From 1fc8092ea69b0eb59a2f01da07eb5e0bd67d5542 Mon Sep 17 00:00:00 2001
From: Nathan Adams <dinnerbone@dinnerbone.com>
Date: Sun, 11 Dec 2011 15:59:55 +0000
Subject: [PATCH] Fixed corrupt mob spawners crashing on load - this fixes
 BUKKIT-69, BUKKIT-144

---
 .../net/minecraft/server/TileEntityMobSpawner.java    | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/main/java/net/minecraft/server/TileEntityMobSpawner.java b/src/main/java/net/minecraft/server/TileEntityMobSpawner.java
index 7b499ebc3a..40acc4d86b 100644
--- a/src/main/java/net/minecraft/server/TileEntityMobSpawner.java
+++ b/src/main/java/net/minecraft/server/TileEntityMobSpawner.java
@@ -48,11 +48,20 @@ public class TileEntityMobSpawner extends TileEntity {
                 byte b0 = 4;
 
                 for (int i = 0; i < b0; ++i) {
-                    EntityLiving entityliving = (EntityLiving) ((EntityLiving) EntityTypes.a(this.mobName, this.world));
+                    // CraftBukkit start - bad entity detection
+                    Entity mob = EntityTypes.a(this.mobName, this.world);
+
+                    if (!(mob instanceof EntityLiving)) {
+                        mobName = "Pig";
+                        return;
+                    }
+
+                    EntityLiving entityliving = (EntityLiving) ((EntityLiving) mob);
 
                     if (entityliving == null) {
                         return;
                     }
+                    // CraftBukkit end
 
                     int j = this.world.a(entityliving.getClass(), AxisAlignedBB.b((double) this.x, (double) this.y, (double) this.z, (double) (this.x + 1), (double) (this.y + 1), (double) (this.z + 1)).b(8.0D, 4.0D, 8.0D)).size();