bpo-29602: fix signed zero handling in complex constructor (#204)
* bpo-29602: fix signed zero handling in complex constructor
* Add missing have_getformat definition; remove use of unittest subtests.
diff --git a/Lib/test/test_complex.py b/Lib/test/test_complex.py
index c0383b2..02b292f 100644
--- a/Lib/test/test_complex.py
+++ b/Lib/test/test_complex.py
@@ -8,6 +8,13 @@
NAN = float("nan")
# These tests ensure that complex math does the right thing
+# decorator for skipping tests on non-IEEE 754 platforms
+have_getformat = hasattr(float, "__getformat__")
+requires_IEEE_754 = unittest.skipUnless(have_getformat and
+ float.__getformat__("double").startswith("IEEE"),
+ "test requires IEEE 754 doubles")
+
+
class ComplexTest(unittest.TestCase):
def assertAlmostEqual(self, a, b):
@@ -441,6 +448,28 @@
b = 'y %s x' % op
self.assertTrue(type(eval(a)) is type(eval(b)) is xcomplex)
+ @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:
+ 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_hash(self):
for x in xrange(-30, 30):
self.assertEqual(hash(x), hash(complex(x, 0)))
diff --git a/Misc/NEWS b/Misc/NEWS
index 8726996..6551a6d 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,10 @@
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.
diff --git a/Objects/complexobject.c b/Objects/complexobject.c
index ef18e3f..aaefa2d 100644
--- a/Objects/complexobject.c
+++ b/Objects/complexobject.c
@@ -1232,11 +1232,11 @@
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;
@@ -1258,7 +1258,7 @@
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);