fixed double firing of EntityDamageByEntityEvent

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

@@ -17,6 +17,10 @@ public class EntityDamageSourceIndirect extends EntityDamageSource {
         // CraftBukkit start
         String source = (this.n == null) ? "Herobrine" : this.n.ad();
         return LocaleI18n.a("death." + this.m, new Object[] { entityhuman.name, source});
+    }
+
+    public Entity getProximateDamageSource() {
+        return super.getEntity();
         // CraftBukkit end
     }
-}
+}

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

@@ -587,7 +587,9 @@ public abstract class EntityHuman extends EntityLiving {
                         // also damage the player in this way. For example, EntitySlime.
 
                         // We handle projectiles in their individual classes!
-                        if (!(entity.getBukkitEntity() instanceof Projectile)) {
+                        boolean isProjectile = damagesource instanceof EntityDamageSourceIndirect && ((EntityDamageSourceIndirect) damagesource).getProximateDamageSource().getBukkitEntity() instanceof Projectile;
+
+                        if (!isProjectile) {
                             org.bukkit.entity.Entity damager = ((Entity) entity1).getBukkitEntity();
                             org.bukkit.entity.Entity damagee = this.getBukkitEntity();