Fix that counter_cache breaks with has_many :dependent => :nullify.

[#1196 state:committed]

Signed-off-by: Jeremy Kemper <jeremy@bitsweat.net>

4 files changed, 32 insertions, 3 deletions

diff --git a/activerecord/lib/active_record/associations/has_many_association.rb b/activerecord/lib/active_record/associations/has_many_association.rb
index e4b631bc54..73d3c23cd3 100644
--- a/activerecord/lib/active_record/associations/has_many_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_association.rb
@@ -74,6 +74,7 @@ module ActiveRecord
                 "#{@reflection.primary_key_name} = NULL", 
                 "#{@reflection.primary_key_name} = #{owner_quoted_id} AND #{@reflection.klass.primary_key} IN (#{ids})"
               )
+              @owner.class.update_counters(@owner.id, cached_counter_attribute_name => -records.size) if has_cached_counter?
           end
         end
 
diff --git a/activerecord/test/cases/associations/has_many_associations_test.rb b/activerecord/test/cases/associations/has_many_associations_test.rb
index 6edb52092f..ee39cf695e 100644
--- a/activerecord/test/cases/associations/has_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_associations_test.rb
@@ -516,6 +516,23 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
     assert_equal 0, new_firm.clients_of_firm.size
   end
 
+  def test_deleting_updates_counter_cache
+    topic = Topic.first
+    assert_equal topic.replies.to_a.size, topic.replies_count
+
+    topic.replies.delete(topic.replies.first)
+    topic.reload
+    assert_equal topic.replies.to_a.size, topic.replies_count
+  end
+
+  def test_deleting_updates_counter_cache_without_dependent_destroy
+    post = posts(:welcome)
+
+    assert_difference "post.reload.taggings_count", -1 do
+      post.taggings.delete(post.taggings.first)
+    end
+  end
+
   def test_deleting_a_collection
     force_signal37_to_load_all_clients_of_firm
     companies(:first_firm).clients_of_firm.create("name" => "Another Client")
@@ -561,6 +578,14 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
     end
   end
 
+  def test_clearing_updates_counter_cache
+    topic = Topic.first
+
+    topic.replies.clear
+    topic.reload
+    assert_equal 0, topic.replies_count
+  end
+
   def test_clearing_a_dependent_association_collection
     firm = companies(:first_firm)
     client_id = firm.dependent_clients_of_firm.first.id
diff --git a/activerecord/test/cases/associations/join_model_test.rb b/activerecord/test/cases/associations/join_model_test.rb
index 4907cfe2b0..c035600e69 100644
--- a/activerecord/test/cases/associations/join_model_test.rb
+++ b/activerecord/test/cases/associations/join_model_test.rb
@@ -319,11 +319,11 @@ class AssociationsJoinModelTest < ActiveRecord::TestCase
   end
 
   def test_belongs_to_polymorphic_with_counter_cache
-    assert_equal 0, posts(:welcome)[:taggings_count]
+    assert_equal 1, posts(:welcome)[:taggings_count]
     tagging = posts(:welcome).taggings.create(:tag => tags(:general))
-    assert_equal 1, posts(:welcome, :reload)[:taggings_count]
+    assert_equal 2, posts(:welcome, :reload)[:taggings_count]
     tagging.destroy
-    assert posts(:welcome, :reload)[:taggings_count].zero?
+    assert_equal 1, posts(:welcome, :reload)[:taggings_count]
   end
 
   def test_unavailable_through_reflection
diff --git a/activerecord/test/fixtures/posts.yml b/activerecord/test/fixtures/posts.yml
index 92e5d1908f..f817493190 100644
--- a/activerecord/test/fixtures/posts.yml
+++ b/activerecord/test/fixtures/posts.yml
@@ -4,6 +4,7 @@ welcome:
   title: Welcome to the weblog
   body: Such a lovely day
   comments_count: 2
+  taggings_count: 1
   type: Post
 
 thinking:
@@ -11,6 +12,8 @@ thinking:
   author_id: 1
   title: So I was thinking
   body: Like I hopefully always am
+  comments_count: 1
+  taggings_count: 1
   type: SpecialPost
 
 authorless: