Bugfix collection association #create method …

When same association is loaded in the model creation callback
The new object is inserted into association twice

2 files changed, 12 insertions, 0 deletions

diff --git a/activerecord/test/cases/associations/has_many_associations_test.rb b/activerecord/test/cases/associations/has_many_associations_test.rb
index 50ca6537cc..ad157582a4 100644
--- a/activerecord/test/cases/associations/has_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_associations_test.rb
@@ -2348,6 +2348,12 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
     assert_equal [first_bulb, second_bulb], car.bulbs
   end
 
+  test 'double insertion of new object to association when same association used in the after create callback of a new object' do
+    car = Car.create!
+    car.bulbs << TrickyBulb.new
+    assert_equal 1, car.bulbs.size
+  end
+
   def test_association_force_reload_with_only_true_is_deprecated
     company = Company.find(1)
 
diff --git a/activerecord/test/models/bulb.rb b/activerecord/test/models/bulb.rb
index c1e491e5c5..dc0296305a 100644
--- a/activerecord/test/models/bulb.rb
+++ b/activerecord/test/models/bulb.rb
@@ -50,3 +50,9 @@ class FailedBulb < Bulb
     throw(:abort)
   end
 end
+
+class TrickyBulb < Bulb
+  after_create do |record|
+    record.car.bulbs.to_a
+  end
+end