gistfile1.diff

diff --git a/chef-server-slice/app/controllers/application.rb b/chef-server-slice/app/controllers/application.rb
index de03021..7978809 100644
--- a/chef-server-slice/app/controllers/application.rb
+++ b/chef-server-slice/app/controllers/application.rb
@@ -22,6 +22,8 @@ require "chef" / "cookbook_loader"
 
 class ChefServerSlice::Application < Merb::Controller
 
+  include Chef::Mixin::Checksum
+
   controller_for_slice
   
   # Generate the absolute url for a slice - takes the slice's :path_prefix into account.
@@ -168,7 +170,8 @@ class ChefServerSlice::Application < Merb::Controller
         file_name = mo[1]
         files << { 
           :cookbook => cookbook.name, 
-          :name => file_name
+          :name => file_name,
+          :checksum => checksum(sf)
         }
       end
     end
diff --git a/chef/lib/chef/client.rb b/chef/lib/chef/client.rb
index 44b26bf..766811f 100644
--- a/chef/lib/chef/client.rb
+++ b/chef/lib/chef/client.rb
@@ -241,22 +241,24 @@ class Chef
           current_checksum ? { 'checksum' => current_checksum } : nil
         )
         Chef::Log.debug(rf_url)
-      
-        changed = true
-        begin
-          raw_file = @rest.get_rest(rf_url, true)
-        rescue Net::HTTPRetriableError => e
-          if e.response.kind_of?(Net::HTTPNotModified)
-            changed = false
-            Chef::Log.debug("Cache file #{cache_file} is unchanged")
-          else
-            raise e
+
+        if current_checksum != rf['checksum']
+          changed = true
+          begin
+            raw_file = @rest.get_rest(rf_url, true)
+          rescue Net::HTTPRetriableError => e
+            if e.response.kind_of?(Net::HTTPNotModified)
+              changed = false
+              Chef::Log.debug("Cache file #{cache_file} is unchanged")
+            else
+              raise e
+            end
+          end
+        
+          if changed
+            Chef::Log.info("Storing updated #{cache_file} in the cache.")
+            Chef::FileCache.move_to(raw_file.path, cache_file)
           end
-        end
-      
-        if changed
-          Chef::Log.info("Storing updated #{cache_file} in the cache.")
-          Chef::FileCache.move_to(raw_file.path, cache_file)
         end
       end
       
@@ -309,7 +311,7 @@ class Chef
     # === Returns
     # true:: Always returns true
     def sync_recipes
-      Chef::Log.debug("Synchronizing recipes") 
+      Chef::Log.debug("Synchronizing recipes")
       update_file_cache("recipes", @rest.get_rest('cookbooks/_recipe_files'))
     end