Make StopIteration a sink state. This is done by clearing out the

di_dict field when the end of the list is reached.  Also make the
error ("dictionary changed size during iteration") a sticky state.

Also remove the next() method -- one is supplied automatically by
PyType_Ready() because the tp_iternext slot is set.  That's a good
thing, because the implementation given here was buggy (it never
raised StopIteration).

diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index d7bbef9d8d7655b3e8cc49b5fbd56247f469b1a0..26191609a193180b6c27cadbb26b814ff77f873e 100644 (file)
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -1916,7 +1916,7 @@ extern PyTypeObject PyDictIter_Type; /* Forward */
 
 typedef struct {
        PyObject_HEAD
-       dictobject *di_dict;
+       dictobject *di_dict; /* Set to NULL when iterator is exhausted */
        int di_used;
        int di_pos;
        binaryfunc di_select;
@@ -1940,27 +1940,10 @@ dictiter_new(dictobject *dict, binaryfunc select)
 static void
 dictiter_dealloc(dictiterobject *di)
 {
-       Py_DECREF(di->di_dict);
+       Py_XDECREF(di->di_dict);
        PyObject_Del(di);
 }
 
-static PyObject *
-dictiter_next(dictiterobject *di, PyObject *args)
-{
-       PyObject *key, *value;
-
-       if (di->di_used != di->di_dict->ma_used) {
-               PyErr_SetString(PyExc_RuntimeError,
-                               "dictionary changed size during iteration");
-               return NULL;
-       }
-       if (PyDict_Next((PyObject *)(di->di_dict), &di->di_pos, &key, &value)) {
-               return (*di->di_select)(key, value);
-       }
-       PyErr_SetObject(PyExc_StopIteration, Py_None);
-       return NULL;
-}
-
 static PyObject *
 dictiter_getiter(PyObject *it)
 {
@@ -1968,24 +1951,24 @@ dictiter_getiter(PyObject *it)
        return it;
 }
 
-static PyMethodDef dictiter_methods[] = {
-       {"next",        (PyCFunction)dictiter_next,     METH_VARARGS,
-        "it.next() -- get the next value, or raise StopIteration"},
-       {NULL,          NULL}           /* sentinel */
-};
-
 static PyObject *dictiter_iternext(dictiterobject *di)
 {
        PyObject *key, *value;
 
+       if (di->di_dict == NULL)
+               return NULL;
+
        if (di->di_used != di->di_dict->ma_used) {
                PyErr_SetString(PyExc_RuntimeError,
                                "dictionary changed size during iteration");
+               di->di_used = -1; /* Make this state sticky */
                return NULL;
        }
-       if (PyDict_Next((PyObject *)(di->di_dict), &di->di_pos, &key, &value)) {
+       if (PyDict_Next((PyObject *)(di->di_dict), &di->di_pos, &key, &value))
                return (*di->di_select)(key, value);
-       }
+
+       Py_DECREF(di->di_dict);
+       di->di_dict = NULL;
        return NULL;
 }
 
@@ -2019,7 +2002,7 @@ PyTypeObject PyDictIter_Type = {
        0,                                      /* tp_weaklistoffset */
        (getiterfunc)dictiter_getiter,          /* tp_iter */
        (iternextfunc)dictiter_iternext,        /* tp_iternext */
-       dictiter_methods,                       /* tp_methods */
+       0,                                      /* tp_methods */
        0,                                      /* tp_members */
        0,                                      /* tp_getset */
        0,                                      /* tp_base */