From 5fc1fe33db88d6e3e89f0084b240e8126b64de6a Mon Sep 17 00:00:00 2001
From: fullwall <fullwall25@gmail.com>
Date: Thu, 31 Mar 2016 17:44:25 +0800
Subject: [PATCH] Workaround Spigot knockback bug by setting high knockback
 resistance on protected NPCs

---
 src/main/java/net/citizensnpcs/npc/CitizensNPC.java        | 6 ++++++
 .../net/citizensnpcs/npc/entity/CreeperController.java     | 3 ++-
 src/main/java/net/citizensnpcs/util/NMS.java               | 7 +++++--
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/main/java/net/citizensnpcs/npc/CitizensNPC.java b/src/main/java/net/citizensnpcs/npc/CitizensNPC.java
index 50c9602b3..aecd663cc 100644
--- a/src/main/java/net/citizensnpcs/npc/CitizensNPC.java
+++ b/src/main/java/net/citizensnpcs/npc/CitizensNPC.java
@@ -311,6 +311,12 @@ public class CitizensNPC extends AbstractNPC {
             if (getEntity() instanceof LivingEntity) {
                 boolean nameplateVisible = data().get(NPC.NAMEPLATE_VISIBLE_METADATA, true);
                 ((LivingEntity) getEntity()).setCustomNameVisible(nameplateVisible);
+
+                if (data().get(NPC.DEFAULT_PROTECTED_METADATA, true)) {
+                    NMS.setKnockbackResistance((LivingEntity) getEntity(), 1D);
+                } else {
+                    NMS.setKnockbackResistance((LivingEntity) getEntity(), 0D);
+                }
             }
         } catch (Exception ex) {
             Throwable error = Throwables.getRootCause(ex);
diff --git a/src/main/java/net/citizensnpcs/npc/entity/CreeperController.java b/src/main/java/net/citizensnpcs/npc/entity/CreeperController.java
index a9f310120..05a0fdddb 100644
--- a/src/main/java/net/citizensnpcs/npc/entity/CreeperController.java
+++ b/src/main/java/net/citizensnpcs/npc/entity/CreeperController.java
@@ -130,8 +130,9 @@ public class CreeperController extends MobEntityController {
                 return;
             }
             if (NPCPushEvent.getHandlerList().getRegisteredListeners().length == 0) {
-                if (!npc.data().get(NPC.DEFAULT_PROTECTED_METADATA, true))
+                if (!npc.data().get(NPC.DEFAULT_PROTECTED_METADATA, true)) {
                     super.g(x, y, z);
+                }
                 return;
             }
             Vector vector = new Vector(x, y, z);
diff --git a/src/main/java/net/citizensnpcs/util/NMS.java b/src/main/java/net/citizensnpcs/util/NMS.java
index f1bb3834f..fd1d791ad 100644
--- a/src/main/java/net/citizensnpcs/util/NMS.java
+++ b/src/main/java/net/citizensnpcs/util/NMS.java
@@ -737,6 +737,11 @@ public class NMS {
         handle.aP = yaw;
     }
 
+    public static void setKnockbackResistance(org.bukkit.entity.LivingEntity entity, double d) {
+        EntityLiving handle = NMS.getHandle(entity);
+        handle.getAttributeInstance(GenericAttributes.c).setValue(d);
+    }
+
     public static void setProfile(SkullMeta meta, GameProfile profile) {
         if (SKULL_PROFILE_FIELD == null) {
             try {
@@ -894,7 +899,6 @@ public class NMS {
         }
     }
 
-    private static Field CRAFT_TEAM_FIELD;
     private static final float DEFAULT_SPEED = 1F;
     private static Map<Class<?>, Integer> ENTITY_CLASS_TO_INT;
     private static Map<Class<?>, String> ENTITY_CLASS_TO_NAME;
@@ -909,7 +913,6 @@ public class NMS {
     private static final Field RABBIT_FIELD = getField(EntityRabbit.class, "bv");
     private static final Random RANDOM = Util.getFastRandom();
     private static Field SKULL_PROFILE_FIELD;
-
     private static Field TRACKED_ENTITY_SET = NMS.getField(EntityTracker.class, "c");
 
     static {