PVS-Studio warning V519 for WinMerge

int TimeSizeCompare::CompareFiles(int compMethod,
                                  const DIFFITEM &di)
{
  UINT code = DIFFCODE::SAME;
  ...
  if (di.left.size != di.right.size)
  {
    code &= ~DIFFCODE::SAME;
    code = DIFFCODE::DIFF;
  }
  ...
}

This suspicious code was found in WinMerge project by PVS-Studio static code analyzer.
Warning message is:
V519 The 'code' variable is assigned values twice successively. Perhaps this is a mistake. Check lines: 79, 80. Merge timesizecompare.cpp 80

PVS-Studio is a static analyzer for detecting bugs in the source code of applications written in C, C++, C++11, C++/CX. Site: http://www.viva64.com/en/pvs-studio/