Fix company context domain when company is not in context

sale.py

@@ -18,7 +18,8 @@ class Sale(ModelWorkflow, ModelSQL, ModelView):
     company = fields.Many2One('company.company', 'Company', required=True,
             states={
                 'readonly': "state != 'draft' or bool(lines)",
-            }, domain=["('id', '=', context.get('company', 0))"])
+            }, domain=["('id', 'company' in context and '=' or '!=', " \
+                    "context.get('company', 0))"])
     reference = fields.Char('Reference', readonly=True, select=1)
     description = fields.Char('Description', states={
         'readonly': "state != 'draft'",