fixed a potential refcount bug (thanks Raymond!).

diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index 0eb835793a0ec6f0a27e326abd71465c22c6c5f5..6c1a3d290ca3dcae8d0054aa18184fa9340aa9a9 100644 (file)
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -1824,10 +1824,10 @@ builtin_sum(PyObject *self, PyObject *args)
                if (PyObject_TypeCheck(result, &PyBaseString_Type)) {
                        PyErr_SetString(PyExc_TypeError,
                                "can't sum strings [use ''.join(seq) instead]");
-                       Py_DECREF(result);
                        Py_DECREF(iter);
                        return NULL;
                }
+               Py_INCREF(result);
        }
 
        for(;;) {