From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Max Lee <max@themoep.de>
Date: Thu, 27 May 2021 14:52:30 -0700
Subject: [PATCH] Fix invulnerable end crystals

MC-108513

diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
index 74f2413773fbe30597314e02a5284172e0fc40b2..dc5ebbb44238cb5928f385d2962c9057388575f8 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -826,4 +826,9 @@ public class PaperWorldConfig {
     private void fixItemsMergingThroughWalls() {
         fixItemsMergingThroughWalls = getBoolean("fix-items-merging-through-walls", fixItemsMergingThroughWalls);
     }
+
+    public boolean fixInvulnerableEndCrystalExploit = true;
+    private void fixInvulnerableEndCrystalExploit() {
+        fixInvulnerableEndCrystalExploit = getBoolean("unsupported-settings.fix-invulnerable-end-crystal-exploit", fixInvulnerableEndCrystalExploit);
+    }
 }
diff --git a/src/main/java/net/minecraft/world/entity/boss/enderdragon/EndCrystal.java b/src/main/java/net/minecraft/world/entity/boss/enderdragon/EndCrystal.java
index 6292d04464950ac52fcd6d69345db5125d3127eb..8583209750e4bb70e86d7243a47c525f1726ee42 100644
--- a/src/main/java/net/minecraft/world/entity/boss/enderdragon/EndCrystal.java
+++ b/src/main/java/net/minecraft/world/entity/boss/enderdragon/EndCrystal.java
@@ -29,6 +29,7 @@ public class EndCrystal extends Entity {
     private static final EntityDataAccessor<Optional<BlockPos>> DATA_BEAM_TARGET = SynchedEntityData.defineId(EndCrystal.class, EntityDataSerializers.OPTIONAL_BLOCK_POS);
     private static final EntityDataAccessor<Boolean> DATA_SHOW_BOTTOM = SynchedEntityData.defineId(EndCrystal.class, EntityDataSerializers.BOOLEAN);
     public int time;
+    public boolean generatedByDragonFight = false; // Paper - Fix invulnerable end crystals
 
     public EndCrystal(EntityType<? extends EndCrystal> type, Level world) {
         super(type, world);
@@ -65,6 +66,17 @@ public class EndCrystal extends Entity {
                 }
                 // CraftBukkit end
             }
+            // Paper start - Fix invulnerable end crystals
+            if (this.level.paperConfig.fixInvulnerableEndCrystalExploit && this.generatedByDragonFight && this.isInvulnerable()) {
+                if ((this.origin.getWorld() != null && !((ServerLevel) this.level).uuid.equals(this.origin.getWorld().getUID()))
+                    || ((ServerLevel) this.level).dragonFight() == null
+                    || ((ServerLevel) this.level).dragonFight().respawnStage == null
+                    || ((ServerLevel) this.level).dragonFight().respawnStage.ordinal() > net.minecraft.world.level.dimension.end.DragonRespawnAnimation.SUMMONING_DRAGON.ordinal()) {
+                    this.setInvulnerable(false);
+                    this.setBeamTarget(null);
+                }
+            }
+            // Paper end
         }
 
     }
@@ -76,6 +88,7 @@ public class EndCrystal extends Entity {
         }
 
         tag.putBoolean("ShowBottom", this.showsBottom());
+        if (this.generatedByDragonFight) tag.putBoolean("Paper.GeneratedByDragonFight", this.generatedByDragonFight); // Paper - Fix invulnerable end crystals
     }
 
     @Override
@@ -87,6 +100,7 @@ public class EndCrystal extends Entity {
         if (tag.contains("ShowBottom", 1)) {
             this.setShowBottom(tag.getBoolean("ShowBottom"));
         }
+        if (tag.contains("Paper.GeneratedByDragonFight", 1)) this.generatedByDragonFight = tag.getBoolean("Paper.GeneratedByDragonFight"); // Paper - Fix invulnerable end crystals
 
     }
 
diff --git a/src/main/java/net/minecraft/world/level/levelgen/feature/SpikeFeature.java b/src/main/java/net/minecraft/world/level/levelgen/feature/SpikeFeature.java
index b99576b524a65cc1a0de88c49324d929503d655f..d51d2fb6d24bfee63b04f32f2cb157fec9d8ee6c 100644
--- a/src/main/java/net/minecraft/world/level/levelgen/feature/SpikeFeature.java
+++ b/src/main/java/net/minecraft/world/level/levelgen/feature/SpikeFeature.java
@@ -42,11 +42,11 @@ public class SpikeFeature extends Feature<SpikeConfiguration> {
         return (List) SpikeFeature.SPIKE_CACHE.getUnchecked(i);
     }
 
-    public boolean place(WorldGenLevel world, ChunkGenerator chunkGenerator, Random random, BlockPos pos, SpikeConfiguration config) {
-        List<SpikeFeature.EndSpike> list = config.getSpikes();
+    public boolean generate(WorldGenLevel generatoraccessseed, ChunkGenerator chunkgenerator, Random random, BlockPos blockposition, SpikeConfiguration worldgenfeatureendspikeconfiguration) { // Paper - decompile fix
+        List<SpikeFeature.EndSpike> list = worldgenfeatureendspikeconfiguration.getSpikes();
 
         if (list.isEmpty()) {
-            list = getSpikesForLevel(world);
+            list = getSpikesForLevel(generatoraccessseed);
         }
 
         Iterator iterator = list.iterator();
@@ -54,8 +54,8 @@ public class SpikeFeature extends Feature<SpikeConfiguration> {
         while (iterator.hasNext()) {
             SpikeFeature.EndSpike worldgenender_spike = (SpikeFeature.EndSpike) iterator.next();
 
-            if (worldgenender_spike.isCenterWithinChunk(pos)) {
-                this.placeSpike(world, random, config, worldgenender_spike);
+            if (worldgenender_spike.isCenterWithinChunk(blockposition)) {
+                this.placeSpike(generatoraccessseed, random, worldgenfeatureendspikeconfiguration, worldgenender_spike);
             }
         }
 
@@ -106,6 +106,7 @@ public class SpikeFeature extends Feature<SpikeConfiguration> {
         entityendercrystal.setBeamTarget(config.getCrystalBeamTarget());
         entityendercrystal.setInvulnerable(config.isCrystalInvulnerable());
         entityendercrystal.moveTo((double) spike.getCenterX() + 0.5D, (double) (spike.getHeight() + 1), (double) spike.getCenterZ() + 0.5D, random.nextFloat() * 360.0F, 0.0F);
+        entityendercrystal.generatedByDragonFight = true;
         world.addFreshEntity(entityendercrystal);
         this.setBlock(world, new BlockPos(spike.getCenterX(), spike.getHeight(), spike.getCenterZ()), Blocks.BEDROCK.defaultBlockState());
     }