Issue #7070: Fix problem with builtin round function for large odd

integer arguments.  Also fixes the sign of round(-0.0).
This commit is contained in:
Mark Dickinson 2009-11-09 17:45:40 +00:00
parent c747d3a5d2
commit f263724ea0
3 changed files with 20 additions and 5 deletions

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@ -1,5 +1,6 @@
# Python test set -- built-in functions
import platform
import test.test_support, unittest
from test.test_support import fcmp, have_unicode, TESTFN, unlink, \
run_unittest, run_with_locale
@ -1259,6 +1260,14 @@ class BuiltinTest(unittest.TestCase):
self.assertRaises(TypeError, round, t)
self.assertRaises(TypeError, round, t, 0)
def test_round_large(self):
# Issue #1869: integral floats should remain unchanged
self.assertEqual(round(5e15-1), 5e15-1)
self.assertEqual(round(5e15), 5e15)
self.assertEqual(round(5e15+1), 5e15+1)
self.assertEqual(round(5e15+2), 5e15+2)
self.assertEqual(round(5e15+3), 5e15+3)
def test_setattr(self):
setattr(sys, 'spam', 1)
self.assertEqual(sys.spam, 1)

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@ -12,6 +12,8 @@ What's New in Python 2.6.5
Core and Builtins
-----------------
- Issue #7070: Fix round bug for large odd integer arguments.
- Issue #7078: Set struct.__doc__ from _struct.__doc__.
- Issue #1722344: threading._shutdown() is now called in Py_Finalize(), which

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@ -2120,7 +2120,7 @@ For most object types, eval(repr(object)) == object.");
static PyObject *
builtin_round(PyObject *self, PyObject *args, PyObject *kwds)
{
double number;
double number, abs_number, abs_result;
double f;
int ndigits = 0;
int i;
@ -2137,10 +2137,14 @@ builtin_round(PyObject *self, PyObject *args, PyObject *kwds)
number /= f;
else
number *= f;
if (number >= 0.0)
number = floor(number + 0.5);
else
number = ceil(number - 0.5);
/* round `number` to nearest integer, rounding halves away from zero */
abs_number = fabs(number);
abs_result = floor(abs_number);
if (abs_number - abs_result >= 0.5)
abs_result += 1.0;
number = copysign(abs_result, number);
if (ndigits < 0)
number *= f;
else