Campfire smoke graphical issue

When a block is placed above a campfire to prevent the smoke from rising into the air, the smoke bunches up, as it should. However, as the smoke starts to fade away, it usually just disappears with the empty texture remaining while it "fades"

This is a bit hard to explain over text, so I have attached a sceenshot as well.

(P.S. Keep up the good work Mojang!)