Liquid::Drop should not return a string representation of standard ruby objects

lib/liquid/drop.rb

@@ -52,6 +52,10 @@ module Liquid
       self
     end
 
+    def to_s
+      self.class.name
+    end
+
     alias :[] :invoke_drop
 
     private

test/liquid/drop_test.rb

@@ -237,4 +237,9 @@ class DropsTest < Test::Unit::TestCase
   def test_nil_value_access
     assert_equal '', Liquid::Template.parse('{{ product[value] }}').render('product' => ProductDrop.new, 'value' => nil)
   end
+
+  def test_default_to_s_on_drops
+    assert_equal 'ProductDrop', Liquid::Template.parse("{{ product }}").render('product' => ProductDrop.new)
+    assert_equal 'EnumerableDrop', Liquid::Template.parse('{{ collection }}').render('collection' => EnumerableDrop.new)
+  end
 end # DropsTest