fixes #2110

app/controllers/forum_posts_controller.rb

@@ -55,14 +55,14 @@ class ForumPostsController < ApplicationController
   def destroy
     @forum_post = ForumPost.find(params[:id])
     check_privilege(@forum_post)
-    @forum_post.update_column(:is_deleted, true)
+    @forum_post.delete!
     respond_with(@forum_post)
   end
 
   def undelete
     @forum_post = ForumPost.find(params[:id])
     check_privilege(@forum_post)
-    @forum_post.update_attribute(:is_deleted, false)
+    @forum_post.undelete!
     respond_with(@forum_post)
   end
 

app/models/forum_post.rb

@@ -119,8 +119,18 @@ class ForumPost < ActiveRecord::Base
     end
   end
 
+  def delete!
+    update_attribute(:is_deleted, true)
+    update_topic_updated_at_on_destroy
+  end
+
+  def undelete!
+    update_attribute(:is_deleted, true)
+    update_topic_updated_at_on_create
+  end
+
   def update_topic_updated_at_on_destroy
-    max = ForumPost.where(:topic_id => topic.id).maximum(:updated_at)
+    max = ForumPost.where(:topic_id => topic.id, :is_deleted => false).maximum(:updated_at)
     if max
       ForumTopic.update_all(["response_count = response_count - 1, updated_at = ?", max], {:id => topic.id})
     else

test/unit/forum_post_test.rb

@@ -26,6 +26,16 @@ class ForumPostTest < ActiveSupport::TestCase
         end
       end
 
+      context "that is deleted" do
+        should "update the topic's updated_at timestamp" do
+          @topic.reload
+          assert_equal(@posts[-1].updated_at.to_i, @topic.updated_at.to_i)
+          @posts[-1].delete!
+          @topic.reload
+          assert_equal(@posts[-2].updated_at.to_i, @topic.updated_at.to_i)
+        end
+      end
+
       should "know which page it's on" do
         assert_equal(2, @posts[3].forum_topic_page)
         assert_equal(2, @posts[4].forum_topic_page)
@@ -102,7 +112,7 @@ class ForumPostTest < ActiveSupport::TestCase
     context "that is deleted" do
       setup do
         @post = FactoryGirl.create(:forum_post, :topic_id => @topic.id)
-        @post.update_attribute(:is_deleted, true)
+        @post.delete!
         @topic.reload
       end