The Bug
Passenger riding on a mob has a delay before it falls when the mob is killed. This can be easily seen with Baby Striders on top of adults.
Steps to Reproduce
Summon a baby strider riding an adult strider.
/summon minecraft:strider ~ ~ ~ {Passengers:[{id:"minecraft:strider",Age:-25000}]}Kill the adult strider and watch the baby strider closely as you do this.
Take note as to whether or not baby striders riding adults striders have a delay before they're dismounted after the adult is killed.
Observed Behavior
Passengers riding mobs have a delay before they're dismounted after the mob is killed.
Expected Behavior
Passengers riding mobs would be instantly dismounted after the mob is killed.
Code Analysis
Code analysis by @unknown can be found in this comment.
Linked issues
is duplicated by 1
Attachments
Comments 18
Hi there!
I can confirm for 20w27a.
Can confirm in 20w49a.
Can confirm in 21w03a.
Can confirm in 21w06a.
Can confirm in 1.16.5 and 21w08b.
Can confirm in 21w16a.
Can confirm in 1.17.
Can confirm in 1.17.1.
Can confirm in 21w42a. Here are some extra details regarding this problem.
The Bug:
Baby striders riding adults striders have a delay before they're dismounted after the adult is killed.
Steps to Reproduce:
Summon a baby strider riding an adult strider.
/summon minecraft:strider ~ ~ ~ {Passengers:[{id:"minecraft:strider",Age:-25000}]}Kill the adult strider and watch the baby strider closely as you do this.
Take note as to whether or not baby striders riding adults striders have a delay before they're dismounted after the adult is killed.
Observed Behavior:
Baby striders riding adults striders have a delay before they're dismounted after the adult is killed.
Expected Behavior:
Baby striders riding adults striders would not have a delay before they're dismounted after the adult is killed.
Can confirm in 1.18.1.
Can confirm in 1.18.2 and 22w15a.
I can confirm this behavior in 1.19 Pre-release 3. It's important to note that this issue can be seen with any entity riding anything and isn't just exclusive to striders and baby striders. Here's a code analysis of this issue along with a fix.
Code Analysis:
The following is based on a decompiled version of Minecraft 1.19.2 using MCP-Reborn.
net.minecraft.world.entity.LivingEntity.java
public abstract class Entity implements Nameable, EntityAccess, CommandSource {
...
public void baseTick() {
...
if (this.isPassenger() && this.getVehicle().isRemoved()) {
this.stopRiding();
}
...If we look at the above class, we can see that there are two checks that are carried out before allowing an entity to be dismounted from its vehicle. One of them is to check if the said entity is a passenger and the other is to check if their vehicle is removed. If both these requirements are met, the entity is dismounted from its vehicle. The game doesn't check if the entity's vehicle is alive (is currently in its death animation) before allowing its passengers to be dismounted, therefore resulting in this problem occurring.
Fix:
Simply altering the existing "if" statement within this piece of code to check if the entity's vehicle is alive (is currently in its death animation) before allowing its passengers to be dismounted will resolve this problem. Additionally, adding a null check here where appropriate will help to avoid the possibilities of NullPointerExceptions.
Current "if" statement:
if (this.isPassenger() && this.getVehicle().isRemoved()) {
this.stopRiding();
}Fixed "if" statement:
if (this.isPassenger() && this.getVehicle() != null) {
if (!this.getVehicle().isAlive() || this.getVehicle().isRemoved()) {
this.stopRiding();
}
}Can confirm in 1.19.
Can confirm in 1.19.2.
Following on from my code analysis, I've double-checked my proposed fix and I can confidently confirm that it's fully functioning and works as expected, so I've attached two screenshots to this report, one of which shows the current code and the other that shows the fixed code. I feel this information may be quite insightful hence my reasoning for providing it. 🙂
[media][media]A consequence of this seems to be that, during the death animation of the mount, the rider has entity collision but not yet block collision. So the temporarily dismounted-but-not-dismounted rider, no longer moored to the dead mount, can be "pushed" by other entities into/through solid blocks until the dismount sequence has been completed.
Can confirm in 1.19.4 and 23w12a.
Hi there!
I can confirm for 1.16.1.