default scope can accept any object that responds to #call

activerecord/lib/active_record/base.rb

@@ -1145,7 +1145,7 @@ MSG
         def current_scoped_methods #:nodoc:
           method = scoped_methods.last
           if method.respond_to?(:call)
-            unscoped(&method)
+            relation.scoping { method.call }
           else
             method
           end

activerecord/test/cases/relation_scoping_test.rb

@@ -322,6 +322,24 @@ class DefaultScopingTest < ActiveRecord::TestCase
     assert_equal expected, received
   end
 
+  def test_default_scope_with_thing_that_responds_to_call
+    klass = Class.new(ActiveRecord::Base) do
+      self.table_name = 'posts'
+    end
+
+    klass.class_eval do
+      default_scope Class.new(Struct.new(:klass)) {
+        def call
+          klass.where(:author_id => 2)
+        end
+      }.new(self)
+    end
+
+    records = klass.all
+    assert_equal 1, records.length
+    assert_equal 2, records.first.author_id
+  end
+
   def test_default_scope_is_unscoped_on_find
     assert_equal 1, DeveloperCalledDavid.count
     assert_equal 11, DeveloperCalledDavid.unscoped.count