PaperMC/nms-patches/MobSpawnerAbstract.patch

--- ../work/decompile-bb26c12b/net/minecraft/server/MobSpawnerAbstract.java	2014-11-27 08:59:46.805421389 +1100
+++ src/main/java/net/minecraft/server/MobSpawnerAbstract.java	2014-11-27 08:42:10.108850996 +1100
@@ -4,6 +4,8 @@
 import java.util.Iterator;
 import java.util.List;
 
+import org.bukkit.event.entity.CreatureSpawnEvent; // CraftBukkit
+
 public abstract class MobSpawnerAbstract {
 
     public int spawnDelay = 20;
@@ -129,7 +131,7 @@
 
             entity.f(nbttagcompound);
             if (entity.world != null && flag) {
-                entity.world.addEntity(entity);
+                entity.world.addEntity(entity, CreatureSpawnEvent.SpawnReason.SPAWNER); // CraftBukkit
             }
 
             NBTTagCompound nbttagcompound1;
@@ -154,7 +156,7 @@
                     entity2.f(nbttagcompound2);
                     entity2.setPositionRotation(entity1.locX, entity1.locY, entity1.locZ, entity1.yaw, entity1.pitch);
                     if (entity.world != null && flag) {
-                        entity.world.addEntity(entity2);
+                        entity.world.addEntity(entity2, CreatureSpawnEvent.SpawnReason.SPAWNER); // CraftBukkit
                     }
 
                     entity1.mount(entity2);
@@ -164,7 +166,7 @@
             }
         } else if (entity instanceof EntityLiving && entity.world != null && flag) {
             ((EntityInsentient) entity).prepare(entity.world.E(new BlockPosition(entity)), (GroupDataEntity) null);
-            entity.world.addEntity(entity);
+            entity.world.addEntity(entity, CreatureSpawnEvent.SpawnReason.SPAWNER); // CraftBukkit
         }
 
         return entity;