From f8bc3dbb3e883bfae68fc44d2dfd9515b8eb43ff Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sat, 7 Jan 2017 15:41:58 -0500
Subject: [PATCH] Enforce Sync Player Saves

Saving players async is extremely dangerous. This will force it to main
the same way we handle async chunk loads.

diff --git a/src/main/java/net/minecraft/server/PlayerList.java b/src/main/java/net/minecraft/server/PlayerList.java
index f675a7013..a9d59bbf5 100644
--- a/src/main/java/net/minecraft/server/PlayerList.java
+++ b/src/main/java/net/minecraft/server/PlayerList.java
@@ -1212,6 +1212,7 @@ public abstract class PlayerList {
     }
 
     public void savePlayers(Integer interval) {
+        MCUtil.ensureMain("Save Players", () -> { // Paper - ensure main
         long now = MinecraftServer.currentTick;
         MinecraftTimings.savePlayers.startTiming(); // Paper
         for (int i = 0; i < this.players.size(); ++i) {
@@ -1221,6 +1222,7 @@ public abstract class PlayerList {
             }
         }
         MinecraftTimings.savePlayers.stopTiming(); // Paper
+        return null; }); // Paper - ensure main
     }
     // Paper end
 
-- 
2.11.0