Christian Tismer's "trashcan" patch:

Added wrapping macros to dictobject.c, listobject.c, tupleobject.c,
frameobject.c, traceback.c that safely prevends core dumps
on stack overflow. Macros and functions in object.c, object.h.
The method is an "elevator destructor" that turns cascading
deletes into tail recursive behavior when some limit is hit.

1 files changed, 45 insertions, 0 deletions

diff --git a/Objects/object.c b/Objects/object.c
index 7a41aa2e2f..d2aa5428d4 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -906,3 +906,48 @@ Py_ReprLeave(obj)
 		}
 	}
 }
+
+/*
+  trashcan
+  CT 2k0130
+  non-recursively destroy nested objects
+
+  CT 2k0223
+  everything is now done in a macro.
+
+  CT 2k0305
+  modified to use functions, after Tim Peter's suggestion.
+
+  CT 2k0309
+  modified to restore a possible error.
+*/
+
+int _PyTrash_delete_nesting = 0;
+PyObject * _PyTrash_delete_later = NULL;
+
+void
+_PyTrash_deposit_object(op)
+	PyObject *op;
+{
+	PyObject *error_type, *error_value, *error_traceback;
+	PyErr_Fetch(&error_type, &error_value, &error_traceback);
+
+	if (!_PyTrash_delete_later)
+		_PyTrash_delete_later = PyList_New(0);
+	if (_PyTrash_delete_later)
+		PyList_Append(_PyTrash_delete_later, (PyObject *)op);
+
+	PyErr_Restore(error_type, error_value, error_traceback);
+}
+
+void
+_PyTrash_destroy_list()
+{
+	while (_PyTrash_delete_later) {
+		PyObject *shredder = _PyTrash_delete_later;
+		_PyTrash_delete_later = NULL;
+		++_PyTrash_delete_nesting;
+		Py_DECREF(shredder);
+		--_PyTrash_delete_nesting;
+	}
+}