From 11b5d09894304d6fc730dadb581b06196c71d704 Mon Sep 17 00:00:00 2001
From: Shane Freeder <theboyetronic@gmail.com>
Date: Tue, 14 Jan 2020 09:12:55 +0000
Subject: [PATCH] Fix entity teleportation exceptions


diff --git a/src/main/java/net/minecraft/server/Entity.java b/src/main/java/net/minecraft/server/Entity.java
index 58e79df57..810a5edb6 100644
--- a/src/main/java/net/minecraft/server/Entity.java
+++ b/src/main/java/net/minecraft/server/Entity.java
@@ -2574,6 +2574,20 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
         return teleportTo(dimensionmanager, null);
     }
 
+    // Paper start
+    private EntityPortalEvent callEntityPortalEvent(WorldServer worldserver1, BlockPosition blockposition, int searchRadius) {
+        Location enter = this.getBukkitEntity().getLocation();
+        Location exit = new Location(worldserver1.getWorld(), blockposition.getX(), blockposition.getY(), blockposition.getZ());
+
+        EntityPortalEvent event = new EntityPortalEvent(this.getBukkitEntity(), enter, exit, searchRadius);
+        event.getEntity().getServer().getPluginManager().callEvent(event);
+        if (event.isCancelled() || event.getTo() == null || event.getTo().getWorld() == null || !this.isAlive()) {
+            return null;
+        }
+
+        return event;
+    }
+    // paper end
     @Nullable
     public Entity teleportTo(DimensionManager dimensionmanager, BlockPosition location) {
         // CraftBukkit end
@@ -2599,7 +2613,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
             // CraftBukkit start - EntityPortalEvent
             // SPIGOT-5136 - don't fire event for CraftEntity.teleport
             int searchRadius = world.paperConfig.portalSearchRadius; // Paper - use portal search radius as default
-            if (location == null) {
+            if (location == null) { /* // Paper - move up
                 Location enter = this.getBukkitEntity().getLocation();
                 Location exit = new Location(worldserver1.getWorld(), blockposition.getX(), blockposition.getY(), blockposition.getZ());
 
@@ -2613,14 +2627,27 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
                 worldserver1 = ((CraftWorld) exit.getWorld()).getHandle();
                 blockposition = new BlockPosition(exit.getX(), exit.getY(), exit.getZ());
                 searchRadius = event.getSearchRadius();
-            }
+            */} // Paper - move up
             // CraftBukkit end
 
         if (blockposition == null) { // CraftBukkit
+            ;
             if (dimensionmanager1.getType() == DimensionManager.THE_END && dimensionmanager == DimensionManager.OVERWORLD) { // CraftBukkit
-                blockposition = worldserver1.getHighestBlockYAt(HeightMap.Type.MOTION_BLOCKING_NO_LEAVES, worldserver1.getSpawn());
+                EntityPortalEvent portalEvent = callEntityPortalEvent(worldserver1, worldserver1.getHighestBlockYAt(HeightMap.Type.MOTION_BLOCKING_NO_LEAVES, worldserver1.getSpawn()), 1); // Paper - EntityPortalEvent - hardcode 1, no search here
+                // Paper start
+                if (portalEvent == null) return null;
+                Location exit = portalEvent.getTo();
+                worldserver1 = ((CraftWorld) exit.getWorld()).getHandle();
+                blockposition = new BlockPosition(exit.getX(), exit.getY(), exit.getZ());
+                //Paper end
             } else if (dimensionmanager.getType() == DimensionManager.THE_END) { // CraftBukkit
-                blockposition = worldserver1.getDimensionSpawn();
+                EntityPortalEvent portalEvent = callEntityPortalEvent(worldserver1, worldserver1.getDimensionSpawn(), 1); // Paper - EntityPortalEvent - hardcode 1, no search here
+                // Paper start
+                if (portalEvent == null) return null;
+                Location exit = portalEvent.getTo();
+                worldserver1 = ((CraftWorld) exit.getWorld()).getHandle();
+                blockposition = new BlockPosition(exit.getX(), exit.getY(), exit.getZ());
+                //Paper end
             } else {
                 double d0 = this.locX();
                 double d1 = this.locZ();
@@ -2644,6 +2671,14 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
                 Vec3D vec3d1 = this.getPortalOffset();
 
                 blockposition = new BlockPosition(d0, this.locY(), d1);
+                // Paper start - EntityPortalEvent
+                EntityPortalEvent portalEvent = callEntityPortalEvent(worldserver1, blockposition, searchRadius);
+                if (portalEvent == null) return null;
+                Location exit = portalEvent.getTo();
+                worldserver1 = ((CraftWorld) exit.getWorld()).getHandle();
+                blockposition = new BlockPosition(exit.getX(), exit.getY(), exit.getZ());
+                searchRadius = portalEvent.getSearchRadius();
+                // Paper end
                 ShapeDetector.Shape shapedetector_shape = worldserver1.getTravelAgent().findPortal(blockposition, vec3d, this.getPortalDirection(), vec3d1.x, vec3d1.y, this instanceof EntityHuman, searchRadius); // CraftBukkit - search radius
 
                 if (shapedetector_shape == null) {
-- 
2.24.1