3 files changed, 24 insertions, 9 deletions

diff --git a/actionpack/lib/abstract_controller/base.rb b/actionpack/lib/abstract_controller/base.rb
index acdfb33efa..51c661f735 100644
--- a/actionpack/lib/abstract_controller/base.rb
+++ b/actionpack/lib/abstract_controller/base.rb
@@ -82,7 +82,7 @@ module AbstractController
             # Except for public instance methods of Base and its ancestors
             internal_methods +
             # Be sure to include shadowed public instance methods of this class
-            public_instance_methods(false)).uniq.map { |x| x.to_s } -
+            public_instance_methods(false)).uniq.map(&:to_s) -
             # And always exclude explicitly hidden actions
             hidden_actions.to_a
 
@@ -164,6 +164,14 @@ module AbstractController
       _find_action_name(action_name).present?
     end
 
+    # Returns true if the given controller is capable of rendering
+    # a path. A subclass of +AbstractController::Base+
+    # may return false. An Email controller for example does not
+    # support paths, only full URLs.
+    def self.supports_path?
+      true
+    end
+
     private
 
       # Returns true if the name can be considered an action because
@@ -255,7 +263,7 @@ module AbstractController
 
       # Checks if the action name is valid and returns false otherwise.
       def _valid_action_name?(action_name)
-        action_name !~ Regexp.new(File::SEPARATOR)
+        !action_name.to_s.include? File::SEPARATOR
       end
   end
 end
diff --git a/actionpack/lib/abstract_controller/helpers.rb b/actionpack/lib/abstract_controller/helpers.rb
index e77e4e01e9..df7382f02d 100644
--- a/actionpack/lib/abstract_controller/helpers.rb
+++ b/actionpack/lib/abstract_controller/helpers.rb
@@ -27,9 +27,6 @@ module AbstractController
     end
 
     module ClassMethods
-      MissingHelperError = ActiveSupport::Deprecation::DeprecatedConstantProxy.new('AbstractController::Helpers::ClassMethods::MissingHelperError',
-                                                                                   'AbstractController::Helpers::MissingHelperError')
-
       # When a class is inherited, wrap its helper module in a new module.
       # This ensures that the parent class's module can be changed
       # independently of the child class's.
@@ -153,7 +150,17 @@ module AbstractController
             rescue LoadError => e
               raise AbstractController::Helpers::MissingHelperError.new(e, file_name)
             end
-            file_name.camelize.constantize
+
+            mod_name = file_name.camelize
+            begin
+              mod_name.constantize
+            rescue LoadError
+              # dependencies.rb gives a similar error message but its wording is
+              # not as clear because it mentions autoloading. To the user all it
+              # matters is that a helper module couldn't be loaded, autoloading
+              # is an internal mechanism that should not leak.
+              raise NameError, "Couldn't find #{mod_name}, expected it to be defined in helpers/#{file_name}.rb"
+            end
           when Module
             arg
           else
diff --git a/actionpack/lib/abstract_controller/railties/routes_helpers.rb b/actionpack/lib/abstract_controller/railties/routes_helpers.rb
index 6684f46f64..568c47e43a 100644
--- a/actionpack/lib/abstract_controller/railties/routes_helpers.rb
+++ b/actionpack/lib/abstract_controller/railties/routes_helpers.rb
@@ -1,14 +1,14 @@
 module AbstractController
   module Railties
     module RoutesHelpers
-      def self.with(routes)
+      def self.with(routes, include_path_helpers = true)
         Module.new do
           define_method(:inherited) do |klass|
             super(klass)
             if namespace = klass.parents.detect { |m| m.respond_to?(:railtie_routes_url_helpers) }
-              klass.send(:include, namespace.railtie_routes_url_helpers)
+              klass.send(:include, namespace.railtie_routes_url_helpers(include_path_helpers))
             else
-              klass.send(:include, routes.url_helpers)
+              klass.send(:include, routes.url_helpers(include_path_helpers))
             end
           end
         end