Ranged attacks blocked by decorations

This bug occurs when a projectile would normally not collide with object such a trees and firesticks when the projectile hits a thing (Any) where the thing is higher than the projectile. This effect can easily be seen in Alien Vendetta's Map 31 in the Green Section where the fireballs from the Hell Knights are blocked by the candles. This effect is also seen in some DWANGO 5 Levels. In some Source Ports this is normal, ZDoom uses this as an effect, projectiles are always blocked by solid objects(trees, columns, etc). in Vanilla Doom, projectiles are designed to pass through most objects,(the Barrel is an execption) regardless if they are solid or not.