Allow to generate Application routes inside Engine

This requires knowledge about original SCRIPT_NAME and
the parent router. It should be pass through the env
as ORIGIAL_SCRIPT_NAME and action_dispatch.parent_routes

2 files changed, 4 insertions, 4 deletions

diff --git a/actionpack/lib/action_dispatch/routing/mapper.rb b/actionpack/lib/action_dispatch/routing/mapper.rb
index f3aa09f4a7..0e138524cd 100644
--- a/actionpack/lib/action_dispatch/routing/mapper.rb
+++ b/actionpack/lib/action_dispatch/routing/mapper.rb
@@ -289,7 +289,7 @@ module ActionDispatch
             app.routes.class_eval do
               define_method :_generate_prefix do |options|
                 keys = _route.segment_keys + ActionDispatch::Routing::RouteSet::RESERVED_OPTIONS
-                prefix_options = options.reject { |k, v| !(keys).include?(k) }
+                prefix_options = options.slice(*keys)
                 # we must actually delete prefix segment keys to avoid passing them to next url_for
                 _route.segment_keys.each { |k| options.delete(k) }
                 _router.url_helpers.send("#{name}_path", prefix_options)
diff --git a/actionpack/lib/action_dispatch/routing/url_for.rb b/actionpack/lib/action_dispatch/routing/url_for.rb
index f73067688c..deaf1cdf03 100644
--- a/actionpack/lib/action_dispatch/routing/url_for.rb
+++ b/actionpack/lib/action_dispatch/routing/url_for.rb
@@ -129,9 +129,9 @@ module ActionDispatch
           options
         when nil, Hash
           routes = (options ? options.delete(:routes) : nil) || _routes
-
-          if respond_to?(:env) && env && routes.equal?(env["action_dispatch.routes"])
-             options[:skip_prefix] = true
+          if respond_to?(:env) && env
+              options[:skip_prefix] = true if routes.equal?(env["action_dispatch.routes"])
+              options[:script_name] = env["ORIGINAL_SCRIPT_NAME"] if routes.equal?(env["action_dispatch.parent_routes"])
           end
 
           routes.url_for((options || {}).reverse_merge!(url_options).symbolize_keys)