"-1" string cannot be stored by custom field of Text Field (< 255 characters) type

    private void createValuesInt(CustomField field, Long issueId, PersistenceFieldType persistenceFieldType, Collection values, String parentKey)
    {
        if (values == null)
            return;

        for (Iterator iterator = values.iterator(); iterator.hasNext();)
        {
            Object value = iterator.next();
            if (value == null || "".equals(value) || "-1".equals(value))
                continue; // we don't create null values in the database

            Map entityFields = new HashMap();
            entityFields.put(ENTITY_ISSUE_ID, issueId);
            entityFields.put(ENTITY_PARENT_KEY, parentKey);
            entityFields.put(ENTITY_CUSTOMFIELD_ID, CustomFieldUtils.getCustomFieldId(field.getId()));
            entityFields.put(getColumnName(persistenceFieldType), value);
            delegator.createValue(TABLE_CUSTOMFIELD_VALUE, entityFields);
        }
    }