Paper/patches/server/1000-Only-call-EntityDamageEvents-before-actuallyHurt.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

74 lines
3.8 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Bjarne Koll <git@lynxplay.dev>
Date: Mon, 8 Jul 2024 22:01:08 +0200
Subject: [PATCH] Only call EntityDamageEvents before actuallyHurt
The recent upstream update moved around the event logic for
EntiyDamageEvent and its derivatives.
However, the event was called on every call to #hurt as it was moved out
of actuallyHurt.
This patch moves the invocation directly before the #actuallyHurt calls,
respective invulnerable timings.
diff --git a/src/main/java/net/minecraft/world/entity/LivingEntity.java b/src/main/java/net/minecraft/world/entity/LivingEntity.java
index 5616391f02f8599f5786a6d8e740a0ed9290627f..cfef1bff0080ffc662e3a4428116f7d4dc71eab2 100644
--- a/src/main/java/net/minecraft/world/entity/LivingEntity.java
+++ b/src/main/java/net/minecraft/world/entity/LivingEntity.java
@@ -1489,12 +1489,7 @@ public abstract class LivingEntity extends Entity implements Attackable {
}
// CraftBukkit start
- EntityDamageEvent event = this.handleEntityDamage(source, amount);
- amount = 0;
- amount += (float) event.getDamage(DamageModifier.BASE);
- amount += (float) event.getDamage(DamageModifier.BLOCKING);
- amount += (float) event.getDamage(DamageModifier.FREEZING);
- amount += (float) event.getDamage(DamageModifier.HARD_HAT);
+ EntityDamageEvent event; // Paper - move this into the actual invuln check....
// CraftBukkit end
this.walkAnimation.setSpeed(1.5F);
@@ -1509,6 +1504,11 @@ public abstract class LivingEntity extends Entity implements Attackable {
return false;
}
+ // Paper start - only call damage event when actuallyHurt will be called - move call logic down
+ event = this.handleEntityDamage(source, amount);
+ amount = computeAmountFromEntityDamageEvent(event);
+ // Paper end - only call damage event when actuallyHurt will be called - move call logic down
+
// CraftBukkit start
if (!this.actuallyHurt(world, source, (float) event.getFinalDamage() - this.lastHurt, event)) {
return false;
@@ -1518,6 +1518,10 @@ public abstract class LivingEntity extends Entity implements Attackable {
this.lastHurt = amount;
flag1 = false;
} else {
+ // Paper start - only call damage event when actuallyHurt will be called - move call logic down
+ event = this.handleEntityDamage(source, amount);
+ amount = computeAmountFromEntityDamageEvent(event);
+ // Paper end - only call damage event when actuallyHurt will be called - move call logic down
// CraftBukkit start
if (!this.actuallyHurt(world, source, (float) event.getFinalDamage(), event)) {
return false;
@@ -1653,6 +1657,18 @@ public abstract class LivingEntity extends Entity implements Attackable {
}
}
+ // Paper start - only call damage event when actuallyHurt will be called - move out amount computation logic
+ private float computeAmountFromEntityDamageEvent(final EntityDamageEvent event) {
+ // Taken from hurt()'s craftbukkit diff.
+ float amount = 0;
+ amount += (float) event.getDamage(DamageModifier.BASE);
+ amount += (float) event.getDamage(DamageModifier.BLOCKING);
+ amount += (float) event.getDamage(DamageModifier.FREEZING);
+ amount += (float) event.getDamage(DamageModifier.HARD_HAT);
+ return amount;
+ }
+ // Paper end - only call damage event when actuallyHurt will be called - move out amount computation logic
+
protected void blockUsingShield(LivingEntity attacker) {
attacker.blockedByShield(this);
}