fix MC-187100 (#427)

* fix MC-187100

* fix root cause

---------

Co-authored-by: isxander <xander@isxander.dev>

Author: MicrocontrollersDev

PATCHED.md

@@ -24,6 +24,7 @@
 | Basic    | [MC-165381](https://bugs.mojang.com/browse/MC-165381) | Block breaking can be delayed by dropping/throwing the tool while breaking a block                                                  |                                                             |
 | Basic    | [MC-176559](https://bugs.mojang.com/browse/MC-176559) | Breaking process resets when a pickaxe enchanted with Mending mends by XP / Mending slows down breaking blocks again                |
 | Basic    | [MC-183776](https://bugs.mojang.com/browse/MC-183776) | After switching gamemodes using F3+F4, you need to press F3 twice to toggle the debug screen                                        |
+| Basic    | [MC-187100](https://bugs.mojang.com/browse/MC-187100) | End crystals try to heal dying Ender dragons                                                                                        |
 | Basic    | [MC-197260](https://bugs.mojang.com/browse/MC-197260) | Armor Stand renders itself and armor dark if its head is in a solid block                                                           |
 | Basic    | [MC-201723](https://bugs.mojang.com/browse/MC-201723) | Statistics sprites don't look pressed when clicked                                                                                  |
 | Basic    | [MC-206540](https://bugs.mojang.com/browse/MC-206540) | Increased input delay when riding an entity                                                                                         |

src/main/java/dev/isxander/debugify/mixins/basic/mc187100/EnderDragonMixin.java

@@ -0,0 +1,36 @@
+package dev.isxander.debugify.mixins.basic.mc187100;
+
+import com.llamalad7.mixinextras.injector.wrapmethod.WrapMethod;
+import com.llamalad7.mixinextras.injector.wrapoperation.Operation;
+import net.minecraft.world.entity.boss.enderdragon.EndCrystal;
+import net.minecraft.world.entity.boss.enderdragon.EnderDragon;
+import org.jetbrains.annotations.Nullable;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+@Mixin(EnderDragon.class)
+public class EnderDragonMixin {
+    @Shadow
+    public int dragonDeathTime;
+
+    @Shadow
+    @Nullable
+    public EndCrystal nearestCrystal;
+
+    @WrapMethod(method = "checkCrystals")
+    private void dontFindNearestCrystalIfDying(Operation<Void> original) {
+        if (this.dragonDeathTime > 0) {
+            this.nearestCrystal = null;
+        } else {
+            original.call();
+        }
+    }
+
+    @Inject(method = "tickDeath", at = @At("HEAD"))
+    private void clearNearestCrystalOnDeath(CallbackInfo ci) {
+        this.nearestCrystal = null;
+    }
+}

src/main/resources/debugify.mixins.json

@@ -23,6 +23,7 @@
     "basic.mc170462.MobEffectsMixin",
     "basic.mc179072.SwellGoalMixin",
     "basic.mc183990.MobMixin",
+    "basic.mc187100.EnderDragonMixin",
     "basic.mc199467.MthMixin",
     "basic.mc200418.ZombieVillagerMixin",
     "basic.mc2025.EntityMixin",