gh-110012: Fix RuntimeWarning in test_socket

Author: sobolevn

Lib/test/test_socket.py

@@ -3,6 +3,7 @@
 from test.support import os_helper
 from test.support import socket_helper
 from test.support import threading_helper
+from test.support import warnings_helper
 
 import _thread as thread
 import array
@@ -165,6 +166,15 @@ def socket_setdefaulttimeout(timeout):
         socket.setdefaulttimeout(old_timeout)
 
 
+@contextlib.contextmanager
+def catch_mailformed_data_warning(quite=False):
+    with warnings_helper.check_warnings(
+        ("received malformed or improperly-truncated ancillary data", RuntimeWarning),
+        quite=quite,
+    ):
+        yield
+
+
 HAVE_SOCKET_CAN = _have_socket_can()
 
 HAVE_SOCKET_CAN_ISOTP = _have_socket_can_isotp()
@@ -3874,8 +3884,9 @@ def checkTruncatedArray(self, ancbuf, maxdata, mindata=0):
         # mindata and maxdata bytes when received with buffer size
         # ancbuf, and that any complete file descriptor numbers are
         # valid.
-        msg, ancdata, flags, addr = self.doRecvmsg(self.serv_sock,
-                                                   len(MSG), ancbuf)
+        with catch_mailformed_data_warning():
+            msg, ancdata, flags, addr = self.doRecvmsg(self.serv_sock,
+                                                    len(MSG), ancbuf)
         self.assertEqual(msg, MSG)
         self.checkRecvmsgAddress(addr, self.cli_addr)
         self.checkFlags(flags, eor=True, checkset=socket.MSG_CTRUNC)
@@ -4217,8 +4228,9 @@ def testSingleCmsgTruncInData(self):
         self.serv_sock.setsockopt(socket.IPPROTO_IPV6,
                                   socket.IPV6_RECVHOPLIMIT, 1)
         self.misc_event.set()
-        msg, ancdata, flags, addr = self.doRecvmsg(
-            self.serv_sock, len(MSG), socket.CMSG_LEN(SIZEOF_INT) - 1)
+        with catch_mailformed_data_warning():
+            msg, ancdata, flags, addr = self.doRecvmsg(
+                self.serv_sock, len(MSG), socket.CMSG_LEN(SIZEOF_INT) - 1)
 
         self.assertEqual(msg, MSG)
         self.checkRecvmsgAddress(addr, self.cli_addr)
@@ -4321,9 +4333,10 @@ def testSecondCmsgTruncInData(self):
         self.serv_sock.setsockopt(socket.IPPROTO_IPV6,
                                   socket.IPV6_RECVTCLASS, 1)
         self.misc_event.set()
-        msg, ancdata, flags, addr = self.doRecvmsg(
-            self.serv_sock, len(MSG),
-            socket.CMSG_SPACE(SIZEOF_INT) + socket.CMSG_LEN(SIZEOF_INT) - 1)
+        with catch_mailformed_data_warning():
+            msg, ancdata, flags, addr = self.doRecvmsg(
+                self.serv_sock, len(MSG),
+                socket.CMSG_SPACE(SIZEOF_INT) + socket.CMSG_LEN(SIZEOF_INT) - 1)
 
         self.assertEqual(msg, MSG)
         self.checkRecvmsgAddress(addr, self.cli_addr)