Issue #11749: try to fix transient test_socket failure
diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index 8b23ae9..6ee94b5 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -1411,6 +1411,10 @@
         self.evt1.set()
         self.evt2.wait(1.0)
         first_seg = self.read_file.read(len(self.read_msg) - 3)
+        if first_seg is None:
+            # Data not arrived (can happen under Windows), wait a bit
+            time.sleep(0.5)
+            first_seg = self.read_file.read(len(self.read_msg) - 3)
         buf = bytearray(10)
         n = self.read_file.readinto(buf)
         self.assertEqual(n, 3)