Merge branch 'master' into adequaterecord

* master: (311 commits)
  Add a missing changelog entry for #13981 and #14035
  Revert "Fixed plugin_generator test"
  implements new option :month_format_string for date select helpers [Closes #13618]
  add factory methods for empty alias trackers
  guarantee a list in the alias tracker so we can remove a conditional
  stop exposing table_joins
  make most parameters to the AliasTracker required
  make a singleton for AssociationScope
  pass the association and connection to the scope method
  pass the tracker down the stack and construct it in the scope method
  clean up add_constraints signature
  remove the reflection delegate
  remove klass delegator
  remove railties changes. fixes #14054
  remove chain delegate
  remove scope_chain delegate
  Add verb to sanitization note
  fix path shown in mailer's templates
  updated Travis build status image url
  fix guide active_support_core_extensions. add Note to String#indent [ci skip]
  ...

Conflicts:
	activerecord/lib/active_record/associations/join_dependency.rb
	activerecord/test/cases/associations/association_scope_test.rb

1 files changed, 11 insertions, 9 deletions

diff --git a/guides/source/active_record_validations.md b/guides/source/active_record_validations.md
index efa826e8df..a483a6dd24 100644
--- a/guides/source/active_record_validations.md
+++ b/guides/source/active_record_validations.md
@@ -575,7 +575,9 @@ This helper validates that the attribute's value is unique right before the
 object gets saved. It does not create a uniqueness constraint in the database,
 so it may happen that two different database connections create two records
 with the same value for a column that you intend to be unique. To avoid that,
-you must create a unique index in your database.
+you must create a unique index on both columns in your database. See
+[the MySQL manual](http://dev.mysql.com/doc/refman/5.6/en/multiple-column-indexes.html)
+for more details about multiple column indexes.
 
 ```ruby
 class Account < ActiveRecord::Base
@@ -616,10 +618,6 @@ The default error message is _"has already been taken"_.
 This helper passes the record to a separate class for validation.
 
 ```ruby
-class Person < ActiveRecord::Base
-  validates_with GoodnessValidator
-end
-
 class GoodnessValidator < ActiveModel::Validator
   def validate(record)
     if record.first_name == "Evil"
@@ -627,6 +625,10 @@ class GoodnessValidator < ActiveModel::Validator
     end
   end
 end
+
+class Person < ActiveRecord::Base
+  validates_with GoodnessValidator
+end
 ```
 
 NOTE: Errors added to `record.errors[:base]` relate to the state of the record
@@ -644,10 +646,6 @@ Like all other validations, `validates_with` takes the `:if`, `:unless` and
 validator class as `options`:
 
 ```ruby
-class Person < ActiveRecord::Base
-  validates_with GoodnessValidator, fields: [:first_name, :last_name]
-end
-
 class GoodnessValidator < ActiveModel::Validator
   def validate(record)
     if options[:fields].any?{|field| record.send(field) == "Evil" }
@@ -655,6 +653,10 @@ class GoodnessValidator < ActiveModel::Validator
     end
   end
 end
+
+class Person < ActiveRecord::Base
+  validates_with GoodnessValidator, fields: [:first_name, :last_name]
+end
 ```
 
 Note that the validator will be initialized *only once* for the whole application