This can happen as a result of using `convTHING' in an attribute `set'
function, and the Python program trying to `del' the attribute.
Unfortunately, these conversion functions are already being used in this
context, and it leads to segfaults, e.g., from
del C.Key(C.KeyFile('', C.KOPEN_WRITE | C.KOPEN_NOFILE), 0, 'k').exptime
Easy fix.
int rc = 0;
uint32 lo, hi;
+ if (!o) VALERR("can't delete");
if (init_i32()) goto end;
if ((i = PyNumber_Int(o)) == 0) goto end;
lo = PyInt_AsUnsignedLongMask(i);