bpo-29602: fix signed zero handling in complex constructor. (#203)

* Fix incorrect handling of signed zeros for complex-related classes.

* Add Misc/NEWS entry.
This commit is contained in:
Mark Dickinson 2017-02-20 20:28:15 +00:00 committed by GitHub
parent 1b8df107f8
commit 112ec38c15
3 changed files with 30 additions and 3 deletions

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@ -387,6 +387,29 @@ class ComplexTest(unittest.TestCase):
self.assertAlmostEqual(complex(complex1(1j)), 2j)
self.assertRaises(TypeError, complex, complex2(1j))
@support.requires_IEEE_754
def test_constructor_special_numbers(self):
class complex2(complex):
pass
for x in 0.0, -0.0, INF, -INF, NAN:
for y in 0.0, -0.0, INF, -INF, NAN:
with self.subTest(x=x, y=y):
z = complex(x, y)
self.assertFloatsAreIdentical(z.real, x)
self.assertFloatsAreIdentical(z.imag, y)
z = complex2(x, y)
self.assertIs(type(z), complex2)
self.assertFloatsAreIdentical(z.real, x)
self.assertFloatsAreIdentical(z.imag, y)
z = complex(complex2(x, y))
self.assertIs(type(z), complex)
self.assertFloatsAreIdentical(z.real, x)
self.assertFloatsAreIdentical(z.imag, y)
z = complex2(complex(x, y))
self.assertIs(type(z), complex2)
self.assertFloatsAreIdentical(z.real, x)
self.assertFloatsAreIdentical(z.imag, y)
def test_underscores(self):
# check underscores
for lit in VALID_UNDERSCORE_LITERALS:

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@ -10,6 +10,10 @@ What's New in Python 3.7.0 alpha 1?
Core and Builtins
-----------------
- bpo-29602: Fix incorrect handling of signed zeros in complex constructor for
complex subclasses and for inputs having a __complex__ method. Patch
by Serhiy Storchaka.
- bpo-29347: Fixed possibly dereferencing undefined pointers
when creating weakref objects.

View File

@ -1025,11 +1025,11 @@ complex_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
return NULL;
}
cr.real = PyFloat_AsDouble(tmp);
cr.imag = 0.0; /* Shut up compiler warning */
cr.imag = 0.0;
Py_DECREF(tmp);
}
if (i == NULL) {
ci.real = 0.0;
ci.real = cr.imag;
}
else if (PyComplex_Check(i)) {
ci = ((PyComplexObject*)i)->cval;
@ -1051,7 +1051,7 @@ complex_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
if (ci_is_complex) {
cr.real -= ci.imag;
}
if (cr_is_complex) {
if (cr_is_complex && i != NULL) {
ci.real += cr.imag;
}
return complex_subtype_from_doubles(type, cr.real, ci.real);