Allow deletion of a post belonging to a deleted topic, so that users can be destroyed

lib/post_destroyer.rb

@@ -53,26 +53,25 @@ class PostDestroyer
   # When a post is properly deleted. Well, it's still soft deleted, but it will no longer
   # show up in the topic
   def staff_destroyed
-    # the topic may be trashed, skip it
-    return unless @post.topic
-
     Post.transaction do
 
-      # Update the last post id to the previous post if it exists
-      last_post = Post.where("topic_id = ? and id <> ?", @post.topic_id, @post.id).order('created_at desc').limit(1).first
-      if last_post.present?
-        @post.topic.update_attributes(last_posted_at: last_post.created_at,
-                                      last_post_user_id: last_post.user_id,
-                                      highest_post_number: last_post.post_number)
+      if @post.topic
+        # Update the last post id to the previous post if it exists
+        last_post = Post.where("topic_id = ? and id <> ?", @post.topic_id, @post.id).order('created_at desc').limit(1).first
+        if last_post.present?
+          @post.topic.update_attributes(last_posted_at: last_post.created_at,
+                                        last_post_user_id: last_post.user_id,
+                                        highest_post_number: last_post.post_number)
 
-        # If the poster doesn't have any other posts in the topic, clear their posted flag
-        unless Post.exists?(["topic_id = ? and user_id = ? and id <> ?", @post.topic_id, @post.user_id, @post.id])
-          TopicUser.where(topic_id: @post.topic_id, user_id: @post.user_id).update_all 'posted = false'
+          # If the poster doesn't have any other posts in the topic, clear their posted flag
+          unless Post.exists?(["topic_id = ? and user_id = ? and id <> ?", @post.topic_id, @post.user_id, @post.id])
+            TopicUser.where(topic_id: @post.topic_id, user_id: @post.user_id).update_all 'posted = false'
+          end
         end
-      end
 
-      # Feature users in the topic
-      Jobs.enqueue(:feature_topic_users, topic_id: @post.topic_id, except_post_id: @post.id)
+        # Feature users in the topic
+        Jobs.enqueue(:feature_topic_users, topic_id: @post.topic_id, except_post_id: @post.id)
+      end
 
       @post.post_actions.each do |pa|
         pa.trash!(@user)
@@ -83,7 +82,7 @@ class PostDestroyer
 
       @post.trash!(@user)
 
-      Topic.reset_highest(@post.topic_id)
+      Topic.reset_highest(@post.topic_id) if @post.topic
 
       @post.update_flagged_posts_count
 
@@ -98,7 +97,7 @@ class PostDestroyer
       # Remove any notifications that point to this deleted post
       Notification.delete_all topic_id: @post.topic_id, post_number: @post.post_number
 
-      @post.topic.trash!(@user) if @post.post_number == 1
+      @post.topic.trash!(@user) if @post.topic and @post.post_number == 1
     end
   end