8 files changed, 41 insertions, 8 deletions
diff --git a/activerecord/test/models/author.rb b/activerecord/test/models/author.rb
index 09958ca257..cb8686f315 100644
--- a/activerecord/test/models/author.rb
+++ b/activerecord/test/models/author.rb
@@ -21,7 +21,8 @@ class Author < ActiveRecord::Base
   end
   has_many :comments_containing_the_letter_e, through: :posts, source: :comments
   has_many :comments_with_order_and_conditions, -> { order("comments.body").where("comments.body like 'Thank%'") }, through: :posts, source: :comments
-  has_many :comments_with_include, -> { includes(:post) }, through: :posts, source: :comments
+  has_many :comments_with_include, -> { includes(:post).where(posts: { type: "Post" }) }, through: :posts, source: :comments
+  has_many :comments_for_first_author, -> { for_first_author }, through: :posts, source: :comments
 
   has_many :first_posts
   has_many :comments_on_first_posts, -> { order("posts.id desc, comments.id asc") }, through: :first_posts, source: :comments
@@ -40,6 +41,7 @@ class Author < ActiveRecord::Base
            class_name: "Post"
 
   has_many :comments_desc, -> { order("comments.id DESC") }, through: :posts, source: :comments
+  has_many :unordered_comments, -> { unscope(:order).distinct }, through: :posts_sorted_by_id_limited, source: :comments
   has_many :funky_comments, through: :posts, source: :comments
   has_many :ordered_uniq_comments, -> { distinct.order("comments.id") }, through: :posts, source: :comments
   has_many :ordered_uniq_comments_desc, -> { distinct.order("comments.id DESC") }, through: :posts, source: :comments
@@ -78,7 +80,7 @@ class Author < ActiveRecord::Base
            after_add: [:log_after_adding,  Proc.new { |o, r| o.post_log << "after_adding_proc#{r.id || '<new>'}" }]
   has_many :unchangeable_posts, class_name: "Post", before_add: :raise_exception, after_add: :log_after_adding
 
-  has_many :categorizations
+  has_many :categorizations, -> {}
   has_many :categories, through: :categorizations
   has_many :named_categories, through: :categorizations
 
@@ -99,10 +101,12 @@ class Author < ActiveRecord::Base
   has_many :taggings,        through: :posts, source: :taggings
   has_many :taggings_2,      through: :posts, source: :tagging
   has_many :tags,            through: :posts
+  has_many :ordered_tags,    through: :posts
   has_many :post_categories, through: :posts, source: :categories
   has_many :tagging_tags,    through: :taggings, source: :tag
 
   has_many :similar_posts, -> { distinct }, through: :tags, source: :tagged_posts
+  has_many :ordered_posts, -> { distinct }, through: :ordered_tags, source: :tagged_posts
   has_many :distinct_tags, -> { select("DISTINCT tags.*").order("tags.name") }, through: :posts, source: :tags
 
   has_many :tags_with_primary_key, through: :posts
diff --git a/activerecord/test/models/comment.rb b/activerecord/test/models/comment.rb
index 61c54a77a7..5ab433f2d9 100644
--- a/activerecord/test/models/comment.rb
+++ b/activerecord/test/models/comment.rb
@@ -1,5 +1,8 @@
 # frozen_string_literal: true
 
+# `counter_cache` requires association class before `attr_readonly`.
+class Post < ActiveRecord::Base; end
+
 class Comment < ActiveRecord::Base
   scope :limit_by, lambda { |l| limit(l) }
   scope :containing_the_letter_e, -> { where("comments.body LIKE '%e%'") }
@@ -57,6 +60,10 @@ end
 
 class SpecialComment < Comment
   default_scope { where(deleted_at: nil) }
+
+  def self.what_are_you
+    "a special comment..."
+  end
 end
 
 class SubSpecialComment < SpecialComment
diff --git a/activerecord/test/models/developer.rb b/activerecord/test/models/developer.rb
index 56aafca60b..8881c69368 100644
--- a/activerecord/test/models/developer.rb
+++ b/activerecord/test/models/developer.rb
@@ -87,6 +87,17 @@ class Developer < ActiveRecord::Base
   private :track_instance_count
 end
 
