merge: respect parents order when using `graft` on a merge
The previous code did not record the index of the replaced parent. It was always
using the "graft" destination as `p1`. This could switch parents order in some
situation (eg: some of the evolve evolving merge case). Recording and using the
information fixes the issue in evolve.
We are not aware of core commands calling graft in that fashion, so we could not
build a simple test case for it using core commands.
#include <Python.h>
#include <assert.h>
#include <stdlib.h>
#include <unistd.h>
#include <string>
#include "pyutil.h"
extern "C" {
static PyCodeObject *code;
extern "C" int LLVMFuzzerInitialize(int *argc, char ***argv)
{
contrib::initpy(*argv[0]);
code = (PyCodeObject *)Py_CompileString(R"py(
from parsers import fm1readmarkers
def maybeint(s, default):
try:
return int(s)
except ValueError:
return default
try:
parts = data.split('\0', 2)
if len(parts) == 3:
offset, stop, data = parts
elif len(parts) == 2:
stop, data = parts
offset = 0
else:
offset = stop = 0
offset, stop = maybeint(offset, 0), maybeint(stop, len(data))
fm1readmarkers(data, offset, stop)
except Exception as e:
pass
# uncomment this print if you're editing this Python code
# to debug failures.
# print e
)py",
"fuzzer", Py_file_input);
return 0;
}
int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size)
{
PyObject *text =
PyBytes_FromStringAndSize((const char *)Data, (Py_ssize_t)Size);
PyObject *locals = PyDict_New();
PyDict_SetItemString(locals, "data", text);
PyObject *res = PyEval_EvalCode(code, contrib::pyglobals(), locals);
if (!res) {
PyErr_Print();
}
Py_XDECREF(res);
Py_DECREF(locals);
Py_DECREF(text);
return 0; // Non-zero return values are reserved for future use.
}
}