block_admin_configure_validate($form, &$form_state)modules/block/block.admin.inc, line 362
<?php
function block_admin_configure_validate($form, &$form_state) {
if ($form_state['values']['module'] == 'block') {
$custom_block_exists = (bool) db_query_range('SELECT 1 FROM {block_custom} WHERE bid <> :bid AND info = :info', 0, 1, array(
':bid' => $form_state['values']['delta'],
':info' => $form_state['values']['info'],
))->fetchField();
if (empty($form_state['values']['info']) || $custom_block_exists) {
form_set_error('info', t('Ensure that each block description is unique.'));
}
}
}
?>