Ensure sort key always return an integer

When sorting tree model, it is possible that some ids are not in the ordered
list (because they do not fit anymore in the domain). So we return the number
of records so they are moved at the end of the list.

issue8042
review53531002

tryton/gui/window/view_form/view/list.py

@@ -143,7 +143,8 @@ class AdaptModelGroup(gtk.GenericTreeModel):
     def sort(self, ids):
         old_idx = {record.id: i for i, record in enumerate(self.group)}
         new_idx = {id_: i for i, id_ in enumerate(ids)}
-        self.group.sort(key=lambda r: new_idx.get(r.id))
+        size = len(self.group)
+        self.group.sort(key=lambda r: new_idx.get(r.id, size))
         new_order = []
         prev = None
         for record in self.group: