New submission from Ammar Askar <am...@ammaraskar.com>:
When dealing with a heap allocated type (https://docs.python.org/3/c-api/typeobj.html#Py_TPFLAGS_HEAPTYPE / PyType_FromSpec), if the type has a custom tp_dealloc function then it MUST decrement the references to the type object itself due to this code block: https://github.com/python/cpython/blob/4a12a178f4a6b9a59d97fecc727f2b6b28dfc85f/Objects/typeobject.c#L1189-L1192 The only mention of this is within the whatsnew entry for 3.8: https://github.com/python/cpython/commit/364f0b0f19cc3f0d5e63f571ec9163cf41c62958#diff-77c703d9a958f6a4b0dc2f692b3fd5b3 This error was made in https://github.com/python/cpython/pull/16127#pullrequestreview-288312751 and https://github.com/python/cpython/pull/16071#pullrequestreview-287819525 It seems like a common pitfall, let's add a note about this in the doc. ---------- assignee: docs@python components: Documentation messages: 352672 nosy: ammar2, docs@python priority: normal severity: normal status: open title: Clarify that tp_dealloc must decref for heap allocated type type: enhancement versions: Python 3.9 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue38206> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
