Merge pull request #8400 from matthewrobertson/has-many-through-counter-cache

Fix for has_many_through counter_cache bug

Counter caches were not being updated properly when replacing
has_many_through relationships.

1 files changed, 11 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 8e52ce1d91..2b96b42032 100644
--- a/activerecord/test/cases/associations/has_many_through_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_through_associations_test.rb
@@ -330,6 +330,17 @@ class HasManyThroughAssociationsTest < ActiveRecord::TestCase
     end
   end
 
+  def test_update_counter_caches_on_replace_association
+    post = posts(:welcome)
+    tag  = post.tags.create!(:name => 'doomed')
+    tag.tagged_posts << posts(:thinking)
+
+    tag.tagged_posts = []
+    post.reload
+
+    assert_equal(post.taggings.count, post.taggings_count)
+  end
+
   def test_replace_association
     assert_queries(4){posts(:welcome);people(:david);people(:michael); posts(:welcome).people(true)}