From: Guido van Rossum <guido@python.org>
Date: Fri, 18 Jan 2008 20:56:30 +0000 (+0000)
Subject: Fix an edge case whereby the __del__() method of a classic class could
X-Git-Tag: v2.6a1~554
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=9ff1a449732277c340fdf426e89d8460d2d8dd87;p=thirdparty%2FPython%2Fcpython.git

Fix an edge case whereby the __del__() method of a classic class could
create a new weakref to the object.
---

diff --git a/Objects/classobject.c b/Objects/classobject.c
index 89cca5969df5..b4b17f90777a 100644
--- a/Objects/classobject.c
+++ b/Objects/classobject.c
@@ -646,6 +646,16 @@ instance_dealloc(register PyInstanceObject *inst)
 	 */
 	assert(inst->ob_refcnt > 0);
 	if (--inst->ob_refcnt == 0) {
+
+		/* New weakrefs could be created during the finalizer call.
+		    If this occurs, clear them out without calling their
+		    finalizers since they might rely on part of the object
+		    being finalized that has already been destroyed. */
+		while (inst->in_weakreflist != NULL) {
+			_PyWeakref_ClearRef((PyWeakReference *)
+                                            (inst->in_weakreflist));
+		}
+
 		Py_DECREF(inst->in_class);
 		Py_XDECREF(inst->in_dict);
 		PyObject_GC_Del(inst);