14 files changed, 101 insertions, 70 deletions
diff --git a/guides/bug_report_templates/benchmark.rb b/guides/bug_report_templates/benchmark.rb
index 54433b34dd..a0b541d012 100644
--- a/guides/bug_report_templates/benchmark.rb
+++ b/guides/bug_report_templates/benchmark.rb
@@ -8,6 +8,7 @@ end
 gemfile(true) do
   source "https://rubygems.org"
   gem "rails", github: "rails/rails"
+  gem "arel", github: "rails/arel"
   gem "benchmark-ips"
 end
 
diff --git a/guides/source/action_controller_overview.md b/guides/source/action_controller_overview.md
index 22537f960c..7de6542f4a 100644
--- a/guides/source/action_controller_overview.md
+++ b/guides/source/action_controller_overview.md
@@ -1186,7 +1186,7 @@ class ClientsController < ApplicationController
 end
 ```
 
-WARNING: You shouldn't do `rescue_from Exception` or `rescue_from StandardError` unless you have a particular reason as it will cause serious side-effects (e.g. you won't be able to see exception details and tracebacks during development).
+WARNING: Using `rescue_from` with `Exception` or `StandardError` would cause serious side-effects as it prevents Rails from handling exceptions properly. As such, it is not recommended to do so unless there is a strong reason.
 
 NOTE: When running in the production environment, all
 `ActiveRecord::RecordNotFound` errors render the 404 error page. Unless you need
diff --git a/guides/source/action_view_overview.md b/guides/source/action_view_overview.md
index 10412128cc..e5f4e0ec30 100644
--- a/guides/source/action_view_overview.md
+++ b/guides/source/action_view_overview.md
@@ -464,25 +464,6 @@ Returns an HTML script tag for each of the sources provided. You can pass in the
 javascript_include_tag "common" # => <script src="/assets/common.js"></script>
 ```
 
-If the application does not use the asset pipeline, to include the jQuery JavaScript library in your application, pass `:defaults` as the source. When using `:defaults`, if an `application.js` file exists in your `app/assets/javascripts` directory, it will be included as well.
-
-```ruby
-javascript_include_tag :defaults
-```
-
-You can also include all JavaScript files in the `app/assets/javascripts` directory using `:all` as the source.
-
-```ruby
-javascript_include_tag :all
-```
-
-You can also cache multiple JavaScript files into one file, which requires less HTTP connections to download and can better be compressed by gzip (leading to faster transfers). Caching will only happen if `ActionController::Base.perform_caching` is set to true (which is the case by default for the Rails production environment, but not for the development environment).
-
-```ruby
-javascript_include_tag :all, cache: true # =>
-  <script src="/javascripts/all.js"></script>
-```
-
 #### javascript_path
 
 Computes the path to a JavaScript asset in the `app/assets/javascripts` directory. If the source filename has no extension, `.js` will be appended. Full paths from the document root will be passed through. Used internally by `javascript_include_tag` to build the script path.
@@ -507,19 +488,6 @@ Returns a stylesheet link tag for the sources specified as arguments. If you don
 stylesheet_link_tag "application" # => <link href="/assets/application.css" media="screen" rel="stylesheet" />
 ```
 
-You can also include all styles in the stylesheet directory using `:all` as the source:
-
-```ruby
-stylesheet_link_tag :all
-```
-
-You can also cache multiple stylesheets into one file, which requires less HTTP connections and can better be compressed by gzip (leading to faster transfers). Caching will only happen if ActionController::Base.perform_caching is set to true (which is the case by default for the Rails production environment, but not for the development environment).
-
-```ruby
-stylesheet_link_tag :all, cache: true
-# => <link href="/assets/all.css" media="screen" rel="stylesheet" />
-```
-
 #### stylesheet_path
 
 Computes the path to a stylesheet asset in the `app/assets/stylesheets` directory. If the source filename has no extension, `.css` will be appended. Full paths from the document root will be passed through. Used internally by stylesheet_link_tag to build the stylesheet path.
diff --git a/guides/source/active_record_callbacks.md b/guides/source/active_record_callbacks.md
index b1705855d0..fc4f773e3c 100644
--- a/guides/source/active_record_callbacks.md
+++ b/guides/source/active_record_callbacks.md
@@ -428,3 +428,32 @@ end
 ```
 
