I have a custom TreeModel that stores the row index in TreeIter.user_data.

In 3.8.1 (at least) it is no longer possible to store the value 0 in user_data: it will become None. This is unexpected and used to work in 3.2 at least.

I believe my use case of saving a row index in user_data is fairly common.


Here's a test case:

---
import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk

iter = Gtk.TreeIter()
iter.user_data = 0
if (iter.user_data != 0):
  print "oops, unexpected user_data value '%s'" % iter.user_data
---