From c64752d30a01b6780d3ade5c23a2e39a04aa2ccd 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 73d72ef7e3..cc0ed8546f 100644
--- a/src/main/java/net/minecraft/server/PlayerList.java
+++ b/src/main/java/net/minecraft/server/PlayerList.java
@@ -1214,6 +1214,7 @@ public abstract class PlayerList {
     }
 
     public void savePlayers(Integer interval) {
+        MCUtil.ensureMain("Save Players", () -> { // Paper - ensure main
         long now = MinecraftServer.currentTick;
         MinecraftTimings.savePlayers.startTiming(); // Paper
         int numSaved = 0; // Paper
@@ -1225,6 +1226,7 @@ public abstract class PlayerList {
             }
         }
         MinecraftTimings.savePlayers.stopTiming(); // Paper
+        return null; }); // Paper - ensure main
     }
     // Paper end
 
-- 
2.19.0