If there is a gap (coded by ``*``) in a VCF, it is reported as such in the allele list but translated as ``-`` when genotypes are requested (either ``get_genotypes`` or ``as_site`` and consequently ``iter_sites``). A proper bug appears when ``as_site`` is called on an indel position where there is a gap. The alphabet is configured from ``get_alleles``, therefore with ``*``, so alleles coming a ``-`` are found to be invalid. * Change in ``get_alleles()``: the ``*`` allele is not included anymore. * Change in alphabet created by ``as_site()`` and ``iter_sites()`` for indels (alphabets of type ``string``): the ``-`` allele is always included as missing data.