diff options
Diffstat (limited to 'Modules/itertoolsmodule.c')
| -rw-r--r-- | Modules/itertoolsmodule.c | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c index db7cdfeefe..cec1f8746f 100644 --- a/Modules/itertoolsmodule.c +++ b/Modules/itertoolsmodule.c @@ -1492,19 +1492,22 @@ islice_next(isliceobject *lz) Py_ssize_t oldnext; PyObject *(*iternext)(PyObject *); + if (it == NULL) + return NULL; + iternext = *Py_TYPE(it)->tp_iternext; while (lz->cnt < lz->next) { item = iternext(it); if (item == NULL) - return NULL; + goto empty; Py_DECREF(item); lz->cnt++; } if (stop != -1 && lz->cnt >= stop) - return NULL; + goto empty; item = iternext(it); if (item == NULL) - return NULL; + goto empty; lz->cnt++; oldnext = lz->next; /* The (size_t) cast below avoids the danger of undefined @@ -1513,6 +1516,10 @@ islice_next(isliceobject *lz) if (lz->next < oldnext || (stop != -1 && lz->next > stop)) lz->next = stop; return item; + +empty: + Py_CLEAR(lz->it); + return NULL; } static PyObject * @@ -1522,6 +1529,18 @@ islice_reduce(isliceobject *lz) * then 'setstate' with the next and count */ PyObject *stop; + if (lz->it == NULL) { + PyObject *empty_list; + PyObject *empty_it; + empty_list = PyList_New(0); + if (empty_list == NULL) + return NULL; + empty_it = PyObject_GetIter(empty_list); + Py_DECREF(empty_list); + if (empty_it == NULL) + return NULL; + return Py_BuildValue("O(Nn)n", Py_TYPE(lz), empty_it, 0, 0); + } if (lz->stop == -1) { stop = Py_None; Py_INCREF(stop); |