PHP mysql functions allow to specify the port number or socket location inside the hostname[1]. PHP mysqli functions don't, as they need to go in their own parameters[2]. This was fixed for the port number on bug 58153, but still there's no way to specify the socket location
[1] http://php.net/mysql_connect
[2] http://php.net/mysqli_real_connect
Version: 1.23rc
Severity: normal
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=58153