8 files changed, 67 insertions, 9 deletions
diff --git a/actionpack/lib/action_dispatch/routing/mapper.rb b/actionpack/lib/action_dispatch/routing/mapper.rb
index 8ff3b42a40..40b6500553 100644
--- a/actionpack/lib/action_dispatch/routing/mapper.rb
+++ b/actionpack/lib/action_dispatch/routing/mapper.rb
@@ -106,7 +106,7 @@ module ActionDispatch
           @ast                = ast
           @anchor             = anchor
           @via                = via
-          @internal           = options[:internal]
+          @internal           = options.delete(:internal)
 
           path_params = ast.find_all(&:symbol?).map(&:to_sym)
 
diff --git a/actionpack/test/dispatch/cookies_test.rb b/actionpack/test/dispatch/cookies_test.rb
index dfcef14344..c7194cde4a 100644
--- a/actionpack/test/dispatch/cookies_test.rb
+++ b/actionpack/test/dispatch/cookies_test.rb
@@ -520,7 +520,7 @@ class CookiesTest < ActionController::TestCase
 
   def test_accessing_nonexistent_signed_cookie_should_not_raise_an_invalid_signature
     get :set_signed_cookie
-    assert_nil @controller.send(:cookies).signed[:non_existant_attribute]
+    assert_nil @controller.send(:cookies).signed[:non_existent_attribute]
   end
 
   def test_encrypted_cookie_using_default_serializer
@@ -638,7 +638,7 @@ class CookiesTest < ActionController::TestCase
 
   def test_accessing_nonexistent_encrypted_cookie_should_not_raise_invalid_message
     get :set_encrypted_cookie
-    assert_nil @controller.send(:cookies).encrypted[:non_existant_attribute]
+    assert_nil @controller.send(:cookies).encrypted[:non_existent_attribute]
   end
 
   def test_setting_invalid_encrypted_cookie_should_return_nil_when_accessing_it
diff --git a/actionpack/test/dispatch/routing_test.rb b/actionpack/test/dispatch/routing_test.rb
index ade4b0c381..75fdc9469f 100644
--- a/actionpack/test/dispatch/routing_test.rb
+++ b/actionpack/test/dispatch/routing_test.rb
@@ -4795,3 +4795,33 @@ class TestPathParameters < ActionDispatch::IntegrationTest
     assert_equal "/ar | /ar/about", @response.body
   end
 end
+
+class TestInternalRoutingParams < ActionDispatch::IntegrationTest
+  Routes = ActionDispatch::Routing::RouteSet.new.tap do |app|
+    app.draw do
+      get '/test_internal/:internal' => 'internal#internal'
+    end
+  end
+
+  class ::InternalController < ActionController::Base
+    def internal
+      head :ok
+    end
+  end
+
+  APP = build_app Routes
+
+  def app
+    APP
+  end
+
+  def test_paths_with_partial_dynamic_segments_are_recognised
+    get '/test_internal/123'
+    assert_equal 200, response.status
+
+    assert_equal(
+      { controller: 'internal', action: 'internal', internal: '123' },
+      request.path_parameters
+    )
+  end
+end
diff --git a/activesupport/test/core_ext/hash_ext_test.rb b/activesupport/test/core_ext/hash_ext_test.rb
index e70680c773..e8099baa35 100644
--- a/activesupport/test/core_ext/hash_ext_test.rb
+++ b/activesupport/test/core_ext/hash_ext_test.rb
@@ -1042,7 +1042,7 @@ class HashExtTest < ActiveSupport::TestCase
     assert_equal 3, new_hash[2]
 
     new_hash.default = 2
-    assert_equal 2, new_hash[:non_existant]
+    assert_equal 2, new_hash[:non_existent]
   end
 
   def test_to_hash_with_raising_default_proc
diff --git a/guides/source/5_0_release_notes.md b/guides/source/5_0_release_notes.md
index a07ce7e859..71861d079e 100644
--- a/guides/source/5_0_release_notes.md
+++ b/guides/source/5_0_release_notes.md
@@ -37,9 +37,20 @@ Major Features
 --------------
 