+class SubDeveloper < Developer
+end
+
+class SymbolIgnoredDeveloper < ActiveRecord::Base
+  self.table_name = "developers"
+  self.ignored_columns = [:first_name, :last_name]
+
+  attr_accessor :last_name
+  define_attribute_method "last_name"
+end
+
 class AuditLog < ActiveRecord::Base
   belongs_to :developer, validate: true
   belongs_to :unvalidated_developer, class_name: "Developer"
diff --git a/activerecord/test/models/drink_designer.rb b/activerecord/test/models/drink_designer.rb
index 1c407844c5..eb6701b84e 100644
--- a/activerecord/test/models/drink_designer.rb
+++ b/activerecord/test/models/drink_designer.rb
@@ -3,3 +3,6 @@
 class DrinkDesigner < ActiveRecord::Base
   has_one :chef, as: :employable
 end
+
+class MocktailDesigner < DrinkDesigner
+end
diff --git a/activerecord/test/models/mocktail_designer.rb b/activerecord/test/models/mocktail_designer.rb
deleted file mode 100644
index 123ff4fb3d..0000000000
--- a/activerecord/test/models/mocktail_designer.rb
+++ /dev/null
@@ -1,4 +0,0 @@
-# frozen_string_literal: true
-
-class MocktailDesigner < DrinkDesigner
-end
diff --git a/activerecord/test/models/post.rb b/activerecord/test/models/post.rb
index 4b3576fce8..780a2c17f5 100644
--- a/activerecord/test/models/post.rb
+++ b/activerecord/test/models/post.rb
@@ -21,7 +21,7 @@ class Post < ActiveRecord::Base
 
   scope :containing_the_letter_a, -> { where("body LIKE '%a%'") }
   scope :titled_with_an_apostrophe, -> { where("title LIKE '%''%'") }
-  scope :ranked_by_comments,      -> { order("comments_count DESC") }
+  scope :ranked_by_comments, -> { order(arel_attribute(:comments_count).desc) }
 
   scope :limit_by, lambda { |l| limit(l) }
   scope :locked, -> { lock }
@@ -115,6 +115,7 @@ class Post < ActiveRecord::Base
   has_many :misc_tags, -> { where tags: { name: "Misc" } }, through: :taggings, source: :tag
   has_many :funky_tags, through: :taggings, source: :tag
   has_many :super_tags, through: :taggings
+  has_many :ordered_tags, through: :taggings
   has_many :tags_with_primary_key, through: :taggings, source: :tag_with_primary_key
   has_one :tagging, as: :taggable
 
@@ -184,14 +185,19 @@ end
 class SpecialPost < Post; end
 
 class StiPost < Post
-  self.abstract_class = true
   has_one :special_comment, class_name: "SpecialComment"
 end
 
+class AbstractStiPost < Post
+  self.abstract_class = true
+end
+
 class SubStiPost < StiPost
   self.table_name = Post.table_name
 end
 
+class SubAbstractStiPost < AbstractStiPost; end
+
 class FirstPost < ActiveRecord::Base
   self.inheritance_column = :disabled
   self.table_name = "posts"
@@ -313,5 +319,9 @@ class FakeKlass
     def arel_attribute(name, table)
       table[name]
     end
+
+    def enforce_raw_sql_whitelist(*args)
+      # noop
+    end
   end
 end
diff --git a/activerecord/test/models/tag.rb b/activerecord/test/models/tag.rb
index 4495ac4a09..bc13c3a42d 100644
--- a/activerecord/test/models/tag.rb
+++ b/activerecord/test/models/tag.rb
@@ -12,4 +12,5 @@ class OrderedTag < Tag
   self.table_name = "tags"
 
   has_many :taggings, -> { order("taggings.id DESC") }, foreign_key: "tag_id"
+  has_many :tagged_posts, through: :taggings, source: "taggable", source_type: "Post"
 end
diff --git a/activerecord/test/models/tagging.rb b/activerecord/test/models/tagging.rb
index fc0af026c5..861fde633f 100644
--- a/activerecord/test/models/tagging.rb
+++ b/activerecord/test/models/tagging.rb
@@ -8,6 +8,7 @@ class Tagging < ActiveRecord::Base
   belongs_to :tag, -> { includes(:tagging) }
   belongs_to :super_tag,   class_name: "Tag", foreign_key: "super_tag_id"
   belongs_to :invalid_tag, class_name: "Tag", foreign_key: "tag_id"
+  belongs_to :ordered_tag, class_name: "OrderedTag", foreign_key: "tag_id"
   belongs_to :blue_tag, -> { where tags: { name: "Blue" } }, class_name: "Tag", foreign_key: :tag_id
   belongs_to :tag_with_primary_key, class_name: "Tag", foreign_key: :tag_id, primary_key: :custom_primary_key
   belongs_to :taggable, polymorphic: true, counter_cache: :tags_count