Examples of errors detected by the V637 diagnostic

V637. Use of two opposite conditions. The second condition is always false.

OpenCV

V637 Two opposite conditions were encountered. The second condition is always false. Check lines: 195, 197. keypoint.cpp 195

void KeyPointsFilter::retainBest(
  vector<KeyPoint>& keypoints, int n_points)
{
  ....
  if( n_points > 0 && keypoints.size() > (size_t)n_points )
  {
    if (n_points==0)
    {
      keypoints.clear();
      return;
    }
  ....
}

Chromium

V637 Two opposite conditions were encountered. The second condition is always false. Check lines: 500, 501. web_request_api_helpers.cc 500

static void ParseRequestCookieLine(
    const std::string& header_value,
    ParsedRequestCookies* parsed_cookies)
{
  std::string::const_iterator i = header_value.begin();
  ....
  if (*i == '"') {
    while (i != header_value.end() && *i != '"') ++i;
  ....
}

TinyCAD

V637 Two opposite conditions were encountered. The second condition is always false. Check lines: 86, 90. paint.cpp 86

void CTinyCadView::OnDraw(CDC* pDC)
{
  ....
  // Is any of this region in the off-page area?
  if (!pDC->IsPrinting())
  {
    // Paint the region white
    if (pDC->IsPrinting())
    {
      dc.SelectBrush(cWHITE);
      dc.SelectPen(PS_SOLID, 1, cWHITE);
    }
  ....
}

VirtualDub

V637 Two opposite conditions were encountered. The second condition is always false. Check lines: 183, 184. VirtualDub backface.cpp 183

void VDBackfaceService::Execute(
  IVDBackfaceStream& out, char *s)
{
  ....
  if (*s == '"') {
    while(*s && *s != '"')
      ++s;
  } else {
  ....
}

Unreal Engine 4

V637 Two opposite conditions were encountered. The second condition is always false. Check lines: 310, 312. propertystruct.cpp 310

const TCHAR* UStructProperty::ImportText_Internal(....) const
{
  ....
  if (*Buffer == TCHAR('\"'))                     // <=
  {
    while (*Buffer &&
           *Buffer != TCHAR('\"') &&              // <=
           *Buffer != TCHAR('\n') &&
           *Buffer != TCHAR('\r'))
    {
      Buffer++;
    }

    if (*Buffer != TCHAR('\"'))
  ....
}

TortoiseGit

V637 Two opposite conditions were encountered. The second condition is always false. Check lines: 2464, 2466. TortoiseGitMerge mergeinfo.c 2464

svn_error_t *
svn_mergeinfo__adjust_mergeinfo_rangelists(....)
{
  ....
  if (range->start + offset > 0 && range->end + offset > 0)
  {
    if (range->start + offset < 0)
      range->start = 0;
    else
      range->start = range->start + offset;

    if (range->end + offset < 0)
      range->end = 0;
    else
      range->end = range->end + offset;
  ....
}

K Desktop Environment

V637 Two opposite conditions were encountered. The second condition is always false. Check lines: 410, 412. kebsearchline.cpp 410

void
KViewSearchLine::slotColumnsRemoved(const QModelIndex &,
                                    int first, int last)
{
  if(d->treeView)
    updateSearch();
  else
  {
    if(d->listView->modelColumn() >= first &&
       d->listView->modelColumn() <= last)
    {
      if(d->listView->modelColumn()>last)   // <=
        kFatal()<<"...."<<endl;
      updateSearch();
    }
  }
}

.NET CoreCLR

V637 Two opposite conditions were encountered. The second condition is always false. Check lines: 31825, 31827. cee_wks gc.cpp 31825

void gc_heap::verify_heap (BOOL begin_gc_p)
{
  ....
  if (brick_table [curr_brick] < 0)
  {
    if (brick_table [curr_brick] == 0)
    {
      dprintf(3, ("curr_brick %Ix for object %Ix set to 0",
              curr_brick, (size_t)curr_object));
      FATAL_GC_ERROR();
    }
    ....
  }
  ....
}

Similar errors can be found in some other places:

• V637 Two opposite conditions were encountered. The second condition is always false. Check lines: 2898, 2900. daccess nidump.cpp 2898
• V637 Two opposite conditions were encountered. The second condition is always false. Check lines: 337, 339. utilcode prettyprintsig.cpp 337
• V637 Two opposite conditions were encountered. The second condition is always false. Check lines: 774, 776. utilcode prettyprintsig.cpp 774

ReactOS

V637 Two opposite conditions were encountered. The second condition is always false. Check lines: 2532, 2535. devinst.c 2532

HDEVINFO WINAPI SetupDiGetClassDevsExW(....)
{
  ....
  if (flags & DIGCF_ALLCLASSES)
  {
    ....
  }
  else if (!IsEqualIID(&list->ClassGuid, &GUID_NULL))// <=
  {
    if (IsEqualIID(&list->ClassGuid, &GUID_NULL))    // <=
          pClassGuid = &list->ClassGuid;
    ....
  }
  ....
}

Firebird

V637 Two opposite conditions were encountered. The second condition is always false. Check lines: 778, 780. jrd.cpp 778

void Trigger::compile(thread_db* tdbb)
{
  SET_TDBB(tdbb);

  Database* dbb = tdbb->getDatabase();
  Jrd::Attachment* const att = tdbb->getAttachment();

  if (extTrigger)
    return;

  if (!statement /*&& !compile_in_progress*/)
  {
    if (statement)
      return;
    ....
  }
}

Blender

V637 Two opposite conditions were encountered. The second condition is always false. Check lines: 938, 939. editcurve_select.c 938

static int select_less_exec(....)
{
  ....
  if ((lastsel==0)&&(bp->hide==0)&&(bp->f1 & SELECT)){
   if (lastsel != 0) sel = 1;
   else sel = 0;
  ....
  }
  ....
}

LibreOffice

V637 Two opposite conditions were encountered. The second condition is always false. Check lines: 281, 285. authfld.cxx 281

sal_uInt16  SwAuthorityFieldType::GetSequencePos(sal_IntPtr nHandle)
{
  ....
  SwTOXSortTabBase* pOld = aSortArr[i].get();
  if(*pOld == *pNew)
  {
    //only the first occurrence in the document
    //has to be in the array
    if(*pOld < *pNew)
      pNew.reset();
    else // remove the old content
      aSortArr.erase(aSortArr.begin() + i);
    break;
  }
  ....
}

Similar errors can be found in some other places:

• V637 Two opposite conditions were encountered. The second condition is always false. Check lines: 1827, 1829. doctxm.cxx 1827

MuseScore

V637 Two opposite conditions were encountered. The second condition is always false. Check lines: 4439, 4440. exportxml.cpp 4439

virtual Fraction tick() const override { return _tick; }

void ExportMusicXml::hairpin(....)
{
  ....
  if (hp->tick() != tick) {
        writeHairpinText(_xml, hp, hp->tick() == tick);
  }
  ....
}

RPCS3

V637 Two opposite conditions were encountered. The second condition is always false. Check lines: 385, 387. lv2_socket_p2ps.cpp 385

bool lv2_socket_p2ps::handle_listening(p2ps_encapsulated_tcp* tcp_header,
                                       [[maybe_unused]] u8* data,
                                       ::sockaddr_storage* op_addr)
{
  // ....
  if (   tcp_header->flags == p2ps_tcp_flags::SYN
      && backlog.size() < max_backlog)
  {
    if (backlog.size() >= max_backlog)
    {
      // ....
    }
  }
  // ....
}