org.cesecore.certificates.crl.CRLData.crlExistsForCa(EntityManager, String) JavaDoc is incorrect.

The method

    /**
     * @return true if at least one CRL exists for the given CA.
     */
    public static boolean crlExistsForCa(final EntityManager entityManager, final String issuerDn) {
        final Query query = entityManager
                .createQuery("SELECT a.crlNumber FROM CRLData a WHERE a.issuerDN=:issuerDN");
        query.setParameter("issuerDN", issuerDn);
        return QueryResultWrapper.getSingleResult(query) != null;
    }

is lacking a query.setMaxResults(1); and will throw a javax.persistence.NonUniqueResultException if there is more than one CRL present for the issuer (even full+delta or partitions).

Since it is currently only used to check for an illegal state from org.ejbca.core.ejb.ca.caadmin.CAAdminSessionBean.renewCAInternal(AuthenticationToken, int, String, Date, boolean, String) there is no real impact, but future use of this API could fail worse.