10 files changed, 126 insertions, 80 deletions
diff --git a/guides/source/2_2_release_notes.md b/guides/source/2_2_release_notes.md
index 7db4cf07e7..c11d1240c4 100644
--- a/guides/source/2_2_release_notes.md
+++ b/guides/source/2_2_release_notes.md
@@ -327,7 +327,7 @@ Other features of memoization include `unmemoize`, `unmemoize_all`, and `memoize
 The `each_with_object` method provides an alternative to `inject`, using a method backported from Ruby 1.9. It iterates over a collection, passing the current element and the memo into the block.
 
 ```ruby
-%w(foo bar).each_with_object({}) { |str, hsh| hsh[str] = str.upcase } #=> {'foo' => 'FOO', 'bar' => 'BAR'}
+%w(foo bar).each_with_object({}) { |str, hsh| hsh[str] = str.upcase } # => {'foo' => 'FOO', 'bar' => 'BAR'}
 ```
 
 Lead Contributor: [Adam Keys](http://therealadam.com/)
diff --git a/guides/source/action_controller_overview.md b/guides/source/action_controller_overview.md
index 0c06e36de9..de9ead78a6 100644
--- a/guides/source/action_controller_overview.md
+++ b/guides/source/action_controller_overview.md
@@ -348,7 +348,7 @@ For most stores, this ID is used to look up the session data on the server, e.g.
 
 The CookieStore can store around 4kB of data - much less than the others - but this is usually enough. Storing large amounts of data in the session is discouraged no matter which session store your application uses. You should especially avoid storing complex objects (anything other than basic Ruby objects, the most common example being model instances) in the session, as the server might not be able to reassemble them between requests, which will result in an error.
 
-If your user sessions don't store critical data or don't need to be around for long periods (for instance if you just use the flash for messaging), you can consider using ActionDispatch::Session::CacheStore. This will store sessions using the cache implementation you have configured for your application. The advantage of this is that you can use your existing cache infrastructure for storing sessions without requiring any additional setup or administration. The downside, of course, is that the sessions will be ephemeral and could disappear at any time.
+If your user sessions don't store critical data or don't need to be around for long periods (for instance if you just use the flash for messaging), you can consider using `ActionDispatch::Session::CacheStore`. This will store sessions using the cache implementation you have configured for your application. The advantage of this is that you can use your existing cache infrastructure for storing sessions without requiring any additional setup or administration. The downside, of course, is that the sessions will be ephemeral and could disappear at any time.
 
 Read more about session storage in the [Security Guide](security.html).
 
diff --git a/guides/source/active_record_querying.md b/guides/source/active_record_querying.md
index b518a086be..94b8453f04 100644
--- a/guides/source/active_record_querying.md
+++ b/guides/source/active_record_querying.md
@@ -473,7 +473,7 @@ In the case of a belongs_to relationship, an association key can be used to spec
 
 ```ruby
 Post.where(author: author)
-Author.joins(:posts).where(posts: {author: author})
+Author.joins(:posts).where(posts: { author: author })
 ```
 
 NOTE: The values cannot be symbols. For example, you cannot do `Client.where(status: :active)`.
@@ -790,6 +790,32 @@ SELECT * FROM clients WHERE orders_count > 10 ORDER BY clients.id DESC
 
 This method accepts **no** arguments.
 
+### `rewhere`
+
+The `rewhere` method overrides an existing, named where condition. For example:
+
+```ruby
+Post.where(trashed: true).rewhere(trashed: false)
+```
+
+The SQL that would be executed:
+
+```sql
+SELECT * FROM posts WHERE `trashed` = 0
+```
+
+In case the `rewhere` clause is not used,
+
+```ruby
+Post.where(trashed: true).where(trashed: false)
+```
+
+the SQL executed would be:
+
+```sql
+SELECT * FROM posts WHERE `trashed` = 1 AND `trashed` = 0
+```
+
 Null Relation
 -------------
 
@@ -1016,7 +1042,7 @@ Or, in English: "return all posts that have a comment made by a guest."
 #### Joining Nested Associations (Multiple Level)
 
 ```ruby
-Category.joins(posts: [{comments: :guest}, :tags])
+Category.joins(posts: [{ comments: :guest }, :tags])
 ```
 
