From f911fd488006ee117d1063558d1907f0237f030e Mon Sep 17 00:00:00 2001
From: Noah van der Aa <ndvdaa@gmail.com>
Date: Mon, 30 Aug 2021 15:22:18 +0200
Subject: [PATCH] Prevent softlocked end exit portal generation

---
 .../dimension/end/EndDragonFight.java.patch   | 20 +++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/paper-server/patches/sources/net/minecraft/world/level/dimension/end/EndDragonFight.java.patch b/paper-server/patches/sources/net/minecraft/world/level/dimension/end/EndDragonFight.java.patch
index 20092ff84c..c6f337107c 100644
--- a/paper-server/patches/sources/net/minecraft/world/level/dimension/end/EndDragonFight.java.patch
+++ b/paper-server/patches/sources/net/minecraft/world/level/dimension/end/EndDragonFight.java.patch
@@ -61,7 +61,19 @@
  
              this.previouslyKilled = true;
              this.dragonKilled = true;
-@@ -469,6 +489,7 @@
+@@ -449,6 +469,11 @@
+             }
+         }
+ 
++        // Paper start - Prevent "softlocked" exit portal generation
++        if (this.portalLocation.getY() <= this.level.getMinY()) {
++            this.portalLocation = this.portalLocation.atY(this.level.getMinY() + 1);
++        }
++        // Paper end - Prevent "softlocked" exit portal generation
+         if (worldgenendtrophy.place(FeatureConfiguration.NONE, this.level, this.level.getChunkSource().getGenerator(), RandomSource.create(), this.portalLocation)) {
+             int i = Mth.positiveCeilDiv(4, 16);
+ 
+@@ -469,6 +494,7 @@
              entityenderdragon.moveTo((double) this.origin.getX(), (double) (128 + this.origin.getY()), (double) this.origin.getZ(), this.level.random.nextFloat() * 360.0F, 0.0F);
              this.level.addFreshEntity(entityenderdragon);
              this.dragonUUID = entityenderdragon.getUUID();
@@ -69,7 +81,7 @@
          }
  
          return entityenderdragon;
-@@ -513,7 +534,7 @@
+@@ -513,7 +539,7 @@
          return this.previouslyKilled;
      }
  
@@ -78,7 +90,7 @@
          if (this.dragonKilled && this.respawnStage == null) {
              BlockPos blockposition = this.portalLocation;
  
-@@ -540,19 +561,19 @@
+@@ -540,19 +566,19 @@
                  List<EndCrystal> list1 = this.level.getEntitiesOfClass(EndCrystal.class, new AABB(blockposition1.relative(enumdirection, 2)));
  
                  if (list1.isEmpty()) {
@@ -102,7 +114,7 @@
          if (this.dragonKilled && this.respawnStage == null) {
              for (BlockPattern.BlockPatternMatch shapedetector_shapedetectorcollection = this.findExitPortal(); shapedetector_shapedetectorcollection != null; shapedetector_shapedetectorcollection = this.findExitPortal()) {
                  for (int i = 0; i < this.exitPortalPattern.getWidth(); ++i) {
-@@ -571,9 +592,10 @@
+@@ -571,9 +597,10 @@
              this.respawnStage = DragonRespawnAnimation.START;
              this.respawnTime = 0;
              this.spawnExitPortal(false);