RMF: Fix delta compression with non-initialized elevation min-max (OS…

…Geo#4399)
drons · Sep 1, 2021 · ecd9506 · ecd9506
1 parent 86d711e
commit ecd9506
Showing 1 changed file with 6 additions and 3 deletions.
diff --git a/gdal/frmts/rmf/rmfdem.cpp b/gdal/frmts/rmf/rmfdem.cpp
@@ -603,9 +603,12 @@ size_t RMFDataset::DEMCompress(const GByte* pabyIn, GUInt32 nSizeIn,
     const GUInt32 anDeltaTypeSize[8] = {0,0,4,8,12,16,24,32};
     const GUInt32 nMaxRecordSize = 255 + 32;
 
-    DEMWorkT iMin((poDS == nullptr) ? std::numeric_limits<DEMWorkT>::min() :
-                  static_cast<DEMWorkT>(poDS->sHeader.adfElevMinMax[0]));
-
+    DEMWorkT iMin(std::numeric_limits<DEMWorkT>::min() + 1);
+    if(poDS != nullptr &&
+       poDS->sHeader.adfElevMinMax[0] < poDS->sHeader.adfElevMinMax[1])
+    {
+        iMin = static_cast<DEMWorkT>(poDS->sHeader.adfElevMinMax[0]);
+    }
     GUInt32     nLessCount = 0;
     GUInt32     nRecordSize = 0;
     RmfTypes    eRecordType = TYPE_OUT;