New submission from Thomas Wouters <tho...@python.org>:
The PyUnicode_FSConverter function has confusing reference semantics, and confusing documentation. https://docs.python.org/3/c-api/unicode.html#c.PyUnicode_FSConverter says the output argument "must be a PyBytesObject* which must be released when it is no longer used." That seems to suggest one must pass a PyBytesObject to it, and indeed one of the error paths assumes an object was passed (https://github.com/python/cpython/blob/main/Objects/unicodeobject.c#L4116-- 'addr' is called 'result' in the docs). Not passing a valid object would result in trying to DECREF NULL, or garbage. However, the function doesn't actually use the object, and later in the function overwrites the value *without* DECREFing it, so passing a valid object would in fact cause a leak. I understand the function signature is the way it is so it can be used with PyArg_ParseTuple's O& format, but there are reasons to call it directly (e.g. with METH_O functions), and it would be nice if the semantics were more clear. ---------- components: C API messages: 408604 nosy: twouters priority: normal severity: normal status: open title: PyUnicode_FSConverter() has confusing reference semantics versions: Python 3.10, Python 3.11, Python 3.8, Python 3.9 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue46083> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
