
+*   Introduced `undo_changes` method in `ActiveModel::Dirty` to restore the
+    changed (dirty) attributes to their previous values.
+    ([Pull Request](https://github.com/rails/rails/pull/14861))
+
+*   `has_secure_password` now verifies that the given password is less than 72
+    characters if validations are enabled.
+    ([Pull Request](https://github.com/rails/rails/pull/15708))
+
+*   Introduced `#validate` as an alias for `#valid?`.
+    ([Pull Request](https://github.com/rails/rails/pull/14456))
 
 
 Active Support
@@ -286,44 +346,46 @@ Please refer to the [Changelog][active-support] for detailed changes.
 
 ### Removals
 
-* Removed deprecated `Numeric#ago`, `Numeric#until`, `Numeric#since`,
-  `Numeric#from_now`. ([Commit](https://github.com/rails/rails/commit/f1eddea1e3f6faf93581c43651348f48b2b7d8bb))
+*   Removed deprecated `Numeric#ago`, `Numeric#until`, `Numeric#since`,
+    `Numeric#from_now`.
+    ([Commit](https://github.com/rails/rails/commit/f1eddea1e3f6faf93581c43651348f48b2b7d8bb))
 
-* Removed deprecated string based terminators for `ActiveSupport::Callbacks`.
-  ([Pull Request](https://github.com/rails/rails/pull/15100))
+*   Removed deprecated string based terminators for `ActiveSupport::Callbacks`.
+    ([Pull Request](https://github.com/rails/rails/pull/15100))
 
 ### Deprecations
 
-* Deprecated `Class#superclass_delegating_accessor`, use `Class#class_attribute`
-  instead. ([Pull Request](https://github.com/rails/rails/pull/14271))
+*   Deprecated `Class#superclass_delegating_accessor`, use
+    `Class#class_attribute` instead.
+    ([Pull Request](https://github.com/rails/rails/pull/14271))
 
-* Deprecated `ActiveSupport::SafeBuffer#prepend!` as `ActiveSupport::SafeBuffer#prepend`
-  now performs the same function. ([Pull Request](https://github.com/rails/rails/pull/14529))
+*   Deprecated `ActiveSupport::SafeBuffer#prepend!` as
+    `ActiveSupport::SafeBuffer#prepend` now performs the same function.
+    ([Pull Request](https://github.com/rails/rails/pull/14529))
 
 ### Notable changes
 
-* The `humanize` inflector helper now strips any leading underscores.
-  ([Commit](https://github.com/rails/rails/commit/daaa21bc7d20f2e4ff451637423a25ff2d5e75c7))
+*   Added `Hash#transform_values` and `Hash#transform_values!` to simplify a
+    common pattern where the values of a hash must change, but the keys are left
+    the same.
+    ([Pull Request](https://github.com/rails/rails/pull/15819))
 
-* Added `SecureRandom::uuid_v3` and `SecureRandom::uuid_v5`.
-  ([Pull Request](https://github.com/rails/rails/pull/12016))
+*   The `humanize` inflector helper now strips any leading underscores.
+    ([Commit](https://github.com/rails/rails/commit/daaa21bc7d20f2e4ff451637423a25ff2d5e75c7))
 
-* Introduce `Concern#class_methods` as an alternative to `module ClassMethods`,
-  as well as `Kernel#concern` to avoid the `module Foo; extend ActiveSupport::Concern; end`
-  boilerplate. ([Commit](https://github.com/rails/rails/commit/b16c36e688970df2f96f793a759365b248b582ad))
+*   Introduce `Concern#class_methods` as an alternative to
+    `module ClassMethods`, as well as `Kernel#concern` to avoid the
+    `module Foo; extend ActiveSupport::Concern; end` boilerplate.
+    ([Commit](https://github.com/rails/rails/commit/b16c36e688970df2f96f793a759365b248b582ad))
 
-* Added `Hash#transform_values` and `Hash#transform_values!` to simplify a
-  common pattern where the values of a hash must change, but the keys are left
-  the same.
-  ([Pull Request](https://github.com/rails/rails/pull/15819))
 
 Credits
 -------
 
 See the
 [full list of contributors to Rails](http://contributors.rubyonrails.org/) for
-the many people who spent many hours making Rails, the stable and robust
-framework it is. Kudos to all of them.
+the many people who spent many hours making Rails the stable and robust
+framework it is today. Kudos to all of them.
 
 [railties]:       https://github.com/rails/rails/blob/4-2-stable/railties/CHANGELOG.md
 [action-pack]:    https://github.com/rails/rails/blob/4-2-stable/actionpack/CHANGELOG.md
diff --git a/guides/source/action_mailer_basics.md b/guides/source/action_mailer_basics.md
index cb1c1c653d..9ad9319255 100644
--- a/guides/source/action_mailer_basics.md
+++ b/guides/source/action_mailer_basics.md
@@ -414,6 +414,22 @@ globally in `config/application.rb`:
 config.action_mailer.default_url_options = { host: 'example.com' }
 ```
 
+Because of this behavior you cannot use any of the `*_path` helpers inside of
+an email. Instead you will need to use the associated `*_url` helper. For example
+instead of using
+
+```
+<%= link_to 'welcome', welcome_path %>
+```
+
+You will need to use:
+
+```
+<%= link_to 'welcome', welcome_url %>
+```
+
+By using the full URL, your links will now work in your emails.
+
 #### generating URLs with `url_for`
 
 You need to pass the `only_path: false` option when using `url_for`. This will
diff --git a/guides/source/active_model_basics.md b/guides/source/active_model_basics.md
index 1131a83c36..3eaeeff389 100644
--- a/guides/source/active_model_basics.md
+++ b/guides/source/active_model_basics.md
@@ -202,7 +202,7 @@ person.valid?                        # => raises ActiveModel::StrictValidationFa
 ### ActiveModel::Naming
 
 Naming adds a number of class methods which make the naming and routing
-easier to manage. The module defines the `model_name` class method which 
+easier to manage. The module defines the `model_name` class method which
 will define a number of accessors using some `ActiveSupport::Inflector` methods.
 
 ```ruby
@@ -220,4 +220,4 @@ Person.model_name.param_key           # => "person"
 Person.model_name.i18n_key            # => :person
 Person.model_name.route_key           # => "people"
 Person.model_name.singular_route_key  # => "person"
-```
\ No newline at end of file
+```
diff --git a/guides/source/active_record_basics.md b/guides/source/active_record_basics.md
index 21022f1abb..eff93ce41d 100644
--- a/guides/source/active_record_basics.md
+++ b/guides/source/active_record_basics.md
@@ -310,10 +310,10 @@ models and validate that an attribute value is not empty, is unique and not
 already in the database, follows a specific format and many more.
 
