Issue #11127: Raise a TypeError when trying to pickle a socket object.

Lib/socket.py

@@ -112,6 +112,9 @@ class socket(_socket.socket):
                                 s[7:])
         return s
 
+    def __getstate__(self):
+        raise TypeError("Cannot serialize socket object")
+
     def dup(self):
         """dup() -> socket object
 

Lib/test/test_socket.py

@@ -18,6 +18,7 @@ import contextlib
 from weakref import proxy
 import signal
 import math
+import pickle
 try:
     import fcntl
 except ImportError:
@@ -764,6 +765,12 @@ class GeneralModuleTests(unittest.TestCase):
             fp.close()
             self.assertEqual(repr(fp), "<_io.BufferedReader name=-1>")
 
+    def test_pickle(self):
+        sock = socket.socket()
+        with sock:
+            for protocol in range(pickle.HIGHEST_PROTOCOL + 1):
+                self.assertRaises(TypeError, pickle.dumps, sock, protocol)
+
 
 @unittest.skipUnless(thread, 'Threading required for this test.')
 class BasicTCPTest(SocketConnectedTest):

Misc/NEWS

@@ -83,6 +83,8 @@ Library
 
 - Issue #4391: Use proper gettext plural forms in optparse.
 
+- Issue #11127: Raise a TypeError when trying to pickle a socket object.
+
 - Issue #11563: Connection:close header is sent by requests using URLOpener
   class which helps in closing of sockets after connection is over. Patch
   contributions by Jeff McNeil and Nadeem Vawda.