From f0ec950f896ea2c2cf85f7347f944a9c884fcdf2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nicolas=20=C3=89vrard?= <nicoe@b2ck.com>
Date: Thu, 19 Sep 2013 18:45:11 +0200
Subject: [PATCH] Do not override existing lines in invoice creation

review931002
---
 sale.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sale.py b/sale.py
index 68dac98783..311744cca1 100644
--- a/sale.py
+++ b/sale.py
@@ -738,7 +738,9 @@ class Sale(Workflow, ModelSQL, ModelView):
             return
 
         invoice = self._get_invoice_sale(invoice_type)
-        invoice.lines = list(chain.from_iterable(invoice_lines.itervalues()))
+        invoice.lines = ((list(invoice.lines)
+                if hasattr(invoice, 'lines') else [])
+            + list(chain.from_iterable(invoice_lines.itervalues())))
         invoice.save()
 
         with Transaction().set_user(0, set_context=True):