Don't change usage counter on DELETE to non-existing resource

lib/remote_storage/riak.rb

@@ -122,8 +122,10 @@ module RemoteStorage
 
       riak_response = data_bucket.delete("#{user}:#{directory}:#{key}")
 
+      if riak_response[:code] != 404
         log_object_count(user, directory, -1)
         log_object_size(user, directory, 0, existing_object_size)
+      end
 
       timestamp = (Time.now.to_f * 1000).to_i
       delete_or_update_directory_objects(user, directory, timestamp)

spec/riak_spec.rb

@@ -374,6 +374,20 @@ describe "App with Riak backend" do
         info_bucket.get("usage:jimmy:documents").data["count"].must_equal 999
       end
 
+      context "non-existing object" do
+        before do
+          set_usage_info "jimmy", "documents", "size", 10
+          set_usage_info "jimmy", "documents", "count", 10
+          delete "/jimmy/documents/foozius"
+        end
+
+        it "doesn't change the category usage info" do
+          usage = info_bucket.get("usage:jimmy:documents").data
+          usage["size"].must_equal 10
+          usage["count"].must_equal 10
+        end
+      end
+
       context "binary data" do
         before do
           header "Content-Type", "image/jpeg; charset=binary"