Fix a case when a staff user views a topic with a deleted post by a nuked user; might be a temporary solution until we decide what to do with nuked records

app/models/admin_log.rb

@@ -3,7 +3,7 @@
 # Use the AdminLogger class to log records to this table.
 class AdminLog < ActiveRecord::Base
   belongs_to :admin,        class_name: 'User'
-  belongs_to :target_user,  class_name: 'User' # can be nil
+  belongs_to :target_user,  class_name: 'User' # can be nil, or return nil if user record was nuked
 
   validates_presence_of :admin_id
   validates_presence_of :action

app/models/post.rb

@@ -45,6 +45,7 @@ class Post < ActiveRecord::Base
   scope :public_posts, -> { joins(:topic).where('topics.archetype <> ?', Archetype.private_message) }
   scope :private_posts, -> { joins(:topic).where('topics.archetype = ?', Archetype.private_message) }
   scope :with_topic_subtype, ->(subtype) { joins(:topic).where('topics.subtype = ?', subtype) }
+  scope :without_nuked_users, -> { where(nuked_user: false) }
 
   def self.hidden_reasons
     @hidden_reasons ||= Enum.new(:flag_threshold_reached, :flag_threshold_reached_again, :new_user_spam_threshold_reached)

db/migrate/20130710201248_add_nuked_user_to_posts.rb

@@ -0,0 +1,5 @@
+class AddNukedUserToPosts < ActiveRecord::Migration
+  def change
+    add_column :posts, :nuked_user, :boolean, default: false
+  end
+end

lib/admin_logger.rb

@@ -10,6 +10,7 @@ class AdminLogger
     AdminLog.create(
       action: AdminLog.actions[:delete_user],
       admin_id: @admin.id,
+      target_user_id: deleted_user.id,
       details: [:id, :username, :name, :created_at, :trust_level, :last_seen_at, :last_emailed_at].map { |x| "#{x}: #{deleted_user.send(x)}" }.join(', ')
     )
   end

lib/topic_view.rb

@@ -27,7 +27,7 @@ class TopicView
     @limit = options[:limit] || SiteSetting.posts_per_page;
 
     @filtered_posts = @topic.posts
-    @filtered_posts = @filtered_posts.with_deleted if user.try(:staff?)
+    @filtered_posts = @filtered_posts.with_deleted.without_nuked_users if user.try(:staff?)
     @filtered_posts = @filtered_posts.best_of if options[:filter] == 'best_of'
     @filtered_posts = @filtered_posts.where('posts.post_type <> ?', Post.types[:moderator_action]) if options[:best].present?
 

lib/user_destroyer.rb

@@ -19,6 +19,7 @@ class UserDestroyer
     User.transaction do
       user.destroy.tap do |u|
         if u
+          Post.with_deleted.where(user_id: user.id).update_all("nuked_user = true")
           AdminLogger.new(@admin).log_user_deletion(user)
           DiscourseHub.unregister_nickname(user.username) if SiteSetting.call_discourse_hub?
           MessageBus.publish "/file-change", ["refresh"], user_ids: [user.id]

spec/components/admin_logger_spec.rb

@@ -29,6 +29,7 @@ describe AdminLogger do
 
     it 'creates a new AdminLog record' do
       expect { log_user_deletion }.to change { AdminLog.count }.by(1)
+      AdminLog.last.target_user_id.should == deleted_user.id
     end
   end
 

spec/components/user_destroyer_spec.rb

@@ -97,6 +97,12 @@ describe UserDestroyer do
           DiscourseHub.expects(:unregister_nickname).never
           destroy
         end
+
+        it "should mark the user's deleted posts as belonging to a nuked user" do
+          post = Fabricate(:post, user: @user, deleted_at: 1.hour.ago)
+          expect { destroy }.to change { User.count }.by(-1)
+          post.reload.nuked_user.should be_true
+        end
       end
 
       context 'and destroy fails' do