Verification builds:
1.1.0.9 Retail

Summary:
Pistons don't push arrows upwards when powered.

Steps to Reproduce:

1. Place a piston (either type)
2. Fire arrows onto the piston head
3. Power the piston

Observed Results:
The arrows stay stuck in the same position, and the piston arm / head moves through them

Expected Results:
The arrows should move with the piston head.

Screenshots/Videos attached: Yes

Notes:
In the Java version they move with the piston extension as it moves out, and fall back when it moves in: