Hello everyone. I just spend almost 2 hours on trying to upgrade from moodle 2.2 to 2.5.3 on server, where mysql has it own, nondefault port.
I copied config.php - error connecting to database (saying wrong user/pass!).
I made an installation from a scratch - error connecting to database (saying wrong user/pass!).

It all would be easily resolved, if u simply add "Database port" with description "leave blank if you are not sure" in installation process.
Or at least, for default, in config.php include 'dbport', not only config_redist.php.

Cheers.