 WARNING. The `after_commit` and `after_rollback` callbacks are called for all models created, updated, or destroyed within a transaction block. However, if an exception is raised within one of these callbacks, the exception will bubble up and any remaining `after_commit` or `after_rollback` methods will _not_ be executed. As such, if your callback code could raise an exception, you'll need to rescue it and handle it within the callback in order to allow other callbacks to run.
+
+WARNING. Using `after_create_commit` and `after_update_commit` both in the same model will override the callback which was registered first amongst them.
+
+```ruby
+class User < ApplicationRecord
+  after_create_commit :log_user_saved_to_db
+  after_update_commit :log_user_saved_to_db
+
+  private
+  def log_user_saved_to_db
+    puts 'User was saved to database'
+  end
+end
+
+# prints nothing
+>> @user = User.create
+
+# updating @user
+>> @user.save
+=> User was saved to database
+```
+
+To register callbacks for both create and update actions, use `after_commit` instead.
+
+```ruby
+class User < ApplicationRecord
+  after_commit :log_user_saved_to_db, on: [:create, :update]
+end
+```
diff --git a/guides/source/active_record_postgresql.md b/guides/source/active_record_postgresql.md
index 8543fcd20f..58c61f0864 100644
--- a/guides/source/active_record_postgresql.md
+++ b/guides/source/active_record_postgresql.md
@@ -29,8 +29,8 @@ that are supported by the PostgreSQL adapter.
 
 ### Bytea
 
-* [type definition](http://www.postgresql.org/docs/current/static/datatype-binary.html)
-* [functions and operators](http://www.postgresql.org/docs/current/static/functions-binarystring.html)
+* [type definition](https://www.postgresql.org/docs/current/static/datatype-binary.html)
+* [functions and operators](https://www.postgresql.org/docs/current/static/functions-binarystring.html)
 
 ```ruby
 # db/migrate/20140207133952_create_documents.rb
@@ -49,8 +49,8 @@ Document.create payload: data
 
 ### Array
 
-* [type definition](http://www.postgresql.org/docs/current/static/arrays.html)
-* [functions and operators](http://www.postgresql.org/docs/current/static/functions-array.html)
+* [type definition](https://www.postgresql.org/docs/current/static/arrays.html)
+* [functions and operators](https://www.postgresql.org/docs/current/static/functions-array.html)
 
 ```ruby
 # db/migrate/20140207133952_create_books.rb
@@ -83,8 +83,8 @@ Book.where("array_length(ratings, 1) >= 3")
 
 ### Hstore
 
-* [type definition](http://www.postgresql.org/docs/current/static/hstore.html)
-* [functions and operators](http://www.postgresql.org/docs/current/static/hstore.html#AEN179902)
+* [type definition](https://www.postgresql.org/docs/current/static/hstore.html)
+* [functions and operators](https://www.postgresql.org/docs/current/static/hstore.html#AEN179902)
 
 NOTE: You need to enable the `hstore` extension to use hstore.
 
@@ -116,8 +116,8 @@ Profile.where("settings->'color' = ?", "yellow")
 
