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/net/minecraft/world/entity/boss/enderdragon/EndCrystal.java b/src/main/java/net/minecraft/world/entity/boss/enderdragon/EndCrystal.java
index 671e8aa7ecc2b3fcc98af62356ff690a2604bcb0..7cb3d69a69e0e3ef4b7f9f9c8b1eb67edb5d116d 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
@@ -30,6 +30,7 @@ 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);
@@ -68,6 +69,17 @@ public class EndCrystal extends Entity {
                 }
                 // CraftBukkit end
             }
+            // Paper start - Fix invulnerable end crystals
+            if (this.level().paperConfig().unsupportedSettings.fixInvulnerableEndCrystalExploit && this.generatedByDragonFight && this.isInvulnerable()) {
+                if (!java.util.Objects.equals(((ServerLevel) this.level()).uuid, this.getOriginWorld())
+                    || ((ServerLevel) this.level()).getDragonFight() == null
+                    || ((ServerLevel) this.level()).getDragonFight().respawnStage == null
+                    || ((ServerLevel) this.level()).getDragonFight().respawnStage.ordinal() > net.minecraft.world.level.dimension.end.DragonRespawnAnimation.SUMMONING_DRAGON.ordinal()) {
+                    this.setInvulnerable(false);
+                    this.setBeamTarget(null);
+                }
+            }
+            // Paper end - Fix invulnerable end crystals
         }
 
     }
@@ -79,6 +91,7 @@ public class EndCrystal extends Entity {
         }
 
         nbt.putBoolean("ShowBottom", this.showsBottom());
+        if (this.generatedByDragonFight) nbt.putBoolean("Paper.GeneratedByDragonFight", this.generatedByDragonFight); // Paper - Fix invulnerable end crystals
     }
 
     @Override
@@ -87,6 +100,7 @@ public class EndCrystal extends Entity {
         if (nbt.contains("ShowBottom", 1)) {
             this.setShowBottom(nbt.getBoolean("ShowBottom"));
         }
+        if (nbt.contains("Paper.GeneratedByDragonFight", 1)) this.generatedByDragonFight = nbt.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 6f0cd7121bf191d8fd01baf4c9b87df7f4f44564..fe5b2bcfaa243c3089f3df83ec1ae0948a63d1eb 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
@@ -115,6 +115,7 @@ public class SpikeFeature extends Feature<SpikeConfiguration> {
             endCrystal.moveTo(
                 (double)spike.getCenterX() + 0.5, (double)(spike.getHeight() + 1), (double)spike.getCenterZ() + 0.5, random.nextFloat() * 360.0F, 0.0F
             );
+            endCrystal.generatedByDragonFight = true; // Paper - Fix invulnerable end crystals
             world.addFreshEntity(endCrystal);
             BlockPos blockPos2 = endCrystal.blockPosition();
             this.setBlock(world, blockPos2.below(), Blocks.BEDROCK.defaultBlockState());