 This produces:
@@ -1042,7 +1068,7 @@ An alternative and cleaner syntax is to nest the hash conditions:
 
 ```ruby
 time_range = (Time.now.midnight - 1.day)..Time.now.midnight
-Client.joins(:orders).where(orders: {created_at: time_range})
+Client.joins(:orders).where(orders: { created_at: time_range })
 ```
 
 This will find all clients who have orders that were created yesterday, again using a `BETWEEN` SQL expression.
@@ -1103,7 +1129,7 @@ This loads all the posts and the associated category and comments for each post.
 #### Nested Associations Hash
 
 ```ruby
-Category.includes(posts: [{comments: :guest}, :tags]).find(1)
+Category.includes(posts: [{ comments: :guest }, :tags]).find(1)
 ```
 
 This will find the category with id 1 and eager load all of the associated posts, the associated posts' tags and comments, and every comment's guest association.
@@ -1604,7 +1630,7 @@ Client.where(first_name: 'Ryan').count
 You can also use various finder methods on a relation for performing complex calculations:
 
 ```ruby
-Client.includes("orders").where(first_name: 'Ryan', orders: {status: 'received'}).count
+Client.includes("orders").where(first_name: 'Ryan', orders: { status: 'received' }).count
 ```
 
 Which will execute:
diff --git a/guides/source/active_record_validations.md b/guides/source/active_record_validations.md
index 0df52a655f..cbd1ac9bdf 100644
--- a/guides/source/active_record_validations.md
+++ b/guides/source/active_record_validations.md
@@ -175,28 +175,28 @@ class Person < ActiveRecord::Base
 end
 
 >> p = Person.new
-#=> #<Person id: nil, name: nil>
+# => #<Person id: nil, name: nil>
 >> p.errors.messages
-#=> {}
+# => {}
 
 >> p.valid?
-#=> false
+# => false
 >> p.errors.messages
-#=> {name:["can't be blank"]}
+# => {name:["can't be blank"]}
 
 >> p = Person.create
-#=> #<Person id: nil, name: nil>
+# => #<Person id: nil, name: nil>
 >> p.errors.messages
-#=> {name:["can't be blank"]}
+# => {name:["can't be blank"]}
 
 >> p.save
-#=> false
+# => false
 
 >> p.save!
-#=> ActiveRecord::RecordInvalid: Validation failed: Name can't be blank
+# => ActiveRecord::RecordInvalid: Validation failed: Name can't be blank
 
 >> Person.create!
-#=> ActiveRecord::RecordInvalid: Validation failed: Name can't be blank
+# => ActiveRecord::RecordInvalid: Validation failed: Name can't be blank
 ```
 
 `invalid?` is simply the inverse of `valid?`. It triggers your validations,
diff --git a/guides/source/active_support_core_extensions.md b/guides/source/active_support_core_extensions.md
index 84a169b3b9..452ddf01eb 100644
--- a/guides/source/active_support_core_extensions.md
+++ b/guides/source/active_support_core_extensions.md
@@ -179,14 +179,14 @@ duplicate = array.dup
 duplicate.push 'another-string'
 
 # the object was duplicated, so the element was added only to the duplicate
-array     #=> ['string']
-duplicate #=> ['string', 'another-string']
+array     # => ['string']
+duplicate # => ['string', 'another-string']
 
 duplicate.first.gsub!('string', 'foo')
 
 # first element was not duplicated, it will be changed in both arrays
-array     #=> ['foo']
-duplicate #=> ['foo', 'another-string']
+array     # => ['foo']
+duplicate # => ['foo', 'another-string']
 ```
 
 As you can see, after duplicating the `Array` instance, we got another object, therefore we can modify it and the original object will stay unchanged. This is not true for array's elements, however. Since `dup` does not make deep copy, the string inside the array is still the same object.
@@ -199,8 +199,8 @@ duplicate = array.deep_dup
 
 duplicate.first.gsub!('string', 'foo')
 
