Issue 10538: PyArg_ParseTuple("s*") does not always incref object (original) (raw)

The new "s*" code for PyArg_ParseTuple is used to fill a Py_buffer object from the arguments. This object must be relased using PyBuffer_Release() after use.

However, if the object in the tuple does not support the new buffer interface, the old buffer interface is queried and the Py_buffer object is manually filled in. For this case, the source object is not increfed and buffer.obj remains set to 0.

This causes different semantics in the function for objects that are passed in: If the Py_buffer interface is supported directly, then it is safe for the function to store this and release this at a later time. If it isn't supported, then no extra reference to the object is got and the function cannot safely keep the Py_buffer object around.

The Fix is as follows: Change line 1402 of getargs.c from: PyBuffer_FillInfo(view, NULL, buf, count, 1, 0); to PyBuffer_FillInfo(view, arg, buf, count, 1, 0);