// don't try to migrate it.
        continue;
    }
    $value = $action->getTarget();
    if (!is_array($value)) {
        // Only migrate PHID lists.
        continue;
    }
    foreach ($value as $v) {
        if (!is_string($v)) {
            // Only migrate PHID lists where all members are PHIDs.
            continue 2;
        }
    }
    $new = array();
    $any_change = false;
    foreach ($value as $v) {
        if (isset($map[$v])) {
            $new[] = $map[$v];
            $any_change = true;
        } else {
            $new[] = $v;
        }
    }
    if (!$any_change) {
        continue;
    }
    $id = $action->getID();
    queryfx($conn_w, 'UPDATE %T SET target = %s WHERE id = %d', $table->getTableName(), json_encode($new), $id);
    echo pht('Updated mailing lists in Herald action %d.', $id) . "\n";
}