Drop hostname from cache key

By default, Rails will cache

    example.com/mywiki/show/SomePage
and
    www.example.com/mywiki/show/SomePage

In Instiki, this just leads to stale cached pages and frustration.
Fix that behaviour.

config/environment.rb

@@ -58,3 +58,4 @@ end
 require_dependency 'instiki_errors'
 
 #require 'jcode'
+require 'caching_stuff'

lib/caching_stuff.rb

@@ -0,0 +1,20 @@
+# based on http://pastie.org/49840
+# override the fragment_cache_key method in actionpack/lib/action_controller/caching/fragments.rb
+# to remove hostname in fragment caching
+# so instead of caching different fragments for "example.com/posts/list" and 
+# "www.example.com/posts/list", instead it will just use "posts/list"
+module CachingStuff
+  module ActionController
+    module Caching
+      module Fragments
+        def fragment_cache_key(key)
+          ActiveSupport::Cache.expand_cache_key(key.is_a?(Hash) ? url_for(key.merge(:host=>"")).split(":///").last : key.split('/')[1..-1].join('/'), :views)
+        end
+      end
+    end
+  end
+end
+
+ActionController::Base.class_eval do
+  include CachingStuff::ActionController::Caching::Fragments
+end