Issue #16743: Fix mmap overflow check on 32 bit Windows
diff --git a/Lib/test/test_mmap.py b/Lib/test/test_mmap.py
index 0701b96..f84b20a 100644
--- a/Lib/test/test_mmap.py
+++ b/Lib/test/test_mmap.py
@@ -682,6 +682,13 @@
 
     def test_large_filesize(self):
         with self._make_test_file(0x17FFFFFFF, b" ") as f:
+            if sys.maxsize < 0x180000000:
+                # On 32 bit platforms the file is larger than sys.maxsize so
+                # mapping the whole file should fail -- Issue #16743
+                with self.assertRaises(OverflowError):
+                    mmap.mmap(f.fileno(), 0x180000000, access=mmap.ACCESS_READ)
+                with self.assertRaises(ValueError):
+                    mmap.mmap(f.fileno(), 0, access=mmap.ACCESS_READ)
             m = mmap.mmap(f.fileno(), 0x10000, access=mmap.ACCESS_READ)
             try:
                 self.assertEqual(m.size(), 0x180000000)