From 831e570a9d59d466810523e85b1fa31867af7cf2 Mon Sep 17 00:00:00 2001
From: Minecrell <minecrell@minecrell.net>
Date: Fri, 13 Jul 2018 14:54:43 +0200
Subject: [PATCH] Refresh player inventory when cancelling
 PlayerInteractEntityEvent

When interacting with entities with an item, the client will assume
the interaction is successful, and update the held item on the
client. However, if the interaction is cancelled on the server side,
the client will still mistakenly remove/replace the item in hand.

Examples for this are milking cows with a bucket or dyeing sheep.
The bucket is replaced with milk and the dye removed from inventory.

Refresh the player inventory when PlayerInteractEntityEvent is
cancelled to avoid this problem.

diff --git a/src/main/java/net/minecraft/server/PlayerConnection.java b/src/main/java/net/minecraft/server/PlayerConnection.java
index 0b5dc66897..6d04c5733c 100644
--- a/src/main/java/net/minecraft/server/PlayerConnection.java
+++ b/src/main/java/net/minecraft/server/PlayerConnection.java
@@ -1916,6 +1916,7 @@ public class PlayerConnection implements PacketListenerPlayIn, ITickable {
                     }
 
                     if (event.isCancelled()) {
+                        this.player.updateInventory(this.player.activeContainer); // Paper - Refresh player inventory
                         return;
                     }
                     // CraftBukkit end
-- 
2.21.0