Allow use of other ports so the test can pass if 9091 is in use

Lib/test/test_telnetlib.py

@@ -6,12 +6,14 @@ import time
 from unittest import TestCase
 from test import test_support
 
+PORT = 9091
 
 def server(evt):
     serv = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
     serv.settimeout(3)
     serv.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
-    serv.bind(("", 9091))
+    global PORT
+    PORT = test_support.bind_port(serv, "", PORT)
     serv.listen(5)
     evt.set()
     try:
@@ -36,24 +38,24 @@ class GeneralTests(TestCase):
 
     def testBasic(self):
         # connects
-        telnet = telnetlib.Telnet("localhost", 9091)
+        telnet = telnetlib.Telnet("localhost", PORT)
         telnet.sock.close()
 
     def testTimeoutDefault(self):
         # default
-        telnet = telnetlib.Telnet("localhost", 9091)
+        telnet = telnetlib.Telnet("localhost", PORT)
         self.assertTrue(telnet.sock.gettimeout() is None)
         telnet.sock.close()
 
     def testTimeoutValue(self):
         # a value
-        telnet = telnetlib.Telnet("localhost", 9091, timeout=30)
+        telnet = telnetlib.Telnet("localhost", PORT, timeout=30)
         self.assertEqual(telnet.sock.gettimeout(), 30)
         telnet.sock.close()
 
     def testTimeoutDifferentOrder(self):
         telnet = telnetlib.Telnet(timeout=30)
-        telnet.open("localhost", 9091)
+        telnet.open("localhost", PORT)
         self.assertEqual(telnet.sock.gettimeout(), 30)
         telnet.sock.close()
 
@@ -62,7 +64,7 @@ class GeneralTests(TestCase):
         previous = socket.getdefaulttimeout()
         socket.setdefaulttimeout(30)
         try:
-            telnet = telnetlib.Telnet("localhost", 9091, timeout=None)
+            telnet = telnetlib.Telnet("localhost", PORT, timeout=None)
         finally:
             socket.setdefaulttimeout(previous)
         self.assertEqual(telnet.sock.gettimeout(), 30)