Prevent duplicate raider in RaidSpawnWaveEvent list (#12040)

paper-server/patches/sources/net/minecraft/world/entity/raid/Raid.java.patch

@@ -99,42 +99,20 @@
                      this.stop();
                      return;
                  }
-@@ -491,6 +_,10 @@
+@@ -486,7 +_,7 @@
+ 
+     private void spawnGroup(BlockPos pos) {
+         boolean flag = false;
+-        int i = this.groupsSpawned + 1;
++        int i = this.groupsSpawned + 1; final int wave = i; // Paper - OBFHELPER
+         this.totalHealth = 0.0F;
          DifficultyInstance currentDifficultyAt = this.level.getCurrentDifficultyAt(pos);
          boolean shouldSpawnBonusGroup = this.shouldSpawnBonusGroup();
- 
-+        // CraftBukkit start
-+        Raider leader = null;
-+        List<Raider> raiders = new java.util.ArrayList<>();
-+        // CraftBukkit end
-         for (Raid.RaiderType raiderType : Raid.RaiderType.VALUES) {
-             int i1 = this.getDefaultNumSpawns(raiderType, i, shouldSpawnBonusGroup)
-                 + this.getPotentialBonusSpawns(raiderType, this.random, i, currentDifficultyAt, shouldSpawnBonusGroup);
-@@ -506,9 +_,11 @@
-                     raider.setPatrolLeader(true);
-                     this.setLeader(i, raider);
-                     flag = true;
-+                    leader = raider; // CraftBukkit
-                 }
- 
-                 this.joinRaid(i, raider, pos, false);
-+                raiders.add(raider); // CraftBukkit
-                 if (raiderType.entityType == EntityType.RAVAGER) {
-                     Raider raider1 = null;
-                     if (i == this.getNumGroups(Difficulty.NORMAL)) {
-@@ -526,6 +_,7 @@
-                         this.joinRaid(i, raider1, pos, false);
-                         raider1.moveTo(pos, 0.0F, 0.0F);
-                         raider1.startRiding(raider);
-+                        raiders.add(raider); // CraftBukkit
-                     }
-                 }
-             }
 @@ -535,6 +_,7 @@
          this.groupsSpawned++;
          this.updateBossbar();
          this.setDirty();
-+        org.bukkit.craftbukkit.event.CraftEventFactory.callRaidSpawnWaveEvent(this, leader, raiders); // CraftBukkit
++        org.bukkit.craftbukkit.event.CraftEventFactory.callRaidSpawnWaveEvent(this, java.util.Objects.requireNonNull(this.getLeader(wave)), this.groupRaiderMap.get(wave)); // CraftBukkit
      }
  
      public void joinRaid(int wave, Raider raider, @Nullable BlockPos pos, boolean isRecruited) {