Segmentation fault when loading object with slots

[Richard Collins]

I am getting a segmentation fault on line 472 of src/persistent/cPersistence.c of version 3.8.1b4 of ZODB. I'm using version 2.5 of Python.

This happened when I added a __slots__ declaration to a class. The segmentation fault occurs when an instance of this class is loaded from the object database. The problem goes away when i remove the slots declaration.

Inspection of cPersistence.c suggest the if statement on line 464 needs an else for when dict is null.

    450 static PyObject *
    451 pickle___setstate__(PyObject *self, PyObject *state)
    452 {
    453 PyObject *slots=NULL;
    454
    455 if (PyTuple_Check(state)) {
    456 if (!PyArg_ParseTuple(state, "OO:__setstate__", &state, &slots))
    457 return NULL;
    458 }
    459
    460 if (state != Py_None) {
    461 PyObject **dict;
    462
    463 dict = _PyObject_GetDictPtr(self);
    464 if (dict) {
    465 if (!*dict) {
    466 *dict = PyDict_New();
    467 if (!*dict)
    468 return NULL;
    469 }
    470 }
    471
    472 if (*dict) {
    473 PyDict_Clear(*dict);
    474 if (PyDict_Update(*dict, state) < 0)
    475 return NULL;
    476 }

[Jim Fulton (jim-zope)]

The fix for this is comitted. Now, you'll get a type error in a situation like this.

The slot support in persistent is a bit brittle. If we're going to support slots, we need to do a lot more work.

[Tres Seaver (tseaver)]

Fix released with ZODB 3.9.0:

 http://pypi.python.org/pypi/ZODB3/3.9.0#id14