 ### JSON and JSONB
 
-* [type definition](http://www.postgresql.org/docs/current/static/datatype-json.html)
-* [functions and operators](http://www.postgresql.org/docs/current/static/functions-json.html)
+* [type definition](https://www.postgresql.org/docs/current/static/datatype-json.html)
+* [functions and operators](https://www.postgresql.org/docs/current/static/functions-json.html)
 
 ```ruby
 # db/migrate/20131220144913_create_events.rb
@@ -147,8 +147,8 @@ Event.where("payload->>'kind' = ?", "user_renamed")
 
 ### Range Types
 
-* [type definition](http://www.postgresql.org/docs/current/static/rangetypes.html)
-* [functions and operators](http://www.postgresql.org/docs/current/static/functions-range.html)
+* [type definition](https://www.postgresql.org/docs/current/static/rangetypes.html)
+* [functions and operators](https://www.postgresql.org/docs/current/static/functions-range.html)
 
 This type is mapped to Ruby [`Range`](http://www.ruby-doc.org/core-2.2.2/Range.html) objects.
 
@@ -182,7 +182,7 @@ event.ends_at # => Thu, 13 Feb 2014
 
 ### Composite Types
 
-* [type definition](http://www.postgresql.org/docs/current/static/rowtypes.html)
+* [type definition](https://www.postgresql.org/docs/current/static/rowtypes.html)
 
 Currently there is no special support for composite types. They are mapped to
 normal text columns:
@@ -222,7 +222,7 @@ contact.save!
 
 ### Enumerated Types
 
-* [type definition](http://www.postgresql.org/docs/current/static/datatype-enum.html)
+* [type definition](https://www.postgresql.org/docs/current/static/datatype-enum.html)
 
 Currently there is no special support for enumerated types. They are mapped as
 normal text columns:
@@ -260,7 +260,7 @@ article.status = "published"
 article.save!
 ```
 
-To add a new value before/after existing one you should use [ALTER TYPE](http://www.postgresql.org/docs/current/static/sql-altertype.html):
+To add a new value before/after existing one you should use [ALTER TYPE](https://www.postgresql.org/docs/current/static/sql-altertype.html):
 
 ```ruby
 # db/migrate/20150720144913_add_new_state_to_articles.rb
@@ -274,7 +274,7 @@ def up
 end
 ```
 
-NOTE: ENUM values can't be dropped currently. You can read why [here](http://www.postgresql.org/message-id/29F36C7C98AB09499B1A209D48EAA615B7653DBC8A@mail2a.alliedtesting.com).
+NOTE: ENUM values can't be dropped currently. You can read why [here](https://www.postgresql.org/message-id/29F36C7C98AB09499B1A209D48EAA615B7653DBC8A@mail2a.alliedtesting.com).
 
 Hint: to show all the values of the all enums you have, you should call this query in `bin/rails db` or `psql` console:
 
@@ -289,9 +289,9 @@ SELECT n.nspname AS enum_schema,
 
 ### UUID
 
-* [type definition](http://www.postgresql.org/docs/current/static/datatype-uuid.html)
-* [pgcrypto generator function](http://www.postgresql.org/docs/current/static/pgcrypto.html#AEN182570)
-* [uuid-ossp generator functions](http://www.postgresql.org/docs/current/static/uuid-ossp.html)
+* [type definition](https://www.postgresql.org/docs/current/static/datatype-uuid.html)
+* [pgcrypto generator function](https://www.postgresql.org/docs/current/static/pgcrypto.html#AEN182570)
+* [uuid-ossp generator functions](https://www.postgresql.org/docs/current/static/uuid-ossp.html)
 
 NOTE: You need to enable the `pgcrypto` (only PostgreSQL >= 9.4) or `uuid-ossp`
 extension to use uuid.
@@ -340,8 +340,8 @@ See [this section](#uuid-primary-keys) for more details on using UUIDs as primar
 
