After fresh installation on my development machine using root without password, it tries to connect the db with password.

This is because in conf/database.php there is missing this line (as it should be there):
$Configuration['DATABASE_PASSWORD'] = '';

So workaround is to add this line manually.

I know about using root access without pass is unsecure, but this is standard development thing. So if this is not a test for developers to filter those stupid ;) then I think it should be fixed.


Another workaround might be:

in setup/installer.php on line 29 there is this line:
$Configuration['DATABASE_PASSWORD'] = '';

Before installation I put there something like this
$Configuration['DATABASE_PASSWORD'] = 'this is not empty string so if somebody wants to have blank one, it differs and will be saved';

That is because installer saves only those setting which differ.

This might be actually the easiest fix for the bug, just need to use there some really long string which we can be sure won't be really used by some crazy user :)

I rather don't say it is bug of ConfigurationManager because it seems to be a feature (i.e. not bug) to me :)