Minecart on powered activator rail gets broken by 0 damage hits

Steps to reproduce

1. Place an activator rail.
2. Power the activator rail.
3. Place a minecart on the activator rail.
4. Throw a snowball or egg at the minecart, or try to hook it with a fishing rod.

Expected result

The minecart does not break, since snowballs, eggs, and fishing rods do 0 damage.

Observed result

The minecart breaks.