Bugfixes and Rails Edge

Update to Rails 2.3.1.
  (Actually, not quite. Doesn't look like 2.3.1 will be released
   today, but I REALLY want to push these bugfixes out.)
Removed bundled Rack (Rails 2.3.1 comes bundled with Rack 1.0).
Add
     config.action_view.cache_template_loading = true
  to production environment.
Fix FastCGI bug (http://rubyforge.org/tracker/index.php?func=detail&aid=24191&group_id=186&atid=783).
Fix WikiWords bug (http://rubyforge.org/pipermail/instiki-users/2009-February/001181.html).

vendor/rails/actionpack/lib/action_controller/verification.rb

@@ -90,7 +90,7 @@ module ActionController #:nodoc:
     def verify_action(options) #:nodoc:
       if prereqs_invalid?(options)
         flash.update(options[:add_flash])              if options[:add_flash]
-        response.headers.update(options[:add_headers]) if options[:add_headers]
+        response.headers.merge!(options[:add_headers]) if options[:add_headers]
         apply_remaining_actions(options)               unless performed?
       end
     end