1 files changed, 19 insertions, 13 deletions

diff --git a/activerecord/lib/active_record/nested_attributes.rb b/activerecord/lib/active_record/nested_attributes.rb
index 08b27b6a8e..f51fd21077 100644
--- a/activerecord/lib/active_record/nested_attributes.rb
+++ b/activerecord/lib/active_record/nested_attributes.rb
@@ -276,15 +276,15 @@ module ActiveRecord
 
             type = (reflection.collection? ? :collection : :one_to_one)
 
-            # def pirate_attributes=(attributes)
-            #   assign_nested_attributes_for_one_to_one_association(:pirate, attributes)
+            # def pirate_attributes=(attributes, assignment_opts = {})
+            #   assign_nested_attributes_for_one_to_one_association(:pirate, attributes, assignment_opts)
             # end
             class_eval <<-eoruby, __FILE__, __LINE__ + 1
               if method_defined?(:#{association_name}_attributes=)
                 remove_method(:#{association_name}_attributes=)
               end
-              def #{association_name}_attributes=(attributes)
-                assign_nested_attributes_for_#{type}_association(:#{association_name}, attributes)
+              def #{association_name}_attributes=(attributes, assignment_opts = {})
+                assign_nested_attributes_for_#{type}_association(:#{association_name}, attributes, assignment_opts)
               end
             eoruby
           else
@@ -319,21 +319,21 @@ module ActiveRecord
     # If the given attributes include a matching <tt>:id</tt> attribute, or
     # update_only is true, and a <tt>:_destroy</tt> key set to a truthy value,
     # then the existing record will be marked for destruction.
-    def assign_nested_attributes_for_one_to_one_association(association_name, attributes)
+    def assign_nested_attributes_for_one_to_one_association(association_name, attributes, assignment_opts = {})
       options = self.nested_attributes_options[association_name]
       attributes = attributes.with_indifferent_access
 
       if (options[:update_only] || !attributes['id'].blank?) && (record = send(association_name)) &&
           (options[:update_only] || record.id.to_s == attributes['id'].to_s)
-        assign_to_or_mark_for_destruction(record, attributes, options[:allow_destroy]) unless call_reject_if(association_name, attributes)
+        assign_to_or_mark_for_destruction(record, attributes, options[:allow_destroy], assignment_opts) unless call_reject_if(association_name, attributes)
 
-      elsif attributes['id'].present?
+      elsif attributes['id'].present? && !assignment_opts[:without_protection]
         raise_nested_attributes_record_not_found(association_name, attributes['id'])
 
       elsif !reject_new_record?(association_name, attributes)
         method = "build_#{association_name}"
         if respond_to?(method)
-          send(method, attributes.except(*UNASSIGNABLE_KEYS))
+          send(method, attributes.except(*unassignable_keys(assignment_opts)), assignment_opts)
         else
           raise ArgumentError, "Cannot build association #{association_name}. Are you trying to build a polymorphic one-to-one association?"
         end
@@ -367,7 +367,7 @@ module ActiveRecord
     #     { :name => 'John' },
     #     { :id => '2', :_destroy => true }
     #   ])
-    def assign_nested_attributes_for_collection_association(association_name, attributes_collection)
+    def assign_nested_attributes_for_collection_association(association_name, attributes_collection, assignment_opts = {})
       options = self.nested_attributes_options[association_name]
 
       unless attributes_collection.is_a?(Hash) || attributes_collection.is_a?(Array)
@@ -401,7 +401,7 @@ module ActiveRecord
 
         if attributes['id'].blank?
           unless reject_new_record?(association_name, attributes)
-            association.build(attributes.except(*UNASSIGNABLE_KEYS))
+            association.build(attributes.except(*unassignable_keys(assignment_opts)), assignment_opts)
           end
         elsif existing_record = existing_records.detect { |record| record.id.to_s == attributes['id'].to_s }
           unless association.loaded? || call_reject_if(association_name, attributes)
@@ -418,8 +418,10 @@ module ActiveRecord
           end
 
           if !call_reject_if(association_name, attributes)
-            assign_to_or_mark_for_destruction(existing_record, attributes, options[:allow_destroy])
+            assign_to_or_mark_for_destruction(existing_record, attributes, options[:allow_destroy], assignment_opts)
           end
+        elsif assignment_opts[:without_protection]
+          association.build(attributes.except(*unassignable_keys(assignment_opts)), assignment_opts)
         else
           raise_nested_attributes_record_not_found(association_name, attributes['id'])
         end
@@ -428,8 +430,8 @@ module ActiveRecord
 
     # Updates a record with the +attributes+ or marks it for destruction if
     # +allow_destroy+ is +true+ and has_destroy_flag? returns +true+.
-    def assign_to_or_mark_for_destruction(record, attributes, allow_destroy)
-      record.attributes = attributes.except(*UNASSIGNABLE_KEYS)
+    def assign_to_or_mark_for_destruction(record, attributes, allow_destroy, assignment_opts)
+      record.assign_attributes(attributes.except(*unassignable_keys(assignment_opts)), assignment_opts)
       record.mark_for_destruction if has_destroy_flag?(attributes) && allow_destroy
     end
 
@@ -458,5 +460,9 @@ module ActiveRecord
     def raise_nested_attributes_record_not_found(association_name, record_id)
       raise RecordNotFound, "Couldn't find #{self.class.reflect_on_association(association_name).klass.name} with ID=#{record_id} for #{self.class.name} with ID=#{id}"
     end
+
+    def unassignable_keys(assignment_opts)
+      assignment_opts[:without_protection] ? UNASSIGNABLE_KEYS - %w[id] : UNASSIGNABLE_KEYS
+    end
   end
 end