1 files changed, 9 insertions, 0 deletions

diff --git a/tests/integration/test_stats.py b/tests/integration/test_stats.py
index 088d8a1..c4ac95a 100644
--- a/tests/integration/test_stats.py
+++ b/tests/integration/test_stats.py
@@ -177,6 +177,15 @@ class StatsNetworks(TrackerTestCase):
         for line in lines:
             self.assertEqual(int(line.split(b":")[0]), 3, "three peers from the one network")
 
+    def test_the_report_survives_a_torrent_with_no_v4_peers(self):
+        # A torrent whose only peer is v6 has no v4 peer list once the lists
+        # are allocated on demand. The s24 report walks the v4 list of every
+        # torrent, so it has to skip the absent one rather than follow a null
+        # pointer. Needs WANT_IP_FROM_QUERY_STRING to force the family; without
+        # it the peer is loopback v4 and the walk is never asked to skip.
+        self.tracker.announce(self.hash_for("s24v6only"), ip="2001:db8::1", port=6001, left=0)
+        self.assertIn(b"Networks, limit /24:", self.tracker.stats("s24s"))
+
 
 if __name__ == "__main__":
     unittest.main()