 Validation is a very important issue to consider when persisting to the database, so
-the methods `create`, `save` and `update` take it into account when
+the methods `save` and `update` take it into account when
 running: they return `false` when validation fails and they didn't actually
 perform any operation on the database. All of these have a bang counterpart (that
-is, `create!`, `save!` and `update!`), which are stricter in that
+is, `save!` and `update!`), which are stricter in that
 they raise the exception `ActiveRecord::RecordInvalid` if validation fails.
 A quick example to illustrate:
 
@@ -322,8 +322,9 @@ class User < ActiveRecord::Base
   validates :name, presence: true
 end
 
-User.create  # => false
-User.create! # => ActiveRecord::RecordInvalid: Validation failed: Name can't be blank
+user = User.new
+user.save  # => false
+user.save! # => ActiveRecord::RecordInvalid: Validation failed: Name can't be blank
 ```
 
 You can learn more about validations in the [Active Record Validations
diff --git a/guides/source/active_record_querying.md b/guides/source/active_record_querying.md
index 486e7b80ff..35467fe95b 100644
--- a/guides/source/active_record_querying.md
+++ b/guides/source/active_record_querying.md
@@ -93,9 +93,9 @@ The primary operation of `Model.find(options)` can be summarized as:
 
 Active Record provides several different ways of retrieving a single object.
 
-#### Using a Primary Key
+#### `find`
 
-Using `Model.find(primary_key)`, you can retrieve the object corresponding to the specified _primary key_ that matches any supplied options. For example:
+Using the `find` method, you can retrieve the object corresponding to the specified _primary key_ that matches any supplied options. For example:
 
 ```ruby
 # Find the client with primary key (id) 10.
@@ -109,119 +109,103 @@ The SQL equivalent of the above is:
 SELECT * FROM clients WHERE (clients.id = 10) LIMIT 1
 ```
 
-`Model.find(primary_key)` will raise an `ActiveRecord::RecordNotFound` exception if no matching record is found.
+The `find` method will raise an `ActiveRecord::RecordNotFound` exception if no matching record is found.
 
-#### `take`
-
-`Model.take` retrieves a record without any implicit ordering. For example:
+You can also use this method to query for multiple objects. Call the `find` method and pass in an array of primary keys. The return will be an array containing all of the matching records for the supplied _primary keys_. For example:
 
 ```ruby
-client = Client.take
-# => #<Client id: 1, first_name: "Lifo">
+# Find the clients with primary keys 1 and 10.
+client = Client.find([1, 10]) # Or even Client.find(1, 10)
+# => [#<Client id: 1, first_name: "Lifo">, #<Client id: 10, first_name: "Ryan">]
 ```
 
 The SQL equivalent of the above is:
 
 ```sql
-SELECT * FROM clients LIMIT 1
+SELECT * FROM clients WHERE (clients.id IN (1,10))
 ```
 
-`Model.take` returns `nil` if no record is found and no exception will be raised.
+WARNING: The `find` method will raise an `ActiveRecord::RecordNotFound` exception unless a matching record is found for **all** of the supplied primary keys.
 
-TIP: The retrieved record may vary depending on the database engine.
-
-#### `first`
+#### `take`
 
-`Model.first` finds the first record ordered by the primary key. For example:
+The `take` method retrieves a record without any implicit ordering. For example:
 
 ```ruby
-client = Client.first
+client = Client.take
 # => #<Client id: 1, first_name: "Lifo">
 ```
 
 The SQL equivalent of the above is:
 
 ```sql
-SELECT * FROM clients ORDER BY clients.id ASC LIMIT 1
+SELECT * FROM clients LIMIT 1
 ```
 
-`Model.first` returns `nil` if no matching record is found and no exception will be raised.
-
-#### `last`
+The `take` method returns `nil` if no record is found and no exception will be raised.
 
-`Model.last` finds the last record ordered by the primary key. For example:
+You can pass in a numerical argument to the `take` method to return up to that number of results. For example
 
 ```ruby
-client = Client.last
-# => #<Client id: 221, first_name: "Russel">
+client = Client.take(2)
+# => [
+  #<Client id: 1, first_name: "Lifo">,
+  #<Client id: 220, first_name: "Sara">
+]
 ```
 
 The SQL equivalent of the above is:
 
 ```sql
-SELECT * FROM clients ORDER BY clients.id DESC LIMIT 1
-```
-
-`Model.last` returns `nil` if no matching record is found and no exception will be raised.
-
-#### `find_by`
-
-`Model.find_by` finds the first record matching some conditions. For example:
-
-```ruby
-Client.find_by first_name: 'Lifo'
-# => #<Client id: 1, first_name: "Lifo">
-
-Client.find_by first_name: 'Jon'
-# => nil
+SELECT * FROM clients LIMIT 2
 ```
 
-It is equivalent to writing:
+The `take!` method behaves exactly like `take`, except that it will raise `ActiveRecord::RecordNotFound` if no matching record is found.
 
-```ruby
-Client.where(first_name: 'Lifo').take
-```
+TIP: The retrieved record may vary depending on the database engine.
 
-#### `take!`
+#### `first`
 
-`Model.take!` retrieves a record without any implicit ordering. For example:
+The `first` method finds the first record ordered by the primary key. For example:
 
 ```ruby
-client = Client.take!
+client = Client.first
 # => #<Client id: 1, first_name: "Lifo">
 ```
 
 The SQL equivalent of the above is:
 
 ```sql
-SELECT * FROM clients LIMIT 1
+SELECT * FROM clients ORDER BY clients.id ASC LIMIT 1
 ```
 
-`Model.take!` raises `ActiveRecord::RecordNotFound` if no matching record is found.
-
-#### `first!`
+The `first` method returns `nil` if no matching record is found and no exception will be raised.
 
-`Model.first!` finds the first record ordered by the primary key. For example:
+You can pass in a numerical argument to the `first` method to return up to that number of results. For example
 
 ```ruby
-client = Client.first!
-# => #<Client id: 1, first_name: "Lifo">
+client = Client.first(3)
+# => [
+  #<Client id: 1, first_name: "Lifo">,
+  #<Client id: 2, first_name: "Fifo">,
+  #<Client id: 3, first_name: "Filo">
+]
 ```
 
 The SQL equivalent of the above is:
 
 ```sql
-SELECT * FROM clients ORDER BY clients.id ASC LIMIT 1
+SELECT * FROM clients ORDER BY clients.id ASC LIMIT 3
 ```
 
-`Model.first!` raises `ActiveRecord::RecordNotFound` if no matching record is found.
+The `first!` method behaves exactly like `first`, except that it will raise `ActiveRecord::RecordNotFound` if no matching record is found.
 
-#### `last!`
+#### `last`
 
-`Model.last!` finds the last record ordered by the primary key. For example:
+The `last` method finds the last record ordered by the primary key. For example:
 
 ```ruby
-client = Client.last!
+client = Client.last
 # => #<Client id: 221, first_name: "Russel">
 ```
 
@@ -231,92 +215,56 @@ The SQL equivalent of the above is:
 SELECT * FROM clients ORDER BY clients.id DESC LIMIT 1
 ```
 
-`Model.last!` raises `ActiveRecord::RecordNotFound` if no matching record is found.
-
-#### `find_by!`
-
-`Model.find_by!` finds the first record matching some conditions. It raises `ActiveRecord::RecordNotFound` if no matching record is found. For example:
-
-```ruby
-Client.find_by! first_name: 'Lifo'
-# => #<Client id: 1, first_name: "Lifo">
-
-Client.find_by! first_name: 'Jon'
-# => ActiveRecord::RecordNotFound
-```
-
-It is equivalent to writing:
-
-```ruby
-Client.where(first_name: 'Lifo').take!
-```
-
-### Retrieving Multiple Objects
+The `last` method returns `nil` if no matching record is found and no exception will be raised.
 
