Issue #13872: socket.detach() now marks the socket closed (as mirrored in the socket repr()).
Patch by Matt Joiner.
diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index d77b7dc..cce0d1b 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -951,6 +951,7 @@
         f = self.cli_conn.detach()
         self.assertEqual(f, fileno)
         # cli_conn cannot be used anymore...
+        self.assertTrue(self.cli_conn._closed)
         self.assertRaises(socket.error, self.cli_conn.recv, 1024)
         self.cli_conn.close()
         # ...but we can create another socket using the (still open)