From dce9fdfe267867b506973c2743efcf46190c378f Mon Sep 17 00:00:00 2001
From: Nabin Hait <nabinhait@gmail.com>
Date: Mon, 29 Jul 2013 16:16:03 +0530
Subject: [PATCH] [minor] [fix]

---
 stock/doctype/delivery_note/delivery_note.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/stock/doctype/delivery_note/delivery_note.py b/stock/doctype/delivery_note/delivery_note.py
index 3f8a43883f..7ea512daad 100644
--- a/stock/doctype/delivery_note/delivery_note.py
+++ b/stock/doctype/delivery_note/delivery_note.py
@@ -114,7 +114,8 @@ class DocType(SellingController):
 		
 	def validate_with_previous_doc(self):
 		prev_doctype = [d.prevdoc_doctype for d in self.doclist.get({
-			"parentfield": "delivery_note_details", "prevdoc_doctype": ["!=", ""]})]
+			"parentfield": "delivery_note_details"}) if cstr(d.prevdoc_doctype) != ""]
+			
 		if prev_doctype:
 			super(DocType, self).validate_with_previous_doc(self.tname, {
 				prev_doctype[0]: {