Paper/patches/unapplied/server/0351-MC-145656-Fix-Follow-Range-Initial-Target.patch

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 a9ab8cbb739a72222dc7775f52ef2cfdc49fd29f..72fc65fde0be760ef6a98d26ee7adf45c8a0242e 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -467,5 +467,10 @@ 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 6cbd2fc4a7041f957966e5b09616e70aae63c0d4..b5bbcb9fa6de4c919e4d4fabbab483054d81574e 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 = TargetingConditions.forCombat().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 e45434b844c98c322e1432c2382c1ccb8c3e57a7..3ee691d4caccbc1b3e0f52decb41d436ac0d08ec 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
@@ -75,7 +75,7 @@ public class TargetingConditions {
 
                 if (this.range > 0.0D) {
                     double d = this.testInvisible ? targetEntity.getVisibilityPercent(baseEntity) : 1.0D;
-                    double e = Math.max(this.range * d, 2.0D);
+                    double e = Math.max((this.useFollowRange ? this.getFollowRange(baseEntity) : this.range) * d, 2.0D); // Paper
                     double f = baseEntity.distanceToSqr(targetEntity.getX(), targetEntity.getY(), targetEntity.getZ());
                     if (f > e * e) {
                         return false;
@@ -90,4 +90,18 @@ public class TargetingConditions {
             return true;
         }
     }
+
+    // Paper start
+    private boolean useFollowRange = false;
+
+    public TargetingConditions useFollowRange() {
+        this.useFollowRange = true;
+        return this;
+    }
+
+    private double getFollowRange(LivingEntity entityliving) {
+        net.minecraft.world.entity.ai.attributes.AttributeInstance attributeinstance = entityliving.getAttribute(net.minecraft.world.entity.ai.attributes.Attributes.FOLLOW_RANGE);
+        return attributeinstance == null ? 16.0D : attributeinstance.getValue();
+    }
+    // Paper end
 }