 ### Bit String Types
 
-* [type definition](http://www.postgresql.org/docs/current/static/datatype-bit.html)
-* [functions and operators](http://www.postgresql.org/docs/current/static/functions-bitstring.html)
+* [type definition](https://www.postgresql.org/docs/current/static/datatype-bit.html)
+* [functions and operators](https://www.postgresql.org/docs/current/static/functions-bitstring.html)
 
 ```ruby
 # db/migrate/20131220144913_create_users.rb
@@ -364,7 +364,7 @@ user.save!
 
 ### Network Address Types
 
-* [type definition](http://www.postgresql.org/docs/current/static/datatype-net-types.html)
+* [type definition](https://www.postgresql.org/docs/current/static/datatype-net-types.html)
 
 The types `inet` and `cidr` are mapped to Ruby
 [`IPAddr`](http://www.ruby-doc.org/stdlib-2.2.2/libdoc/ipaddr/rdoc/IPAddr.html)
@@ -399,7 +399,7 @@ macbook.address
 
 ### Geometric Types
 
-* [type definition](http://www.postgresql.org/docs/current/static/datatype-geometric.html)
+* [type definition](https://www.postgresql.org/docs/current/static/datatype-geometric.html)
 
 All geometric types, with the exception of `points` are mapped to normal text.
 A point is casted to an array containing `x` and `y` coordinates.
@@ -457,7 +457,7 @@ Document.where("to_tsvector('english', title || ' ' || body) @@ to_tsquery(?)",
 Database Views
 --------------
 
-* [view creation](http://www.postgresql.org/docs/current/static/sql-createview.html)
+* [view creation](https://www.postgresql.org/docs/current/static/sql-createview.html)
 
 Imagine you need to work with a legacy database containing the following table:
 
diff --git a/guides/source/active_record_querying.md b/guides/source/active_record_querying.md
index 215142223d..c79c86ac0c 100644
--- a/guides/source/active_record_querying.md
+++ b/guides/source/active_record_querying.md
@@ -2045,4 +2045,4 @@ following pointers may be helpful:
 
 * MariaDB: [EXPLAIN](https://mariadb.com/kb/en/mariadb/explain/)
 
-* PostgreSQL: [Using EXPLAIN](http://www.postgresql.org/docs/current/static/using-explain.html)
+* PostgreSQL: [Using EXPLAIN](https://www.postgresql.org/docs/current/static/using-explain.html)
diff --git a/guides/source/active_record_validations.md b/guides/source/active_record_validations.md
index 6eb5de78be..a086363cf1 100644
--- a/guides/source/active_record_validations.md
+++ b/guides/source/active_record_validations.md
@@ -638,7 +638,7 @@ class Holiday < ApplicationRecord
     message: "should happen once per year" }
 end
 ```
-Should you wish to create a database constraint to prevent possible violations of a uniqueness validation using the `:scope` option, you must create a unique index on both columns in your database. See [the MySQL manual](http://dev.mysql.com/doc/refman/5.7/en/multiple-column-indexes.html) for more details about multiple column indexes or [the PostgreSQL manual](http://www.postgresql.org/docs/current/static/ddl-constraints.html) for examples of unique constraints that refer to a group of columns.
+Should you wish to create a database constraint to prevent possible violations of a uniqueness validation using the `:scope` option, you must create a unique index on both columns in your database. See [the MySQL manual](http://dev.mysql.com/doc/refman/5.7/en/multiple-column-indexes.html) for more details about multiple column indexes or [the PostgreSQL manual](https://www.postgresql.org/docs/current/static/ddl-constraints.html) for examples of unique constraints that refer to a group of columns.
 
 There is also a `:case_sensitive` option that you can use to define whether the
 uniqueness constraint will be case sensitive or not. This option defaults to
diff --git a/guides/source/active_support_core_extensions.md b/guides/source/active_support_core_extensions.md
index 23f53ac084..4c37f6aba9 100644
--- a/guides/source/active_support_core_extensions.md
+++ b/guides/source/active_support_core_extensions.md
@@ -927,8 +927,7 @@ The generation of the writer instance method can be prevented by setting the opt
 ```ruby
 module ActiveRecord
   class Base
-    class_attribute :table_name_prefix, instance_writer: false
-    self.table_name_prefix = ""
+    class_attribute :table_name_prefix, instance_writer: false, default: "my"
   end
 end
 ```
diff --git a/guides/source/configuring.md b/guides/source/configuring.md
index 21b3ca0efa..61c4bd1e61 100644
--- a/guides/source/configuring.md
+++ b/guides/source/configuring.md
@@ -375,6 +375,28 @@ The MySQL adapter adds one additional configuration option:
 
 * `ActiveRecord::ConnectionAdapters::Mysql2Adapter.emulate_booleans` controls whether Active Record will consider all `tinyint(1)` columns as booleans. Defaults to `true`.
 
