Make Levels Use Correct Spawn Settings (#6419)

Author: tahmid-23

patches/server/0468-Fix-Per-World-Difficulty-Remembering-Difficulty.patch

@@ -8,9 +8,18 @@ makes it so that the server keeps the last difficulty used instead
 of restoring the server.properties every single load.
 
 diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
-index f3a1af9299f3c0b03309b838b00d3eca7caf5966..186193d1d652876e9ad7cdf5223ec2c6f5c65779 100644
+index b4ca88f9285fb5a55ed5b03355a77fd564ebaa80..58652325de8c3978359a9864bb68da9347990774 100644
 --- a/src/main/java/net/minecraft/server/MinecraftServer.java
 +++ b/src/main/java/net/minecraft/server/MinecraftServer.java
+@@ -856,7 +856,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
+         chunkproviderserver.getLightEngine().setTaskPerBatch(worldserver.paperConfig.lightQueueSize); // Paper - increase light queue size
+         // CraftBukkit start
+         // this.updateSpawnFlags();
+-        worldserver.setSpawnSettings(this.isSpawningMonsters(), this.isSpawningAnimals());
++        worldserver.setSpawnSettings(worldserver.serverLevelData.getDifficulty() != Difficulty.PEACEFUL && ((DedicatedServer) this).settings.getProperties().spawnMonsters, this.isSpawningAnimals()); // Paper - per level difficulty (from setDifficulty(ServerLevel, Difficulty, boolean))
+ 
+         this.forceTicks = false;
+         // CraftBukkit end
 @@ -1726,11 +1726,14 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
          }
      }
@@ -31,6 +40,15 @@ index f3a1af9299f3c0b03309b838b00d3eca7caf5966..186193d1d652876e9ad7cdf5223ec2c6
          }
      }
 
+@@ -1744,7 +1747,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
+         while (iterator.hasNext()) {
+             ServerLevel worldserver = (ServerLevel) iterator.next();
+ 
+-            worldserver.setSpawnSettings(this.isSpawningMonsters(), this.isSpawningAnimals());
++            worldserver.setSpawnSettings(worldserver.serverLevelData.getDifficulty() != Difficulty.PEACEFUL && ((DedicatedServer) this).settings.getProperties().spawnMonsters, this.isSpawningAnimals()); // Paper - per level difficulty (from setDifficulty(ServerLevel, Difficulty, boolean))
+         }
+ 
+     }
 diff --git a/src/main/java/net/minecraft/server/commands/DifficultyCommand.java b/src/main/java/net/minecraft/server/commands/DifficultyCommand.java
 index 33c859df0b669d0c3e97ccba29f17c1ba2166a27..9f03b738aea623fe409ca176397f48be055466da 100644
 --- a/src/main/java/net/minecraft/server/commands/DifficultyCommand.java
@@ -75,3 +93,18 @@ index 7bd2a88de8eaf9d72d9424a39d5df2600bed7e58..c0ae236619bbdf9293fbf1c4a1764a78
          }
      }
 
+diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+index ecc65fe9783f0f369695edc1183f3d49686d66f9..d1038dc34735e666ea35d5b0fcec67120a15ff85 100644
+--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
++++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+@@ -865,8 +865,8 @@ public final class CraftServer implements Server {
+         org.spigotmc.SpigotConfig.init((File) console.options.valueOf("spigot-settings")); // Spigot
+         com.destroystokyo.paper.PaperConfig.init((File) console.options.valueOf("paper-settings")); // Paper
+         for (ServerLevel world : this.console.getAllLevels()) {
+-            world.serverLevelData.setDifficulty(config.difficulty);
+-            world.setSpawnSettings(config.spawnMonsters, config.spawnAnimals);
++            // world.serverLevelData.setDifficulty(config.difficulty); // Paper - per level difficulty
++            world.setSpawnSettings(world.serverLevelData.getDifficulty() != Difficulty.PEACEFUL && config.spawnMonsters, config.spawnAnimals); // Paper - per level difficulty (from MinecraftServer#setDifficulty(ServerLevel, Difficulty, boolean))
+             if (this.getTicksPerAnimalSpawns() < 0) {
+                 world.ticksPerAnimalSpawns = 400;
+             } else {