Fix AsyncTabCompleteEvent not setting isCommand

Spigot-Server-Patches/0256-AsyncTabCompleteEvent.patch

@@ -1,4 +1,4 @@
-From ffc314382bb537a85a3e0f1deb92137679ae98a4 Mon Sep 17 00:00:00 2001
+From b2e3579ec648950cc3b9f373b19e02cbfd4dc0d0 Mon Sep 17 00:00:00 2001
 From: Aikar <aikar@aikar.co>
 Date: Sun, 26 Nov 2017 13:19:58 -0500
 Subject: [PATCH] AsyncTabCompleteEvent
@@ -14,7 +14,7 @@ completion, such as offline players.
 Also adds isCommand and getLocation to the sync TabCompleteEvent
 
 diff --git a/src/main/java/net/minecraft/server/PlayerConnection.java b/src/main/java/net/minecraft/server/PlayerConnection.java
-index 5a620f3fd..35774f8bf 100644
+index 5a620f3fd..ead0994f8 100644
 --- a/src/main/java/net/minecraft/server/PlayerConnection.java
 +++ b/src/main/java/net/minecraft/server/PlayerConnection.java
 @@ -2275,24 +2275,51 @@ public class PlayerConnection implements PacketListenerPlayIn, ITickable {
@@ -41,7 +41,7 @@ index 5a620f3fd..35774f8bf 100644
 +        java.util.List<String> completions = new ArrayList<>();
 +        BlockPosition blockpos = packet.b();
 +        String buffer = packet.a();
-+        boolean isCommand = packet.c();
++        boolean isCommand = buffer.startsWith("/") || packet.c();
 +        event = new com.destroystokyo.paper.event.server.AsyncTabCompleteEvent(this.getPlayer(), completions,
 +            buffer, isCommand, blockpos != null ? MCUtil.toLocation(player.world, blockpos) : null);
 +        event.callEvent();