1 files changed, 43 insertions, 18 deletions

diff --git a/actionpack/lib/action_dispatch/routing/route_set.rb b/actionpack/lib/action_dispatch/routing/route_set.rb
index ce04f0b08a..0f3734dd74 100644
--- a/actionpack/lib/action_dispatch/routing/route_set.rb
+++ b/actionpack/lib/action_dispatch/routing/route_set.rb
@@ -199,12 +199,9 @@ module ActionDispatch
             private
 
             def optimized_helper(args)
-              params = parameterize_args(args)
-              missing_keys = missing_keys(params)
-
-              unless missing_keys.empty?
-                raise_generation_error(params, missing_keys)
-              end
+              params = parameterize_args(args) { |k|
+                raise_generation_error(args)
+              }
 
               @route.format params
             end
@@ -215,16 +212,21 @@ module ActionDispatch
 
             def parameterize_args(args)
               params = {}
-              @required_parts.zip(args.map(&:to_param)) { |k,v| params[k] = v }
+              @arg_size.times { |i|
+                key = @required_parts[i]
+                value = args[i].to_param
+                yield key if value.nil? || value.empty?
+                params[key] = value
+              }
               params
             end
 
-            def missing_keys(args)
-              args.select{ |part, arg| arg.nil? || arg.empty? }.keys
-            end
-
-            def raise_generation_error(args, missing_keys)
-              constraints = Hash[@route.requirements.merge(args).sort]
+            def raise_generation_error(args)
+              missing_keys = []
+              params = parameterize_args(args) { |missing_key|
+                missing_keys << missing_key
+              }
+              constraints = Hash[@route.requirements.merge(params).sort]
               message = "No route matches #{constraints.inspect}"
               message << " missing required keys: #{missing_keys.sort.inspect}"
 
@@ -307,7 +309,8 @@ module ActionDispatch
 
       attr_accessor :formatter, :set, :named_routes, :default_scope, :router
       attr_accessor :disable_clear_and_finalize, :resources_path_names
-      attr_accessor :default_url_options, :request_class
+      attr_accessor :default_url_options
+      attr_reader :env_key
 
       alias :routes :set
 
@@ -315,22 +318,44 @@ module ActionDispatch
         { :new => 'new', :edit => 'edit' }
       end
 
-      def initialize(request_class = ActionDispatch::Request)
+      def self.new_with_config(config)
+        if config.respond_to? :relative_url_root
+          new Config.new config.relative_url_root
+        else
+          # engines apparently don't have this set
+          new
+        end
+      end
+
+      Config = Struct.new :relative_url_root
+
+      DEFAULT_CONFIG = Config.new(nil)
+
+      def initialize(config = DEFAULT_CONFIG)
         self.named_routes = NamedRouteCollection.new
         self.resources_path_names = self.class.default_resources_path_names
         self.default_url_options = {}
-        self.request_class = request_class
 
+        @config                     = config
         @append                     = []
         @prepend                    = []
         @disable_clear_and_finalize = false
         @finalized                  = false
+        @env_key                    = "ROUTES_#{object_id}_SCRIPT_NAME".freeze
 
         @set    = Journey::Routes.new
         @router = Journey::Router.new @set
         @formatter = Journey::Formatter.new @set
       end
 
+      def relative_url_root
+        @config.relative_url_root
+      end
+
+      def request_class
+        ActionDispatch::Request
+      end
+
       def draw(&block)
         clear! unless @disable_clear_and_finalize
         eval_block(block)
@@ -539,7 +564,7 @@ module ActionDispatch
 
         conditions.keep_if do |k, _|
           k == :action || k == :controller || k == :required_defaults ||
-            @request_class.public_method_defined?(k) || path_values.include?(k)
+            request_class.public_method_defined?(k) || path_values.include?(k)
         end
       end
       private :build_conditions
@@ -693,7 +718,7 @@ module ActionDispatch
       end
 
       def find_script_name(options)
-        options.delete(:script_name) || ''
+        options.delete(:script_name) || relative_url_root || ''
       end
 
       def path_for(options, route_name = nil)