From 6de786d243b7dd9f39b5b6dba5bedaa88c579a3d Mon Sep 17 00:00:00 2001
From: baldurk <baldurk@baldurk.org>
Date: Wed, 6 Aug 2025 13:14:47 +0100
Subject: [PATCH] Fix a crash when patching ray dispatches after device lost

---
 renderdoc/driver/d3d12/d3d12_manager.cpp | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/renderdoc/driver/d3d12/d3d12_manager.cpp b/renderdoc/driver/d3d12/d3d12_manager.cpp
index b5b1fade9..38bf36a0c 100644
--- a/renderdoc/driver/d3d12/d3d12_manager.cpp
+++ b/renderdoc/driver/d3d12/d3d12_manager.cpp
@@ -2292,8 +2292,12 @@ void D3D12RTManager::PrepareRayDispatchBuffer(GPUAddressRangeTracker *origAddres
                                D3D12GpuBufferHeapMemoryFlag::Default, lookupData.size(), 256,
                                &m_LookupBuffer);
 
-    memcpy(m_LookupBuffer->Map(), lookupData.data(), lookupData.size());
-    m_LookupBuffer->Unmap();
+    void *ptr = m_LookupBuffer ? m_LookupBuffer->Map() : NULL;
+    if(ptr)
+    {
+      memcpy(m_LookupBuffer->Map(), lookupData.data(), lookupData.size());
+      m_LookupBuffer->Unmap();
+    }
 
     D3D12_GPU_VIRTUAL_ADDRESS baseAddr = m_LookupBuffer->Address();
     m_LookupAddrs[0] = baseAddr + ObjectLookupOffset;