3 files changed, 8 insertions, 2 deletions
diff --git a/actionpack/lib/action_controller/metal/url_for.rb b/actionpack/lib/action_controller/metal/url_for.rb
index c890dc51d4..89ab0b4753 100644
--- a/actionpack/lib/action_controller/metal/url_for.rb
+++ b/actionpack/lib/action_controller/metal/url_for.rb
@@ -12,7 +12,7 @@ module ActionController
         # ROUTES TODO: relative_url_root should be middleware
         # and the generator should take SCRIPT_NAME into
         # consideration
-        :relative_url_root => config.relative_url_root,
+        :script_name => request.env["SCRIPT_NAME"],
         :_path_segments => request.symbolized_path_parameters
       )
     end
diff --git a/actionpack/lib/action_controller/railtie.rb b/actionpack/lib/action_controller/railtie.rb
index e9edf80451..e638be5251 100644
--- a/actionpack/lib/action_controller/railtie.rb
+++ b/actionpack/lib/action_controller/railtie.rb
@@ -51,6 +51,12 @@ module ActionController
       ac.stylesheets_dir = paths.public.stylesheets.to_a.first
       ac.secret = app.config.cookie_secret
 
+      if ac.relative_url_root
+        ActiveSupport::Deprecation.warn "config.action_controller.relative_url_root " \
+          "is no longer effective. Please set it in the router as " \
+          "routes.draw(:script_name => #{ac.relative_url_root.inspect})"
+      end
+
       ActionController::Base.config.replace(ac)
     end
 
diff --git a/actionpack/lib/action_controller/url_rewriter.rb b/actionpack/lib/action_controller/url_rewriter.rb
index 973a6facd7..8821892b3a 100644
--- a/actionpack/lib/action_controller/url_rewriter.rb
+++ b/actionpack/lib/action_controller/url_rewriter.rb
@@ -32,7 +32,7 @@ module ActionController
 
       # ROUTES TODO: Fix the tests
       segments = options.delete(:_path_segments)
-      relative_url_root = options.delete(:relative_url_root).to_s
+      relative_url_root = options.delete(:script_name).to_s
       path_segments = path_segments ? path_segments.merge(segments || {}) : segments
 
       unless options[:only_path]