Fix some setsockopt error messages

Author: naweiss

Lib/test/test_socket.py

@@ -1560,10 +1560,10 @@ def test_setsockopt_errors(self):
         with self.assertRaisesRegex(TypeError, "socket option should be int, bytes-like object or None"):
             sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, dict())
 
-        with self.assertRaisesRegex(TypeError, "take 4 arguments when socket option is None"):
+        with self.assertRaisesRegex(TypeError, "requires 4 arguments when the third argument is None"):
             sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, None)
 
-        with self.assertRaisesRegex(TypeError, "argument 3 must be NoneType"):
+        with self.assertRaisesRegex(TypeError, "only takes 4 arguments when the third argument is None"):
             sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1, 2)
 
         with self.assertRaisesRegex(TypeError, "takes at least 3 arguments"):

Modules/socketmodule.c

@@ -3349,19 +3349,24 @@ sock_setsockopt(PyObject *self, PyObject *args)
     arglen = PyTuple_Size(args);
     if (arglen == 3 && optval == Py_None) {
         PyErr_Format(PyExc_TypeError,
-                        "setsockopt() take 4 arguments when socket option is None (%zd given)",
+                        "setsockopt() requires 4 arguments when the third argument is None",
                         arglen);
         return NULL;
     }
     if (arglen == 4 && optval != Py_None) {
         PyErr_Format(PyExc_TypeError,
-                        "setsockopt() argument 3 must be NoneType, not %T",
+                        "setsockopt() only takes 4 arguments when the third argument is None (got %T)",
                         optval);
         return NULL;
     }
 
 #ifdef AF_VSOCK
     if (s->sock_family == AF_VSOCK) {
+        if (!PyIndex_Check(optval)) {
+            PyErr_Format(PyExc_TypeError,
+                            "setsockopt() argument 3 for AF_VSOCK must be an int (got %T)",
+                            optval);
+	}
         uint64_t vflag; // Must be set width of 64 bits
         /* setsockopt(level, opt, flag) */
         if (!PyArg_Parse(optval, "K", &vflag)) {