}
$dao->find(TRUE);
- if (isset($metadata['on_change'])) {
+ if (isset($metadata['on_change']) && !($value == 0 && ($dao->value === NULL || unserialize($dao->value) == 0))) {
foreach ($metadata['on_change'] as $callback) {
call_user_func(
\Civi\Core\Resolver::singleton()->get($callback),