Ziyue Jiang added the comment:
Thanks for replying.
I did fix my code by adding Py_TPFLAGS_DEFAULT. It's okay. I just think the
behavior is a little strange when I don't set the default flag, thus adding
this issue.
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Python track
Ziyue Jiang added the comment:
I just take over a Python3.6 project from a friend, migrating it to the newest
Python version. Then this problem happened. After debugging, I think it's a
possible double Py_XDECREF if using C-API like this.
But I'm not familiar with Python C-API bef
Ziyue Jiang added the comment:
Sorry, not inherited from Time, Time is the class I use in a real project.
Time -> A
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Python tracker
<https://bugs.python.org/issu
Ziyue Jiang added the comment:
I have no detailed code. The way to I produce it is that using
PyType_FromSpec() to generate a type A without the flag
Py_TPFLAGS_DEFAULT(which sets the flag Py_TPFLAGS_HAVE_VERSION_TAG).
Then compile and run in Python.
from my_pkg import A
class Time1(Time
Ziyue Jiang added the comment:
Maybe a little complicared but you can still construct a case to trigger the
double free action, thus causing a SIGABRT.
Program received signal SIGABRT, Aborted.
0x77c3718b in raise () from /lib/x86_64-linux-gnu/libc.so.6
(gdb) bt
#0
New submission from Ziyue Jiang :
The type_mro_modified() function in Object/typeobject.c may produce double
Py_XDECREF on mro_meth and type_mro_meth when enter the code:
if (!_PyType_HasFeature(cls, Py_TPFLAGS_HAVE_VERSION_TAG) ||
!PyType_IsSubtype(type, cls)) {
goto clear;
}
I think
