Problem in TEncSampleAdaptiveOffset::rdoSaoUnit() function,

The following code checks valid slice/tile for non first row and non first column, but i think that should not be case. If first line contains two slices, it will still try merge left and similarly vertically as well.

if (rx!=0)
  { 
    // check tile id and slice id 
    if ( (m_pcPic->getPicSym()->getTileIdxMap(addr-1) != m_pcPic->getPicSym()->getTileIdxMap(addr)) || (m_pcPic->getCU(addr-1)->getSlice()->getSliceIdx() != m_pcPic->getCU(addr)->getSlice()->getSliceIdx()))
    {
      allowMergeLeft = 0;
    }
  }
  if (ry!=0)
  {
    if ( (m_pcPic->getPicSym()->getTileIdxMap(addr-m_iNumCuInWidth) != m_pcPic->getPicSym()->getTileIdxMap(addr)) || (m_pcPic->getCU(addr-m_iNumCuInWidth)->getSlice()->getSliceIdx() != m_pcPic->getCU(addr)->getSlice()->getSliceIdx()))
    {
      allowMergeUp = 0;
    }
  }