`_xxtestfuzz` crashes if `_elementtree` is not available about cpython

[mgorny]

Closing then. Sorry for the trouble.

[sobolevn]

So, here are my 2c:

• looks like a crash is desired here, because of abort(), see

  cpython/Modules/_xxtestfuzz/fuzzer.c

  Lines 701 to 703 in 8223544

  	if (!ELEMENTTREE_PARSEWHOLE_INITIALIZED && !init_elementtree_parsewhole()) {
  	PyErr_Print();
  	abort();

• looks like xmlparser_type and bytesio_type are never actually decrefed (and in error paths as well)

  cpython/Modules/_xxtestfuzz/fuzzer.c

  Lines 443 to 469 in 8223544

  	PyObject* xmlparser_type = NULL;
  	PyObject* bytesio_type = NULL;
  	/* Called by LLVMFuzzerTestOneInput for initialization */
  	static int init_elementtree_parsewhole(void) {
  	PyObject* elementtree_module = PyImport_ImportModule("_elementtree");
  	if (elementtree_module == NULL) {
  	return 0;
  	}
  	xmlparser_type = PyObject_GetAttrString(elementtree_module, "XMLParser");
  	Py_DECREF(elementtree_module);
  	if (xmlparser_type == NULL) {
  	return 0;
  	}
  	PyObject* io_module = PyImport_ImportModule("io");
  	if (io_module == NULL) {
  	return 0;
  	}
  	bytesio_type = PyObject_GetAttrString(io_module, "BytesIO");
  	Py_DECREF(io_module);
  	if (bytesio_type == NULL) {
  	return 0;
  	}
  	return 1;
  	}

  But, since any errors will crash the app after this function - it is not a big deal.
• since _elementtree is always expected, I don't think that we should guard this function in any special way

[Eclips4]

I guess this is intentional.
One of the fuzzing targets is elementtree (see Modules/__xxtestfuzz.c::LLVMFuzzerTestOneInput. We could probably improve error handling here, but would it improve anything? Fuzzing is not a feature of Python and I guess anyone who tries to run a fuzzer would understand this error.

[mgorny]

Ok. Shouldn't then test_xxtestfuzz be skipped if _elementtree is not available? I can try making a pull request.

[mgorny]

Hmm, on the other hand, since the whole extension is broken, I suppose leaving the tests on lets the person building it know that they should probably be disabling _xxtestfuzz as well.