bpo-37645: clear exception in check_args_iterable()

jdemeyer · jdemeyer · commit 733158d78dbb · 2019-08-18T18:18:06.000+02:00
diff --git a/Python/ceval.c b/Python/ceval.c
@@ -5341,6 +5341,9 @@ static int
 check_args_iterable(PyThreadState *tstate, PyObject *func, PyObject *args)
 {
     if (args->ob_type->tp_iter == NULL && !PySequence_Check(args)) {
+        /* check_args_iterable() may be called with a live exception,
+         * clear it. */
+        PyErr_Clear();
         PyObject *funcstr = PyObject_FunctionStr(func);
         if (funcstr != NULL) {
             _PyErr_Format(tstate, PyExc_TypeError,
