Dupe Fix - Make bag logic more lag resistant

src/main/java/forestry/core/inventory/ItemInventory.java

@@ -87,14 +87,18 @@ private void setUID() {
     public boolean isParentItemEquipped() {
         return switch (location.type()) {
             case HELD_BY_PLAYER, UNKNOWN -> isSameItemInventory(player.getCurrentEquippedItem(), parent);
-            case PLAYER_INVENTORY -> true;
+            case PLAYER_INVENTORY -> isSameItemInventory(player.inventory.getStackInSlot(location.slotIdx()), parent);
         };
     }
 
     public EntityPlayer getPlayer() {
         return player;
     }
 
+    public ItemLocation getLocation() {
+        return location;
+    }
+
     public boolean isParentItemInventory(ItemStack itemStack) {
         ItemStack parent = getParent();
         return isSameItemInventory(parent, itemStack);

src/main/java/forestry/core/items/ItemWithGui.java

@@ -33,7 +33,7 @@ public ItemStack onItemRightClick(ItemStack itemstack, World world, EntityPlayer
     }
 
     protected void openGui(EntityPlayer entityplayer) {
-        GuiHandler.openGui(entityplayer, this);
+        GuiHandler.openGui(entityplayer, this, (short) 0, entityplayer.inventory.currentItem);
     }
 
     @Override

src/main/java/forestry/storage/inventory/ItemInventoryBackpackPaged.java

@@ -28,6 +28,11 @@ public ItemInventoryBackpackPaged(EntityPlayer player, int size, ItemStack items
 
     @Override
     public void flipPage(EntityPlayer player, short page) {
-        GuiHandler.openGui(player, backpackNaturalist, page);
+        ItemLocation loc = getLocation();
+        if (loc.type() == ItemLocation.Type.PLAYER_INVENTORY) {
+            GuiHandler.openGui(player, backpackNaturalist, page, loc.slotIdx());
+        } else {
+            GuiHandler.openGui(player, backpackNaturalist, page);
+        }
     }
 }

src/main/java/forestry/storage/items/ItemBackpack.java

@@ -72,7 +72,7 @@ public boolean getShareTag() {
 
     @Override
     protected void openGui(EntityPlayer entityplayer) {
-        GuiHandler.openGui(entityplayer, this, (short) type.ordinal());
+        GuiHandler.openGui(entityplayer, this, (short) type.ordinal(), entityplayer.inventory.currentItem);
     }
 
     @Override

src/main/java/forestry/storage/items/ItemBackpackNaturalist.java

@@ -34,7 +34,7 @@ public ItemBackpackNaturalist(ISpeciesRoot speciesRoot, IBackpackDefinition defi
 
     @Override
     protected void openGui(EntityPlayer entityplayer) {
-        GuiHandler.openGui(entityplayer, this);
+        GuiHandler.openGui(entityplayer, this, (short) 0, entityplayer.inventory.currentItem);
     }
 
     @Override