+The SQLite3Adapter adapter adds one additional configuration option:
+
+* `ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer`
+indicates whether boolean values are stored in sqlite3 databases as 1 and 0 or
+'t' and 'f'. Leaving `ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer`
+set to false is deprecated. SQLite databases have used 't' and 'f' to serialize
+boolean values and must have old data converted to 1 and 0 (its native boolean
+serialization) before setting this flag to true. Conversion can be accomplished
+by setting up a rake task which runs
+
+    ```ruby
+    ExampleModel.where("boolean_column = 't'").update_all(boolean_column: 1)
+    ExampleModel.where("boolean_column = 'f'").update_all(boolean_column: 0)
+    ```
+
+  for all models and all boolean columns, after which the flag must be set to true
+by adding the following to your application.rb file:
+
+    ```ruby
+    Rails.application.config.active_record.sqlite3.represent_boolean_as_integer = true
+    ```
+
 The schema dumper adds one additional configuration option:
 
 * `ActiveRecord::SchemaDumper.ignore_tables` accepts an array of tables that should _not_ be included in any generated schema file. This setting is ignored unless `config.active_record.schema_format == :ruby`.
@@ -401,6 +423,8 @@ The schema dumper adds one additional configuration option:
 
 * `config.action_controller.per_form_csrf_tokens` configures whether CSRF tokens are only valid for the method/action they were generated for.
 
+* `config.action_controller.default_protect_from_forgery` determines whether forgery protection is added on `ActionController:Base`.  This is false by default, but enabled when loading defaults for Rails 5.2.
+
 * `config.action_controller.relative_url_root` can be used to tell Rails that you are [deploying to a subdirectory](configuring.html#deploy-to-a-subdirectory-relative-url-root). The default is `ENV['RAILS_RELATIVE_URL_ROOT']`.
 
 * `config.action_controller.permit_all_parameters` sets all the parameters for mass assignment to be permitted by default. The default value is `false`.
diff --git a/guides/source/initialization.md b/guides/source/initialization.md
index 86aea2c24d..ccad10f07d 100644
--- a/guides/source/initialization.md
+++ b/guides/source/initialization.md
@@ -109,7 +109,7 @@ A standard Rails application depends on several gems, specifically:
 * arel
 * builder
 * bundler
-* erubis
+* erubi
 * i18n
 * mail
 * mime-types
diff --git a/guides/source/routing.md b/guides/source/routing.md
index f7dbbc510e..f52b1862a8 100644
--- a/guides/source/routing.md
+++ b/guides/source/routing.md
@@ -418,7 +418,7 @@ resources :articles do
 end
 ```
 
-Also you can use them in any place that you want inside the routes, for example in a scope or namespace call:
+Also you can use them in any place that you want inside the routes, for example in a `scope` or `namespace` call:
 
 ```ruby
 namespace :articles do
@@ -484,7 +484,7 @@ resources :photos do
 end
 ```
 
-This will recognize `/photos/1/preview` with GET, and route to the `preview` action of `PhotosController`, with the resource id value passed in `params[:id]`. It will also create the `preview_photo_url` and `preview_photo_path` helpers.
+This will recognize `/photos/1/preview` with GET, and route to the `preview` action of `PhotosController`, with the resource id value passed in `params[:id]`. It will also create the `photo_preview_url` and `photo_preview_path` helpers.
 
 Within the block of member routes, each route name specifies the HTTP verb
 will be recognized. You can use `get`, `patch`, `put`, `post`, or `delete` here
@@ -640,7 +640,7 @@ 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.
+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
 
@@ -808,14 +808,14 @@ NOTE: For the curious, `'articles#index'` actually expands out to `ArticlesContr
 
 If you specify a Rack application as the endpoint for a matcher, remember that
 the route will be unchanged in the receiving application. With the following
-route your Rack application should expect the route to be '/admin':
+route your Rack application should expect the route to be `/admin`:
 
 ```ruby
 match '/admin', to: AdminApp, via: :all
 ```
 
 If you would prefer to have your Rack application receive requests at the root
-path instead, use mount:
+path instead, use `mount`:
 
 ```ruby
 mount AdminApp, at: '/admin'
diff --git a/guides/source/testing.md b/guides/source/testing.md
index 7abf3af187..f71e963716 100644
--- a/guides/source/testing.md
+++ b/guides/source/testing.md
@@ -18,7 +18,7 @@ Why Write Tests for your Rails Applications?
 
