'Process a GNU tar extended sparse header, version 1.0.'

def _proc_gnusparse_10(self, next, pax_headers, tarfile):

    fields = None
    sparse = []
    buf = tarfile.fileobj.read(BLOCKSIZE)
    (fields, buf) = buf.split('\n', 1)
    fields = int(fields)
    while (len(sparse) < (fields * 2)):
        if ('\n' not in buf):
            buf += tarfile.fileobj.read(BLOCKSIZE)
        (number, buf) = buf.split('\n', 1)
        sparse.append(int(number))
    next.offset_data = tarfile.fileobj.tell()
    next.sparse = list(zip(sparse[::2], sparse[1::2]))
