Paper/patches/server/0835-Only-erase-allay-memory-on-non-item-targets.patch
Bjarne Koll d0dcd7d251
Fix incorrect invulnerability damage reduction (#11599)
Fixes incorrect spigot handling of the invulnerability damage
reduction applied when an already invulnerable entity is damaged with a
larger damage amount than the initial damage.
Vanilla still damages entities even if invulnerable if the damage to be
applied is larger than the previous damage taken. In that case, vanilla
applies the difference between the previous damage taken and the
proposed damage.

Spigot's damage modifier API takes over the computation of damage
reducing effects, however spigot invokes this handling with the initial
damage before computing the difference to the previous damage amount.
This leads to the reduction values to generally be larger than expected,
as they are computed on the not-yet-reduced value.
Spigot applies these reductions after calling the EntityDamageEvent and
*then* subtracts the previous damage point, leading to the final damage
amount being smaller than expected.

This patch cannot simply call the EntityDamageEvent with the reduced
damage, as that would lead to EntityDamageEvent#getDamage() returning
the already reduced damage, which breaks its method contract.
Instead, this patch makes use of the DamageModifier API, implementing
the last-damage-reduction as a DamageModifier.
2024-11-19 11:54:58 +01:00

30 lines
1.7 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Bjarne Koll <git@lynxplay.dev>
Date: Fri, 4 Aug 2023 15:53:36 +0200
Subject: [PATCH] Only erase allay memory on non-item targets
Spigot incorrectly instanceOf checks the EntityTargetEvent#getTarget
against the internal ItemEntity type and removes the nearest wanted item
memory if said instanceOf check fails, (which is always the case)
causing allays to behave differently as they constantly loose their
target item.
This commit fixes the faulty behaviour by instance performing a check
against the CraftItem type.
diff --git a/src/main/java/net/minecraft/world/entity/ai/behavior/GoToWantedItem.java b/src/main/java/net/minecraft/world/entity/ai/behavior/GoToWantedItem.java
index 07db92870f9efd515751453569f0dd7b6fada8fc..7d814e5b4b634674995d55ab97155f949f14ef3b 100644
--- a/src/main/java/net/minecraft/world/entity/ai/behavior/GoToWantedItem.java
+++ b/src/main/java/net/minecraft/world/entity/ai/behavior/GoToWantedItem.java
@@ -35,8 +35,9 @@ public class GoToWantedItem {
if (event.isCancelled()) {
return false;
}
- if (!(event.getTarget() instanceof ItemEntity)) {
+ if (!(event.getTarget() instanceof org.bukkit.craftbukkit.entity.CraftItem)) { // Paper - only erase allay memory on non-item targets
memoryaccessor2.erase();
+ return false; // Paper - only erase allay memory on non-item targets
}
entityitem = (ItemEntity) ((org.bukkit.craftbukkit.entity.CraftEntity) event.getTarget()).getHandle();