Issue #7406: Fix some occurrences of potential signed overflow in int
arithmetic.
diff --git a/Python/ceval.c b/Python/ceval.c
index dd820f2..e5e7046 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -1321,7 +1321,9 @@
register long a, b, i;
a = PyInt_AS_LONG(v);
b = PyInt_AS_LONG(w);
- i = a + b;
+ /* cast to avoid undefined behaviour
+ on overflow */
+ i = (long)((unsigned long)a + b);
if ((i^a) < 0 && (i^b) < 0)
goto slow_add;
x = PyInt_FromLong(i);
@@ -1351,7 +1353,9 @@
register long a, b, i;
a = PyInt_AS_LONG(v);
b = PyInt_AS_LONG(w);
- i = a - b;
+ /* cast to avoid undefined behaviour
+ on overflow */
+ i = (long)((unsigned long)a - b);
if ((i^a) < 0 && (i^~b) < 0)
goto slow_sub;
x = PyInt_FromLong(i);