message: imgcodecs(sunras): avoid buffer overrun
  `src_pitch` may be large than data `step`
diff: @@ -175,8 +175,6 @@ bool SunRasterDecoder::readData( Mat& img )
  AutoBuffer<uchar> _src(src_pitch + 32);
  uchar* src = _src;
  - AutoBuffer<uchar> _bgr(m_width*3 + 32);
  - uchar* bgr = _bgr;
  if( !color && m_maptype == RMT_EQUAL_RGB )
  CvtPaletteToGray( m_palette, gray_palette, 1 << m_bpp );
  @@ -340,16 +338,18 @@ bad_decoding_end:
  case 24:
  for( y = 0; y < m_height; y++, data += step )
  {
  - m_strm.getBytes( color ? data : bgr, src_pitch );
  + m_strm.getBytes(src, src_pitch );
  if( color )
  {
  if( m_type == RAS_FORMAT_RGB )
  - icvCvt_RGB2BGR_8u_C3R( data, 0, data, 0, cvSize(m_width,1) );
  + icvCvt_RGB2BGR_8u_C3R(src, 0, data, 0, cvSize(m_width,1) );
  + else
  + memcpy(data, src, std::min(step, (size_t)src_pitch));
  }
  else
  {
  - icvCvt_BGR2Gray_8u_C3C1R( bgr, 0, data, 0, cvSize(m_width,1),
  + icvCvt_BGR2Gray_8u_C3C1R(src, 0, data, 0, cvSize(m_width,1),
  m_type == RAS_FORMAT_RGB ? 2 : 0 );
  }
  }
  