Confirm a record has not already been destroyed before decrementing

counter cache

At present, calling destroy multiple times on the same record results
in the belongs_to counter cache being decremented multiple times. With
this change the record is checked for whether it is already destroyed
prior to decrementing the counter cache.

1 files changed, 20 insertions, 0 deletions

diff --git a/activerecord/test/cases/associations/belongs_to_associations_test.rb b/activerecord/test/cases/associations/belongs_to_associations_test.rb
index f5316952b8..87af24cbe6 100644
--- a/activerecord/test/cases/associations/belongs_to_associations_test.rb
+++ b/activerecord/test/cases/associations/belongs_to_associations_test.rb
@@ -414,6 +414,26 @@ class BelongsToAssociationsTest < ActiveRecord::TestCase
     assert_equal 15, topic.replies.size
   end
 
+  def test_counter_cache_double_destroy
+    topic = Topic.create :title => "Zoom-zoom-zoom"
+
+    5.times do
+      topic.replies.create(:title => "re: zoom", :content => "speedy quick!")
+    end
+
+    assert_equal 5, topic.reload[:replies_count]
+    assert_equal 5, topic.replies.size
+
+    reply = topic.replies.first
+
+    reply.destroy
+    assert_equal 4, topic.reload[:replies_count]
+
+    reply.destroy
+    assert_equal 4, topic.reload[:replies_count]
+    assert_equal 4, topic.replies.size
+  end
+
   def test_custom_counter_cache
     reply = Reply.create(:title => "re: zoom", :content => "speedy quick!")
     assert_equal 0, reply[:replies_count]