Check in some documentation tweaks for PEP 3141, add some tests, and implement
the promotion to complex on pow(negative, fraction).
diff --git a/Objects/floatobject.c b/Objects/floatobject.c
index 7c489d9..eb540e6 100644
--- a/Objects/floatobject.c
+++ b/Objects/floatobject.c
@@ -680,9 +680,10 @@
* bugs so we have to figure it out ourselves.
*/
if (iw != floor(iw)) {
- PyErr_SetString(PyExc_ValueError, "negative number "
- "cannot be raised to a fractional power");
- return NULL;
+ /* Negative numbers raised to fractional powers
+ * become complex.
+ */
+ return PyComplex_Type.tp_as_number->nb_power(v, w, z);
}
/* iw is an exact integer, albeit perhaps a very large one.
* -1 raised to an exact integer should never be exceptional.