I've either fixed going to The End, or made it worse. I'm sure we'll find out soon!

src/main/java/net/minecraft/server/PortalTravelAgent.java

@@ -3,8 +3,13 @@ package net.minecraft.server;
 import java.util.Random;
 
 // CraftBukkit start
-import org.bukkit.event.world.PortalCreateEvent;
+/*
-import org.bukkit.Bukkit;
+ * HEAR ME, HE WHOM WISHES TO COMMAND THE UPDATERING
+ *
+ * FOR SOME REASON WE HAVE OUR OWN PORTAL TRAVEL AGENT IN OBC, WE NEED TO UPDATE
+ * THAT WITH ANY NEW UPDATES TO THIS FILE. THIS FILE LEFT HERE AS A REMINDER.
+ *
+ */
 // CraftBukkit end
 
 public class PortalTravelAgent {
@@ -247,53 +252,6 @@ public class PortalTravelAgent {
 
         boolean flag;
 
-        // CraftBukkit start - portal create event
-        java.util.Collection<org.bukkit.block.Block> blocks = new java.util.HashSet<org.bukkit.block.Block>();
-        // Find out what blocks the portal is going to modify, duplicated from below
-        org.bukkit.World bworld = world.getWorld();
-
-        if (d0 < 0.0D) {
-            if (i1 < 70) {
-                i1 = 70;
-            }
-
-            if (i1 > world.height - 10) {
-                i1 = world.height - 10;
-            }
-
-            j5 = i1;
-
-            for (l2 = -1; l2 <= 1; ++l2) {
-                for (k2 = 1; k2 < 3; ++k2) {
-                    for (j3 = -1; j3 < 3; ++j3) {
-                        i3 = i5 + (k2 - 1) * k5 + l2 * l5;
-                        l3 = j5 + j3;
-                        k3 = j2 + (k2 - 1) * l5 - l2 * k5;
-                        blocks.add(bworld.getBlockAt(i3, l3, k3));
-                    }
-                }
-            }
-        }
-
-        for (l2 = 0; l2 < 4; ++l2) {
-            for (k2 = 0; k2 < 4; ++k2) {
-                for (j3 = -1; j3 < 4; ++j3) {
-                    i3 = i5 + (k2 - 1) * k5;
-                    l3 = j5 + j3;
-                    k3 = j2 + (k2 - 1) * l5;
-                    blocks.add(bworld.getBlockAt(i3, l3, k3));
-                }
-            }
-        }
-
-        PortalCreateEvent event = new PortalCreateEvent(blocks, bworld);
-        Bukkit.getServer().getPluginManager().callEvent(event);
-
-        if (event.isCancelled()) {
-            return true;
-        }
-        // CraftBukkit end
-
         if (d0 < 0.0D) {
             if (i1 < 70) {
                 i1 = 70;

src/main/java/net/minecraft/server/ServerConfigurationManager.java

@@ -305,7 +305,7 @@ public class ServerConfigurationManager {
 
     public void a(EntityPlayer entityplayer, int i) {
         // CraftBukkit start -- Replaced the standard handling of portals with a more customised method.
-        int dimension = entityplayer.dimension;
+        int dimension = i;
         WorldServer fromWorld = this.server.getWorldServer(dimension);
         WorldServer toWorld = null;
         if (dimension < 10) {
@@ -315,13 +315,28 @@ public class ServerConfigurationManager {
                 }
             }
         }
-        double blockRatio = dimension == -1 ? 8 : 0.125;
 
         Location fromLocation = new Location(fromWorld.getWorld(), entityplayer.locX, entityplayer.locY, entityplayer.locZ, entityplayer.yaw, entityplayer.pitch);
-        Location toLocation = toWorld == null ? null : new Location(toWorld.getWorld(), (entityplayer.locX * blockRatio), entityplayer.locY, (entityplayer.locZ * blockRatio), entityplayer.yaw, entityplayer.pitch);
+        Location toLocation = null;
+
+        if (toWorld != null) {
+            if ((dimension == -1) || (dimension == 0)) {
+                double blockRatio = dimension == 0 ? 8 : 0.125;
+
+                toLocation = toWorld == null ? null : new Location(toWorld.getWorld(), (entityplayer.locX * blockRatio), entityplayer.locY, (entityplayer.locZ * blockRatio), entityplayer.yaw, entityplayer.pitch);
+            } else {
+                ChunkCoordinates coords = toWorld.d();
+                toLocation = new Location(toWorld.getWorld(), coords.x, coords.y, coords.z, 90, 0);
+            }
+        }
 
         org.bukkit.craftbukkit.PortalTravelAgent pta = new org.bukkit.craftbukkit.PortalTravelAgent();
         PlayerPortalEvent event = new PlayerPortalEvent((Player) entityplayer.getBukkitEntity(), fromLocation, toLocation, pta);
+
+        if (entityplayer.dimension == 1) {
+            event.useTravelAgent(false);
+        }
+
         Bukkit.getServer().getPluginManager().callEvent(event);
         if (event.isCancelled() || event.getTo() == null) {
             return;

src/main/java/org/bukkit/craftbukkit/PortalTravelAgent.java

@@ -3,11 +3,13 @@ package org.bukkit.craftbukkit;
 import java.util.Random;
 
