Merge branch 'fix_potential_crash' into 'master'

Fix potential crashes

See merge request OpenMW/openmw!2699

apps/openmw/mwphysics/physicssystem.cpp

@@ -822,6 +822,7 @@ namespace MWPhysics
         // copy new ptr position in temporary vector. player is handled separately as its movement might change active
         // cell.
         mActorsPositions.clear();
+        if (!mActors.empty())
             mActorsPositions.reserve(mActors.size() - 1);
         for (const auto& [ptr, physicActor] : mActors)
         {
@@ -833,6 +834,7 @@ namespace MWPhysics
         for (const auto& [ptr, pos] : mActorsPositions)
             world->moveObject(ptr, pos, false, false);
 
+        if (player != nullptr)
             world->moveObject(player->getPtr(), player->getSimulationPosition(), false, false);
     }
 

components/resource/objectcache.hpp

@@ -61,7 +61,8 @@ namespace Resource
             {
                 // If ref count is greater than 1, the object has an external reference.
                 // If the timestamp is yet to be initialized, it needs to be updated too.
-                if (itr->second.first->referenceCount() > 1 || itr->second.second == 0.0)
+                if ((itr->second.first != nullptr && itr->second.first->referenceCount() > 1)
+                    || itr->second.second == 0.0)
                     itr->second.second = referenceTime;
             }
         }