-array     #=> ['string']
-duplicate #=> ['foo']
+array     # => ['string']
+duplicate # => ['foo']
 ```
 
 If the object is not duplicable, `deep_dup` will just return it:
@@ -1554,7 +1554,7 @@ ActiveSupport::Inflector.inflections do |inflect|
   inflect.acronym 'SSL'
 end
 
-"SSLError".underscore.camelize #=> "SSLError"
+"SSLError".underscore.camelize # => "SSLError"
 ```
 
 `camelize` is aliased to `camelcase`.
diff --git a/guides/source/engines.md b/guides/source/engines.md
index af48768fe9..2266b1fd7f 100644
--- a/guides/source/engines.md
+++ b/guides/source/engines.md
@@ -253,7 +253,7 @@ The helper inside `app/helpers/blorgh/posts_helper.rb` is also namespaced:
 
 ```ruby
 module Blorgh
-  class PostsHelper
+  module PostsHelper
     ...
   end
 end
diff --git a/guides/source/i18n.md b/guides/source/i18n.md
index 6b36f67874..6f79b3ddd7 100644
--- a/guides/source/i18n.md
+++ b/guides/source/i18n.md
@@ -101,7 +101,7 @@ This means, that in the `:en` locale, the key _hello_ will map to the _Hello wor
 
 The I18n library will use **English** as a **default locale**, i.e. if you don't set a different locale, `:en` will be used for looking up translations.
 
-NOTE: The i18n library takes a **pragmatic approach** to locale keys (after [some discussion](http://groups.google.com/group/rails-i18n/browse_thread/thread/14dede2c7dbe9470/80eec34395f64f3c?hl=en), including only the _locale_ ("language") part, like `:en`, `:pl`, not the _region_ part, like `:en-US` or `:en-GB`, which are traditionally used for separating "languages" and "regional setting" or "dialects". Many international applications use only the "language" element of a locale such as `:cs`, `:th` or `:es` (for Czech, Thai and Spanish). However, there are also regional differences within different language groups that may be important. For instance, in the `:en-US` locale you would have $ as a currency symbol, while in `:en-GB`, you would have £. Nothing stops you from separating regional and other settings in this way: you just have to provide full "English - United Kingdom" locale in a `:en-GB` dictionary. Various [Rails I18n plugins](http://rails-i18n.org/wiki) such as [Globalize3](https://github.com/svenfuchs/globalize3) may help you implement it.
+NOTE: The i18n library takes a **pragmatic approach** to locale keys (after [some discussion](http://groups.google.com/group/rails-i18n/browse_thread/thread/14dede2c7dbe9470/80eec34395f64f3c?hl=en)), including only the _locale_ ("language") part, like `:en`, `:pl`, not the _region_ part, like `:en-US` or `:en-GB`, which are traditionally used for separating "languages" and "regional setting" or "dialects". Many international applications use only the "language" element of a locale such as `:cs`, `:th` or `:es` (for Czech, Thai and Spanish). However, there are also regional differences within different language groups that may be important. For instance, in the `:en-US` locale you would have $ as a currency symbol, while in `:en-GB`, you would have £. Nothing stops you from separating regional and other settings in this way: you just have to provide full "English - United Kingdom" locale in a `:en-GB` dictionary. Various [Rails I18n plugins](http://rails-i18n.org/wiki) such as [Globalize3](https://github.com/svenfuchs/globalize3) may help you implement it.
 
 The **translations load path** (`I18n.load_path`) is just a Ruby Array of paths to your translation files that will be loaded automatically and available in your application. You can pick whatever directory and translation file naming scheme makes sense for you.
 
@@ -1035,7 +1035,7 @@ If you found this guide useful, please consider recommending its authors on [wor
 Footnotes
 ---------
 
-[^1]: Or, to quote [Wikipedia](http://en.wikipedia.org/wiki/Internationalization_and_localization:) _"Internationalization is the process of designing a software application so that it can be adapted to various languages and regions without engineering changes. Localization is the process of adapting software for a specific region or language by adding locale-specific components and translating text."_
+[^1]: Or, to quote [Wikipedia](http://en.wikipedia.org/wiki/Internationalization_and_localization): _"Internationalization is the process of designing a software application so that it can be adapted to various languages and regions without engineering changes. Localization is the process of adapting software for a specific region or language by adding locale-specific components and translating text."_
 
 [^2]: Other backends might allow or require to use other formats, e.g. a GetText backend might allow to read GetText files.
 
diff --git a/guides/source/initialization.md b/guides/source/initialization.md
index 33eb74dcd9..5e2e0ad3e3 100644
--- a/guides/source/initialization.md
+++ b/guides/source/initialization.md
@@ -126,7 +126,9 @@ A standard Rails application depends on several gems, specifically:
 
 ### `rails/commands.rb`
 
-Once `config/boot.rb` has finished, the next file that is required is `rails/commands` which will execute a command based on the arguments passed in. In this case, the `ARGV` array simply contains `server` which is extracted into the `command` variable using these lines:
+Once `config/boot.rb` has finished, the next file that is required is
+`rails/commands`, which helps in expanding aliases. In the current case, the
+`ARGV` array simply contains `server` which will be passed over:
 
