Add a header that tells Internet Explorer (all versions) to use the best available standards support. This ensures that IE doesn't go into quirks mode because it has been blacklisted by too many users pressing the incompatible button. It also tells IE to use the ChromeFrame renderer, if the user has installed the plugin.

This guarantees that the best available standards support will be used on the client.

2 files changed, 3 insertions, 1 deletions

diff --git a/actionpack/lib/action_dispatch.rb b/actionpack/lib/action_dispatch.rb
index 50d8e91c47..aeec934be8 100644
--- a/actionpack/lib/action_dispatch.rb
+++ b/actionpack/lib/action_dispatch.rb
@@ -47,6 +47,7 @@ module ActionDispatch
   end
 
   autoload_under 'middleware' do
+    autoload :BestStandardsSupport
     autoload :Callbacks
     autoload :Cookies
     autoload :Flash
diff --git a/actionpack/lib/action_dispatch/railtie.rb b/actionpack/lib/action_dispatch/railtie.rb
index ed93211255..a3af37947a 100644
--- a/actionpack/lib/action_dispatch/railtie.rb
+++ b/actionpack/lib/action_dispatch/railtie.rb
@@ -7,10 +7,11 @@ module ActionDispatch
     config.action_dispatch.x_sendfile_header = ""
     config.action_dispatch.ip_spoofing_check = true
     config.action_dispatch.show_exceptions = true
+    config.action_dispatch.best_standards_support = true
 
     # Prepare dispatcher callbacks and run 'prepare' callbacks
     initializer "action_dispatch.prepare_dispatcher" do |app|
       ActionDispatch::Callbacks.to_prepare { app.routes_reloader.execute_if_updated }
     end
   end
-end
\ No newline at end of file
+end