 import net.minecraft.server.Block;
+import net.minecraft.server.MathHelper;
 import net.minecraft.server.WorldServer;
 
 import org.bukkit.Bukkit;
 import org.bukkit.Location;
 import org.bukkit.TravelAgent;
+import org.bukkit.World.Environment;
 import org.bukkit.event.world.PortalCreateEvent;
 
 public class PortalTravelAgent implements TravelAgent {
@@ -43,6 +45,32 @@ public class PortalTravelAgent implements TravelAgent {
 
     public Location findPortal(Location location) {
         net.minecraft.server.World world = ((CraftWorld) location.getWorld()).getHandle();
+
+        if (location.getWorld().getEnvironment() == Environment.THE_END) {
+            int i = MathHelper.floor(location.getBlockX());
+            int j = MathHelper.floor(location.getBlockY()) - 1;
+            int k = MathHelper.floor(location.getBlockZ());
+            byte b0 = 1;
+            byte b1 = 0;
+
+            for (int l = -2; l <= 2; ++l) {
+                for (int i1 = -2; i1 <= 2; ++i1) {
+                    for (int j1 = -1; j1 < 3; ++j1) {
+                        int k1 = i + i1 * b0 + l * b1;
+                        int l1 = j + j1;
+                        int i2 = k + i1 * b1 - l * b0;
+                        boolean flag = j1 < 0;
+
+                        if (world.getTypeId(k1, l1, i2) != (flag ? Block.OBSIDIAN.id : 0)) {
+                            return null;
+                        }
+                    }
+                }
+            }
+
+            return location;
+        }
+
         // short short1 = 128;
         double d0 = -1.0D;
         int i = 0;
@@ -59,7 +87,7 @@ public class PortalTravelAgent implements TravelAgent {
             for (int k1 = i1 - this.searchRadius; k1 <= i1 + this.searchRadius; ++k1) {
                 double d3 = (double) k1 + 0.5D - location.getZ();
 
-                for (int l1 = 127; l1 >= 0; --l1) {
+                for (int l1 = world.height - 1; l1 >= 0; --l1) {
                     if (world.getTypeId(j1, l1, k1) == Block.PORTAL.id) {
                         while (world.getTypeId(j1, l1 - 1, k1) == Block.PORTAL.id) {
                             --l1;
@@ -108,6 +136,31 @@ public class PortalTravelAgent implements TravelAgent {
 
     public boolean createPortal(Location location) {
         net.minecraft.server.World world = ((CraftWorld) location.getWorld()).getHandle();
+
+        
+        if (location.getWorld().getEnvironment() == Environment.THE_END) {
+            int i = MathHelper.floor(location.getBlockX());
+            int j = MathHelper.floor(location.getBlockY()) - 1;
+            int k = MathHelper.floor(location.getBlockZ());
+            byte b0 = 1;
+            byte b1 = 0;
+
+            for (int l = -2; l <= 2; ++l) {
+                for (int i1 = -2; i1 <= 2; ++i1) {
+                    for (int j1 = -1; j1 < 3; ++j1) {
+                        int k1 = i + i1 * b0 + l * b1;
+                        int l1 = j + j1;
+                        int i2 = k + i1 * b1 - l * b0;
+                        boolean flag = j1 < 0;
+
+                        world.setTypeId(k1, l1, i2, flag ? Block.OBSIDIAN.id : 0);
+                    }
+                }
+            }
+
+            return true;
+        }
+
         // byte b0 = 16;
         double d0 = -1.0D;
         int i = location.getBlockX();
@@ -142,7 +195,7 @@ public class PortalTravelAgent implements TravelAgent {
                 d2 = (double) j2 + 0.5D - location.getZ();
 
                 label271:
-                for (l2 = 127; l2 >= 0; --l2) {
+                for (l2 = world.height - 1; l2 >= 0; --l2) {
                     if (world.isEmpty(i2, l2, j2)) {
                         while (l2 > 0 && world.isEmpty(i2, l2 - 1, j2)) {
                             --l2;
@@ -193,7 +246,7 @@ public class PortalTravelAgent implements TravelAgent {
                     d2 = (double) j2 + 0.5D - location.getZ();
 
                     label219:
-                    for (l2 = 127; l2 >= 0; --l2) {
+                    for (l2 = world.height - 1; l2 >= 0; --l2) {
                         if (world.isEmpty(i2, l2, j2)) {
                             while (l2 > 0 && world.isEmpty(i2, l2 - 1, j2)) {
                                 --l2;
@@ -254,8 +307,8 @@ public class PortalTravelAgent implements TravelAgent {
                 i1 = 70;
             }
 
-            if (i1 > 118) {
+            if (i1 > world.height - 10) {
-                i1 = 118;
+                i1 = world.height - 10;
             }
 
             j5 = i1;
@@ -301,8 +354,8 @@ public class PortalTravelAgent implements TravelAgent {
                 i1 = 70;
             }
 
-            if (i1 > 118) {
+            if (i1 > world.height - 10) {
-                i1 = 118;
+                i1 = world.height - 10;
             }
 
             j5 = i1;