Last week I had the problem, that – due to a wrong database-entry – a serialized value got scrambled. And due to that (and some missconfiguration of the server) the application broke. Instead of a search result the user simply got an error message about not being able to unserialize the value due to an offset-error.

So how could I avoid the error (which actually is a notice) being thrown and besides that get to know whether unserializing worked or not?

The hack I finaly came up with is as follows:

• suppress the notice in any way
• check whether the returned value is a boolean false and the given string is ‘b:0;’ (which represents a boolean false in a serialized string).
• If so, the unserialize() failed, so lets throw an InvalidArgumentException

And here it is:

public function my_unserialize ( $value )
{
    $unserialized = @unserialize ( $value );
    if ( false === $unserialized && 'b:0;' !== $value ) {
        $le = error_get_last ();
        throw new InvalidArgumentException ( $le['message'] );
    }
    return $unserialized;
}