3 files changed, 34 insertions, 24 deletions

diff --git a/actionpack/lib/abstract_controller/base.rb b/actionpack/lib/abstract_controller/base.rb
index 0951267fea..08a1273a39 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 action_methods.include?("foo") may return
+    # false and available_action?("foo") return 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/action_controller/metal/implicit_render.rb b/actionpack/lib/action_controller/metal/implicit_render.rb
index 3ec0c4c6a4..e8e465d3ba 100644
--- a/actionpack/lib/action_controller/metal/implicit_render.rb
+++ b/actionpack/lib/action_controller/metal/implicit_render.rb
@@ -1,21 +1,19 @@
 module ActionController
   module ImplicitRender
     def send_action(method, *args)
-      if respond_to?(method, true)
-        ret = super
-        default_render unless response_body
-        ret
-      else
-        default_render
-      end
+      ret = super
+      default_render unless response_body
+      ret
     end
 
     def default_render(*args)
       render(*args)
     end
 
-    def action_method?(action_name)
-      super || template_exists?(action_name.to_s, _prefixes)
+    def method_for_action(action_name)
+      super || if template_exists?(action_name.to_s, _prefixes)
+        "default_render"
+      end
     end
   end
 end