[Libguestfs] [PATCH 2/2] python: change return type for RBufferOut with Python 3 (RHBZ#1661871)

So far RBufferOut return values are 'str' on all the versions of Python. Python 3 distinguishes between 'str' (unicode strings), and 'bytes', with 'str' no more able to hold arbitrary data. For this reason, switch the return value of RBufferOut functions to bytes on Python 3: while this is a potentially incompatibile change, this is the only way to handle safely sequences of arbitrary bytes, like all the ones returned by RBufferOut functions. --- generator/python.ml | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/generator/python.ml b/generator/python.ml index a70faec8c..c10adcb69 100644 --- a/generator/python.ml +++ b/generator/python.ml @@ -511,7 +511,11 @@ and generate_python_actions actions () = pr " guestfs_int_free_string_list (r);\n"; pr " if (py_r == NULL) goto out;\n"; | RBufferOut _ -> + pr "#if PY_MAJOR_VERSION >= 3\n"; + pr " py_r = PyBytes_FromStringAndSize (r, size);\n"; + pr "#else\n"; pr " py_r = guestfs_int_py_fromstringsize (r, size);\n"; + pr "#endif\n"; pr " free (r);\n"; pr " if (py_r == NULL) goto out;\n"; ); -- 2.20.1