Reset RefNum when copying an object (Fixes #1723)

apps/openmw/mwworld/cellref.cpp

@@ -10,6 +10,12 @@ namespace MWWorld
         return mCellRef.mRefNum;
     }
 
+    void CellRef::unsetRefNum()
+    {
+        mCellRef.mRefNum.mContentFile = -1;
+        mCellRef.mRefNum.mIndex = 0;
+    }
+
     std::string CellRef::getRefId() const
     {
         return mCellRef.mRefID;

apps/openmw/mwworld/cellref.hpp

@@ -25,6 +25,9 @@ namespace MWWorld
         // Note: Currently unused for items in containers
         ESM::RefNum getRefNum() const;
 
+        // Set RefNum to its default state.
+        void unsetRefNum();
+
         // Id of object being referenced
         std::string getRefId() const;
 

apps/openmw/mwworld/containerstore.cpp

@@ -255,6 +255,7 @@ MWWorld::ContainerStoreIterator MWWorld::ContainerStore::add (const Ptr& itemPtr
     pos.pos[1] = 0;
     pos.pos[2] = 0;
     item.getCellRef().setPosition(pos);
+    item.getCellRef().unsetRefNum(); // destroy link to content file
 
     std::string script = item.getClass().getScript(item);
     if(script != "")

apps/openmw/mwworld/worldimp.cpp

@@ -1718,6 +1718,7 @@ namespace MWWorld
         localRotation.rot[2] = 0;
         dropped.getRefData().setLocalRotation(localRotation);
         dropped.getCellRef().setPosition(pos);
+        dropped.getCellRef().unsetRefNum();
 
         if (mWorldScene->isCellActive(*cell)) {
             if (dropped.getRefData().isEnabled()) {