PVS-Studio warning V529 for xpdfwin

BOOL AddTail(LPVOID p)
{
  ...
  if(queue.GetSize() >= this->_limit);
  {
    while(queue.GetSize() > this->_limit-1)
    {
      ::WaitForSingleObject(handles[SemaphoreIndex], 1);
      queue.Delete(0);
    }
  }
  ...
}

This suspicious code was found in xpdfwin project by PVS-Studio static code analyzer.
Warning message is:
V529 Odd semicolon ';' after 'if' operator. AFPDFLib queue.h 66

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