Fire charges do not trigger tripwires

The bug

When a fire charge is launched (vertically or horizontally) using a dispenser, it does not trigger tripwire. When a dispenser is filled by arrows, for example, it does trigger.
However, the tripwire is supposed to trigger on all entities.

How to reproduce

1. Build a setup shown on screenshot
2. Put fire charges into dispenser
3. Pull the lever
   → Observe that the fire charge doesn't activate the tripwire