From cbe17bc833a073c04a5e37568cedcd8e4f48303f Mon Sep 17 00:00:00 2001
From: William Blake Galbreath <Blake.Galbreath@GMail.com>
Date: Wed, 18 Dec 2019 22:21:35 -0600
Subject: [PATCH] MC-145656 Fix Follow Range Initial Target


diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
index 3bbf77a8e..f8d8cb865 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -633,4 +633,9 @@ public class PaperWorldConfig {
     private void pillagerSettings() {
         disablePillagerPatrols = getBoolean("game-mechanics.disable-pillager-patrols", disablePillagerPatrols);
     }
+
+    public boolean entitiesTargetWithFollowRange = false;
+    private void entitiesTargetWithFollowRange() {
+        entitiesTargetWithFollowRange = getBoolean("entities-target-with-follow-range", entitiesTargetWithFollowRange);
+    }
 }
diff --git a/src/main/java/net/minecraft/server/PathfinderGoalNearestAttackableTarget.java b/src/main/java/net/minecraft/server/PathfinderGoalNearestAttackableTarget.java
index 5a2fa079e..b81b9a9a4 100644
--- a/src/main/java/net/minecraft/server/PathfinderGoalNearestAttackableTarget.java
+++ b/src/main/java/net/minecraft/server/PathfinderGoalNearestAttackableTarget.java
@@ -25,6 +25,7 @@ public class PathfinderGoalNearestAttackableTarget<T extends EntityLiving> exten
         this.b = i;
         this.a(EnumSet.of(PathfinderGoal.Type.TARGET));
         this.d = (new PathfinderTargetCondition()).a(this.k()).a(predicate);
+        if (entityinsentient.world.paperConfig.entitiesTargetWithFollowRange) this.d.useFollowRange(); // Paper
     }
 
     @Override
diff --git a/src/main/java/net/minecraft/server/PathfinderTargetCondition.java b/src/main/java/net/minecraft/server/PathfinderTargetCondition.java
index c76a43837..e35ec2db0 100644
--- a/src/main/java/net/minecraft/server/PathfinderTargetCondition.java
+++ b/src/main/java/net/minecraft/server/PathfinderTargetCondition.java
@@ -80,7 +80,7 @@ public class PathfinderTargetCondition {
 
                 if (this.b > 0.0D) {
                     double d0 = this.g ? entityliving1.A(entityliving) : 1.0D;
-                    double d1 = this.b * d0;
+                    double d1 = (useFollowRange ? getFollowRange(entityliving) : this.b) * d0; // Paper
                     double d2 = entityliving.g(entityliving1.locX(), entityliving1.locY(), entityliving1.locZ());
 
                     if (d2 > d1 * d1) {
@@ -96,4 +96,18 @@ public class PathfinderTargetCondition {
             return true;
         }
     }
+
+    // Paper start
+    private boolean useFollowRange = false;
+
+    public PathfinderTargetCondition useFollowRange() {
+        this.useFollowRange = true;
+        return this;
+    }
+
+    private double getFollowRange(EntityLiving entityliving) {
+        AttributeInstance attributeinstance = entityliving.getAttributeInstance(GenericAttributes.FOLLOW_RANGE);
+        return attributeinstance == null ? 16.0D : attributeinstance.getValue();
+    }
+    // Paper end
 }
-- 
2.25.0