diff options
| -rw-r--r-- | Lib/test/test_complex.py | 13 | ||||
| -rw-r--r-- | Objects/complexobject.c | 24 |
2 files changed, 28 insertions, 9 deletions
diff --git a/Lib/test/test_complex.py b/Lib/test/test_complex.py index 5397ad6..1bb31dd 100644 --- a/Lib/test/test_complex.py +++ b/Lib/test/test_complex.py @@ -2,6 +2,7 @@ import unittest, os from test import test_support from random import random +from math import atan2 # These tests ensure that complex math does the right thing @@ -207,6 +208,18 @@ class ComplexTest(unittest.TestCase): self.assertAlmostEqual(complex(real=17+23j, imag=23), 17+46j) self.assertAlmostEqual(complex(real=1+2j, imag=3+4j), -3+5j) + # check that the sign of a zero in the real or imaginary part + # is preserved when constructing from two floats. (These checks + # are harmless on systems without support for signed zeros.) + def split_zeros(x): + """Function that produces different results for 0. and -0.""" + return atan2(x, -1.) + + self.assertEqual(split_zeros(complex(1., 0.).imag), split_zeros(0.)) + self.assertEqual(split_zeros(complex(1., -0.).imag), split_zeros(-0.)) + self.assertEqual(split_zeros(complex(0., 1.).real), split_zeros(0.)) + self.assertEqual(split_zeros(complex(-0., 1.).real), split_zeros(-0.)) + c = 3.14 + 1j self.assert_(complex(c) is c) del c diff --git a/Objects/complexobject.c b/Objects/complexobject.c index a22f22f..458d0ba 100644 --- a/Objects/complexobject.c +++ b/Objects/complexobject.c @@ -809,6 +809,8 @@ complex_new(PyTypeObject *type, PyObject *args, PyObject *kwds) PyNumberMethods *nbr, *nbi = NULL; Py_complex cr, ci; int own_r = 0; + int cr_is_complex = 0; + int ci_is_complex = 0; static PyObject *complexstr; static char *kwlist[] = {"real", "imag", 0}; @@ -889,6 +891,7 @@ complex_new(PyTypeObject *type, PyObject *args, PyObject *kwds) retaining its real & imag parts here, and the return value is (properly) of the builtin complex type. */ cr = ((PyComplexObject*)r)->cval; + cr_is_complex = 1; if (own_r) { Py_DECREF(r); } @@ -897,7 +900,6 @@ complex_new(PyTypeObject *type, PyObject *args, PyObject *kwds) /* The "real" part really is entirely real, and contributes nothing in the imaginary direction. Just treat it as a double. */ - cr.imag = 0.0; tmp = PyNumber_Float(r); if (own_r) { /* r was a newly created complex number, rather @@ -917,15 +919,14 @@ complex_new(PyTypeObject *type, PyObject *args, PyObject *kwds) } if (i == NULL) { ci.real = 0.0; - ci.imag = 0.0; } - else if (PyComplex_Check(i)) + else if (PyComplex_Check(i)) { ci = ((PyComplexObject*)i)->cval; - else { + ci_is_complex = 1; + } else { /* The "imag" part really is entirely imaginary, and contributes nothing in the real direction. Just treat it as a double. */ - ci.imag = 0.0; tmp = (*nbi->nb_float)(i); if (tmp == NULL) return NULL; @@ -933,11 +934,16 @@ complex_new(PyTypeObject *type, PyObject *args, PyObject *kwds) Py_DECREF(tmp); } /* If the input was in canonical form, then the "real" and "imag" - parts are real numbers, so that ci.real and cr.imag are zero. + parts are real numbers, so that ci.imag and cr.imag are zero. We need this correction in case they were not real numbers. */ - cr.real -= ci.imag; - cr.imag += ci.real; - return complex_subtype_from_c_complex(type, cr); + + if (ci_is_complex) { + cr.real -= ci.imag; + } + if (cr_is_complex) { + ci.real += cr.imag; + } + return complex_subtype_from_doubles(type, cr.real, ci.real); } PyDoc_STRVAR(complex_doc, |