Document kwnames in _PyObject_FastCallKeywords() and _PyStack_AsDict()
Issue #27213.
diff --git a/Objects/abstract.c b/Objects/abstract.c
index a929be9..17da5c9 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -2457,6 +2457,9 @@
assert(nargs >= 0);
assert(kwnames == NULL || PyTuple_CheckExact(kwnames));
assert((nargs == 0 && nkwargs == 0) || stack != NULL);
+ /* kwnames must only contains str strings, no subclass, and all keys must
+ be unique: these are implemented in Python/ceval.c and
+ _PyArg_ParseStack(). */
if (PyFunction_Check(func)) {
return _PyFunction_FastCallKeywords(func, stack, nargs, kwnames);