1 files changed, 14 insertions, 0 deletions
diff --git a/activerecord/test/cases/associations/has_many_through_associations_test.rb b/activerecord/test/cases/associations/has_many_through_associations_test.rb
index bb8c9fa19c..aff0dabee7 100644
--- a/activerecord/test/cases/associations/has_many_through_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_through_associations_test.rb
@@ -11,7 +11,9 @@ require 'models/tagging'
 require 'models/author'
 require 'models/owner'
 require 'models/pet'
+require 'models/pet_treasure'
 require 'models/toy'
+require 'models/treasure'
 require 'models/contract'
 require 'models/company'
 require 'models/developer'
@@ -1082,6 +1084,18 @@ class HasManyThroughAssociationsTest < ActiveRecord::TestCase
     assert_equal [], person.posts
   end
 
+  def test_preloading_empty_through_with_polymorphic_source_association
+    owner = Owner.create!(name: "Rainbow Unicat")
+    pet = Pet.create!(owner: owner)
+    person = Person.create!(first_name: "Gaga")
+    treasure = Treasure.create!(looter: person)
+    non_looted_treasure = Treasure.create!()
+    PetTreasure.create!(pet: pet, treasure: treasure, rainbow_color: "Ultra violet indigo")
+    PetTreasure.create!(pet: pet, treasure: non_looted_treasure, rainbow_color: "Ultra violet indigo")
+
+    assert_equal [person], Owner.where(name: "Rainbow Unicat").includes(pets: :persons).first.persons.to_a
+  end
+
   def test_explicitly_joining_join_table
     assert_equal owners(:blackbeard).toys, owners(:blackbeard).toys.with_pet
   end