Exclude unchanged records from the collection being considered for au…

…tosave. [#2578 state:resolved]

Signed-off-by: Eloy Duran <eloy.de.enige@gmail.com>

activerecord/lib/active_record/autosave_association.rb

@@ -225,10 +225,10 @@ def marked_for_destruction?
     def associated_records_to_validate_or_save(association, new_record, autosave)
       if new_record
         association
-      elsif association.loaded?
-        autosave ? association : association.select { |record| record.new_record? }
+      elsif autosave
+        association.target.select { |record| record.new_record? || record.changed? || record.marked_for_destruction? }
       else
-        autosave ? association.target : association.target.select { |record| record.new_record? }
+        association.target.select { |record| record.new_record? }
       end
     end
 

activerecord/test/cases/autosave_association_test.rb

@@ -694,23 +694,18 @@ def save(*args)
 
     define_method("test_should_rollback_destructions_if_an_exception_occurred_while_saving_#{association_name}") do
       2.times { |i| @pirate.send(association_name).create!(:name => "#{association_name}_#{i}") }
-      before = @pirate.send(association_name).map { |c| c }
+      before = @pirate.send(association_name).map { |c| c.mark_for_destruction ; c }
 
-      # Stub the save method of the first child to destroy and the second to raise an exception
-      class << before.first
-        def save(*args)
-          super
-          destroy
-        end
-      end
+      # Stub the destroy method of the the second child to raise an exception
       class << before.last
-        def save(*args)
+        def destroy(*args)
           super
           raise 'Oh noes!'
         end
       end
 
       assert_raise(RuntimeError) { assert !@pirate.save }
+      assert before.first.frozen? # the first child was indeed destroyed
       assert_equal before, @pirate.reload.send(association_name)
     end