-#### Using Multiple Primary Keys
-
-`Model.find(array_of_primary_key)` accepts an array of _primary keys_, returning an array containing all of the matching records for the supplied _primary keys_. For example:
+You can pass in a numerical argument to the `last` method to return up to that number of results. For example
 
 ```ruby
-# Find the clients with primary keys 1 and 10.
-client = Client.find([1, 10]) # Or even Client.find(1, 10)
-# => [#<Client id: 1, first_name: "Lifo">, #<Client id: 10, first_name: "Ryan">]
+client = Client.last(3)
+# => [
+  #<Client id: 219, first_name: "James">,
+  #<Client id: 220, first_name: "Sara">,
+  #<Client id: 221, first_name: "Russel">
+]
 ```
 
 The SQL equivalent of the above is:
 
 ```sql
-SELECT * FROM clients WHERE (clients.id IN (1,10))
+SELECT * FROM clients ORDER BY clients.id DESC LIMIT 3
 ```
 
-WARNING: `Model.find(array_of_primary_key)` will raise an `ActiveRecord::RecordNotFound` exception unless a matching record is found for **all** of the supplied primary keys.
+The `last!` method behaves exactly like `last`, except that it will raise `ActiveRecord::RecordNotFound` if no matching record is found.
 
-#### take
+#### `find_by`
 
-`Model.take(limit)` retrieves the first number of records specified by `limit` without any explicit ordering:
+The `find_by` method finds the first record matching some conditions. For example:
 
 ```ruby
-Client.take(2)
-# => [#<Client id: 1, first_name: "Lifo">,
-      #<Client id: 2, first_name: "Raf">]
-```
-
-The SQL equivalent of the above is:
+Client.find_by first_name: 'Lifo'
+# => #<Client id: 1, first_name: "Lifo">
 
-```sql
-SELECT * FROM clients LIMIT 2
+Client.find_by first_name: 'Jon'
+# => nil
 ```
 
-#### first
-
-`Model.first(limit)` finds the first number of records specified by `limit` ordered by primary key:
+It is equivalent to writing:
 
 ```ruby
-Client.first(2)
-# => [#<Client id: 1, first_name: "Lifo">,
-      #<Client id: 2, first_name: "Raf">]
-```
-
-The SQL equivalent of the above is:
-
-```sql
-SELECT * FROM clients ORDER BY id ASC LIMIT 2
+Client.where(first_name: 'Lifo').take
 ```
 
-#### last
-
-`Model.last(limit)` finds the number of records specified by `limit` ordered by primary key in descending order:
+The `find_by!` method behaves exactly like `find_by`, except that it will raise `ActiveRecord::RecordNotFound` if no matching record is found. For example:
 
 ```ruby
-Client.last(2)
-# => [#<Client id: 10, first_name: "Ryan">,
-      #<Client id: 9, first_name: "John">]
+Client.find_by! first_name: 'does not exist'
+# => ActiveRecord::RecordNotFound
 ```
 
-The SQL equivalent of the above is:
+This is equivalent to writing:
 
-```sql
-SELECT * FROM clients ORDER BY id DESC LIMIT 2
+```ruby
+Client.where(first_name: 'does not exist').take!
 ```
 
 ### Retrieving Multiple Objects in Batches
@@ -328,7 +276,7 @@ This may appear straightforward:
 ```ruby
 # This is very inefficient when the users table has thousands of rows.
 User.all.each do |user|
-  NewsLetter.weekly_deliver(user)
+  NewsMailer.weekly(user).deliver
 end
 ```
 
@@ -344,7 +292,15 @@ The `find_each` method retrieves a batch of records and then yields _each_ recor
 
 ```ruby
 User.find_each do |user|
-  NewsLetter.weekly_deliver(user)
+  NewsMailer.weekly(user).deliver
+end
+```
+
+To add conditions to a `find_each` operation you can chain other Active Record methods such as `where`:
+
+```ruby
+User.where(weekly_subscriber: true).find_each do |user|
+  NewsMailer.weekly(user).deliver
 end
 ```
 
@@ -360,7 +316,7 @@ The `:batch_size` option allows you to specify the number of records to be retri
 
 ```ruby
 User.find_each(batch_size: 5000) do |user|
-  NewsLetter.weekly_deliver(user)
+  NewsMailer.weekly(user).deliver
 end
 ```
 
@@ -372,7 +328,7 @@ For example, to send newsletters only to users with the primary key starting fro
 
 ```ruby
 User.find_each(start: 2000, batch_size: 5000) do |user|
-  NewsLetter.weekly_deliver(user)
+  NewsMailer.weekly(user).deliver
 end
 ```
 
@@ -707,7 +663,7 @@ Overriding Conditions
 You can specify certain conditions to be removed using the `unscope` method. For example:
 
 ```ruby
-Article.where('id > 10').limit(20).order('id asc').except(:order)
+Article.where('id > 10').limit(20).order('id asc').unscope(:order)
 ```
 
 The SQL that would be executed:
@@ -720,7 +676,7 @@ SELECT * FROM articles WHERE id > 10 ORDER BY id asc LIMIT 20
 
 ```
 
-You can additionally unscope specific where clauses. For example:
+You can also unscope specific `where` clauses. For example:
 
 ```ruby
 Article.where(id: 10, trashed: false).unscope(where: :id)
@@ -759,8 +715,6 @@ The `reorder` method overrides the default scope order. For example:
 
 ```ruby
 class Article < ActiveRecord::Base
-  ..
-  ..
   has_many :comments, -> { order('posted_at DESC') }
 end
 
@@ -1487,6 +1441,11 @@ If you'd like to use your own SQL to find records in a table you can use `find_b
 Client.find_by_sql("SELECT * FROM clients
   INNER JOIN orders ON clients.id = orders.client_id
   ORDER BY clients.created_at desc")
+# =>  [
+  #<Client id: 1, first_name: "Lucas" >,
+  #<Client id: 2, first_name: "Jan" >,
+  # ...
+]
 ```
 
 `find_by_sql` provides you with a simple way of making custom calls to the database and retrieving instantiated objects.
@@ -1496,7 +1455,11 @@ Client.find_by_sql("SELECT * FROM clients
 `find_by_sql` has a close relative called `connection#select_all`. `select_all` will retrieve objects from the database using custom SQL just like `find_by_sql` but will not instantiate them. Instead, you will get an array of hashes where each hash indicates a record.
 
