Examples of errors detected by the V789 diagnostic

V789. Iterators for the container, used in the range-based for loop, become invalid upon a function call.

ClickHouse

V789 Iterators for the 'input_files' container, used in the range-based for loop, become invalid upon the call of the 'erase' function. PerformanceTest.cpp 1471


using Strings = std::vector<std::string>;

int mainEntryClickhousePerformanceTest(int argc, char ** argv)
{
  ....
  Strings input_files;
  ....
  for (const String filename : input_files)   // <=
  {
    FS::path file(filename);

    if (!FS::exists(file))
      throw DB::Exception(....);

    if (FS::is_directory(file))
    {
      input_files.erase(                      // <=
        std::remove(input_files.begin(),      // <=
                    input_files.end(),        // <=
                    filename) ,               // <=
        input_files.end() );                  // <=

      getFilesFromDir(file, input_files, recursive);
    }
    else
    {
      if (file.extension().string() != ".xml")
        throw DB::Exception(....);
    }
  }
  ....
}

MuseScore

V789 Iterators for the 'oldList' container, used in the range-based for loop, become invalid upon the call of the 'erase' function. layout.cpp 1760


void Score::createMMRest(....)
{
  ElementList oldList = mmr->takeElements();

  for (Element* ee : oldList) {    // <=
    if (ee->type() == e->type()) {
      mmr->add(ee);
      auto i = std::find(oldList.begin(), oldList.end(), ee);
      if (i != oldList.end())
        oldList.erase(i);          // <=
      found = true;
      break;
    }
  }
  ....
}

WebRTC

V789 CWE-672 Iterators for the 'formats' container, used in the range-based for loop, become invalid upon the call of the 'push_back' function. stereocodecfactory.cc 89


std::vector<SdpVideoFormat>
StereoDecoderFactory::GetSupportedFormats() const
{
  std::vector<SdpVideoFormat> formats = ....;
  for (const auto& format : formats) {           // <=
    if (cricket::CodecNamesEq(....)) {
      ....
      formats.push_back(stereo_format);          // <=
    }
  }
  return formats;
}