#14814: Use correct comparison for IP addresses

ipaddress._BaseV4.is_unspecified() compared IP addresses using "in" which
fails.

Lib/ipaddress.py

@@ -1130,7 +1130,7 @@ class _BaseV4:
         """
         unspecified_address = IPv4Address('0.0.0.0')
         if isinstance(self, _BaseAddress):
-            return self in unspecified_address
+            return self == unspecified_address
         return (self.network_address == self.broadcast_address ==
                 unspecified_address)
 

Lib/test/test_ipaddress.py

@@ -837,6 +837,7 @@ class IpaddrUnitTest(unittest.TestCase):
         self.assertEqual(False, ipaddress.ip_network('128.0.0.0').is_loopback)
 
         # test addresses
+        self.assertEqual(True, ipaddress.ip_address('0.0.0.0').is_unspecified)
         self.assertEqual(True, ipaddress.ip_address('224.1.1.1').is_multicast)
         self.assertEqual(False, ipaddress.ip_address('240.0.0.0').is_multicast)