Issue #28871: Fixed a crash when deallocate deep ElementTree.
Fixed running MiscTests in test_xml_etree_c.
diff --git a/Lib/test/test_xml_etree_c.py b/Lib/test/test_xml_etree_c.py
index 98410c5..8d9bd17 100644
--- a/Lib/test/test_xml_etree_c.py
+++ b/Lib/test/test_xml_etree_c.py
@@ -17,6 +17,7 @@
"""
+@unittest.skipUnless(cET, 'requires _elementtree')
class MiscTests(unittest.TestCase):
# Issue #8651.
@precisionbigmemtest(size=_2G + 100, memuse=1)
@@ -62,12 +63,22 @@
del element.attrib
self.assertEqual(element.attrib, {'A': 'B', 'C': 'D'})
+ def test_trashcan(self):
+ # If this test fails, it will most likely die via segfault.
+ e = root = cET.Element('root')
+ for i in range(200000):
+ e = cET.SubElement(e, 'x')
+ del e
+ del root
+ test_support.gc_collect()
+
def test_main():
from test import test_xml_etree, test_xml_etree_c
# Run the tests specific to the C implementation
test_support.run_doctest(test_xml_etree_c, verbosity=True)
+ test_support.run_unittest(MiscTests)
# Assign the C implementation before running the doctests
# Patch the __name__, to prevent confusion with the pure Python test
diff --git a/Misc/NEWS b/Misc/NEWS
index b6474eb..9f749f4 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -18,6 +18,8 @@
- Issue #29019: Fix dict.fromkeys(x) overallocates when x is sparce dict.
Original patch by Rasmus Villemoes.
+- Issue #28871: Fixed a crash when deallocate deep ElementTree.
+
- Issue #19542: Fix bugs in WeakValueDictionary.setdefault() and
WeakValueDictionary.pop() when a GC collection happens in another
thread.
diff --git a/Modules/_elementtree.c b/Modules/_elementtree.c
index b01167b..8e5b587 100644
--- a/Modules/_elementtree.c
+++ b/Modules/_elementtree.c
@@ -121,6 +121,18 @@
#define JOIN_SET(p, flag) ((void*) ((Py_uintptr_t) (JOIN_OBJ(p)) | (flag)))
#define JOIN_OBJ(p) ((PyObject*) ((Py_uintptr_t) (p) & ~1))
+/* Py_CLEAR for a PyObject* that uses a join flag. Pass the pointer by
+ * reference since this function sets it to NULL.
+*/
+static void _clear_joined_ptr(PyObject **p)
+{
+ if (*p) {
+ PyObject *tmp = JOIN_OBJ(*p);
+ *p = NULL;
+ Py_DECREF(tmp);
+ }
+}
+
/* glue functions (see the init function for details) */
static PyObject* elementtree_parseerror_obj;
static PyObject* elementtree_copyelement_obj;
@@ -538,17 +550,20 @@
static void
element_dealloc(ElementObject* self)
{
- if (self->extra)
- element_dealloc_extra(self);
+ Py_TRASHCAN_SAFE_BEGIN(self)
/* discard attributes */
Py_DECREF(self->tag);
- Py_DECREF(JOIN_OBJ(self->text));
- Py_DECREF(JOIN_OBJ(self->tail));
+ _clear_joined_ptr(&self->text);
+ _clear_joined_ptr(&self->tail);
+
+ if (self->extra)
+ element_dealloc_extra(self);
RELEASE(sizeof(ElementObject), "destroy element");
PyObject_Del(self);
+ Py_TRASHCAN_SAFE_END(self)
}
/* -------------------------------------------------------------------- */