Fix filter :only and :except with implicit actions

The method_name argument is "default_render" for implicit actions
so use the action_name attribute to determine which callbacks to run.

[#5673 state:resolved]

actionpack/lib/abstract_controller/callbacks.rb

@@ -14,7 +14,7 @@ module Callbacks
     # Override AbstractController::Base's process_action to run the
     # process_action callbacks around the normal behavior.
     def process_action(method_name, *args)
-      run_callbacks(:process_action, method_name) do
+      run_callbacks(:process_action, action_name) do
         super
       end
     end

actionpack/test/controller/filters_test.rb

@@ -503,6 +503,22 @@ def show
       render :text => 'hello world'
     end
   end
+
+  class ImplicitActionsController < ActionController::Base
+    before_filter :find_only, :only => :edit
+    before_filter :find_except, :except => :edit
+
+    private
+
+    def find_only
+      @only = 'Only'
+    end
+
+    def find_except
+      @except = 'Except'
+    end
+  end
+
   def test_sweeper_should_not_block_rendering
     response = test_process(SweeperTestController)
     assert_equal 'hello world', response.body
@@ -781,6 +797,19 @@ def test_a_rescuing_around_filter
     assert_equal("I rescued this: #<FilterTest::ErrorToRescue: Something made the bad noise.>", response.body)
   end
 
+  def test_filters_obey_only_and_except_for_implicit_actions
+    test_process(ImplicitActionsController, 'show')
+    assert_nil assigns(:user)
+    assert_equal 'Except', assigns(:except)
+    assert_nil assigns(:only)
+    assert_equal 'show', response.body
+
+    test_process(ImplicitActionsController, 'edit')
+    assert_equal 'Only', assigns(:only)
+    assert_nil assigns(:except)
+    assert_equal 'edit', response.body
+  end
+
   private
     def test_process(controller, action = "show")
       @controller = controller.is_a?(Class) ? controller.new : controller

actionpack/test/fixtures/filter_test/implicit_actions/edit.html.erb

@@ -0,0 +1 @@
+edit

actionpack/test/fixtures/filter_test/implicit_actions/show.html.erb

@@ -0,0 +1 @@
+show