Fix cloning documents with deep embedded documents (#4504)

Author: alexandrebini

lib/mongoid/copyable.rb

@@ -73,8 +73,9 @@ def process_localized_attributes(klass, attrs)
         next unless attrs.present? && attrs[association.key].present?
 
         if association.is_a?(Association::Embedded::EmbedsMany)
-          attrs[association.name.to_s].each_with_index do |attr, index|
-            process_localized_attributes(send(association.name)[index].class, attr)
+          attrs[association.name.to_s].each do |attr|
+            embedded_klass = attr.fetch('_type', association.class_name).constantize
+            process_localized_attributes(embedded_klass, attr)
           end
         else
           process_localized_attributes(association.klass, attrs[association.key])

spec/mongoid/copyable_spec.rb

@@ -35,6 +35,10 @@
         person.build_game(name: "Tron")
       end
 
+      let!(:name_translations) do
+        person.name.translations.build(language: 'en')
+      end
+
       context "when the document has an id field in the database" do
 
         let!(:band) do
@@ -245,14 +249,26 @@
             expect(copy.addresses).to eq(person.addresses)
           end
 
+          it "copys deep embeds many documents" do
+            expect(copy.name.translations).to eq(person.name.translations)
+          end
+
           it "sets the embedded many documents as new" do
             expect(copy.addresses.first).to be_new_record
           end
 
+          it "sets the deep embedded many documents as new" do
+            expect(copy.name.translations.first).to be_new_record
+          end
+
           it "creates new embeds many instances" do
             expect(copy.addresses).to_not equal(person.addresses)
           end
 
+          it "creates new deep embeds many instances" do
+            expect(copy.name.translations).to_not equal(person.name.translations)
+          end
+
           it "copys embeds one documents" do
             expect(copy.name).to eq(person.name)
           end