 Rails makes it super easy to write your tests. It starts by producing skeleton test code while you are creating your models and controllers.
 
-By simply running your Rails tests you can ensure your code adheres to the desired functionality even after some major code refactoring.
+By running your Rails tests you can ensure your code adheres to the desired functionality even after some major code refactoring.
 
 Rails tests can also simulate browser requests and thus you can test your application's response without having to test it through your browser.
 
@@ -273,7 +273,7 @@ When a test fails you are presented with the corresponding backtrace. By default
 Rails filters that backtrace and will only print lines relevant to your
 application. This eliminates the framework noise and helps to focus on your
 code. However there are situations when you want to see the full
-backtrace. Simply set the `-b` (or `--backtrace`) argument to enable this behavior:
+backtrace. Set the `-b` (or `--backtrace`) argument to enable this behavior:
 
 ```bash
 $ bin/rails test -b test/models/article_test.rb
@@ -516,7 +516,7 @@ steve:
 
 Each fixture is given a name followed by an indented list of colon-separated key/value pairs. Records are typically separated by a blank line. You can place comments in a fixture file by using the # character in the first column.
 
-If you are working with [associations](/association_basics.html), you can simply
+If you are working with [associations](/association_basics.html), you can
 define a reference node between two different fixtures. Here's an example with
 a `belongs_to`/`has_many` association:
 
@@ -641,7 +641,7 @@ When you generate a new application or scaffold, an `application_system_test_cas
 is created in the test directory. This is where all the configuration for your
 system tests should live.
 
-If you want to change the default settings you can simply change what the system
+If you want to change the default settings you can change what the system
 tests are "driven by". Say you want to change the driver from Selenium to
 Poltergeist. First add the `poltergeist` gem to your Gemfile. Then in your
 `application_system_test_case.rb` file do the following:
diff --git a/guides/source/upgrading_ruby_on_rails.md b/guides/source/upgrading_ruby_on_rails.md
index 88a7d0a464..6e927d7244 100644
--- a/guides/source/upgrading_ruby_on_rails.md
+++ b/guides/source/upgrading_ruby_on_rails.md
@@ -276,6 +276,16 @@ You can now just call the dependency once with a wildcard.
 <% # Template Dependency: recordings/threads/events/* %>
 ```
 
+### `ActionView::Helpers::RecordTagHelper` moved to external gem (record_tag_helper)
+
+`content_tag_for` and `div_for` has been removed in favor of just using `content_tag`. To continue using it, add the `record_tag_helper` gem to your Gemfile:
+
+```ruby
+gem 'record_tag_helper', '~> 1.0'
+```
+
+See [#18411](https://github.com/rails/rails/pull/18411) for more details.
+
 ### Removed Support for `protected_attributes` Gem
 
 The `protected_attributes` gem is no longer supported in Rails 5.
diff --git a/guides/source/working_with_javascript_in_rails.md b/guides/source/working_with_javascript_in_rails.md
index ed27752a06..304ac97b32 100644
--- a/guides/source/working_with_javascript_in_rails.md
+++ b/guides/source/working_with_javascript_in_rails.md
@@ -151,7 +151,7 @@ Because of Unobtrusive JavaScript, the Rails "Ajax helpers" are actually in two
 parts: the JavaScript half and the Ruby half.
 
 Unless you have disabled the Asset Pipeline,
-[rails-ujs](https://github.com/rails/rails/blob/master/actionview/app/assets/javascripts/rails-ujs.coffee)
+[rails-ujs](https://github.com/rails/rails/tree/master/actionview/app/assets/javascripts)
 provides the JavaScript half, and the regular Ruby view helpers add appropriate
 tags to your DOM.