fixes #2102

app/logical/post_sets/favorite.rb

@@ -25,7 +25,7 @@ module PostSets
     end
 
     def posts
-      favorites.includes(:post).map(&:post)
+      favorites.includes(:post).map(&:post).compact
     end
 
     def presenter

app/models/artist_commentary.rb

@@ -2,7 +2,7 @@ class ArtistCommentary < ActiveRecord::Base
   attr_accessible :post_id, :original_description, :original_title, :translated_description, :translated_title
   validates_uniqueness_of :post_id
   belongs_to :post
-  has_many :versions, :class_name => "ArtistCommentaryVersion", :foreign_key => :post_id, :primary_key => :post_id, :order => "artist_commentary_versions.id ASC"
+  has_many :versions, :class_name => "ArtistCommentaryVersion", :dependent => :destroy, :foreign_key => :post_id, :primary_key => :post_id, :order => "artist_commentary_versions.id ASC"
   after_save :create_version
 
   def original_present?

app/models/note.rb

@@ -9,7 +9,7 @@ class Note < ActiveRecord::Base
   validates_presence_of :post_id, :creator_id, :updater_id, :x, :y, :width, :height
   validate :post_must_exist
   validate :note_within_image, :message => "must be inside the image"
-  has_many :versions, :class_name => "NoteVersion", :order => "note_versions.id ASC"
+  has_many :versions, :class_name => "NoteVersion", :dependent => :destroy, :order => "note_versions.id ASC"
   after_save :update_post
   after_save :create_version
   validate :post_must_not_be_note_locked

app/models/post.rb

@@ -23,7 +23,7 @@ class Post < ActiveRecord::Base
   belongs_to :uploader, :class_name => "User"
   belongs_to :parent, :class_name => "Post"
   has_one :upload, :dependent => :destroy
-  has_one :artist_commentary
+  has_one :artist_commentary, :dependent => :destroy
   has_many :flags, :class_name => "PostFlag", :dependent => :destroy
   has_many :appeals, :class_name => "PostAppeal", :dependent => :destroy
   has_many :versions, :class_name => "PostVersion", :dependent => :destroy, :order => "post_versions.updated_at ASC, post_versions.id ASC"
@@ -32,7 +32,7 @@ class Post < ActiveRecord::Base
   has_many :comments, :order => "comments.id", :dependent => :destroy
   has_many :children, :class_name => "Post", :foreign_key => "parent_id", :order => "posts.id"
   has_many :disapprovals, :class_name => "PostDisapproval", :dependent => :destroy
-  has_many :favorites
+  has_many :favorites, :dependent => :destroy
   validates_uniqueness_of :md5
   validate :post_is_not_its_own_parent
   attr_accessible :source, :rating, :tag_string, :old_tag_string, :old_parent_id, :old_source, :old_rating, :last_noted_at, :parent_id, :as => [:member, :builder, :gold, :platinum, :contributor, :janitor, :moderator, :admin, :default]