message: read back file content when in the append mode
diff: @@ -87,6 +87,12 @@ void HDF5WriterP::Init()
  m_H5File.Init(m_Name, m_Comm, true);
  }
  m_H5File.ParseParameters(m_IO);
  +
  + if (m_OpenMode == Mode::Append)
  + {
  + m_H5File.ReadAttrToIO(m_IO);
  + m_H5File.ReadAllVariables(m_IO);
  + }
  #endif
  }
  