[Python-checkins] Fix division by 0 when checking for overflow in math.prod (GH-11808)

Sun Feb 10 14:57:02 EST 2019

https://github.com/python/cpython/commit/4207907c2b8c0b3da62de2acdb8b22b5bbe7f7a2
commit: 4207907c2b8c0b3da62de2acdb8b22b5bbe7f7a2
branch: master
author: Pablo Galindo <Pablogsal at gmail.com>
committer: GitHub <noreply at github.com>
date: 2019年02月10日T19:56:58Z
summary:
Fix division by 0 when checking for overflow in math.prod (GH-11808)
files:
M Lib/test/test_math.py
M Modules/mathmodule.c

diff --git a/Lib/test/test_math.py b/Lib/test/test_math.py
index 083759ca75e1..856b1e8ac11e 100644
--- a/Lib/test/test_math.py
+++ b/Lib/test/test_math.py
@@ -1756,6 +1756,10 @@ def test_prod(self):
 with self.assertRaises(TypeError):
 prod([10, 20], [30, 40]) # start is a keyword-only argument
 
+ self.assertEqual(prod([0, 1, 2, 3]), 0)
+ self.assertEqual(prod([1, 0, 2, 3]), 0)
+ self.assertEqual(prod(range(10)), 0)
+
 def test_main():
 from doctest import DocFileSuite
 suite = unittest.TestSuite()
diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
index d2f8d5334736..2272f622f0b9 100644
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -2561,8 +2561,8 @@ math_prod_impl(PyObject *module, PyObject *iterable, PyObject *start)
 long x = i_result * b;
 /* Continue if there is no overflow */
 if (overflow == 0
- && x < INT_MAX && x > INT_MIN
- && !(b != 0 && x / i_result != b)) {
+ && x < LONG_MAX && x > LONG_MIN
+ && !(b != 0 && x / b != i_result)) {
 i_result = x;
 Py_DECREF(item);
 continue;
