Since properties are supported here, is possible that

instance_getattr2() raises an exception.  Fix all code that made this
assumption.

Backport candidate.

diff --git a/Objects/classobject.c b/Objects/classobject.c
index ff6f11e08940c481f447b17c414b6d8772502998..f7b442a80a3e134b67b6e0fc75a45f432b64d154 100644 (file)
--- a/Objects/classobject.c
+++ b/Objects/classobject.c
@@ -549,6 +549,10 @@ PyInstance_New(PyObject *klass, PyObject *arg, PyObject *kw)
                initstr = PyString_InternFromString("__init__");
        init = instance_getattr2(inst, initstr);
        if (init == NULL) {
+               if (PyErr_Occurred()) {
+                       Py_DECREF(inst);
+                       return NULL;
+               }
                if ((arg != NULL && (!PyTuple_Check(arg) ||
                                     PyTuple_Size(arg) != 0))
                    || (kw != NULL && (!PyDict_Check(kw) ||
@@ -694,7 +698,7 @@ instance_getattr1(register PyInstanceObject *inst, PyObject *name)
                }
        }
        v = instance_getattr2(inst, name);
-       if (v == NULL) {
+       if (v == NULL && !PyErr_Occurred()) {
                PyErr_Format(PyExc_AttributeError,
                             "%.50s instance has no attribute '%.400s'",
                             PyString_AS_STRING(inst->in_class->cl_name), sname);
@@ -1809,25 +1813,20 @@ half_richcompare(PyObject *v, PyObject *w, int op)
        /* If the instance doesn't define an __getattr__ method, use
           instance_getattr2 directly because it will not set an
           exception on failure. */
-       if (((PyInstanceObject *)v)->in_class->cl_getattr == NULL) {
+       if (((PyInstanceObject *)v)->in_class->cl_getattr == NULL)
                method = instance_getattr2((PyInstanceObject *)v,
                                           name_op[op]);
-               if (method == NULL) {
-                       assert(!PyErr_Occurred());
-                       res = Py_NotImplemented;
-                       Py_INCREF(res);
-                       return res;
-               }
-       } else {
+       else
                method = PyObject_GetAttr(v, name_op[op]);
-               if (method == NULL) {
+       if (method == NULL) {
+               if (PyErr_Occurred()) {
                        if (!PyErr_ExceptionMatches(PyExc_AttributeError))
                                return NULL;
                        PyErr_Clear();
-                       res = Py_NotImplemented;
-                       Py_INCREF(res);
-                       return res;
                }
+               res = Py_NotImplemented;
+               Py_INCREF(res);
+               return res;
        }
 
        args = Py_BuildValue("(O)", w);