From e377a4526b65479a5ec83e5bfd1eaf214ffac945 Mon Sep 17 00:00:00 2001
From: "seer-by-sentry[bot]"
 <157164994+seer-by-sentry[bot]@users.noreply.github.com>
Date: Sun, 5 Oct 2025 02:56:11 +0000
Subject: [PATCH] W3DTerrainTracks: Prevent crash when flushing after release

---
 .../W3DDevice/GameClient/W3DTerrainTracks.cpp   | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/Generals/Code/GameEngineDevice/Source/W3DDevice/GameClient/W3DTerrainTracks.cpp b/Generals/Code/GameEngineDevice/Source/W3DDevice/GameClient/W3DTerrainTracks.cpp
index 7e1d5b352cc..d482e8f9eb2 100644
--- a/Generals/Code/GameEngineDevice/Source/W3DDevice/GameClient/W3DTerrainTracks.cpp
+++ b/Generals/Code/GameEngineDevice/Source/W3DDevice/GameClient/W3DTerrainTracks.cpp
@@ -625,6 +625,8 @@ void TerrainTracksRenderObjClassSystem::ReleaseResources(void)
 {
 	REF_PTR_RELEASE(m_indexBuffer);
 	REF_PTR_RELEASE(m_vertexBuffer);
+	// Reset edge count to prevent flush() from attempting to use released resources
+	m_edgesToFlush = 0;
 	// Note - it is ok to not release the material, as it is a w3d object that
 	// has no dx8 resources. jba.
 }
@@ -823,8 +825,23 @@ Try improving the fit to vertical surfaces like cliffs.
 	//check if there is anything to draw and fill vertex buffer
 	if (m_edgesToFlush >= 2)
 	{
+		// Validate that vertex buffer exists before attempting to lock it
+		if (!m_vertexBuffer)
+		{
+			m_edgesToFlush = 0;
+			return;
+		}
+		
 		DX8VertexBufferClass::WriteLockClass lockVtxBuffer(m_vertexBuffer);
 		VertexFormatXYZDUV1 *verts = (VertexFormatXYZDUV1*)lockVtxBuffer.Get_Vertex_Array();
+		
+		// Validate that vertex array lock succeeded before writing to it
+		if (!verts)
+		{
+			m_edgesToFlush = 0;
+			return;
+		}
+		
 		trackStartIndex=0;
 
 		mod=m_usedModules;