message: check compressed buffer size for mgard
diff: */
  #include "CompressMGARD.h"
  +#include "CompressNull.h"
  #include "adios2/helper/adiosFunctions.h"
  #include <cstring>
  #include <mgard/MGARDConfig.hpp>
  @@ -141,8 +142,19 @@ size_t CompressMGARD::Operate(const char *dataIn, const Dims &blockStart,
  void *compressedData = nullptr;
  mgard_x::compress(mgardDim, mgardType, mgardCount, tolerance, s,
  errorBoundType, dataIn, compressedData, sizeOut, false);
  +
  + if (bufferOutOffset + sizeOut >
  + helper::GetTotalSize(blockCount, helper::GetDataTypeSize(type)))
  + {
  + CompressNull c({});
  + bufferOutOffset =
  + c.Operate(dataIn, blockStart, blockCount, type, bufferOut);
  + }
  + else
  + {
  std::memcpy(bufferOut + bufferOutOffset, compressedData, sizeOut);
  bufferOutOffset += sizeOut;
  + }
  if (compressedData)
  {
  