backport of #5706 and #5579 to 3-0-stable

[#5706 state:resolved]

Signed-off-by: José Valim <jose.valim@gmail.com>

activerecord/lib/active_record/nested_attributes.rb

@@ -293,7 +293,7 @@ def assign_nested_attributes_for_one_to_one_association(association_name, attrib
 
       if check_existing_record && (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])
+        assign_to_or_mark_for_destruction(record, attributes, options[:allow_destroy]) unless call_reject_if(association_name, attributes)
 
       elsif attributes['id']
         existing_record = self.class.reflect_on_association(association_name).klass.find(attributes['id'])
@@ -376,11 +376,11 @@ def assign_nested_attributes_for_collection_association(association_name, attrib
 
         elsif existing_records.count == 0 #Existing record but not yet associated
           existing_record = self.class.reflect_on_association(association_name).klass.find(attributes['id'])
-          association.send(:add_record_to_target_with_callbacks, existing_record) unless association.loaded?
+          association.send(:add_record_to_target_with_callbacks, existing_record) if !association.loaded? && !call_reject_if(association_name, attributes)
           assign_to_or_mark_for_destruction(existing_record, attributes, options[:allow_destroy])
 
         elsif existing_record = existing_records.detect { |record| record.id.to_s == attributes['id'].to_s }
-          association.send(:add_record_to_target_with_callbacks, existing_record) unless association.loaded?
+          association.send(:add_record_to_target_with_callbacks, existing_record) if !association.loaded? && !call_reject_if(association_name, attributes)
           assign_to_or_mark_for_destruction(existing_record, attributes, options[:allow_destroy])
 
         end

activerecord/test/cases/nested_attributes_test.rb

@@ -122,6 +122,22 @@ def test_has_many_association_updating_a_single_record
     man.update_attributes({:interests_attributes => {:topic => 'gardening', :id => interest.id}})
     assert_equal 'gardening', interest.reload.topic
   end
+
+def test_reject_if_with_a_proc_which_returns_true_always_for_has_one
+     Pirate.accepts_nested_attributes_for :ship, :reject_if => proc {|attributes| true }
+     pirate = Pirate.new(:catchphrase => "Stop wastin' me time")
+     ship = pirate.create_ship(:name => 's1')
+     pirate.update_attributes({:ship_attributes => { :name => 's2', :id => ship.id } })
+     assert_equal 's1', ship.reload.name
+   end
+
+  def test_reject_if_with_a_proc_which_returns_true_always_for_has_many
+    Man.accepts_nested_attributes_for :interests, :reject_if => proc {|attributes| true }
+    man = Man.create(:name => "John")
+    interest = man.interests.create(:topic => 'photography')
+    man.update_attributes({:interests_attributes => { :topic => 'gardening', :id => interest.id } })
+    assert_equal 'photography', interest.reload.topic
+  end
 
 end