pass the parsed path from mapper to the Strexp

actionpack/lib/action_dispatch/routing/mapper.rb

@@ -80,7 +80,7 @@ def initialize(set, scope, path, options)
           path_params = path_params ast
           @options = normalize_options!(options, path_params, ast)
           normalize_requirements!(path_params)
-          normalize_conditions!(path_params, path)
+          normalize_conditions!(path_params, path, ast)
           normalize_defaults!
         end
 
@@ -192,8 +192,9 @@ def verify_callable_constraint(callable_constraint)
             end
           end
 
-          def normalize_conditions!(path_params, path)
+          def normalize_conditions!(path_params, path, ast)
             @conditions[:path_info] = path
+            @conditions[:parsed_path_info] = ast
 
             constraints.each do |key, condition|
               unless path_params.include?(key) || key == :controller

actionpack/lib/action_dispatch/routing/route_set.rb

@@ -418,7 +418,9 @@ def add_route(app, conditions = {}, requirements = {}, defaults = {}, name = nil
             "http://guides.rubyonrails.org/routing.html#restricting-the-routes-created"
         end
 
-        path = build_path(conditions.delete(:path_info), requirements, SEPARATORS, anchor)
+        path = conditions.delete :path_info
+        ast  = conditions.delete :parsed_path_info
+        path = build_path(path, ast, requirements, SEPARATORS, anchor)
         conditions = build_conditions(conditions, path.names.map { |x| x.to_sym })
 
         route = @set.add_route(app, path, conditions, defaults, name)
@@ -426,8 +428,9 @@ def add_route(app, conditions = {}, requirements = {}, defaults = {}, name = nil
         route
       end
 
-      def build_path(path, requirements, separators, anchor)
-        strexp = Journey::Router::Strexp.build(
+      def build_path(path, ast, requirements, separators, anchor)
+        strexp = Journey::Router::Strexp.new(
+            ast,
             path,
             requirements,
             SEPARATORS,