Re: [Libguestfs] [nbdkit PATCH] python: Make sure callbacks are actually callable

Rather than catching a Python error at runtime when trying to call an object that wasn't callable, just ignore that object up front when loading the plugin. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- Various examples on calling Python functions from C recommend doing this filtering check. plugins/python/python.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/plugins/python/python.c b/plugins/python/python.c index 0206b80..35e8df2 100644 --- a/plugins/python/python.c +++ b/plugins/python/python.c @@ -94,6 +94,11 @@ callback_defined (const char *name, PyObject **obj_rtn) obj = PyObject_GetAttrString (module, name); if (!obj) return 0; + if (!PyCallable_Check (obj)) { + nbdkit_debug ("object %s isn't callable", name); + Py_DECREF (obj); + return 0; + } if (obj_rtn != NULL) *obj_rtn = obj;