 ```ruby
-Client.connection.select_all("SELECT * FROM clients WHERE id = '1'")
+Client.connection.select_all("SELECT first_name, created_at FROM clients WHERE id = '1'")
+# => [
+  {"first_name"=>"Rafael", "created_at"=>"2012-11-10 23:23:45.281189"},
+  {"first_name"=>"Eileen", "created_at"=>"2013-12-09 11:22:35.221282"}
+]
 ```
 
 ### `pluck`
diff --git a/guides/source/active_record_validations.md b/guides/source/active_record_validations.md
index 7ec4ab312d..582bb240dd 100644
--- a/guides/source/active_record_validations.md
+++ b/guides/source/active_record_validations.md
@@ -910,8 +910,8 @@ end
 The easiest way to add custom validators for validating individual attributes
 is with the convenient `ActiveModel::EachValidator`. In this case, the custom
 validator class must implement a `validate_each` method which takes three
-arguments: record, attribute and value which correspond to the instance, the
-attribute to be validated and the value of the attribute in the passed
+arguments: record, attribute, and value. These correspond to the instance, the
+attribute to be validated, and the value of the attribute in the passed
 instance.
 
 ```ruby
diff --git a/guides/source/asset_pipeline.md b/guides/source/asset_pipeline.md
index 84cda9222e..e31cefa5bb 100644
--- a/guides/source/asset_pipeline.md
+++ b/guides/source/asset_pipeline.md
@@ -124,19 +124,22 @@ with a built-in helper. In the source the generated code looked like this:
 The query string strategy has several disadvantages:
 
 1. **Not all caches will reliably cache content where the filename only differs by
-query parameters**  
+query parameters**
+
     [Steve Souders recommends](http://www.stevesouders.com/blog/2008/08/23/revving-filenames-dont-use-querystring/),
  "...avoiding a querystring for cacheable resources". He found that in this
 case 5-20% of requests will not be cached. Query strings in particular do not
 work at all with some CDNs for cache invalidation.
 
-2. **The file name can change between nodes in multi-server environments.**  
+2. **The file name can change between nodes in multi-server environments.**
+
     The default query string in Rails 2.x is based on the modification time of
 the files. When assets are deployed to a cluster, there is no guarantee that the
 timestamps will be the same, resulting in different values being used depending
 on which server handles the request.
 
-3. **Too much cache invalidation**  
+3. **Too much cache invalidation**
+
     When static assets are deployed with each new release of code, the mtime
 (time of last modification) of _all_ these files changes, forcing all remote
 clients to fetch them again, even when the content of those assets has not changed.
@@ -490,8 +493,7 @@ The directives that work in JavaScript files also work in stylesheets
 one, requiring all stylesheets from the current directory.
 
 In this example, `require_self` is used. This puts the CSS contained within the
-file (if any) at the precise location of the `require_self` call. If
-`require_self` is called more than once, only the last call is respected.
+file (if any) at the precise location of the `require_self` call.
 
 NOTE. If you want to use multiple Sass files, you should generally use the [Sass `@import` rule](http://sass-lang.com/docs/yardoc/file.SASS_REFERENCE.html#import)
 instead of these Sprockets directives. When using Sprockets directives, Sass files exist within
diff --git a/guides/source/association_basics.md b/guides/source/association_basics.md
index 7e99da3f6d..daf4113b66 100644
--- a/guides/source/association_basics.md
+++ b/guides/source/association_basics.md
@@ -105,7 +105,7 @@ class CreateOrders < ActiveRecord::Migration
     end
 
     create_table :orders do |t|
-      t.belongs_to :customer
+      t.belongs_to :customer, index: true
       t.datetime :order_date
       t.timestamps
     end
@@ -136,7 +136,7 @@ class CreateSuppliers < ActiveRecord::Migration
     end
 
     create_table :accounts do |t|
-      t.belongs_to :supplier
+      t.belongs_to :supplier, index: true
       t.string :account_number
       t.timestamps
     end
@@ -169,7 +169,7 @@ class CreateCustomers < ActiveRecord::Migration
     end
 
     create_table :orders do |t|
-      t.belongs_to :customer
+      t.belongs_to :customer, index:true
       t.datetime :order_date
       t.timestamps
     end
@@ -216,8 +216,8 @@ class CreateAppointments < ActiveRecord::Migration
     end
 
     create_table :appointments do |t|
-      t.belongs_to :physician
-      t.belongs_to :patient
+      t.belongs_to :physician, index: true
+      t.belongs_to :patient, index: true
       t.datetime :appointment_date
       t.timestamps
     end
@@ -295,13 +295,13 @@ class CreateAccountHistories < ActiveRecord::Migration
     end
 
     create_table :accounts do |t|
-      t.belongs_to :supplier
+      t.belongs_to :supplier, index: true
       t.string :account_number
       t.timestamps
     end
 
     create_table :account_histories do |t|
-      t.belongs_to :account
+      t.belongs_to :account, index: true
       t.integer :credit_rating
       t.timestamps
     end
@@ -341,8 +341,8 @@ class CreateAssembliesAndParts < ActiveRecord::Migration
     end
 
     create_table :assemblies_parts, id: false do |t|
-      t.belongs_to :assembly
-      t.belongs_to :part
+      t.belongs_to :assembly, index: true
+      t.belongs_to :part, index: true
     end
   end
 end
@@ -379,6 +379,8 @@ class CreateSuppliers < ActiveRecord::Migration
       t.string  :account_number
       t.timestamps
     end
+
+    add_index :accounts, :supplier_id
   end
 end
 ```
@@ -455,6 +457,8 @@ class CreatePictures < ActiveRecord::Migration
       t.string  :imageable_type
       t.timestamps
     end
+
+    add_index :pictures, :imageable_id
   end
 end
 ```
@@ -466,7 +470,7 @@ class CreatePictures < ActiveRecord::Migration
   def change
     create_table :pictures do |t|
       t.string :name
-      t.references :imageable, polymorphic: true
+      t.references :imageable, polymorphic: true, index: true
       t.timestamps
     end
   end
@@ -496,7 +500,7 @@ In your migrations/schema, you will add a references column to the model itself.
 class CreateEmployees < ActiveRecord::Migration
   def change
     create_table :employees do |t|
-      t.references :manager
+      t.references :manager, index: true
       t.timestamps
     end
   end
@@ -561,6 +565,8 @@ class CreateOrders < ActiveRecord::Migration
       t.string   :order_number
       t.integer  :customer_id
     end
+
+    add_index :orders, :customer_id
   end
 end
 ```
@@ -594,6 +600,9 @@ class CreateAssembliesPartsJoinTable < ActiveRecord::Migration
       t.integer :assembly_id
       t.integer :part_id
     end
+
+    add_index :assemblies_parts, :assembly_id
+    add_index :assemblies_parts, :part_id
   end
 end
 ```
diff --git a/guides/source/command_line.md b/guides/source/command_line.md
index cb0228fa75..a074b849c6 100644
--- a/guides/source/command_line.md
+++ b/guides/source/command_line.md
@@ -7,7 +7,6 @@ After reading this guide, you will know:
 * How to generate models, controllers, database migrations, and unit tests.
 * How to start a development server.
 * How to experiment with objects through an interactive shell.
-* How to profile and benchmark your new creation.
 
