Projectiles collide at different areas on glass panes, fences, cauldrons, composters, brewing stands, iron bars, and fence gates than those blocks' bounding boxes are actually located at for other entities. The bounding box is ignored and relies on the selection box for collision instead (except for stairs).
The bug
Referring to the statement above, this means if the player is inside the selection box of the blocks affected (like standing in the corner of iron bars or glass panes), they can throw projectiles through those blocks' bounding boxes, colliding with the opposite side of their selection box.
Steps to reproduce
Place fences in an "x" shape at head height
Stand in one of the corners, facing said corner
Throw a trident, shoot a bow, or throw an ender pearl
If done correctly, the projectile should collide with the opposite side of the fence's selection box, not the bounding box.
Video Example
Related issues
is duplicated by
Comments
migrated
Makzevu
The issue that I was referring to here is that projectiles don't collide with bounding boxes, which allows them to be thrown through some blocks if the thrower is clipping inside a block's hitbox. Since entities are normally stopped from moving into spaces by bounding boxes, having the current mechanics for projectiles will cause issues regardless of the Java Edition's presence.
migrated
Affects 1.17.40.20
Yes can confirm its also a parity not really a bug
edit label it vanilla-parity