Fix handling SCRIPT_NAME from within mounted engine's

When you mount your application at a path, for example /myapp, server
should set SCRIPT_NAME to /myapp. With such information, rails
application knows that it's mounted at /myapp path and it should generate
routes relative to that path.

Before this patch, rails handled SCRIPT_NAME correctly only for regular
apps, but it failed to do it for mounted engines. The solution was to
hardcode default_url_options[:script_name], which is not the best answer
- it will work only when application is mounted at a fixed path.

This patch fixes the situation by respecting original value of
SCRIPT_NAME when generating application's routes from engine and the
other way round - when you generate engine's routes from application.

This is done by using one of 2 pieces of information in env - current
SCRIPT_NAME or SCRIPT_NAME for a corresponding router. This is because
we have 2 cases to handle:

- generating engine's route from application: in this situation
  SCRIPT_NAME is basically SCRIPT_NAME set by the server and it
  indicates the place where application is mounted, so we can just pass
  it as :original_script_name in url_options. :original_script_name is
  used because if we use :script_name, router will ignore generating
  prefix for engine

- generating application's route from engine: in this situation we
  already lost information about the SCRIPT_NAME that server used. For
  example if application is mounted at /myapp and engine is mounted at
  /blog, at this point SCRIPT_NAME is equal /myapp/blog. Because of that
  we need to keep reference to /myapp SCRIPT_NAME by binding it to the
  current router. Later on we can extract it and use when generating url

Please note that starting from now you *should not* use
default_url_options[:script_name] explicitly if your server already
passes correct SCRIPT_NAME to rack env.

(closes #6933)

1 files changed, 0 insertions, 15 deletions

diff --git a/railties/test/railties/mounted_engine_test.rb b/railties/test/railties/mounted_engine_test.rb
index 4c0fdee556..bd13c3aba3 100644
--- a/railties/test/railties/mounted_engine_test.rb
+++ b/railties/test/railties/mounted_engine_test.rb
@@ -163,24 +163,14 @@ module ApplicationTests
       end
     end
 
-    def reset_script_name!
-      Rails.application.routes.default_url_options = {}
-    end
-
-    def script_name(script_name)
-      Rails.application.routes.default_url_options = {:script_name => script_name}
-    end
-
     test "routes generation in engine and application" do
       # test generating engine's route from engine
       get "/john/blog/posts"
       assert_equal "/john/blog/posts/1", last_response.body
 
       # test generating engine's route from engine with default_url_options
-      script_name "/foo"
       get "/john/blog/posts", {}, 'SCRIPT_NAME' => "/foo"
       assert_equal "/foo/john/blog/posts/1", last_response.body
-      reset_script_name!
 
       # test generating engine's route from application
       get "/engine_route"
@@ -193,14 +183,11 @@ module ApplicationTests
       assert_equal "/john/blog/posts", last_response.body
 
       # test generating engine's route from application with default_url_options
-      script_name "/foo"
       get "/engine_route", {}, 'SCRIPT_NAME' => "/foo"
       assert_equal "/foo/anonymous/blog/posts", last_response.body
 
-      script_name "/foo"
       get "/url_for_engine_route", {}, 'SCRIPT_NAME' => "/foo"
       assert_equal "/foo/john/blog/posts", last_response.body
-      reset_script_name!
 
       # test generating application's route from engine
       get "/someone/blog/generate_application_route"
@@ -210,10 +197,8 @@ module ApplicationTests
       assert_equal "/", last_response.body
 
       # test generating application's route from engine with default_url_options
-      script_name "/foo"
       get "/someone/blog/generate_application_route", {}, 'SCRIPT_NAME' => '/foo'
       assert_equal "/foo/", last_response.body
-      reset_script_name!
 
       # test polymorphic routes
       get "/polymorphic_route"