 ```ruby
 ARGV << '--help' if ARGV.empty?
@@ -142,31 +144,64 @@ aliases = {
 
 command = ARGV.shift
 command = aliases[command] || command
+
+require 'rails/commands/commands_tasks'
+
+Rails::CommandsTasks.new(ARGV).run_command!(command)
 ```
 
 TIP: As you can see, an empty ARGV list will make Rails show the help
 snippet.
 
-If we used `s` rather than `server`, Rails will use the `aliases` defined in the file and match them to their respective commands. With the `server` command, Rails will run this code:
+If we had used `s` rather than `server`, Rails would have used the `aliases`
+defined here to find the matching command.
+
+### `rails/commands/command_tasks.rb`
+
+When one types an incorrect rails command, the `run_command` is responsible for
+throwing an error message. If the command is valid, a method of the same name
+is called.
+
+```ruby
+COMMAND_WHITELIST = %(plugin generate destroy console server dbconsole application runner new version help)
+
+def run_command!(command)
+  if COMMAND_WHITELIST.include?(command)
+    send(command)
+  else
+    write_error_message(command)
+  end
+end
+```
+
+With the `server` command, Rails will further run the following code:
 
 ```ruby
-when 'server'
-  # Change to the application's path if there is no config.ru file in current directory.
-  # This allows us to run `rails server` from other directories, but still get
-  # the main config.ru and properly set the tmp directory.
-  Dir.chdir(File.expand_path('../../', APP_PATH)) unless File.exist?(File.expand_path("config.ru"))
+def set_application_directory!
+  Dir.chdir(File.expand_path('../../', APP_PATH)) unless
+  File.exist?(File.expand_path("config.ru"))
+end
+
+def server
+  set_application_directory!
+  require_command!("server")
 
-  require 'rails/commands/server'
   Rails::Server.new.tap do |server|
-    # We need to require application after the server sets environment,
-    # otherwise the --environment option given to the server won't propagate.
     require APP_PATH
     Dir.chdir(Rails.application.root)
     server.start
   end
+end
+
+def require_command!(command)
+  require "rails/commands/#{command}"
+end
 ```
 
-This file will change into the Rails root directory (a path two directories up from `APP_PATH` which points at `config/application.rb`), but only if the `config.ru` file isn't found. This then requires `rails/commands/server` which sets up the `Rails::Server` class.
+This file will change into the Rails root directory (a path two directories up
+from `APP_PATH` which points at `config/application.rb`), but only if the
+`config.ru` file isn't found. This then requires `rails/commands/server` which
+sets up the `Rails::Server` class.
 
 ```ruby
 require 'fileutils'
@@ -294,37 +329,43 @@ and it's free for you to change based on your needs.
 
