fix a bug when has_many :through does not have paper_trail enabled

lib/paper_trail/version_concern.rb

@@ -337,6 +337,7 @@ module PaperTrail
     # This must be called after the direct has_manys have been reified (reify_has_many_directly)
     def reify_has_many_through(associations, model, options = {})
       associations.each do |assoc|
+        next unless assoc.klass.paper_trail_enabled_for_model?
         through_collection = model.send(assoc.options[:through])
         collection_keys = through_collection.map { |through_model| through_model.send(assoc.foreign_key) }
 

test/dummy/app/models/book.rb

@@ -1,5 +1,9 @@
 class Book < ActiveRecord::Base
   has_many :authorships, :dependent => :destroy
   has_many :authors, :through => :authorships, :source => :person
+
+  has_many :editorships, :dependent => :destroy
+  has_many :editors, :through => :editorships
+
   has_paper_trail
 end

test/dummy/app/models/editor.rb

@@ -0,0 +1,4 @@
+# to demonstrate a has_through association that does not have paper_trail enabled
+class Editor < ActiveRecord::Base
+  has_many :editorships, :dependent => :destroy
+end

test/dummy/app/models/editorship.rb

@@ -0,0 +1,5 @@
+class Editorship < ActiveRecord::Base
+  belongs_to :book
+  belongs_to :editor
+  has_paper_trail
+end

test/dummy/db/migrate/20110208155312_set_up_test_tables.rb

@@ -93,6 +93,15 @@ class SetUpTestTables < ActiveRecord::Migration
       t.string :time_zone
     end
 
+    create_table :editorships, :force => true do |t|
+      t.integer :book_id
+      t.integer :editor_id
+    end
+
+    create_table :editors, :force => true do |t|
+      t.string :name
+    end
+
     create_table :songs, :force => true do |t|
       t.integer :length
     end
@@ -152,6 +161,8 @@ class SetUpTestTables < ActiveRecord::Migration
     drop_table :animals
     drop_table :posts
     drop_table :songs
+    drop_table :editors
+    drop_table :editorships
     drop_table :people
     drop_table :authorships
     drop_table :books
@@ -167,6 +178,9 @@ class SetUpTestTables < ActiveRecord::Migration
     drop_table :legacy_widgets
     drop_table :translations
     drop_table :gadgets
+    drop_table :customers
+    drop_table :orders
+    drop_table :line_items
     remove_index :version_associations, :column => [:version_id]
     remove_index :version_associations, :name => 'index_version_associations_on_foreign_key'
     drop_table :version_associations

test/dummy/db/schema.rb

@@ -42,6 +42,15 @@ ActiveRecord::Schema.define(version: 20110208155312) do
     t.string "name"
   end
 
+  create_table "editors", force: true do |t|
+    t.string "name"
+  end
+
+  create_table "editorships", force: true do |t|
+    t.integer "book_id"
+    t.integer "editor_id"
+  end
+
   create_table "fluxors", force: true do |t|
     t.integer "widget_id"
     t.string  "name"
@@ -114,7 +123,7 @@ ActiveRecord::Schema.define(version: 20110208155312) do
     t.integer "foreign_key_id"
   end
 
-  add_index "version_associations", ["foreign_key_name", "foreign_key_id"], name: "index_on_foreign_key_name_and foreign_key_id"
+  add_index "version_associations", ["foreign_key_name", "foreign_key_id"], name: "index_version_associations_on_foreign_key"
   add_index "version_associations", ["version_id"], name: "index_version_associations_on_version_id"
 
   create_table "versions", force: true do |t|

test/unit/model_test.rb

@@ -1710,5 +1710,20 @@ class HasPaperTrailModelTransactionalTest < ActiveSupport::TestCase
         end
       end
     end
+
+    context 'updated before the associated without paper_trail was created' do
+      setup do
+        @book.update_attributes! :title => 'book_1'
+        @book.editors.create! :name => 'editor_0'
+      end
+
+      context 'when reified' do
+        setup { @book_0 = @book.versions.last.reify(:has_many => true) }
+
+        should 'see the live association' do
+          assert_equal ['editor_0'], @book_0.editors.map(&:name)
+        end
+      end
+    end
   end
 end