Prevent expandtabs() on string and unicode objects from causing a segfault when

a large width is passed on 32-bit platforms.  Found by Google.

It would be good for people to review this especially carefully and verify
I don't have an off by one error and there is no other way to cause overflow.

1 files changed, 7 insertions, 2 deletions

diff --git a/Lib/test/test_unicode.py b/Lib/test/test_unicode.py
index 5ad54bf070..3ee5ee2245 100644
--- a/Lib/test/test_unicode.py
+++ b/Lib/test/test_unicode.py
@@ -817,8 +817,13 @@ class UnicodeTest(
         self.assertEqual(repr(s1()), '\\n')
         self.assertEqual(repr(s2()), '\\n')
 
-
-
+    def test_expandtabs_overflows_gracefully(self):
+        # This test only affects 32-bit platforms because expandtabs can only take
+        # an int as the max value, not a 64-bit C long.  If expandtabs is changed
+        # to take a 64-bit long, this test should apply to all platforms.
+        if sys.maxint > (1 << 32):
+            return
+        self.assertRaises(OverflowError, u't\tt\t'.expandtabs, sys.maxint)
 
 
 def test_main():