 --------------------------------------------------------------------------------
 
@@ -150,8 +149,6 @@ $ bin/rails generate controller Greetings hello
      create    test/controllers/greetings_controller_test.rb
      invoke  helper
      create    app/helpers/greetings_helper.rb
-     invoke    test_unit
-     create      test/helpers/greetings_helper_test.rb
      invoke  assets
      invoke    coffee
      create      app/assets/javascripts/greetings.js.coffee
@@ -237,8 +234,6 @@ $ bin/rails generate scaffold HighScore game:string score:integer
     create      test/controllers/high_scores_controller_test.rb
     invoke    helper
     create      app/helpers/high_scores_helper.rb
-    invoke      test_unit
-    create        test/helpers/high_scores_helper_test.rb
     invoke    jbuilder
     create      app/views/high_scores/index.json.jbuilder
     create      app/views/high_scores/show.json.jbuilder
diff --git a/guides/source/configuring.md b/guides/source/configuring.md
index 13020fb286..801cef5ca6 100644
--- a/guides/source/configuring.md
+++ b/guides/source/configuring.md
@@ -137,7 +137,7 @@ numbers. New applications filter out passwords by adding the following `config.f
 * `config.assets.enabled` a flag that controls whether the asset
 pipeline is enabled. It is set to true by default.
 
-*`config.assets.raise_runtime_errors`* Set this flag to `true` to enable additional runtime error checking. Recommended in `config/environments/development.rb` to minimize unexpected behavior when deploying to `production`.
+* `config.assets.raise_runtime_errors`* Set this flag to `true` to enable additional runtime error checking. Recommended in `config/environments/development.rb` to minimize unexpected behavior when deploying to `production`.
 
 * `config.assets.compress` a flag that enables the compression of compiled assets. It is explicitly set to true in `config/environments/production.rb`.
 
@@ -151,6 +151,8 @@ pipeline is enabled. It is set to true by default.
 
 * `config.assets.prefix` defines the prefix where assets are served from. Defaults to `/assets`.
 
+* `config.assets.manifest` defines the full path to be used for the asset precompiler's manifest file. Defaults to a file named `manifest-<random>.json` in the `config.assets.prefix` directory within the public folder.
+
 * `config.assets.digest` enables the use of MD5 fingerprints in asset names. Set to `true` by default in `production.rb`.
 
 * `config.assets.debug` disables the concatenation and compression of assets. Set to `true` by default in `development.rb`.
@@ -996,3 +998,24 @@ If you get the above error, you might want to increase the size of connection
 pool by incrementing the `pool` option in `database.yml`
 
 NOTE. If you are running in a multi-threaded environment, there could be a chance that several threads may be accessing multiple connections simultaneously. So depending on your current request load, you could very well have multiple threads contending for a limited amount of connections.
+
+
+Custom configuration
+--------------------
+
+You can configure your own code through the Rails configuration object with custom configuration. It works like this:
+
+  ```ruby
+  config.x.payment_processing.schedule = :daily
+  config.x.payment_processing.retries  = 3
+  config.x.super_debugger = true
+  ```
+
+These configuration points are then available through the configuration object:
+
+  ```ruby
+  Rails.configuration.x.payment_processing.schedule # => :daily
+  Rails.configuration.x.payment_processing.retries  # => 3
+  Rails.configuration.x.super_debugger              # => true
+  Rails.configuration.x.super_debugger.not_set      # => nil
+  ```
diff --git a/guides/source/contributing_to_ruby_on_rails.md b/guides/source/contributing_to_ruby_on_rails.md
index a8b959c725..0b05725623 100644
--- a/guides/source/contributing_to_ruby_on_rails.md
+++ b/guides/source/contributing_to_ruby_on_rails.md
@@ -318,6 +318,12 @@ You can also run any single test separately:
 $ ARCONN=sqlite3 ruby -Itest test/cases/associations/has_many_associations_test.rb
 ```
 
+To run a single test against all adapters, use:
+
+```bash
+$ bundle exec rake TEST=test/cases/associations/has_many_associations_test.rb
+```
+
 You can invoke `test_jdbcmysql`, `test_jdbcsqlite3` or `test_jdbcpostgresql` also. See the file `activerecord/RUNNING_UNIT_TESTS.rdoc` for information on running more targeted database tests, or the file `ci/travis.rb` for the test suite run by the continuous integration server.
 
 ### Warnings
diff --git a/guides/source/engines.md b/guides/source/engines.md
index a5f8ee27b8..24548a5b01 100644
--- a/guides/source/engines.md
+++ b/guides/source/engines.md
@@ -136,7 +136,7 @@ following to the dummy application's routes file at
 `test/dummy/config/routes.rb`:
 
 ```ruby
-mount Blorgh::Engine, at: "blorgh"
+mount Blorgh::Engine => "/blorgh"
 ```
 
 ### Inside an Engine
@@ -173,7 +173,7 @@ Within `lib/blorgh/engine.rb` is the base class for the engine:
 
 ```ruby
 module Blorgh
-  class Engine < Rails::Engine
+  class Engine < ::Rails::Engine
     isolate_namespace Blorgh
   end
 end
@@ -322,8 +322,6 @@ invoke    test_unit
 create      test/controllers/blorgh/articles_controller_test.rb
 invoke    helper
 create      app/helpers/blorgh/articles_helper.rb
-invoke      test_unit
-create        test/helpers/blorgh/articles_helper_test.rb
 invoke  assets
 invoke    js
 create      app/assets/javascripts/blorgh/articles.js
@@ -560,8 +558,6 @@ invoke  test_unit
 create    test/controllers/blorgh/comments_controller_test.rb
 invoke  helper
 create    app/helpers/blorgh/comments_helper.rb
-invoke    test_unit
-create      test/helpers/blorgh/comments_helper_test.rb
 invoke  assets
 invoke    js
 create      app/assets/javascripts/blorgh/comments.js
diff --git a/guides/source/generators.md b/guides/source/generators.md
index 93fb5eece8..5e88fa0c70 100644
--- a/guides/source/generators.md
+++ b/guides/source/generators.md
@@ -35,7 +35,7 @@ $ bin/rails generate helper --help
 Creating Your First Generator
 -----------------------------
 
-Since Rails 3.0, generators are built on top of [Thor](https://github.com/erikhuda/thor). Thor provides powerful options parsing and a great API for manipulating files. For instance, let's build a generator that creates an initializer file named `initializer.rb` inside `config/initializers`.
+Since Rails 3.0, generators are built on top of [Thor](https://github.com/erikhuda/thor). Thor provides powerful options for parsing and a great API for manipulating files. For instance, let's build a generator that creates an initializer file named `initializer.rb` inside `config/initializers`.
 
