From 1511e788cf0b7d5d9744773f4b8036d784a2c8a7 Mon Sep 17 00:00:00 2001
From: Laetitia Gangloff <laetitia.gangloff@acsone.eu>
Date: Tue, 15 Jul 2014 10:44:19 +0200
Subject: [PATCH] [FIX] fields: error if there is no value when convert a
 many2many relation

Closes #1165
---
 openerp/osv/fields.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/openerp/osv/fields.py b/openerp/osv/fields.py
index 23afb1663c3..65c6c10e42c 100644
--- a/openerp/osv/fields.py
+++ b/openerp/osv/fields.py
@@ -1278,6 +1278,8 @@ class sparse(function):
         """
 
         if self._type == 'many2many':
+            if not value:
+                return []
             assert value[0][0] == 6, 'Unsupported m2m value for sparse field: %s' % value
             return value[0][2]