From 666560fcdd24201569d545452e87e9e70cea49cb Mon Sep 17 00:00:00 2001
From: Nassim Jahnke <nassim@njahnke.dev>
Date: Tue, 29 Oct 2024 22:35:10 +0100
Subject: [PATCH] Fix portal exit resulting in bad teleport transition

---
 patches/server/Add-back-EntityPortalExitEvent.patch | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/patches/server/Add-back-EntityPortalExitEvent.patch b/patches/server/Add-back-EntityPortalExitEvent.patch
index 4849d28e46..c604011b64 100644
--- a/patches/server/Add-back-EntityPortalExitEvent.patch
+++ b/patches/server/Add-back-EntityPortalExitEvent.patch
@@ -13,18 +13,20 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
                  // CraftBukkit start
                  PositionMoveRotation absolutePosition = PositionMoveRotation.calculateAbsolute(PositionMoveRotation.of(this), PositionMoveRotation.of(teleportTarget), teleportTarget.relatives());
 -                Location to = CraftLocation.toBukkit(absolutePosition.position(), teleportTarget.newLevel().getWorld(), absolutePosition.yRot(), absolutePosition.xRot());
++                Vec3 velocity = absolutePosition.deltaMovement(); // Paper
 +                Location to = CraftLocation.toBukkit(absolutePosition.position(), teleportTarget.newLevel().getWorld(), absolutePosition.yRot(), this.getXRot()); // Paper - use getXRot (doesn't respect DimensionTransition pitch) // Why?
                  // Paper start - gateway-specific teleport event
                  final EntityTeleportEvent teleEvent;
                  if (this.portalProcess != null && this.portalProcess.isSamePortal(((net.minecraft.world.level.block.EndGatewayBlock) net.minecraft.world.level.block.Blocks.END_GATEWAY)) && this.level.getBlockEntity(this.portalProcess.getEntryPosition()) instanceof net.minecraft.world.level.block.entity.TheEndGatewayBlockEntity theEndGatewayBlockEntity) {
 @@ -0,0 +0,0 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+                 if (!to.equals(teleEvent.getTo())) {
                      to = teleEvent.getTo();
                      teleportTarget = new TeleportTransition(((CraftWorld) to.getWorld()).getHandle(), CraftLocation.toVec3D(to), Vec3.ZERO, to.getYaw(), to.getPitch(), teleportTarget.missingRespawnBlock(), teleportTarget.asPassenger(), Set.of(), teleportTarget.postTeleportTransition(), teleportTarget.cause());
++                    // Paper start - Call EntityPortalExitEvent
++                    velocity = Vec3.ZERO;
                  }
-+                // Paper start - Call EntityPortalExitEvent
 +                if (this.portalProcess != null) { // if in a portal
 +                    CraftEntity bukkitEntity = this.getBukkitEntity();
-+                    Vec3 velocity = teleportTarget.deltaMovement();
 +                    org.bukkit.event.entity.EntityPortalExitEvent event = new org.bukkit.event.entity.EntityPortalExitEvent(
 +                        bukkitEntity,
 +                        bukkitEntity.getLocation(), to.clone(),
@@ -32,11 +34,12 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +                    );
 +                    event.callEvent();
 +
-+                    if (!event.isCancelled() && event.getTo() != null) {
++                    // Only change the target if actually needed, since we reset relative flags
++                    if (!event.isCancelled() && event.getTo() != null && (!event.getTo().equals(event.getFrom()) || !event.getAfter().equals(event.getBefore()))) {
 +                        to = event.getTo().clone();
 +                        velocity = org.bukkit.craftbukkit.util.CraftVector.toNMS(event.getAfter());
++                        teleportTarget = new TeleportTransition(((CraftWorld) to.getWorld()).getHandle(), CraftLocation.toVec3D(to), velocity, to.getYaw(), to.getPitch(), teleportTarget.missingRespawnBlock(), teleportTarget.asPassenger(), Set.of(), teleportTarget.postTeleportTransition(), teleportTarget.cause());
 +                    }
-+                    teleportTarget = new TeleportTransition(((CraftWorld) to.getWorld()).getHandle(), CraftLocation.toVec3D(to), velocity, to.getYaw(), to.getPitch(), teleportTarget.missingRespawnBlock(), teleportTarget.asPassenger(), Set.of(), teleportTarget.postTeleportTransition(), teleportTarget.cause());
 +                }
 +                if (this.isRemoved()) {
 +                    return null;