Fixed records not findable by old slug when using cached slugs. Close…

…s issue #45.

lib/friendly_id/active_record2/slugged_model.rb

@@ -135,6 +135,12 @@ def raise_scoped_error
       # circumstances unless the +:scope+ argument is present.
       class CachedSingleFinder < SimpleModel::SingleFinder
 
+        def find
+          super
+        rescue ActiveRecord::RecordNotFound
+          SingleFinder.new(id, model_class, options).find
+        end
+
         # The column used to store the cached slug.
         def column
           "#{table_name}.#{friendly_id_config.cache_column}"

lib/friendly_id/test.rb

@@ -139,6 +139,13 @@ module Slugged
         assert_equal instance2, klass.send(find_method, instance2.friendly_id)
       end
 
+      test "should remain findable by previous slugs" do
+        old_friendly_id = instance.friendly_id
+        instance.update_attributes :name => "#{old_friendly_id} updated"
+        assert_not_equal old_friendly_id, instance.friendly_id
+        assert_equal instance, klass.find(old_friendly_id)
+      end
+
     end
 
     # Tests for models to ensure that they properly implement using the
@@ -165,4 +172,4 @@ module CustomNormalizer
 
     end
   end
-end
+end