avoid object creation via useless duping and freezing

actionpack/lib/abstract_controller/view_paths.rb

@@ -63,7 +63,7 @@ module ClassMethods
       #   the default view path. You may also provide a custom view path
       #   (see ActionView::PathSet for more information)
       def append_view_path(path)
-        self.view_paths = view_paths + Array(path)
+        self._view_paths = view_paths + Array(path)
       end
 
       # Prepend a path to the list of view paths for this controller.
@@ -73,7 +73,7 @@ def append_view_path(path)
       #   the default view path. You may also provide a custom view path
       #   (see ActionView::PathSet for more information)
       def prepend_view_path(path)
-        self.view_paths = Array(path) + view_paths
+        self._view_paths = ActionView::PathSet.new(Array(path) + view_paths)
       end
 
       # A list of all of the default view paths for this controller.
@@ -88,7 +88,6 @@ def view_paths
       #   otherwise, process the parameter into a PathSet.
       def view_paths=(paths)
         self._view_paths = ActionView::Base.process_view_paths(paths)
-        self._view_paths.freeze
       end
     end
   end