Merge branch 'master' of github.com:webnotes/erpnext into responsive

Conflicts:
	accounts/doctype/sales_invoice/sales_invoice.py
	accounts/doctype/sales_invoice_item/sales_invoice_item.txt
	buying/doctype/supplier_quotation/supplier_quotation.js
	patches/patch_list.py
diff --git a/controllers/accounts_controller.py b/controllers/accounts_controller.py
index ec7e3e5..69522c4 100644
--- a/controllers/accounts_controller.py
+++ b/controllers/accounts_controller.py
@@ -71,7 +71,7 @@
 				ret = get_item_details(args)
 				for fieldname, value in ret.items():
 					if self.meta.get_field(fieldname, parentfield=self.fname) and \
-						not item.fields.get(fieldname):
+						item.fields.get(fieldname) is None:
 							item.fields[fieldname] = value
 							
 	def set_taxes(self, tax_doctype, tax_parentfield, tax_master_field):