 ### `Rails::Server#start`
 
-After `config/application` is loaded, `server.start` is called. This method is defined like this:
+After `config/application` is loaded, `server.start` is called. This method is
+defined like this:
 
 ```ruby
 def start
-  url = "#{options[:SSLEnable] ? 'https' : 'http'}://#{options[:Host]}:#{options[:Port]}"
-  puts "=> Booting #{ActiveSupport::Inflector.demodulize(server)}"
-  puts "=> Rails #{Rails.version} application starting in #{Rails.env} on #{url}"
-  puts "=> Run `rails server -h` for more startup options"
+  print_boot_information
   trap(:INT) { exit }
-  puts "=> Ctrl-C to shutdown server" unless options[:daemonize]
+  create_tmp_directories
+  log_to_stdout if options[:log_stdout]
+
+  super
+  ...
+end
 
-  #Create required tmp directories if not found
-  %w(cache pids sessions sockets).each do |dir_to_make|
-    FileUtils.mkdir_p(Rails.root.join('tmp', dir_to_make))
+private
+
+  def print_boot_information
+    ...
+    puts "=> Run `rails server -h` for more startup options"
+    puts "=> Ctrl-C to shutdown server" unless options[:daemonize]
+  end
+
+  def create_tmp_directories
+    %w(cache pids sessions sockets).each do |dir_to_make|
+      FileUtils.mkdir_p(File.join(Rails.root, 'tmp', dir_to_make))
+    end
   end
 
-  unless options[:daemonize]
+  def log_to_stdout
     wrapped_app # touch the app so the logger is set up
 
     console = ActiveSupport::Logger.new($stdout)
     console.formatter = Rails.logger.formatter
+    console.level = Rails.logger.level
 
     Rails.logger.extend(ActiveSupport::Logger.broadcast(console))
   end
-
-  super
-ensure
-  # The '-h' option calls exit before @options is set.
-  # If we call 'options' with it unset, we get double help banners.
-  puts 'Exiting' unless @options && options[:daemonize]
-end
 ```
 
 This is where the first output of the Rails initialization happens. This
diff --git a/guides/source/rails_on_rack.md b/guides/source/rails_on_rack.md
index 7ef54a45bc..b42c8fb81b 100644
--- a/guides/source/rails_on_rack.md
+++ b/guides/source/rails_on_rack.md
@@ -182,18 +182,17 @@ You can swap an existing middleware in the middleware stack using `config.middle
 config.middleware.swap ActionDispatch::ShowExceptions, Lifo::ShowExceptions
 ```
 
-#### Middleware Stack is an Enumerable
+#### Deleting a Middleware
 
-The middleware stack behaves just like a normal `Enumerable`. You can use any `Enumerable` methods to manipulate or interrogate the stack. The middleware stack also implements some `Array` methods including `[]`, `unshift` and `delete`. Methods described in the section above are just convenience methods.
-
-Append following lines to your application configuration:
+Add the following lines to your application configuration:
 
 ```ruby
 # config/application.rb
 config.middleware.delete "Rack::Lock"
 ```
 
-And now if you inspect the middleware stack, you'll find that `Rack::Lock` will not be part of it.
+And now if you inspect the middleware stack, you'll find that `Rack::Lock` is
+not a part of it.
 
 ```bash
 $ rake middleware
@@ -319,26 +318,6 @@ Much of Action Controller's functionality is implemented as Middlewares. The fol
 
 TIP: It's possible to use any of the above middlewares in your custom Rack stack.
 
-### Using Rack Builder
-
-The following shows how to replace use `Rack::Builder` instead of the Rails supplied `MiddlewareStack`.
-
-<strong>Clear the existing Rails middleware stack</strong>
-
-```ruby
-# config/application.rb
-config.middleware.clear
-```
-
-<br>
-<strong>Add a `config.ru` file to `Rails.root`</strong>
-
-```ruby
-# config.ru
-use MyOwnStackFromScratch
-run Rails.application
-```
-
 Resources
 ---------
 
diff --git a/guides/source/ruby_on_rails_guides_guidelines.md b/guides/source/ruby_on_rails_guides_guidelines.md
index 5564b0648b..8faf03e58c 100644
--- a/guides/source/ruby_on_rails_guides_guidelines.md
+++ b/guides/source/ruby_on_rails_guides_guidelines.md
@@ -51,7 +51,7 @@ 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. Please have a look at these particular sections of the [API Documentation Guidelines](api_documentation_guidelines.html):
 
 * [Wording](api_documentation_guidelines.html#wording)
 * [Example Code](api_documentation_guidelines.html#example-code)