correct rack::cache so it always punches through users with auth cookies

config/environments/profile.rb

@@ -37,7 +37,7 @@ Discourse::Application.configure do
   config.handlebars.precompile = true
 
   # this setting enable rack_cache so it caches various requests in redis
-  config.enable_rack_cache = false
+  config.enable_rack_cache = true
 
   # allows users to use mini profiler
   config.enable_mini_profiler = false

config/initializers/99-rack-cache.rb

@@ -4,7 +4,21 @@ if Rails.configuration.respond_to?(:enable_rack_cache) && Rails.configuration.en
 
   url = DiscourseRedis.url
 
-  Rails.configuration.middleware.insert 0, Rack::Cache,
+  class Rack::Cache::Discourse < Rack::Cache::Context
+    def initialize(app, options={})
+      @app = app
+      super
+    end
+    def call(env)
+      if CurrentUser.has_auth_cookie?(env)
+        @app.call(env)
+      else
+        super
+      end
+    end
+  end
+
+  Rails.configuration.middleware.insert 0, Rack::Cache::Discourse,
     metastore: "#{url}/metastore",
     entitystore: "#{url}/entitystore",
     verbose: !Rails.env.production?