Issue #1621: Fix undefined behaviour from signed overflow in datetime module hashes, array and list iterations, and get_integer (stringlib/string_format.h)
diff --git a/Modules/_datetimemodule.c b/Modules/_datetimemodule.c
index 718dfe2..26e0ed0 100644
--- a/Modules/_datetimemodule.c
+++ b/Modules/_datetimemodule.c
@@ -2746,13 +2746,13 @@
generic_hash(unsigned char *data, int len)
{
register unsigned char *p;
- register Py_hash_t x;
+ register Py_uhash_t x;
p = (unsigned char *) data;
- x = *p << 7;
+ x = (Py_uhash_t)*p << 7;
while (--len >= 0)
- x = (1000003*x) ^ *p++;
- x ^= len;
+ x = (1000003U*x) ^ (Py_uhash_t)*p++;
+ x ^= (Py_uhash_t)len;
if (x == -1)
x = -2;
diff --git a/Modules/arraymodule.c b/Modules/arraymodule.c
index 5748a3c..8806bd5 100644
--- a/Modules/arraymodule.c
+++ b/Modules/arraymodule.c
@@ -2351,7 +2351,7 @@
self->ob_item + (cur + 1) * itemsize,
lim * itemsize);
}
- cur = start + slicelength * step;
+ cur = start + (size_t)slicelength * step;
if (cur < (size_t)Py_SIZE(self)) {
memmove(self->ob_item + (cur-slicelength) * itemsize,
self->ob_item + cur * itemsize,