From b5319dbb3249a88bdc5d9bc429e03a52c50de59a Mon Sep 17 00:00:00 2001
From: EnZaXD <florian.michael07@gmail.com>
Date: Sat, 20 Jul 2024 17:09:34 +0200
Subject: [PATCH] Check if item is null in 1.17.1->1.17 book conversion (#826)

---
 .../protocol/v1_17_1to1_17/Protocol1_17_1To1_17.java        | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/common/src/main/java/com/viaversion/viabackwards/protocol/v1_17_1to1_17/Protocol1_17_1To1_17.java b/common/src/main/java/com/viaversion/viabackwards/protocol/v1_17_1to1_17/Protocol1_17_1To1_17.java
index 42d282e8..54edd02d 100644
--- a/common/src/main/java/com/viaversion/viabackwards/protocol/v1_17_1to1_17/Protocol1_17_1To1_17.java
+++ b/common/src/main/java/com/viaversion/viabackwards/protocol/v1_17_1to1_17/Protocol1_17_1To1_17.java
@@ -102,6 +102,12 @@ public final class Protocol1_17_1To1_17 extends BackwardsProtocol<ClientboundPac
             boolean signing = wrapper.read(Types.BOOLEAN);
             wrapper.passthrough(Types.VAR_INT); // Slot comes first
 
+            if (item == null) {
+                wrapper.write(Types.VAR_INT, 0); // Pages length
+                wrapper.write(Types.BOOLEAN, false); // Optional title
+                return;
+            }
+
             CompoundTag tag = item.tag();
             ListTag<StringTag> pagesTag;
             StringTag titleTag = null;