ListEqual() routine: Non-functional check for missing plurals?

I’ve been looking at Inform 7’s ListEqual() routine in the ListWriter.i6t template. The first check that it carries out is:

[ ListEqual o1 o2;
	if ((o1.plural == 0) || (o2.plural == 0)) rfalse;

However, as far as I can tell, it is never the case that an object will have no assignment for its .plural property. If the idea is that the object has no plural name text, then there are cases where the empty text is assigned.

As far as I understand the logic, it would be that objects which have no plurals can never be part of an identical group, so this check is designed to be a quick rejection of such objects. If that’s correct, should this logic be altered to make a comparison to the empty text instead of zero?