From 80c04dcbb9981d8d3894c6be31e4d6956c057b8d Mon Sep 17 00:00:00 2001
From: Uladzislau Nikalayevich <thenormalnij@gmail.com>
Date: Sat, 23 Sep 2023 23:27:53 +0300
Subject: [PATCH] Fix engineFreeModel crashes

---
 Client/mods/deathmatch/logic/CClientModel.cpp | 38 ++++++++++++-------
 Client/mods/deathmatch/logic/CClientModel.h   |  5 ++-
 .../deathmatch/logic/CClientModelManager.cpp  |  2 +-
 3 files changed, 29 insertions(+), 16 deletions(-)

diff --git a/Client/mods/deathmatch/logic/CClientModel.cpp b/Client/mods/deathmatch/logic/CClientModel.cpp
index 56bd3f566b..e42ee3a695 100644
--- a/Client/mods/deathmatch/logic/CClientModel.cpp
+++ b/Client/mods/deathmatch/logic/CClientModel.cpp
@@ -78,30 +78,49 @@ bool CClientModel::Allocate(ushort usParentID)
     return false;
 }
 
+// You can call it only in destructor for DFF.
 bool CClientModel::Deallocate()
 {
     if (!m_bAllocatedByUs)
         return false;
+
+    SetParentResource(nullptr);
+
     CModelInfo* pModelInfo = g_pGame->GetModelInfo(m_iModelID, true);
     if (!pModelInfo || !pModelInfo->IsValid())
         return false;
 
-    SetParentResource(nullptr);
+    if (m_eModelType != eClientModelType::TXD)
+    {
+        // Remove model info
+        pModelInfo->DeallocateModel();
+    }
+
+    return true;
+}
+
+void CClientModel::RestoreEntitiesUsingThisModel()
+{
+    CModelInfo* pModelInfo = g_pGame->GetModelInfo(m_iModelID, true);
+    if (!pModelInfo || !pModelInfo->IsValid())
+        return;
 
     switch (m_eModelType)
     {
         case eClientModelType::PED:
         case eClientModelType::OBJECT:
         case eClientModelType::VEHICLE:
-            return DeallocateDFF(pModelInfo);
+            RestoreDFF(pModelInfo);
+            return;
         case eClientModelType::TXD:
-            return DeallocateTXD(pModelInfo);
+            RestoreTXD(pModelInfo);
+            return;
         default:
-            return false;
+            return;
     }
 }
 
-bool CClientModel::DeallocateDFF(CModelInfo* pModelInfo)
+void CClientModel::RestoreDFF(CModelInfo* pModelInfo)
 {
     auto unloadModelsAndCallEvents = [&](auto iterBegin, auto iterEnd, unsigned short usParentID, auto setElementModelLambda) {
         for (auto iter = iterBegin; iter != iterEnd; iter++)
@@ -164,11 +183,6 @@ bool CClientModel::DeallocateDFF(CModelInfo* pModelInfo)
 
     // Restore DFF/TXD
     g_pClientGame->GetManager()->GetDFFManager()->RestoreModel(m_iModelID);
-
-    // Remove model info
-    pModelInfo->DeallocateModel();
-
-    return true;
 }
 
 bool CClientModel::AllocateTXD(std::string &strTxdName)
@@ -182,7 +196,7 @@ bool CClientModel::AllocateTXD(std::string &strTxdName)
     return false;
 }
 
-bool CClientModel::DeallocateTXD(CModelInfo* pModelInfo)
+void CClientModel::RestoreTXD(CModelInfo* pModelInfo)
 {
     uint uiTextureDictonarySlotID = pModelInfo->GetModel() - MAX_MODEL_DFF_ID;
 
@@ -196,6 +210,4 @@ bool CClientModel::DeallocateTXD(CModelInfo* pModelInfo)
 
     g_pGame->GetPools()->RemoveTextureDictonarySlot(uiTextureDictonarySlotID);
     g_pGame->GetStreaming()->SetStreamingInfo(pModelInfo->GetModel(), 0, 0, 0, -1);
-
-    return true;
 }
diff --git a/Client/mods/deathmatch/logic/CClientModel.h b/Client/mods/deathmatch/logic/CClientModel.h
index 27b5db24ee..903148192d 100644
--- a/Client/mods/deathmatch/logic/CClientModel.h
+++ b/Client/mods/deathmatch/logic/CClientModel.h
@@ -42,10 +42,11 @@ class CClientModel final
     bool             Deallocate(void);
     void             SetParentResource(CResource* pResource) { m_pParentResource = pResource; }
     CResource*       GetParentResource(void) const { return m_pParentResource; }
+    void             RestoreEntitiesUsingThisModel();
 
 private:
-    bool DeallocateDFF(CModelInfo* pModelInfo);
-    bool DeallocateTXD(CModelInfo* pModelInfo);
+    void RestoreDFF(CModelInfo* pModelInfo);
+    void RestoreTXD(CModelInfo* pModelInfo);
 
 protected:
     CClientManager* m_pManager;
diff --git a/Client/mods/deathmatch/logic/CClientModelManager.cpp b/Client/mods/deathmatch/logic/CClientModelManager.cpp
index 2323a645c0..21d795e964 100644
--- a/Client/mods/deathmatch/logic/CClientModelManager.cpp
+++ b/Client/mods/deathmatch/logic/CClientModelManager.cpp
@@ -49,7 +49,7 @@ bool CClientModelManager::Remove(const std::shared_ptr<CClientModel>& pModel)
     int modelId = pModel->GetModelID();
     if (m_Models[modelId] != nullptr)
     {
-        m_Models[modelId]->Deallocate();
+        m_Models[modelId]->RestoreEntitiesUsingThisModel();
         m_Models[modelId] = nullptr;
         m_modelCount--;
         return true;