 The first step is to create a file at `lib/generators/initializer_generator.rb` with the following content:
 
@@ -191,8 +191,6 @@ $ bin/rails generate scaffold User name:string
       create      test/controllers/users_controller_test.rb
       invoke    helper
       create      app/helpers/users_helper.rb
-      invoke      test_unit
-      create        test/helpers/users_helper_test.rb
       invoke    jbuilder
       create      app/views/users/index.json.jbuilder
       create      app/views/users/show.json.jbuilder
@@ -387,8 +385,6 @@ $ bin/rails generate scaffold Comment body:text
       create      test/controllers/comments_controller_test.rb
       invoke    my_helper
       create      app/helpers/comments_helper.rb
-      invoke      shoulda
-      create        test/helpers/comments_helper_test.rb
       invoke    jbuilder
       create      app/views/comments/index.json.jbuilder
       create      app/views/comments/show.json.jbuilder
diff --git a/guides/source/getting_started.md b/guides/source/getting_started.md
index ef97cda3bc..1f91352c82 100644
--- a/guides/source/getting_started.md
+++ b/guides/source/getting_started.md
@@ -120,7 +120,7 @@ To verify that you have everything installed correctly, you should be able to
 run the following:
 
 ```bash
-$ bin/rails --version
+$ rails --version
 ```
 
 If it says something like "Rails 4.2.0", you are ready to continue.
@@ -191,14 +191,15 @@ following in the `blog` directory:
 $ bin/rails server
 ```
 
-TIP: Compiling CoffeeScript to JavaScript requires a JavaScript runtime and the
-absence of a runtime will give you an `execjs` error. Usually Mac OS X and
-Windows come with a JavaScript runtime installed. Rails adds the `therubyracer`
-gem to the generated `Gemfile` in a commented line for new apps and you can
-uncomment if you need it. `therubyrhino` is the recommended runtime for JRuby
-users and is added by default to the `Gemfile` in apps generated under JRuby.
-You can investigate about all the supported runtimes at
-[ExecJS](https://github.com/sstephenson/execjs#readme).
+TIP: Compiling CoffeeScript and JavaScript asset compression requires you
+have a JavaScript runtime available on your system, in the absence
+of a runtime you will see an `execjs` error during asset compilation.
+Usually Mac OS X and Windows come with a JavaScript runtime installed.
+Rails adds the `therubyracer` gem to the generated `Gemfile` in a 
+commented line for new apps and you can uncomment if you need it. 
+`therubyrhino` is the recommended runtime for JRuby users and is added by
+default to the `Gemfile` in apps generated under JRuby. You can investigate
+about all the supported runtimes at [ExecJS](https://github.com/sstephenson/execjs#readme).
 
 This will fire up WEBrick, a web server distributed with Ruby by default. To see
 your application in action, open a browser window and navigate to
@@ -256,8 +257,6 @@ invoke  test_unit
 create    test/controllers/welcome_controller_test.rb
 invoke  helper
 create    app/helpers/welcome_helper.rb
-invoke    test_unit
-create      test/helpers/welcome_helper_test.rb
 invoke  assets
 invoke    coffee
 create      app/assets/javascripts/welcome.js.coffee
@@ -909,7 +908,7 @@ And then finally, add the view for this action, located at
 </table>
 ```
 
-Now if you go to `http://localhost:3000/articles` you will see a list of all the
+Now if you go to <http://localhost:3000/articles> you will see a list of all the
 articles that you have created.
 
 ### Adding links
@@ -1105,7 +1104,7 @@ standout.
 
 Now you'll get a nice error message when saving an article without title when
 you attempt to do just that on the new article form
-[(http://localhost:3000/articles/new)](http://localhost:3000/articles/new).
+<http://localhost:3000/articles/new>:
 
 ![Form With Errors](images/getting_started/form_with_errors.png)
 
@@ -1636,7 +1635,6 @@ This creates six files and one empty directory:
 | app/views/comments/                          | Views of the controller are stored here  |
 | test/controllers/comments_controller_test.rb | The test for the controller              |
 | app/helpers/comments_helper.rb               | A view helper file                       |
-| test/helpers/comments_helper_test.rb         | The test for the helper                  |
 | app/assets/javascripts/comment.js.coffee     | CoffeeScript for the controller          |
 | app/assets/stylesheets/comment.css.scss      | Cascading style sheet for the controller |
 
diff --git a/guides/source/plugins.md b/guides/source/plugins.md
index a35648d341..f10699fbeb 100644
--- a/guides/source/plugins.md
+++ b/guides/source/plugins.md
@@ -45,7 +45,7 @@ $ bin/rails plugin new yaffle
 See usage and options by asking for help:
 
 ```bash
-$ bin/rails plugin --help
+$ bin/rails plugin new --help
 ```
 
 Testing Your Newly Generated Plugin
@@ -440,5 +440,5 @@ $ bin/rake rdoc
 
 * [Developing a RubyGem using Bundler](https://github.com/radar/guides/blob/master/gem-development.md)
 * [Using .gemspecs as Intended](http://yehudakatz.com/2010/04/02/using-gemspecs-as-intended/)
-* [Gemspec Reference](http://docs.rubygems.org/read/chapter/20)
+* [Gemspec Reference](http://guides.rubygems.org/specification-reference/)
 * [GemPlugins: A Brief Introduction to the Future of Rails Plugins](http://www.intridea.com/blog/2008/6/11/gemplugins-a-brief-introduction-to-the-future-of-rails-plugins)
diff --git a/guides/source/rails_application_templates.md b/guides/source/rails_application_templates.md
index 0bd608c007..6512b14e60 100644
--- a/guides/source/rails_application_templates.md
+++ b/guides/source/rails_application_templates.md
@@ -38,9 +38,11 @@ generate(:scaffold, "person name:string")
 route "root to: 'people#index'"
 rake("db:migrate")
 
