Handle PySequence_List() and PyObject_Repr() errors in BaseException_repr()

Author: dr-carlos

Objects/exceptions.c

@@ -1100,6 +1100,10 @@ BaseExceptionGroup_repr(PyObject *op)
          * original exception sequence if possible, for backwards compatibility. */
         if (PyList_Check(PyTuple_GET_ITEM(self->args, 1))) {
             PyObject *exceptions_list = PySequence_List(self->excs);
+            if (!exceptions_list) {
+                goto error;
+            }
+
             exceptions_str = PyObject_Repr(exceptions_list);
             Py_DECREF(exceptions_list);
         }
@@ -1108,13 +1112,19 @@ BaseExceptionGroup_repr(PyObject *op)
         }
     }
 
+    if (!exceptions_str) {
+        goto error;
+    }
+
     const char *name = _PyType_Name(Py_TYPE(self));
     PyObject *repr = PyUnicode_FromFormat(
         "%s(%R, %U)", name,
         self->msg, exceptions_str);
 
     Py_DECREF(exceptions_str);
     return repr;
+error:
+    return NULL;
 }
 
 /*[clinic input]