[ARROW-12495] [C++][Python] NumPy buffer sets is_mutable_ to true but does not set mutable_data_ when the NumPy array is writable

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.0.0
• Component/s: C++, Python
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/28260
• Assignee: Antoine Pitrou
• Reporter: Wes McKinney
• Created: 21/Apr/21 13:58
• Updated: 11/Jan/23 08:26
• Resolved: 21/Apr/21 15:50

Description

Bug is evident

NumPyBuffer::NumPyBuffer(PyObject* ao) : Buffer(nullptr, 0) {
  PyAcquireGIL lock;
  arr_ = ao;
  Py_INCREF(ao);

  if (PyArray_Check(ao)) {
    PyArrayObject* ndarray = reinterpret_cast<PyArrayObject*>(ao);
    data_ = reinterpret_cast<const uint8_t*>(PyArray_DATA(ndarray));
    size_ = PyArray_SIZE(ndarray) * PyArray_DESCR(ndarray)->elsize;
    capacity_ = size_;

    if (PyArray_FLAGS(ndarray) & NPY_ARRAY_WRITEABLE) {
      is_mutable_ = true;
    }
  }
}

Issue Links

• relates to: ARROW-12530 [C++] Remove Buffer::mutable_data_ member and use const_cast on data_ only if is_mutable_ is true
• supercedes: ARROW-11172 [Python] NumPyBuffer does not set mutable_data_
• links to: GitHub Pull Request #10122