PVS-Studio warning V519 for QT

int QCleanlooksStyle::pixelMetric(....)
{
  ... //cases

  case PM_SpinBoxFrameWidth:
    ret = 3;
    break;
  case PM_MenuBarItemSpacing:
    ret = 6;
  case PM_MenuBarHMargin:
    ret = 0;
    break;

  ... //cases
}

The break operator is missing.

This suspicious code was found in QT project by PVS-Studio static code analyzer.
Warning message is:
V519 The 'ret' variable is assigned values twice successively. Perhaps this is a mistake. Check lines: 3765, 3767. QtGui qcleanlooksstyle.cpp 3767

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/