Fix integer negation and absolute value to not rely

on undefined behaviour of the C compiler anymore.
This commit is contained in:
Martin v. Löwis 2006-10-04 05:47:47 +00:00
parent a027bac30a
commit 10525ad313
3 changed files with 7 additions and 4 deletions

View File

@ -116,6 +116,7 @@ class BuiltinTest(unittest.TestCase):
self.assertEqual(abs(0), 0)
self.assertEqual(abs(1234), 1234)
self.assertEqual(abs(-1234), 1234)
self.assertTrue(abs(-sys.maxint-1) > 0)
# float
self.assertEqual(abs(0.0), 0.0)
self.assertEqual(abs(3.14), 3.14)

View File

@ -12,6 +12,9 @@ What's New in Python 2.5.1c1?
Core and builtins
-----------------
- Integer negation and absolute value were fixed to not rely
on undefined behaviour of the C compiler anymore.
- Bug #1566800: make sure that EnvironmentError can be called with any
number of arguments, as was the case in Python 2.4.

View File

@ -760,10 +760,9 @@ int_pow(PyIntObject *v, PyIntObject *w, PyIntObject *z)
static PyObject *
int_neg(PyIntObject *v)
{
register long a, x;
register long a;
a = v->ob_ival;
x = -a;
if (a < 0 && x < 0) {
if (a < 0 && (unsigned long)a == 0-(unsigned long)a) {
PyObject *o = PyLong_FromLong(a);
if (o != NULL) {
PyObject *result = PyNumber_Negative(o);
@ -772,7 +771,7 @@ int_neg(PyIntObject *v)
}
return NULL;
}
return PyInt_FromLong(x);
return PyInt_FromLong(-a);
}
static PyObject *