Recalculate last reply of thread on message deletion #968

app/models/message.rb

@@ -80,9 +80,15 @@ class Message < ActiveRecord::Base
   end
 
   def after_destroy
+    parent.reset_last_reply_id! if parent
     board.reset_counters!
   end
 
+  def reset_last_reply_id!
+    clid = children.present? ? children.last.id : nil
+    self.update_attribute(:last_reply_id, clid)
+  end
+
   def sticky=(arg)
     write_attribute :sticky, (arg == true || arg.to_s == '1' ? 1 : 0)
   end

test/unit/message_test.rb

@@ -101,6 +101,18 @@ class MessageTest < ActiveSupport::TestCase
     # Watchers removed
   end
 
+  def test_destroy_last_reply
+    message = Message.find(4)
+    last_reply = message.last_reply
+    penultimate_reply = message.children[-2]
+
+    assert last_reply.destroy
+
+    message.reload
+
+    assert_equal penultimate_reply, message.last_reply
+  end
+
   def test_destroy_reply
     message = Message.find(5)
     board = message.board