[minor-fix] pricing rule test-case fix
diff --git a/erpnext/accounts/doctype/pricing_rule/pricing_rule.py b/erpnext/accounts/doctype/pricing_rule/pricing_rule.py
index b9c4cbb..0dcfc1f 100644
--- a/erpnext/accounts/doctype/pricing_rule/pricing_rule.py
+++ b/erpnext/accounts/doctype/pricing_rule/pricing_rule.py
@@ -171,8 +171,8 @@
 			})
 		else:
 			# if user changed the discount percentage then set discount_percentage of user
-			item_details.discount_percentage = pricing_rule.discount_percentage if args.discount_percentage == pricing_rule.discount_percentage\
-				else args.discount_percentage
+			item_details.discount_percentage = args.discount_percentage if args.discount_percentage != pricing_rule.discount_percentage\
+				and args.discount_percentage > 0 else pricing_rule.discount_percentage
 	return item_details
 
 def get_pricing_rules(args):