[3.7] bpo-34587, test_socket: remove RDSTest.testCongestion() (GH-9277)

Lib/test/test_socket.py

@@ -2054,33 +2054,6 @@ def _testSelect(self):
         self.data = b'select'
         self.cli.sendto(self.data, 0, (HOST, self.port))
 
-    def testCongestion(self):
-        # wait until the sender is done
-        self.evt.wait()
-
-    def _testCongestion(self):
-        # test the behavior in case of congestion
-        self.data = b'fill'
-        self.cli.setblocking(False)
-        try:
-            # try to lower the receiver's socket buffer size
-            self.cli.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 16384)
-        except OSError:
-            pass
-        with self.assertRaises(OSError) as cm:
-            try:
-                # fill the receiver's socket buffer
-                while True:
-                    self.cli.sendto(self.data, 0, (HOST, self.port))
-            finally:
-                # signal the receiver we're done
-                self.evt.set()
-        # sendto() should have failed with ENOBUFS
-        self.assertEqual(cm.exception.errno, errno.ENOBUFS)
-        # and we should have received a congestion notification through poll
-        r, w, x = select.select([self.serv], [], [], 3.0)
-        self.assertIn(self.serv, r)
-
 
 @unittest.skipIf(fcntl is None, "need fcntl")
 @unittest.skipUnless(HAVE_SOCKET_VSOCK,

Misc/NEWS.d/next/Tests/2018-09-13-20-58-07.bpo-34587.rCcxp3.rst

@@ -0,0 +1,5 @@
+test_socket: Remove RDSTest.testCongestion(). The test tries to fill the
+receiver's socket buffer and expects an error. But the RDS protocol doesn't
+require that. Moreover, the Linux implementation of RDS expects that the
+producer of the messages reduces its rate, it's not the role of the receiver to
+trigger an error. The test fails on Fedora 28 by design, so just remove it.