use 'send' to access controller current_ability in case it's private

CHANGELOG.rdoc

@@ -10,9 +10,9 @@
 
 * Abilities can be defined with a string of SQL in addition to a block so accessible_by works with a block - see issue #150
 
-* Adding etter support for InheritedResource - see issue #23
+* Adding better support for InheritedResource - see issue #23
 
-* Loading the collection instance variable with accessible_by - see issue #137
+* Loading the collection instance variable (for index action) using accessible_by - see issue #137
 
 * Adding action and subject variables to I18n unauthorized message - closes #142
 

lib/cancan/controller_resource.rb

@@ -53,11 +53,11 @@ def load_resource_instance
 
     def load_collection?
       resource_base.respond_to?(:accessible_by) &&
-      !@controller.current_ability.has_block?(authorization_action, resource_class)
+      !current_ability.has_block?(authorization_action, resource_class)
     end
 
     def load_collection
-      resource_base.accessible_by(@controller.current_ability)
+      resource_base.accessible_by(current_ability)
     end
 
     def build_resource
@@ -70,7 +70,7 @@ def build_resource
     end
 
     def initial_attributes
-      @controller.current_ability.attributes_for(@params[:action].to_sym, resource_class)
+      current_ability.attributes_for(@params[:action].to_sym, resource_class)
     end
 
     def find_resource
@@ -156,6 +156,10 @@ def fetch_parent(name)
       end
     end
 
+    def current_ability
+      @controller.send(:current_ability)
+    end
+
     def name
       @name || name_from_controller
     end