SPIGOT-6186: Canceling a CreatureSpawnEvent​ results in a "Unable to summon entity due to duplicate UUIDs" error

By: md_5 <git@md-5.net>

paper-server/nms-patches/WorldServer.patch

@@ -395,7 +395,7 @@
              return true;
          }
      }
-@@ -813,11 +954,16 @@
+@@ -813,10 +954,16 @@
      }
  
      public boolean addAllEntitiesSafely(Entity entity) {
@@ -409,12 +409,11 @@
              return false;
          } else {
 -            this.addAllEntities(entity);
--            return true;
-+            return this.addAllEntities(entity, reason); // CraftBukkit
++            this.addAllEntities(entity, reason); // CraftBukkit
+             return true;
          }
      }
- 
-@@ -867,10 +1013,17 @@
+@@ -867,10 +1014,17 @@
          }
  
          this.getScoreboard().a(entity);
@@ -432,7 +431,7 @@
      }
  
      private void registerEntity(Entity entity) {
-@@ -891,9 +1044,16 @@
+@@ -891,9 +1045,16 @@
  
              this.entitiesByUUID.put(entity.getUniqueID(), entity);
              this.getChunkProvider().addEntity(entity);
@@ -449,7 +448,7 @@
          }
  
      }
-@@ -923,10 +1083,33 @@
+@@ -923,10 +1084,33 @@
          this.everyoneSleeping();
      }
  
@@ -483,7 +482,7 @@
          while (iterator.hasNext()) {
              EntityPlayer entityplayer = (EntityPlayer) iterator.next();
  
-@@ -935,6 +1118,12 @@
+@@ -935,6 +1119,12 @@
                  double d1 = (double) blockposition.getY() - entityplayer.locY();
                  double d2 = (double) blockposition.getZ() - entityplayer.locZ();
  
@@ -496,7 +495,7 @@
                  if (d0 * d0 + d1 * d1 + d2 * d2 < 1024.0D) {
                      entityplayer.playerConnection.sendPacket(new PacketPlayOutBlockBreakAnimation(i, blockposition, j));
                  }
-@@ -995,10 +1184,20 @@
+@@ -995,10 +1185,20 @@
  
      @Override
      public Explosion createExplosion(@Nullable Entity entity, @Nullable DamageSource damagesource, @Nullable ExplosionDamageCalculator explosiondamagecalculator, double d0, double d1, double d2, float f, boolean flag, Explosion.Effect explosion_effect) {
@@ -517,7 +516,7 @@
          if (explosion_effect == Explosion.Effect.NONE) {
              explosion.clearBlocks();
          }
-@@ -1063,13 +1262,20 @@
+@@ -1063,13 +1263,20 @@
      }
  
      public <T extends ParticleParam> int a(T t0, double d0, double d1, double d2, int i, double d3, double d4, double d5, double d6) {
@@ -540,7 +539,7 @@
                  ++j;
              }
          }
-@@ -1111,7 +1317,7 @@
+@@ -1111,7 +1318,7 @@
  
      @Nullable
      public BlockPosition a(StructureGenerator<?> structuregenerator, BlockPosition blockposition, int i, boolean flag) {
@@ -549,7 +548,7 @@
      }
  
      @Nullable
-@@ -1149,7 +1355,13 @@
+@@ -1149,7 +1356,13 @@
      @Override
      public WorldMap a(String s) {
          return (WorldMap) this.getMinecraftServer().E().getWorldPersistentData().b(() -> {
@@ -564,7 +563,7 @@
          }, s);
      }
  
-@@ -1460,6 +1672,11 @@
+@@ -1460,6 +1673,11 @@
      @Override
      public void update(BlockPosition blockposition, Block block) {
          if (!this.isDebugWorld()) {
@@ -576,7 +575,7 @@
              this.applyPhysics(blockposition, block);
          }
  
-@@ -1474,12 +1691,12 @@
+@@ -1474,12 +1692,12 @@
      }
  
      public boolean isFlatWorld() {
@@ -591,7 +590,7 @@
      }
  
      @Nullable
-@@ -1499,9 +1716,9 @@
+@@ -1499,9 +1717,9 @@
  
      @VisibleForTesting
      public String F() {
@@ -603,7 +602,7 @@
              return IRegistry.BLOCK_ENTITY_TYPE.getKey(tileentity.getTileType());
          }), this.getBlockTickList().a(), this.getFluidTickList().a(), this.P());
      }
-@@ -1509,7 +1726,7 @@
+@@ -1509,7 +1727,7 @@
      private static <T> String a(Collection<T> collection, Function<T, MinecraftKey> function) {
          try {
              Object2IntOpenHashMap<MinecraftKey> object2intopenhashmap = new Object2IntOpenHashMap();
@@ -612,7 +611,7 @@
  
              while (iterator.hasNext()) {
                  T t0 = iterator.next();
-@@ -1518,7 +1735,8 @@
+@@ -1518,7 +1736,8 @@
                  object2intopenhashmap.addTo(minecraftkey, 1);
              }
  
@@ -622,7 +621,7 @@
                  return it_unimi_dsi_fastutil_objects_object2intmap_entry.getKey() + ":" + it_unimi_dsi_fastutil_objects_object2intmap_entry.getIntValue();
              }).collect(Collectors.joining(","));
          } catch (Exception exception) {
-@@ -1527,16 +1745,32 @@
+@@ -1527,16 +1746,32 @@
      }
  
      public static void a(WorldServer worldserver) {