From 356dbf62c8a896d62f4a3149b796eee925ff190b Mon Sep 17 00:00:00 2001
From: Chris Hapgood <cch1@hapgoods.com>
Date: Wed, 10 Sep 2008 17:40:09 -0400
Subject: [PATCH] Ensured compute_asset_host always returns an appropriate value.

---
 actionpack/lib/action_controller/base.rb           |    2 +-
 .../lib/action_view/helpers/asset_tag_helper.rb    |   20 +++++++++++---------
 2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/actionpack/lib/action_controller/base.rb b/actionpack/lib/action_controller/base.rb
index 670a049..1c1b0e7 100644
--- a/actionpack/lib/action_controller/base.rb
+++ b/actionpack/lib/action_controller/base.rb
@@ -269,7 +269,7 @@ module ActionController #:nodoc:
     # Prepends all the URL-generating helpers from AssetHelper. This makes it possible to easily move javascripts, stylesheets,
     # and images to a dedicated asset server away from the main web server. Example:
     #   ActionController::Base.asset_host = "http://assets.example.com"
-    @@asset_host = ""
+    @@asset_host = nil
     cattr_accessor :asset_host
 
     # All requests are considered local by default, so everyone will be exposed to detailed debugging screens on errors.
diff --git a/actionpack/lib/action_view/helpers/asset_tag_helper.rb b/actionpack/lib/action_view/helpers/asset_tag_helper.rb
index ed33f08..d39be83 100644
--- a/actionpack/lib/action_view/helpers/asset_tag_helper.rb
+++ b/actionpack/lib/action_view/helpers/asset_tag_helper.rb
@@ -520,17 +520,19 @@ module ActionView
         # numbers 0-3 if it contains <tt>%d</tt> (the number is the source hash mod 4),
         # or the value returned from invoking the proc if it's a proc.
         def compute_asset_host(source)
-          if host = ActionController::Base.asset_host
-            if host.is_a?(Proc)
-              case host.arity
-              when 2
-                host.call(source, @controller.request)
-              else
-                host.call(source)
-              end
+          case host = ActionController::Base.asset_host
+          when Proc
+            case host.arity
+            when 2
+              host.call(source, @controller.request)
             else
-              (host =~ /%d/) ? host % (source.hash % 4) : host
+              host.call(source)
             end
+          when String
+            (host =~ /%d/) ? host % (source.hash % 4) : host
+          when NilClass
+#              host.blank? ? url_for(:use_route => :root, :only_path => false) : host
+            respond_to?(:root_url) ? root_url : host
           end
         end
 
-- 
1.6.0