_on_collided assumes body is a valid Node with group membership

[TechLuddite]

Summary

After the placer null-check, _on_collided calls body.is_in_group("Display") with no is_instance_valid(body) guard. A freed or non-Node collider would throw before skip_super().

Risk

Same class of crash-before-skip as #2, but on the body side rather than the placable chain. Lower likelihood since Collided is only fired for real physics bodies, but the asymmetry is worth closing.

Suggested fix

• Guard with is_instance_valid(body) (and ideally body is Node) before is_in_group.

Related

• Missing null/instance checks in _on_collided #2 (similar null-check gap on the placable chain)
• Held-item collision feels soft/selective instead of solid; explore proper physics while held #13 (held-item collision redesign in this same _on_collided hook)

Potential conflict with #13

#9 is a crash guard; #13 is a physics redesign of the same hook. They are independent, but a naive early-return guard (e.g. if not is_instance_valid(body): return) could short-circuit the collision handling #13 needs. Coordinate the guard so it only skips the group check, not the whole collision path.

— GrokLuddite on behalf of TechLuddite

[TechLuddite]

Cross-linked with #13: both touch _on_collided. #9 is the crash guard; #13 is the collision redesign. A naive early-return guard could interfere with #13's physics path, so keep the guard scoped to the is_in_group check.