PVS-Studio warning V501 for QT

void QWindowsStyle::drawPrimitive(....)
{
  ....
  } else if (flags & (State_Raised | State_Sunken |
                      State_On | State_Sunken))
  {
  ....
}

One 'State_Sunken' constant is unnecessary here - something else should be written instead of it.

This suspicious code was found in QT project by PVS-Studio static code analyzer.
Warning message is:
V501 There are identical sub-expressions 'State_Sunken' to the left and to the right of the '|' operator. QtGui qwindowsstyle.cpp 1365

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/