Merge branch 'master' into experiment

* master: (49 commits)
  avoid creating a set if no where values are removed
  remove bind values for where clauses that were removed
  push partitioning up so bind elimination can get the removed wheres
  push partion logic down and initialization logic up
  the rake task `db:test:prepare` needs to load the configuration
  In batches test @total was assigned but not used. Use it in tests instead of Post.count
  partition the where values so we can access the removed ones
  eliminate some conditionals
  change method name to reflect what it actually does.
  save the where values in variables so we don't need to look them up all the time
  pass where values to the helper function rather than rely on internal state
  Spelling correction in Upgrading Guide
  Add has_named_route? to the mapper API
  No need CHANGELOG entry for a test fix
  Fix wrong `case_sensitive` in uniqueness validity test
  Fix typo in test name and documentation
  Missing ending ``` at 14.2 Merging of scopes
  copy edits[ci skip]
  Revert "Corrected documentation and added some more for the classify method in inflectors"
  Revert "Changed the CHANGELOG for active_support and improved the doc for inflector method classify"
  ...

4 files changed, 65 insertions, 11 deletions

diff --git a/guides/source/active_record_querying.md b/guides/source/active_record_querying.md
index 19b214f114..c4d69908ed 100644
--- a/guides/source/active_record_querying.md
+++ b/guides/source/active_record_querying.md
@@ -1202,6 +1202,7 @@ class User < ActiveRecord::Base
   scope :active, -> { where state: 'active' }
   scope :inactive, -> { where state: 'inactive' }
 end
+```
 
 ```ruby
 User.active.inactive
diff --git a/guides/source/active_record_validations.md b/guides/source/active_record_validations.md
index dfc951f10e..621d2222ff 100644
--- a/guides/source/active_record_validations.md
+++ b/guides/source/active_record_validations.md
@@ -162,8 +162,8 @@ Person.create(name: nil).valid? # => false
 ```
 
 After Active Record has performed validations, any errors found can be accessed
-through the `errors` instance method, which returns a collection of errors. By
-definition, an object is valid if this collection is empty after running
+through the `errors.messages` instance method, which returns a collection of errors.
+By definition, an object is valid if this collection is empty after running
 validations.
 
 Note that an object instantiated with `new` will not report errors even if it's
@@ -176,17 +176,17 @@ end
 
 >> p = Person.new
 #=> #<Person id: nil, name: nil>
->> p.errors
+>> p.errors.messages
 #=> {}
 
 >> p.valid?
 #=> false
->> p.errors
+>> p.errors.messages
 #=> {name:["can't be blank"]}
 
 >> p = Person.create
 #=> #<Person id: nil, name: nil>
->> p.errors
+>> p.errors.messages
 #=> {name:["can't be blank"]}
 
 >> p.save
@@ -993,12 +993,12 @@ end
 
 person = Person.new
 person.valid? # => false
-person.errors
+person.errors.messages
  # => {:name=>["can't be blank", "is too short (minimum is 3 characters)"]}
 
 person = Person.new(name: "John Doe")
 person.valid? # => true
-person.errors # => []
+person.errors.messages # => {}
 ```
 
 ### `errors[]`
diff --git a/guides/source/migrations.md b/guides/source/migrations.md
index fcfc54a3d7..550f8fdc3c 100644
--- a/guides/source/migrations.md
+++ b/guides/source/migrations.md
@@ -852,7 +852,7 @@ end
 # app/models/product.rb
 
 class Product < ActiveRecord::Base
-  validates :flag, :inclusion => { :in => [true, false] }
+  validates :flag, inclusion: { in: [true, false] }
 end
 ```
 
@@ -877,7 +877,7 @@ end
 # app/models/product.rb
 
 class Product < ActiveRecord::Base
-  validates :flag, :inclusion => { :in => [true, false] }
+  validates :flag, inclusion:  { in: [true, false] }
   validates :fuzz, presence: true
 end
 ```
@@ -1065,8 +1065,8 @@ with foreign key constraints in the database.
 
 Although Active Record does not provide any tools for working directly with
 such features, the `execute` method can be used to execute arbitrary SQL. You
-could also use some gem like
-[foreigner](https://github.com/matthuhiggins/foreigner) which add foreign key
+can also use a gem like
+[foreigner](https://github.com/matthuhiggins/foreigner) which adds foreign key
 support to Active Record (including support for dumping foreign keys in
 `db/schema.rb`).
 
diff --git a/guides/source/upgrading_ruby_on_rails.md b/guides/source/upgrading_ruby_on_rails.md
index 1d14656f79..6c3e763f53 100644
--- a/guides/source/upgrading_ruby_on_rails.md
+++ b/guides/source/upgrading_ruby_on_rails.md
@@ -22,6 +22,59 @@ Rails generally stays close to the latest released Ruby version when it's releas
 
 TIP: Ruby 1.8.7 p248 and p249 have marshaling bugs that crash Rails. Ruby Enterprise Edition has these fixed since the release of 1.8.7-2010.02. On the 1.9 front, Ruby 1.9.1 is not usable because it outright segfaults, so if you want to use 1.9.x, jump straight to 1.9.3 for smooth sailing.
 
+### HTTP PATCH
+
+Rails 4 now uses `PATCH` as the primary HTTP verb for updates. When a resource
+is declared in `config/routes.rb`:
+
+```ruby
+resources :users
+```
+
+the action in `UsersController` to update a user is still `update`.
+
+`PUT` requests to `/users/:id` in Rails 4 get routed to `update` as they are
+today.  So, if you have an API that gets real PUT requests it is going to work.
+The router also routes `PATCH` requests to `/users/:id` to the `update` action.
+
+So, in Rails 4 both `PUT` and `PATCH` are routed to update. We recommend
+switching to `PATCH` as part of your upgrade process if possible, as it's more
+likely what you want.
+
+For more on PATCH and why this change was made, see [this post](http://weblog.rubyonrails.org/2012/2/25/edge-rails-patch-is-the-new-primary-http-method-for-updates/)
+on the Rails blog.
+
+#### A note about media types
+
+The errata for the `PATCH` verb [specifies that a 'diff' media type should be
+used with `PATCH`](http://www.rfc-editor.org/errata_search.php?rfc=5789). One
+such format is [JSON Patch](http://tools.ietf.org/html/rfc6902). While Rails
+does not support JSON Patch natively, it's easy enough to add support:
+
+```
+# in your controller
+def update
+  respond_to do |format|
+    format.json do
+      # perform a partial update
+      @post.update params[:post]
+    end
+
+    format.json_patch do
+      # perform sophisticated change
+    end
+  end
+end
+
+# In config/initializers/json_patch.rb:
+Mime::Type.register 'application/json-patch+json', :json_patch
+```
+
+As JSON Patch was only recently made into an RFC, there aren't a lot of great
+Ruby libraries yet. Aaron Patterson's
+[hana](https://github.com/tenderlove/hana) is one such gem, but doesn't have
+full support for the last few changes in the specification.
+
 Upgrading from Rails 3.2 to Rails 4.0
 -------------------------------------