tiny quarrels are not affixable, except with heir
Tiny quarrels (black hurthling or dark elven) are normally not affixable but dark elven archers with heir talent will start with 40 winged dark elven quarrels of hunting.
I'm not sure which one is the bug here though, is it tiny quarrels not being affixable or heir being able to give them with affixes.
How to reproduce:
Either wish for tiny quarrels/dark elven quarrels/black hurthling quarrels for a few hundred times (archmage) and note that none of them have affixes, or trust the code divers who checked the affixability.