New submission from Richard Hansen: According to https://docs.python.org/2/c-api/buffer.html#the-new-style-py-buffer-struct if the suboffsets member of Py_buffer is non-NULL and all members of the array are negative, the buffer may be contiguous.
PyBuffer_IsContiguous() does not behave this way. It assumes that if the suboffsets member is non-NULL then at least one member of the array is non-negative, and thus assumes that the buffer is non-contiguous. This is not always correct. One consequence of this bug is PyBuffer_ToContiguous() (and thus memoryview.tobytes()) falls back to slow (and currently buggy, see issue #23349) memory copying code. Attached is a patch that fixes this bug. The patch is against 2.7 but can be trivially modified to apply to 3.x. ---------- components: Interpreter Core files: PyBuffer_IsContiguous.patch keywords: patch messages: 235014 nosy: rhansen priority: normal severity: normal status: open title: PyBuffer_IsContiguous() sometimes returns wrong result if suboffsets != NULL versions: Python 2.7, Python 3.2, Python 3.3, Python 3.4, Python 3.5, Python 3.6 Added file: http://bugs.python.org/file37914/PyBuffer_IsContiguous.patch _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue23352> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
