Examples of errors detected by the V765 diagnostic

V765. Compound assignment expression 'X += X + N' is suspicious. Consider inspecting it for a possible error.

MuseScore

V765 A compound assignment expression 'x += x + ...' is suspicious. Consider inspecting it for a possible error. tremolo.cpp 321

void Tremolo::layout()
{
  ....
  if (_chord1->up() != _chord2->up()) {
    beamYOffset += beamYOffset + beamHalfLineWidth; // <=
  }
  else if (!_chord1->up() && !_chord2->up()) {
    beamYOffset = -beamYOffset;
  }
  ....
}

LibreOffice

V765 A compound assignment expression 'x -= x - ...' is suspicious. Consider inspecting it for a possible error. swdtflvr.cxx 3509

bool SwTransferable::PrivateDrop(...)
{
  ....
  if ( rSrcSh.IsSelFrameMode() )
  {
    //Hack: fool the special treatment
    aSttPt -= aSttPt - rSrcSh.GetObjRect().Pos();
  }
  ....
}