From 0000000000000000000000000000000000000000 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 e726b6213cf2e8f5b326f05c0438b8f1ee2b73c5..edda2121f8c1046478beaa77030ebb36d403b334 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -580,4 +580,9 @@ 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/world/entity/ai/goal/target/NearestAttackableTargetGoal.java b/src/main/java/net/minecraft/world/entity/ai/goal/target/NearestAttackableTargetGoal.java
index 7bba2ac71a3cd34a06ec865a3c1828b10decd644..93845edab0e1b0e2ad300cad051b0182cadd46e5 100644
--- a/src/main/java/net/minecraft/world/entity/ai/goal/target/NearestAttackableTargetGoal.java
+++ b/src/main/java/net/minecraft/world/entity/ai/goal/target/NearestAttackableTargetGoal.java
@@ -32,6 +32,7 @@ public class NearestAttackableTargetGoal<T extends LivingEntity> extends TargetG
         this.randomInterval = reciprocalChance;
         this.setFlags(EnumSet.of(Goal.Flag.TARGET));
         this.targetConditions = (new TargetingConditions()).range(this.getFollowDistance()).selector(targetPredicate);
+        if (mob.level.paperConfig.entitiesTargetWithFollowRange) this.targetConditions.useFollowRange(); // Paper
     }
 
     @Override
diff --git a/src/main/java/net/minecraft/world/entity/ai/targeting/TargetingConditions.java b/src/main/java/net/minecraft/world/entity/ai/targeting/TargetingConditions.java
index 1714507fa744b2767e8a66cdb5db7f43c21f5c56..e1a0104a3b52990a83e7732491029d8a20976dc3 100644
--- a/src/main/java/net/minecraft/world/entity/ai/targeting/TargetingConditions.java
+++ b/src/main/java/net/minecraft/world/entity/ai/targeting/TargetingConditions.java
@@ -4,6 +4,8 @@ import java.util.function.Predicate;
 import javax.annotation.Nullable;
 import net.minecraft.world.entity.LivingEntity;
 import net.minecraft.world.entity.Mob;
+import net.minecraft.world.entity.ai.attributes.AttributeInstance;
+import net.minecraft.world.entity.ai.attributes.Attributes;
 
 public class TargetingConditions {
 
@@ -82,7 +84,7 @@ public class TargetingConditions {
 
                 if (this.range > 0.0D) {
                     double d0 = this.testInvisible ? targetEntity.getVisibilityPercent(baseEntity) : 1.0D;
-                    double d1 = Math.max(this.range * d0, 2.0D);
+                    double d1 = Math.max((useFollowRange ? getFollowRange(baseEntity) : this.range) * d0, 2.0D); // Paper
                     double d2 = baseEntity.distanceToSqr(targetEntity.getX(), targetEntity.getY(), targetEntity.getZ());
 
                     if (d2 > d1 * d1) {
@@ -98,4 +100,18 @@ public class TargetingConditions {
             return true;
         }
     }
+
+    // Paper start
+    private boolean useFollowRange = false;
+
+    public TargetingConditions useFollowRange() {
+        this.useFollowRange = true;
+        return this;
+    }
+
+    private double getFollowRange(LivingEntity entityliving) {
+        AttributeInstance attributeinstance = entityliving.getAttribute(Attributes.FOLLOW_RANGE);
+        return attributeinstance == null ? 16.0D : attributeinstance.getValue();
+    }
+    // Paper end
 }