import struct

import collections

import itertools

import gc

class FunctionCalls(unittest.TestCase):

result = _testcapi.pyobject_fastcallkeywords(func, args, kwnames)

self.check_result(result, expected)

def test_fastcall_clearing_dict(self):

# Test bpo-36907: the point of the test is just checking that this

# does not crash.

class IntWithDict:

__slots__ = ["kwargs"]

def __init__(self, **kwargs):

self.kwargs = kwargs

def __index__(self):

self.kwargs.clear()

gc.collect()

return 0

x = IntWithDict(dont_inherit=IntWithDict())

# We test the argument handling of "compile" here, the compilation

# itself is not relevant. When we pass flags=x below, x.__index__() is

# called, which changes the keywords dict.

compile("pass", "", "exec", x, **x.kwargs)

if __name__ == "__main__":

unittest.main()

Fix a crash when calling a C function with a keyword dict (``f(**kwargs)``)

and changing the dict ``kwargs`` while that function is running.

}

result = (*fastmeth) (self, stack, nargs, kwnames);

if (stack != args) {

if (kwnames != NULL) {

Py_ssize_t i, n = nargs + PyTuple_GET_SIZE(kwnames);

for (i = 0; i < n; i++) {

Py_DECREF(stack[i]);

}

PyMem_Free((PyObject **)stack);

Py_DECREF(kwnames);

}

Py_XDECREF(kwnames);

break;

}

return -1;

}

/* Copy position arguments (borrowed references) */

memcpy(stack, args, nargs * sizeof(stack[0]));

/* Copy positional arguments */

for (i = 0; i < nargs; i++) {

Py_INCREF(args[i]);

stack[i] = args[i];

}

kwstack = stack + nargs;

pos = i = 0;

called in the performance critical hot code. */

while (PyDict_Next(kwargs, &pos, &key, &value)) {

Py_INCREF(key);

Py_INCREF(value);

PyTuple_SET_ITEM(kwnames, i, key);

/* The stack contains borrowed references */

kwstack[i] = value;

i++;

}