Issue #22290: PyObject_Call() now fails with an assertion error when called

with an exception set. This new assertion helps to understand if the exception
was already set before calling the function or raised by the function.

diff --git a/Objects/abstract.c b/Objects/abstract.c
index 783a83c3ed091e3e015e6d596e0412fce980b3f3..ec599723ac659fef8718eb4166c90cc3f706cf27 100644 (file)
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -2074,6 +2074,11 @@ PyObject_Call(PyObject *func, PyObject *arg, PyObject *kw)
 {
     ternaryfunc call;
 
+    /* PyObject_Call() must not be called with an exception set,
+       because it may clear it (directly or indirectly) and so the
+       caller looses its exception */
+    assert(!PyErr_Occurred());
+
     if ((call = func->ob_type->tp_call) != NULL) {
         PyObject *result;
         if (Py_EnterRecursiveCall(" while calling a Python object"))