From 416badb6b077321b73d4827b11077617d077adb8 Mon Sep 17 00:00:00 2001
From: Alexander Harkness <me@bearbin.net>
Date: Sun, 30 Jun 2024 23:27:51 +0100
Subject: Count non-air blocks and use the real count not 4096.

---
 src/Protocol/ChunkDataSerializer.cpp | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/Protocol/ChunkDataSerializer.cpp b/src/Protocol/ChunkDataSerializer.cpp
index 6b5553ee7..6f95fb472 100644
--- a/src/Protocol/ChunkDataSerializer.cpp
+++ b/src/Protocol/ChunkDataSerializer.cpp
@@ -502,7 +502,21 @@ inline void cChunkDataSerializer::Serialize477(const int a_ChunkX, const int a_C
 	// Write each chunk section...
 	ChunkDef_ForEachSection(a_BlockData, a_LightData,
 	{
-		m_Packet.WriteBEInt16(ChunkBlockData::SectionBlockCount);  // a temp fix to make sure sections don't disappear
+		// Count non-air blocks.
+		int BlockCount = 0;
+		if (Blocks != nullptr)
+		{
+			for (size_t i = 0; i != ChunkBlockData::SectionBlockCount; i++)
+			{
+				const BLOCKTYPE BlockType = (*Blocks)[i];
+				if (BlockType != E_BLOCK_AIR)
+				{
+					BlockCount++;
+				}
+			}
+		}
+
+		m_Packet.WriteBEInt16(BlockCount);
 		m_Packet.WriteBEUInt8(BitsPerEntry);
 		m_Packet.WriteVarInt32(static_cast<UInt32>(ChunkSectionDataArraySize));
 		WriteBlockSectionSeamless<&Palette477>(Blocks, Metas, BitsPerEntry);
-- 
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