 ### Action Cable
-[Pull Request](https://github.com/rails/rails/pull/22586)
 
-ToDo...
+Action Cable is a new framework in Rails 5. It seamlessly integrates
+[WebSockets](https://en.wikipedia.org/wiki/WebSocket) with the rest of your
+Rails application. 
+
+Action Cable allows for real-time features to be written in Ruby in the
+same style and form as the rest of your Rails application, while still being
+performant and scalable. It's a full-stack offering that provides both a
+client-side JavaScript framework and a server-side Ruby framework. You have
+access to your full domain model written with Active Record or your ORM of
+choice.
+
+See the [Active Cable Overview](action_cable_overview.html) guide for more
+information.
 
 ### Rails API
 [Pull Request](https://github.com/rails/rails/pull/19832)
diff --git a/guides/source/active_record_validations.md b/guides/source/active_record_validations.md
index 936d6a30b8..2737237c1a 100644
--- a/guides/source/active_record_validations.md
+++ b/guides/source/active_record_validations.md
@@ -392,7 +392,8 @@ The `exclusion` helper has an option `:in` that receives the set of values that
 will not be accepted for the validated attributes. The `:in` option has an
 alias called `:within` that you can use for the same purpose, if you'd like to.
 This example uses the `:message` option to show how you can include the
-attribute's value.
+attribute's value. For full options to the message argument please see the
+[message documentation](#message).
 
 The default error message is _"is reserved"_.
 
@@ -427,7 +428,8 @@ end
 The `inclusion` helper has an option `:in` that receives the set of values that
 will be accepted. The `:in` option has an alias called `:within` that you can
 use for the same purpose, if you'd like to. The previous example uses the
-`:message` option to show how you can include the attribute's value.
+`:message` option to show how you can include the attribute's value. For full
+options please see the [message documentation](#message).
 
 The default error message for this helper is _"is not included in the list"_.
 
@@ -768,6 +770,9 @@ class Coffee < ApplicationRecord
 end
 ```
 
+For full options to the message argument please see the
+[message documentation](#message).
+
 ### `:allow_blank`
 
 The `:allow_blank` option is similar to the `:allow_nil` option. This option
@@ -792,7 +797,8 @@ for each validation helper. The `:message` option accepts a `String` or `Proc`.
 
 A `String` `:message` value can optionally contain any/all of `%{value}`,
 `%{attribute}`, and `%{model}` which will be dynamically replaced when
-validation fails.
+validation fails. This replacement is done using the I18n gem, and the
+placeholders must match exactly, no spaces are allowed.
 
 A `Proc` `:message` value is given two arguments: the object being validated, and
 a hash with `:model`, `:attribute`, and `:value` key-value pairs.
diff --git a/guides/source/documents.yaml b/guides/source/documents.yaml
index a5b8a75509..a06a53b250 100644
--- a/guides/source/documents.yaml
+++ b/guides/source/documents.yaml
@@ -195,6 +195,11 @@
       url: upgrading_ruby_on_rails.html
       description: This guide helps in upgrading applications to latest Ruby on Rails versions.
     -
+      name: Ruby on Rails 5.0 Release Notes
+      url: 5_0_release_notes.html
+      description: Release notes for Rails 5.0.
+      work_in_progress: true
+    -
       name: Ruby on Rails 4.2 Release Notes
       url: 4_2_release_notes.html
       description: Release notes for Rails 4.2.
diff --git a/railties/test/rails_info_controller_test.rb b/railties/test/rails_info_controller_test.rb
index c51503c2b7..2e10d63599 100644
--- a/railties/test/rails_info_controller_test.rb
+++ b/railties/test/rails_info_controller_test.rb
@@ -78,4 +78,10 @@ class InfoControllerTest < ActionController::TestCase
     get :routes, params: { path: 'rails/info/routes.html' }
     assert fuzzy_count.call == 0, 'should match optional parts of route literally'
   end
+
+  test "internal routes do not have a default params[:internal] value" do
+    get :properties
+    assert_response :success
+    assert_nil @controller.params[:internal]
+  end
 end