Bug 2075187

Description of problem:

The python3-dns package has a bug where it tries to do a compare between a float and an nonetype causing issues. This causes zone transfer issues in the OpenStack Designate project which is using python3-dns

This is only present in CentOS Stream 8 because it's running version 1.15 where the bug is resolved in >= 2.0.0

See bug report in https://bugs.launchpad.net/designate/+bug/1941988

Version-Release number of selected component (if applicable): python3-dns-1.15.0-10.el8.noarch


How reproducible:
See reproduce in https://bugs.launchpad.net/designate/+bug/1941988


Actual results:
Python exception trying to compare float > nonetype

Expected results:
No error, instead checking value for nonetype before comparing

Additional info:
courtasy patch to solve issue as describe in https://bugs.launchpad.net/designate/+bug/1941988 and fixed in https://github.com/rthalley/dnspython/blob/v2.0.0rc1/dns/query.py#L925

From 2e2ee980ab0fdbf0574b67c415756ba79304ac5a Mon Sep 17 00:00:00 2001
From: Tobias Urdin <tobias.urdin>
Date: Wed, 13 Apr 2022 18:50:12 +0000
Subject: [PATCH] Fix operator compare between NoneType and float

---
 dns/query.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/dns/query.py b/dns/query.py
index bfecd43..19b9fbb 100644
--- a/dns/query.py
+++ b/dns/query.py
@@ -467,7 +467,8 @@ def xfr(where, zone, rdtype=dns.rdatatype.AXFR, rdclass=dns.rdataclass.IN,
     first = True
     while not done:
         mexpiration = _compute_expiration(timeout)
-        if mexpiration is None or mexpiration > expiration:
+        if mexpiration is None or \
+           (expiration is not None and mexpiration > expiration):
             mexpiration = expiration
         if use_udp:
             _wait_for_readable(s, expiration)