Merge pull request #7377 from brainopia/use_inversed_parent_for_first_and_last_child

Use inversed parent for first and last child of has_many association

[Backport] Closes #3223.

Conflicts:
	activerecord/lib/active_record/associations/collection_association.rb

1 files changed, 6 insertions, 0 deletions

diff --git a/activerecord/test/cases/associations/inverse_associations_test.rb b/activerecord/test/cases/associations/inverse_associations_test.rb
index 76282213d8..e03d7916f1 100644
--- a/activerecord/test/cases/associations/inverse_associations_test.rb
+++ b/activerecord/test/cases/associations/inverse_associations_test.rb
@@ -259,6 +259,12 @@ class InverseHasManyTests < ActiveRecord::TestCase
     assert_equal m.name, i.man.name, "Name of man should be the same after changes to replaced-child-owned instance"
   end
 
+  def test_parent_instance_should_be_shared_with_first_and_last_child
+    man = Man.first
+    assert man.interests.first.man.equal? man
+    assert man.interests.last.man.equal? man
+  end
+
   def test_trying_to_use_inverses_that_dont_exist_should_raise_an_error
     assert_raise(ActiveRecord::InverseOfAssociationNotFoundError) { Man.find(:first).secret_interests }
   end