-git :init
-git add: "."
-git commit: %Q{ -m 'Initial commit' }
+after_bundle do
+  git :init
+  git add: "."
+  git commit: %Q{ -m 'Initial commit' }
+end
 ```
 
 The following sections outline the primary methods provided by the API:
@@ -228,6 +230,22 @@ git add: "."
 git commit: "-a -m 'Initial commit'"
 ```
 
+### after_bundle(&block)
+
+Registers a callback to be executed after the gems are bundled and binstubs
+are generated. Useful for all generated files to version control:
+
+```ruby
+after_bundle do
+  git :init
+  git add: '.'
+  git commit: "-a -m 'Initial commit'"
+end
+```
+
+The callbacks gets executed even if `--skip-bundle` and/or `--skip-spring` has
+been passed.
+
 Advanced Usage
 --------------
 
diff --git a/guides/source/routing.md b/guides/source/routing.md
index c8f8ba3044..af8c1bbcc4 100644
--- a/guides/source/routing.md
+++ b/guides/source/routing.md
@@ -645,6 +645,8 @@ match 'photos', to: 'photos#show', via: :all
 
 NOTE: Routing both `GET` and `POST` requests to a single action has security implications. In general, you should avoid routing all verbs to an action unless you have a good reason to.
 
+NOTE: 'GET' in Rails won't check for CSRF token. You should never write to the database from 'GET' requests, for more information see the [security guide](security.html#csrf-countermeasures) on CSRF countermeasures.
+
 ### Segment Constraints
 
 You can use the `:constraints` option to enforce a format for a dynamic segment:
@@ -681,7 +683,7 @@ You can also constrain a route based on any method on the [Request object](actio
 You specify a request-based constraint the same way that you specify a segment constraint:
 
 ```ruby
-get 'photos', constraints: { subdomain: 'admin' }
+get 'photos', to: 'photos#index', constraints: { subdomain: 'admin' }
 ```
 
 You can also specify constraints in a block form:
diff --git a/guides/source/ruby_on_rails_guides_guidelines.md b/guides/source/ruby_on_rails_guides_guidelines.md
index f0230b428b..6206b3c715 100644
--- a/guides/source/ruby_on_rails_guides_guidelines.md
+++ b/guides/source/ruby_on_rails_guides_guidelines.md
@@ -13,17 +13,17 @@ After reading this guide, you will know:
 Markdown
 -------
 
-Guides are written in [GitHub Flavored Markdown](https://help.github.com/articles/github-flavored-markdown). There is comprehensive [documentation for Markdown](http://daringfireball.net/projects/markdown/syntax), a [cheatsheet](http://daringfireball.net/projects/markdown/basics).
+Guides are written in [GitHub Flavored Markdown](https://help.github.com/articles/github-flavored-markdown). There is comprehensive [documentation for Markdown](http://daringfireball.net/projects/markdown/syntax), as well as a [cheatsheet](http://daringfireball.net/projects/markdown/basics).
 
 Prologue
 --------
 
-Each guide should start with motivational text at the top (that's the little introduction in the blue area). The prologue should tell the reader what the guide is about, and what they will learn. See for example the [Routing Guide](routing.html).
+Each guide should start with motivational text at the top (that's the little introduction in the blue area). The prologue should tell the reader what the guide is about, and what they will learn. As an example, see the [Routing Guide](routing.html).
 
-Titles
+Headings
 ------
 
-The title of every guide uses `h1`; guide sections use `h2`; subsections `h3`; etc. However, the generated HTML output will have the heading tag starting from `<h2>`.
+The title of every guide uses an `h1` heading; guide sections use `h2` headings; subsections use `h3` headings; etc. Note that the generated HTML output will use heading tags starting with `<h2>`.
 
 ```
 Guide Title
@@ -35,14 +35,14 @@ Section
 ### Sub Section
 ```
 
-Capitalize all words except for internal articles, prepositions, conjunctions, and forms of the verb to be:
+When writing headings, capitalize all words except for prepositions, conjunctions, internal articles, and forms of the verb "to be":
 
 ```
 #### Middleware Stack is an Array
 #### When are Objects Saved?
 ```
 
-Use the same typography as in regular text:
+Use the same inline formatting as regular text:
 
 ```
 ##### The `:content_type` Option
@@ -51,25 +51,23 @@ Use the same typography as in regular text:
 API Documentation Guidelines
 ----------------------------
 
-The guides and the API should be coherent and consistent where appropriate. Please have a look at these particular sections of the [API Documentation Guidelines](api_documentation_guidelines.html):
+The guides and the API should be coherent and consistent where appropriate. In particular, these sections of the [API Documentation Guidelines](api_documentation_guidelines.html) also apply to the guides:
 
 * [Wording](api_documentation_guidelines.html#wording)
 * [Example Code](api_documentation_guidelines.html#example-code)
-* [Filenames](api_documentation_guidelines.html#filenames)
+* [Filenames](api_documentation_guidelines.html#file-names)
 * [Fonts](api_documentation_guidelines.html#fonts)
 
-Those guidelines apply also to guides.
-
 HTML Guides
 -----------
 
 Before generating the guides, make sure that you have the latest version of Bundler installed on your system. As of this writing, you must install Bundler 1.3.5 on your device.
 
-To install the latest version of Bundler, simply run the `gem install bundler` command
+To install the latest version of Bundler, run `gem install bundler`.
 
 ### Generation
 
-To generate all the guides, just `cd` into the `guides` directory, run `bundle install` and execute:
+To generate all the guides, just `cd` into the `guides` directory, run `bundle install`, and execute:
 
 ```
 bundle exec rake guides:generate
diff --git a/guides/source/testing.md b/guides/source/testing.md
index a88625a40a..2ecd560a87 100644
--- a/guides/source/testing.md
+++ b/guides/source/testing.md
@@ -365,7 +365,7 @@ Ideally, you would like to include a test for everything which could possibly br
 By now you've caught a glimpse of some of the assertions that are available. Assertions are the worker bees of testing. They are the ones that actually perform the checks to ensure that things are going as planned.
 
