bool Segment::AppendCluster(Cluster* pCluster) {
 if (pCluster == NULL || pCluster->m_index < 0)
 return false;

 const long count = m_clusterCount + m_clusterPreloadCount;

 long& size = m_clusterSize;
 const long idx = pCluster->m_index;

 if (size < count || idx != m_clusterCount)
 return false;

 if (count >= size) {
 const long n = (size <= 0) ? 2048 : 2 * size;

 Cluster** const qq = new (std::nothrow) Cluster*[n];
 if (qq == NULL)
 return false;

 Cluster** q = qq;
 Cluster** p = m_clusters;
 Cluster** const pp = p + count;

 while (p != pp)
 *q++ = *p++;

 delete[] m_clusters;

    m_clusters = qq;
    size = n;
 }

 if (m_clusterPreloadCount > 0) {
 Cluster** const p = m_clusters + m_clusterCount;
 if (*p == NULL || (*p)->m_index >= 0)
 return false;

 Cluster** q = p + m_clusterPreloadCount;
 if (q >= (m_clusters + size))
 return false;

 for (;;) {
 Cluster** const qq = q - 1;
 if ((*qq)->m_index >= 0)
 return false;

 *q = *qq;
      q = qq;

 if (q == p)
 break;
 }
 }

  m_clusters[idx] = pCluster;
 ++m_clusterCount;
 return true;
}

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.