5 files changed, 53 insertions, 25 deletions
diff --git a/actionpack/lib/abstract_controller/base.rb b/actionpack/lib/abstract_controller/base.rb
index 0951267fea..f67d0e558e 100644
--- a/actionpack/lib/abstract_controller/base.rb
+++ b/actionpack/lib/abstract_controller/base.rb
@@ -130,27 +130,39 @@ module AbstractController
       self.class.action_methods
     end
 
-    # Returns true if the name can be considered an action. This can
-    # be overridden in subclasses to modify the semantics of what
-    # can be considered an action.
+    # Returns true if a method for the action is available and
+    # can be dispatched, false otherwise.
     #
-    # For instance, this is overriden by ActionController to add
-    # the implicit rendering feature.
-    #
-    # ==== Parameters
-    # * <tt>name</tt> - The name of an action to be tested
-    #
-    # ==== Returns
-    # * <tt>TrueClass</tt>, <tt>FalseClass</tt>
-    def action_method?(name)
-      self.class.action_methods.include?(name)
+    # Notice that <tt>action_methods.include?("foo")</tt> may return
+    # false and <tt>available_action?("foo")</tt> returns true because
+    # available action consider actions that are also available
+    # through other means, for example, implicit render ones.
+    def available_action?(action_name)
+      method_for_action(action_name).present?
     end
 
     private
 
+      # Returns true if the name can be considered an action because
+      # it has a method defined in the controller.
+      #
+      # ==== Parameters
+      # * <tt>name</tt> - The name of an action to be tested
+      #
+      # ==== Returns
+      # * <tt>TrueClass</tt>, <tt>FalseClass</tt>
+      #
+      # :api: private
+      def action_method?(name)
+        self.class.action_methods.include?(name)
+      end
+
       # Call the action. Override this in a subclass to modify the
       # behavior around processing an action. This, and not #process,
       # is the intended way to override action dispatching.
+      #
+      # Notice that the first argument is the method to be dispatched
+      # which is *not* necessarily the same as the action name.
       def process_action(method_name, *args)
         send_action(method_name, *args)
       end
diff --git a/actionpack/lib/abstract_controller/callbacks.rb b/actionpack/lib/abstract_controller/callbacks.rb
index f7b2b7ff53..e8426bc52b 100644
--- a/actionpack/lib/abstract_controller/callbacks.rb
+++ b/actionpack/lib/abstract_controller/callbacks.rb
@@ -13,8 +13,8 @@ module AbstractController
 
     # 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
+    def process_action(*args)
+      run_callbacks(:process_action, action_name) do
         super
       end
     end
diff --git a/actionpack/lib/abstract_controller/layouts.rb b/actionpack/lib/abstract_controller/layouts.rb
index d1b87b67ee..8f73e244d7 100644
--- a/actionpack/lib/abstract_controller/layouts.rb
+++ b/actionpack/lib/abstract_controller/layouts.rb
@@ -292,15 +292,15 @@ module AbstractController
       end
     end
 
-    attr_writer :action_has_layout
+    attr_internal_writer :action_has_layout
 
     def initialize(*)
-      @action_has_layout = true
+      @_action_has_layout = true
       super
     end
 
     def action_has_layout?
-      @action_has_layout
+      @_action_has_layout
     end
 
   private
diff --git a/actionpack/lib/abstract_controller/rendering.rb b/actionpack/lib/abstract_controller/rendering.rb
index f78365afdb..ab2c532859 100644
--- a/actionpack/lib/abstract_controller/rendering.rb
+++ b/actionpack/lib/abstract_controller/rendering.rb
@@ -32,9 +32,13 @@ module AbstractController
 
   module Rendering
     extend ActiveSupport::Concern
-
     include AbstractController::ViewPaths
 
+    included do
+      config_accessor :protected_instance_variables, :instance_reader => false
+      self.protected_instance_variables = []
+    end
+
     # Overwrite process to setup I18n proxy.
     def process(*) #:nodoc:
       old_config, I18n.config = I18n.config, I18nProxy.new(I18n.config, lookup_context)
@@ -53,14 +57,20 @@ module AbstractController
       end
     end
 
-    attr_writer :view_context_class
+    attr_internal_writer :view_context_class
+
+    # Explicitly define protected_instance_variables so it can be
+    # inherited and overwritten by other modules if needed.
+    def protected_instance_variables
+      config.protected_instance_variables
+    end
 
     def view_context_class
-      @view_context_class || self.class.view_context_class
+      @_view_context_class || self.class.view_context_class
     end
 
     def initialize(*)
-      @view_context_class = nil
+      @_view_context_class = nil
       super
     end
 
@@ -79,7 +89,7 @@ module AbstractController
 
     # Returns an object that is able to render templates.
     def view_renderer
-      @view_renderer ||= ActionView::Renderer.new(lookup_context)
+      @_view_renderer ||= ActionView::Renderer.new(lookup_context)
     end
 
     # Normalize arguments, options and then delegates render_to_body and
@@ -112,13 +122,19 @@ module AbstractController
 
     private
 
+    DEFAULT_PROTECTED_INSTANCE_VARIABLES = %w(
+      @_action_name @_response_body @_formats @_prefixes @_config
+      @_view_context_class @_view_renderer @_lookup_context
+    )
+
     # This method should return a hash with assigns.
     # You can overwrite this configuration per controller.
     # :api: public
     def view_assigns
       hash = {}
       variables  = instance_variable_names
-      variables -= protected_instance_variables if respond_to?(:protected_instance_variables)
+      variables -= protected_instance_variables
+      variables -= DEFAULT_PROTECTED_INSTANCE_VARIABLES
       variables.each { |name| hash[name.to_s[1, name.length]] = instance_variable_get(name) }
       hash
     end
diff --git a/actionpack/lib/abstract_controller/view_paths.rb b/actionpack/lib/abstract_controller/view_paths.rb
index 0893459e24..6b7aae8c74 100644
--- a/actionpack/lib/abstract_controller/view_paths.rb
+++ b/actionpack/lib/abstract_controller/view_paths.rb
@@ -39,7 +39,7 @@ module AbstractController
     # templates, i.e. view paths and details. Check ActionView::LookupContext for more
     # information.
     def lookup_context
-      @lookup_context ||=
+      @_lookup_context ||=
         ActionView::LookupContext.new(self.class._view_paths, details_for_lookup, _prefixes)
     end