On Wed, 27 Dec 2017 17:28:41 +0100 Antoine Pitrou <solip...@pitrou.net> wrote: > On Wed, 27 Dec 2017 14:19:16 +0000 > Jonathan Underwood <jonathan.underw...@gmail.com> wrote: > > Hello, > > > > I am not sure if this is expected behaviour, or a bug. > > > > In a C extension module, if I create and return an empty bytes object like > > this: > > > > val = PyBytes_FromStringAndSize (NULL, 20); > > Py_SIZE(val) = 0; > > I wouldn't call it "expected", but bytes objects are supposed to be > NULL-terminated internally, so your code technically creates an invalid > bytes object. The NULL-terminated constraint may be relied on by some > code, for example when the string gets passed to a third-party C > function.
Note this is really happening because you're allocating a 20-long bytes object and then shortening it to 0 bytes. PyBytes_FromStringAndSize() already stored a NULL byte in the 21st place. Regards Antoine. _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
