Fix asset prefixes

Author: melonmanchan

config.ru

@@ -3,8 +3,7 @@
 require ::File.expand_path('../config/environment', __FILE__)
 
 # Serve the rails app under a  prefix. Defaults to '/achrails'
-prefix =  ENV['RAILS_PREFIX'] || '/achrails'
-
+prefix = ENV['RAILS_RELATIVE_URL_ROOT']
 map prefix do
   run Rails.application
 end

config/boot.rb

@@ -6,3 +6,4 @@
 # See: https://github.com/Casecommons/pg_search/issues/144
 require 'pg_search'
 
+ENV['RAILS_RELATIVE_URL_ROOT'] ||= '/achrails'

config/initializers/path_patch.rb

@@ -0,0 +1,19 @@
+# Fix asset paths not being prefixed correctly
+# From http://stackoverflow.com/questions/7293918/broken-precompiled-assets-in-rails-3-1-when-deploying-to-a-sub-uri
+module Sprockets
+  module Helpers
+    module RailsHelper
+
+      def asset_path(source, options = {})
+        source = source.logical_path if source.respond_to?(:logical_path)
+        path = asset_paths.compute_public_path(source, asset_prefix, options.merge(:body => true))
+        path = options[:body] ? "#{path}?body=1" : path
+        if !asset_paths.send(:has_request?)
+          path = ENV['RAILS_RELATIVE_URL_ROOT'] + path if ENV['RAILS_RELATIVE_URL_ROOT']
+        end
+        path
+      end
+
+    end
+  end
+end