Address SF bug #442813. The sequence getitem wrappers should do
interpretation of negative indices, since neither the sq_*item slots
nor the slot_ wrappers do this. (Slices are a different story, there
the size wrapping is done too early.)
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index c49275b..f2e6f4d 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -1661,8 +1661,43 @@
{0}
};
+static int
+getindex(PyObject *self, PyObject *arg)
+{
+ int i;
+
+ i = PyInt_AsLong(arg);
+ if (i == -1 && PyErr_Occurred())
+ return -1;
+ if (i < 0) {
+ PySequenceMethods *sq = self->ob_type->tp_as_sequence;
+ if (sq && sq->sq_length) {
+ int n = (*sq->sq_length)(self);
+ if (n < 0)
+ return -1;
+ i += n;
+ }
+ }
+ return i;
+}
+
+static PyObject *
+wrap_sq_item(PyObject *self, PyObject *args, void *wrapped)
+{
+ intargfunc func = (intargfunc)wrapped;
+ PyObject *arg;
+ int i;
+
+ if (!PyArg_ParseTuple(args, "O", &arg))
+ return NULL;
+ i = getindex(self, arg);
+ if (i == -1 && PyErr_Occurred())
+ return NULL;
+ return (*func)(self, i);
+}
+
static struct wrapperbase tab_getitem_int[] = {
- {"__getitem__", (wrapperfunc)wrap_intargfunc,
+ {"__getitem__", (wrapperfunc)wrap_sq_item,
"x.__getitem__(i) <==> x[i]"},
{0}
};
@@ -1685,13 +1720,16 @@
};
static PyObject *
-wrap_intobjargproc(PyObject *self, PyObject *args, void *wrapped)
+wrap_sq_setitem(PyObject *self, PyObject *args, void *wrapped)
{
intobjargproc func = (intobjargproc)wrapped;
int i, res;
- PyObject *value;
+ PyObject *arg, *value;
- if (!PyArg_ParseTuple(args, "iO", &i, &value))
+ if (!PyArg_ParseTuple(args, "OO", &arg, &value))
+ return NULL;
+ i = getindex(self, arg);
+ if (i == -1 && PyErr_Occurred())
return NULL;
res = (*func)(self, i, value);
if (res == -1 && PyErr_Occurred())
@@ -1701,12 +1739,16 @@
}
static PyObject *
-wrap_delitem_int(PyObject *self, PyObject *args, void *wrapped)
+wrap_sq_delitem(PyObject *self, PyObject *args, void *wrapped)
{
intobjargproc func = (intobjargproc)wrapped;
int i, res;
+ PyObject *arg;
- if (!PyArg_ParseTuple(args, "i", &i))
+ if (!PyArg_ParseTuple(args, "O", &arg))
+ return NULL;
+ i = getindex(self, arg);
+ if (i == -1 && PyErr_Occurred())
return NULL;
res = (*func)(self, i, NULL);
if (res == -1 && PyErr_Occurred())
@@ -1716,9 +1758,9 @@
}
static struct wrapperbase tab_setitem_int[] = {
- {"__setitem__", (wrapperfunc)wrap_intobjargproc,
+ {"__setitem__", (wrapperfunc)wrap_sq_setitem,
"x.__setitem__(i, y) <==> x[i]=y"},
- {"__delitem__", (wrapperfunc)wrap_delitem_int,
+ {"__delitem__", (wrapperfunc)wrap_sq_delitem,
"x.__delitem__(y) <==> del x[y]"},
{0}
};