 There are a bunch of different types of assertions you can use.
-Here's an extract of the assertions you can use with `minitest`, the default testing library used by Rails. The `[msg]` parameter is an optional string message you can specify to make your test failure messages clearer. It's not required.
+Here's an extract of the assertions you can use with [`Minitest`](https://github.com/seattlerb/minitest), the default testing library used by Rails. The `[msg]` parameter is an optional string message you can specify to make your test failure messages clearer. It's not required.
 
 | Assertion                                                        | Purpose |
 | ---------------------------------------------------------------- | ------- |
@@ -377,8 +377,12 @@ Here's an extract of the assertions you can use with `minitest`, the default tes
 | `assert_not_same( expected, actual, [msg] )`                     | Ensures that `expected.equal?(actual)` is false.|
 | `assert_nil( obj, [msg] )`                                       | Ensures that `obj.nil?` is true.|
 | `assert_not_nil( obj, [msg] )`                                   | Ensures that `obj.nil?` is false.|
+| `assert_empty( obj, [msg] )`                                     | Ensures that `obj` is `empty?`.|
+| `assert_not_empty( obj, [msg] )`                                 | Ensures that `obj` is not `empty?`.|
 | `assert_match( regexp, string, [msg] )`                          | Ensures that a string matches the regular expression.|
 | `assert_no_match( regexp, string, [msg] )`                       | Ensures that a string doesn't match the regular expression.|
+| `assert_includes( collection, obj, [msg] )`                      | Ensures that `obj` is in `collection`.|
+| `assert_not_includes( collection, obj, [msg] )`                  | Ensures that `obj` is not in `collection`.|
 | `assert_in_delta( expecting, actual, [delta], [msg] )`           | Ensures that the numbers `expected` and `actual` are within `delta` of each other.|
 | `assert_not_in_delta( expecting, actual, [delta], [msg] )`       | Ensures that the numbers `expected` and `actual` are not within `delta` of each other.|
 | `assert_throws( symbol, [msg] ) { block }`                       | Ensures that the given block throws the symbol.|
@@ -392,9 +396,13 @@ Here's an extract of the assertions you can use with `minitest`, the default tes
 | `assert_not_respond_to( obj, symbol, [msg] )`                    | Ensures that `obj` does not respond to `symbol`.|
 | `assert_operator( obj1, operator, [obj2], [msg] )`               | Ensures that `obj1.operator(obj2)` is true.|
 | `assert_not_operator( obj1, operator, [obj2], [msg] )`           | Ensures that `obj1.operator(obj2)` is false.|
+| `assert_predicate ( obj, predicate, [msg] )`                     | Ensures that `obj.predicate` is true, e.g. `assert_predicate str, :empty?`|
+| `assert_not_predicate ( obj, predicate, [msg] )`                 | Ensures that `obj.predicate` is false, e.g. `assert_not_predicate str, :empty?`|
 | `assert_send( array, [msg] )`                                    | Ensures that executing the method listed in `array[1]` on the object in `array[0]` with the parameters of `array[2 and up]` is true. This one is weird eh?|
 | `flunk( [msg] )`                                                 | Ensures failure. This is useful to explicitly mark a test that isn't finished yet.|
 
+The above are subset of assertions that minitest supports. For an exhaustive & more up-to-date list, please check [Minitest API documentation](http://docs.seattlerb.org/minitest/), specifically [`Minitest::Assertions`](http://docs.seattlerb.org/minitest/Minitest/Assertions.html)
+
 Because of the modular nature of the testing framework, it is possible to create your own assertions. In fact, that's exactly what Rails does. It includes some specialized assertions to make your life easier.
 
 NOTE: Creating your own assertions is an advanced topic that we won't cover in this tutorial.
@@ -1006,17 +1014,9 @@ Testing helpers
 
 In order to test helpers, all you need to do is check that the output of the
 helper method matches what you'd expect. Tests related to the helpers are
-located under the `test/helpers` directory. Rails provides a generator which
-generates both the helper and the test file:
-
-```bash
-$ bin/rails generate helper User
-      create  app/helpers/user_helper.rb
-      invoke  test_unit
-      create    test/helpers/user_helper_test.rb
-```
+located under the `test/helpers` directory.
 
-The generated test file contains the following code:
+A helper test looks like so:
 
 ```ruby
 require 'test_helper'
@@ -1049,7 +1049,6 @@ The built-in `minitest` based testing is not the only way to test Rails applicat
 
 * [NullDB](http://avdi.org/projects/nulldb/), a way to speed up testing by avoiding database use.
 * [Factory Girl](https://github.com/thoughtbot/factory_girl/tree/master), a replacement for fixtures.
-* [Machinist](https://github.com/notahat/machinist/tree/master), another replacement for fixtures.
 * [Fixture Builder](https://github.com/rdy/fixture_builder), a tool that compiles Ruby factories into fixtures before a test run.
 * [MiniTest::Spec Rails](https://github.com/metaskills/minitest-spec-rails), use the MiniTest::Spec DSL within your rails tests.
 * [Shoulda](http://www.thoughtbot.com/projects/shoulda), an extension to `test/unit` with additional helpers, macros, and assertions.
diff --git a/guides/source/upgrading_ruby_on_rails.md b/guides/source/upgrading_ruby_on_rails.md
index 36cd505977..cc20782780 100644
--- a/guides/source/upgrading_ruby_on_rails.md
+++ b/guides/source/upgrading_ruby_on_rails.md
@@ -52,6 +52,44 @@ Upgrading from Rails 4.1 to Rails 4.2
 
 NOTE: This section is a work in progress.
 
+### Serialized attributes
+
+When using a custom coder (e.g. `serialize :metadata, JSON`),
+assigning `nil` to a serialized attribute will save it to the database
+as `NULL` instead of passing the `nil` value through the coder (e.g. `"null"`
+when using the `JSON` coder).
+
+### `after_bundle` in Rails templates
+
+If you have a Rails template that adds all the files in version control, it
+fails to add the generated binstubs because it gets executed before Bundler:
+
+```ruby
+# template.rb
+generate(:scaffold, "person name:string")
+route "root to: 'people#index'"
+rake("db:migrate")
+
+git :init
+git add: "."
+git commit: %Q{ -m 'Initial commit' }
+```
+
+You can now wrap the `git` calls in an `after_bundle` block. It will be run
+after the binstubs have been generated.
+
+```ruby
+# template.rb
+generate(:scaffold, "person name:string")
+route "root to: 'people#index'"
+rake("db:migrate")
+
+after_bundle do
+  git :init
+  git add: "."
+  git commit: %Q{ -m 'Initial commit' }
+end
+```
 
 Upgrading from Rails 4.0 to Rails 4.1
 -------------------------------------
@@ -587,6 +625,9 @@ Rails 4.0 no longer supports loading plugins from `vendor/plugins`. You must rep
 
 * Rails 4.0 has changed `serialized_attributes` and `attr_readonly` to class methods only. You shouldn't use instance methods since it's now deprecated. You should change them to use class methods, e.g. `self.serialized_attributes` to `self.class.serialized_attributes`.
 
+* When using the default coder, assigning `nil` to a serialized attribute will save it
+to the database as `NULL` instead of passing the `nil` value through YAML (`"--- \n...\n"`).
+
 * Rails 4.0 has removed `attr_accessible` and `attr_protected` feature in favor of Strong Parameters. You can use the [Protected Attributes gem](https://github.com/rails/protected_attributes) for a smooth upgrade path.
 
 * If you are not using Protected Attributes, you can remove any options related to