So you suggest to check it in templating.py:make_sort_function rather
that in rdbms_common.py:getnode?
Fixing it there makes sense, but adding a check in getnode too might be
safer (assuming that all the nodeids are numeric (also are they always
supposed to be passed as string? I managed to pass them as ints while
working at the roundup weekly summary script and it worked fine;
checking with a regex in getnode without checking the type will break it)).

I can provide a patch to add the check (in make_sort_function or in
both) and a separate patch to refactor lookupIds and some of its calls a
little without changing its behavior (i.e. put an "if do_lookup:" before
"cl = db.getclass(prop.classname)" and replace calls that use
do_lookup=False and fail_ok=True to just use list() (I'm not sure a copy
of the list is really needed, but that's what happen now)).