Add comment to Cell NAM0 (it's a RefId counter)

apps/esmtool/record.cpp

@@ -513,7 +513,7 @@ void Record<ESM::Cell>::print()
     else
         std::cout << "  Map Color: " << boost::format("0x%08X") % mData.mMapColor << std::endl;
     std::cout << "  Water Level Int: " << mData.mWaterInt << std::endl;
-    std::cout << "  NAM0: " << mData.mNAM0 << std::endl;
+    std::cout << "  RefId counter: " << mData.mRefIdCounter << std::endl;
 
 }
 

components/esm/loadcell.cpp

@@ -58,7 +58,7 @@ void Cell::load(ESMReader &esm, bool saveContext)
 
 void Cell::loadCell(ESMReader &esm, bool saveContext)
 {
-    mNAM0 = 0;
+    mRefIdCounter = 0;
 
     if (mData.mFlags & Interior)
     {
@@ -92,7 +92,7 @@ void Cell::loadCell(ESMReader &esm, bool saveContext)
         esm.getHNOT(mMapColor, "NAM5");
     }
     if (esm.isNextSub("NAM0")) {
-        esm.getHT(mNAM0);
+        esm.getHT(mRefIdCounter);
     }
 
     if (saveContext) {
@@ -150,8 +150,8 @@ void Cell::save(ESMWriter &esm) const
             esm.writeHNT("NAM5", mMapColor);
     }
 
-    if (mNAM0 != 0)
-        esm.writeHNT("NAM0", mNAM0);
+    if (mRefIdCounter != 0)
+        esm.writeHNT("NAM0", mRefIdCounter);
 }
 
 void Cell::restore(ESMReader &esm, int iCtx) const
@@ -220,7 +220,7 @@ bool Cell::getNextMVRF(ESMReader &esm, MovedCellRef &mref)
         mWater = 0;
         mWaterInt = false;
         mMapColor = 0;
-        mNAM0 = 0;
+        mRefIdCounter = 0;
 
         mData.mFlags = 0;
         mData.mX = 0;

components/esm/loadcell.hpp

@@ -94,7 +94,10 @@ struct Cell
   float mWater; // Water level
   bool mWaterInt;
   int mMapColor;
-  int mNAM0;
+  // Counter for RefIds. This is only used during content file editing and has no impact on gameplay.
+  // It prevents overwriting previous refIDs, even if they were deleted.
+  // as that would collide with refs when a content file is upgraded.
+  int mRefIdCounter;
 
   // References "leased" from another cell (i.e. a different cell
   //  introduced this ref, and it has been moved here by a plugin)