Issue #16096: Fix signed overflow in Objects/longobject.c. Thanks Serhiy Storchaka.
diff --git a/Objects/longobject.c b/Objects/longobject.c
index 73413dd..4cc080f 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -668,10 +668,9 @@
assert(ndigits == 0 || v->ob_digit[ndigits - 1] != 0);
if (ndigits > 0) {
digit msd = v->ob_digit[ndigits - 1];
-
- result = (ndigits - 1) * PyLong_SHIFT;
- if (result / PyLong_SHIFT != (size_t)(ndigits - 1))
+ if ((size_t)(ndigits - 1) > PY_SIZE_MAX / (size_t)PyLong_SHIFT)
goto Overflow;
+ result = (size_t)(ndigits - 1) * (size_t)PyLong_SHIFT;
do {
++result;
if (result == 0)