From a82119525251924870bf3f41380d1ebd4f08b35f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E2=96=9F=20=E2=96=96=E2=96=9F=20=E2=96=96?=
 <dodo.the.last@gmail.com>
Date: Sat, 9 Nov 2013 04:34:11 +0100
Subject: [PATCH] only query value from builder when value is undefined

---
 src/xml.coffee | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/xml.coffee b/src/xml.coffee
index 745ad02..3ea0c8c 100644
--- a/src/xml.coffee
+++ b/src/xml.coffee
@@ -126,7 +126,7 @@ class Tag extends EventEmitter
 
     attr: (key, value) =>
         if typeof key is 'string'
-            if not value?
+            if value is undefined
                 attr = @builder?.query('attr', this, key)
                 # attr is not defined if attr is undefined
                 # attr doesn't have a value when attr is null