Improve IplStoreSA validation to avoid crashes (#4572)

* Improve IplStoreSA validation to avoid crashes

Author: Xenius97

Client/game_sa/CIplStoreSA.cpp

@@ -22,16 +22,52 @@ CIplStoreSA::CIplStoreSA() : m_isStreamingEnabled(true), m_ppIplPoolInterface((C
 
 void CIplStoreSA::UnloadAndDisableStreaming(int iplId)
 {
+    // Is pool valid?
+    if (!m_ppIplPoolInterface)
+        return;
+
+    // Is pool object valid?
+    auto pool = *m_ppIplPoolInterface;
+    if (!pool)
+        return;
+
+    // Is IPL in pool?
+    if (!pool->IsContains(iplId))
+        return;
+
+    // Is IPL object valid?
+    auto ipl = pool->GetObject(iplId);
+    if (!ipl)
+        return;
+
     typedef void*(__cdecl * Function_EnableStreaming)(int);
     ((Function_EnableStreaming)(0x405890))(iplId);
 }
 
 void CIplStoreSA::EnableStreaming(int iplId)
 {
-    auto ipl = (*m_ppIplPoolInterface)->GetObject(iplId);
+    // Is pool valid?
+    if (!m_ppIplPoolInterface)
+        return;
+
+    // Is pool object valid?
+    auto pool = *m_ppIplPoolInterface;
+    if (!pool)
+        return;
+
+    // Is IPL in pool?
+    if (!pool->IsContains(iplId))
+        return;
+
+    // Is IPL object valid?
+    auto ipl = pool->GetObject(iplId);
+    if (!ipl)
+        return;
+
     ipl->bDisabledStreaming = false;
 
-    (*gIplQuadTree)->AddItem(ipl, &ipl->rect);
+    if (*gIplQuadTree)
+        (*gIplQuadTree)->AddItem(ipl, &ipl->rect);
 }
 
 void CIplStoreSA::SetDynamicIplStreamingEnabled(bool state)
@@ -42,27 +78,33 @@ void CIplStoreSA::SetDynamicIplStreamingEnabled(bool state)
     // Ipl with 0 index is generic
     // We don't unload this IPL
 
-    auto pPool = *m_ppIplPoolInterface;
+    auto pool = *m_ppIplPoolInterface;
+    if (!pool)
+        return;
+
+    // Collect all IPL ids
+    std::vector<int> iplIds;
+    iplIds.reserve(pool->m_nSize);
+
+    for (int i = 1; i < pool->m_nSize; i++)
+    {
+        if (pool->IsContains(i))
+            iplIds.push_back(i);
+    }
+
+    // Now enable/disable streaming for all IPLs
     if (!state)
     {
-        for (int i = 1; i < pPool->m_nSize; i++)
-        {
-            if (pPool->IsContains(i))
-            {
-                UnloadAndDisableStreaming(i);
-            }
-        }
-        (*gIplQuadTree)->RemoveAllItems();
+        for (int iplId : iplIds)
+            UnloadAndDisableStreaming(iplId);
+
+        if (*gIplQuadTree)
+            (*gIplQuadTree)->RemoveAllItems();
     }
     else
     {
-        for (int i = 1; i < pPool->m_nSize; i++)
-        {
-            if (pPool->IsContains(i))
-            {
-                EnableStreaming(i);
-            }
-        }
+        for (int iplId : iplIds)
+            EnableStreaming(iplId);
     }
 
     m_isStreamingEnabled = state;
@@ -76,27 +118,34 @@ void CIplStoreSA::SetDynamicIplStreamingEnabled(bool state, std::function<bool(C
     // Ipl with 0 index is generic
     // We don't unload this IPL
 
-    auto pPool = *m_ppIplPoolInterface;
+    auto pool = *m_ppIplPoolInterface;
+    if (!pool)
+        return;
+
+    // Collect IPL ids that match the filter
+    std::vector<int> iplIds;
+    iplIds.reserve(pool->m_nSize);
+
+    for (int i = 1; i < pool->m_nSize; i++)
+    {
+        auto ipl = pool->GetObject(i);
+        if (ipl && pool->IsContains(i) && filter(ipl))
+            iplIds.push_back(i);
+    }
+
+    // Apply the streaming state change
     if (!state)
     {
-        for (int i = 1; i < pPool->m_nSize; i++)
-        {
-            if (pPool->IsContains(i) && filter(pPool->GetObject(i)))
-            {
-                UnloadAndDisableStreaming(i);
-            }
-        }
-        (*gIplQuadTree)->RemoveAllItems();
+        for (int iplId : iplIds)
+            UnloadAndDisableStreaming(iplId);
+
+        if (*gIplQuadTree)
+            (*gIplQuadTree)->RemoveAllItems();
     }
     else
     {
-        for (int i = 1; i < pPool->m_nSize; i++)
-        {
-            if (pPool->IsContains(i) && filter(pPool->GetObject(i)))
-            {
-                EnableStreaming(i);
-            }
-        }
+        for (int iplId : iplIds)
+            EnableStreaming(iplId);
     }
 
     m_isStreamingEnabled = state;