SPIGOT-85: Fix NPE in monster spawners when right-clicked with invalid spawn eggs

nms-patches/MobSpawnerAbstract.patch

@@ -1,5 +1,5 @@
---- ../work/decompile-8eb82bde//net/minecraft/server/MobSpawnerAbstract.java	2014-11-28 17:43:43.261707431 +0000
-+++ src/main/java/net/minecraft/server/MobSpawnerAbstract.java	2014-11-28 17:38:17.000000000 +0000
+--- ../work/decompile-8eb82bde//net/minecraft/server/MobSpawnerAbstract.java	2014-12-01 10:08:05.390591149 +0000
++++ src/main/java/net/minecraft/server/MobSpawnerAbstract.java	2014-12-01 10:07:23.810591600 +0000
 @@ -4,6 +4,8 @@
  import java.util.Iterator;
  import java.util.List;
@@ -9,7 +9,19 @@
  public abstract class MobSpawnerAbstract {
  
      public int spawnDelay = 20;
-@@ -129,7 +131,7 @@
+@@ -24,6 +26,11 @@
+ 
+     public String getMobName() {
+         if (this.i() == null) {
++            // CraftBukkit start - fix NPE
++            if (this.mobName == null) {
++                this.mobName = "Pig";
++            }
++            // CraftBukkit end
+             if (this.mobName.equals("Minecart")) {
+                 this.mobName = "MinecartRideable";
+             }
+@@ -129,7 +136,7 @@
  
              entity.f(nbttagcompound);
              if (entity.world != null && flag) {
@@ -18,7 +30,7 @@
              }
  
              NBTTagCompound nbttagcompound1;
-@@ -154,7 +156,7 @@
+@@ -154,7 +161,7 @@
                      entity2.f(nbttagcompound2);
                      entity2.setPositionRotation(entity1.locX, entity1.locY, entity1.locZ, entity1.yaw, entity1.pitch);
                      if (entity.world != null && flag) {
@@ -27,7 +39,7 @@
                      }
  
                      entity1.mount(entity2);
-@@ -164,7 +166,7 @@
+@@ -164,7 +171,7 @@
              }
          } else if (entity instanceof EntityLiving && entity.world != null && flag) {
              ((EntityInsentient) entity).prepare(entity.world.E(new BlockPosition(entity)), (GroupDataEntity) null);