From 497a4af1c5c644f4d6b51dbdacea93816f2ad88d Mon Sep 17 00:00:00 2001
From: TheBusyBiscuit <mrCookieSlime@gmail.com>
Date: Thu, 29 Sep 2022 12:39:40 +0200
Subject: [PATCH] Fixed #3664

---
 CHANGELOG.md                                   |  1 +
 .../slimefun4/api/player/PlayerBackpack.java   | 17 +++++++++++++++++
 .../multiblocks/AbstractCraftingTable.java     |  6 +++++-
 .../listeners/BackpackListener.java            | 18 +++++++++++++-----
 4 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 462ee5fa2..14b65caf7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -57,6 +57,7 @@
 * Fixed an issue related to "Bee Wings"
 * Fixed #3573
 * Fixed "round-robin" mode for cargo networks being very unreliable
+* Fixed #3664
 
 ## Release Candidate 32 (26 Jun 2022)
 https://thebusybiscuit.github.io/builds/TheBusyBiscuit/Slimefun4/stable/#32
diff --git a/src/main/java/io/github/thebusybiscuit/slimefun4/api/player/PlayerBackpack.java b/src/main/java/io/github/thebusybiscuit/slimefun4/api/player/PlayerBackpack.java
index 5d942114f..5af1f1fe7 100644
--- a/src/main/java/io/github/thebusybiscuit/slimefun4/api/player/PlayerBackpack.java
+++ b/src/main/java/io/github/thebusybiscuit/slimefun4/api/player/PlayerBackpack.java
@@ -1,10 +1,13 @@
 package io.github.thebusybiscuit.slimefun4.api.player;
 
 import java.io.File;
+import java.util.ArrayList;
+import java.util.Iterator;
 
 import javax.annotation.Nonnull;
 
 import org.bukkit.Bukkit;
+import org.bukkit.entity.HumanEntity;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.ItemStack;
@@ -132,6 +135,20 @@ public class PlayerBackpack {
         });
     }
 
+    /**
+     * This will close the {@link Inventory} of this backpack for every {@link Player}
+     * that has opened it.
+     */
+    public void closeForAll() {
+        Slimefun.runSync(() -> {
+            Iterator<HumanEntity> iterator = new ArrayList<>(inventory.getViewers()).iterator();
+
+            while (iterator.hasNext()) {
+                iterator.next().closeInventory();
+            }
+        });
+    }
+
     /**
      * This will change the current size of this Backpack to the specified size.
      * 
diff --git a/src/main/java/io/github/thebusybiscuit/slimefun4/implementation/items/multiblocks/AbstractCraftingTable.java b/src/main/java/io/github/thebusybiscuit/slimefun4/implementation/items/multiblocks/AbstractCraftingTable.java
index c45a8c246..4adf57bc9 100644
--- a/src/main/java/io/github/thebusybiscuit/slimefun4/implementation/items/multiblocks/AbstractCraftingTable.java
+++ b/src/main/java/io/github/thebusybiscuit/slimefun4/implementation/items/multiblocks/AbstractCraftingTable.java
@@ -123,7 +123,11 @@ abstract class AbstractCraftingTable extends MultiBlockMachine {
 
                     PlayerProfile.fromUUID(UUID.fromString(idSplit[0]), profile -> {
                         Optional<PlayerBackpack> optional = profile.getBackpack(Integer.parseInt(idSplit[1]));
-                        optional.ifPresent(playerBackpack -> playerBackpack.setSize(size));
+                        optional.ifPresent(playerBackpack -> {
+                            // Safety feature for Issue #3664
+                            playerBackpack.closeForAll();
+                            playerBackpack.setSize(size);
+                        });
                     });
 
                     return Optional.of(id);
diff --git a/src/main/java/io/github/thebusybiscuit/slimefun4/implementation/listeners/BackpackListener.java b/src/main/java/io/github/thebusybiscuit/slimefun4/implementation/listeners/BackpackListener.java
index 796f6917b..1650b0b42 100644
--- a/src/main/java/io/github/thebusybiscuit/slimefun4/implementation/listeners/BackpackListener.java
+++ b/src/main/java/io/github/thebusybiscuit/slimefun4/implementation/listeners/BackpackListener.java
@@ -96,6 +96,7 @@ public class BackpackListener implements Listener {
 
             if (backpack instanceof SlimefunBackpack slimefunBackpack) {
                 if (e.getClick() == ClickType.NUMBER_KEY) {
+                    // Prevent disallowed items from being moved using number keys.
                     if (e.getClickedInventory().getType() != InventoryType.PLAYER) {
                         ItemStack hotbarItem = e.getWhoClicked().getInventory().getItem(e.getHotbarButton());
 
@@ -103,12 +104,19 @@ public class BackpackListener implements Listener {
                             e.setCancelled(true);
                         }
                     }
-                } else if (e.getClick() == ClickType.SWAP_OFFHAND && e.getClickedInventory().getType() != InventoryType.PLAYER) {
-                    // Fixes #3265
-                    ItemStack offHandItem = e.getWhoClicked().getInventory().getItemInOffHand();
+                } else if (e.getClick() == ClickType.SWAP_OFFHAND) {
+                    if (e.getClickedInventory().getType() != InventoryType.PLAYER) {
+                        // Fixes #3265 - Don't move disallowed items using the off hand.
+                        ItemStack offHandItem = e.getWhoClicked().getInventory().getItemInOffHand();
 
-                    if (!isAllowed(slimefunBackpack, offHandItem)) {
-                        e.setCancelled(true);
+                        if (!isAllowed(slimefunBackpack, offHandItem)) {
+                            e.setCancelled(true);
+                        }
+                    } else {
+                        // Fixes #3664 - Do not swap the backpack to your off hand.
+                        if (e.getCurrentItem() != null && e.getCurrentItem().isSimilar(item)) {
+                            e.setCancelled(true);
+                        }
                     }
                 } else if (!isAllowed(slimefunBackpack, e.getCurrentItem())) {
                     e.setCancelled(true);