Re: [libvirt] [PATCH 2/2] python: add error checking for calls to PyList_New

On 11/12/2013 06:53 AM, Martin Kletzander wrote: >> @@ -2621,7 +2630,8 @@ libvirt_virDomainSnapshotListChildrenNames(PyObject *self ATTRIBUTE_UNUSED, >> return VIR_PY_NONE; >> } >> } >> - py_retval = PyList_New(c_retval); >> + if (!(py_retval = PyList_New(c_retval))) >> + goto cleanup; >> > > This function should follow others and return VIR_PY_NONE, but cleanup > path returns py_retval. Actually, you WANT to return NULL, not VIR_PY_NONE, when PyList_New() fails. Returning NULL is the hint to python to report the OOM exception; returning VIR_PY_NONE is not NULL and therefore silently papers over the exception. Worse, the rest of the libvirt python code treats a return of the python object 'None' as meaning 'the API call failed, dig out the last virError and turn it into a python exception'; but in this case, there is no virError (our failure was not related to a failed C API call). This code rewrite is correct as-is.