PVS-Studio warning V521 for TPP

double SpectraSTPeakList::calcDot(SpectraSTPeakList* other) {
  ....
  for (i = this->m_bins->begin(), j = other->m_bins->begin();
       i != this->m_bins->end(), j != other->m_bins->end();
       i++, j++) {
    d = (*i) * (*j);
    dot += d;
  }
  ....
}

This suspicious code was found in TPP project by PVS-Studio static code analyzer.
Warning message is:
V521 Such expressions using the ',' operator are dangerous. Make sure the expression is correct. spectrastpeaklist.cpp 504

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