Multisite: in sunrise.php $wpdb->prefix is empty

[lordspace]

I was working on a multisite WP install and noticed that within sunrise.php
$wpdb->prefix is empty. I had to do this kind of workaround.

$db_prefix = preg_replace( '#_blogs$#', '_', $wpdb->blogs );

I also noticed that $wpdb->posts is empty too. Strange.

[johnbillion]

This is intended behaviour.

sunrise.php can be used to override the site determination in multisite with your own logic (the most common use of this is domain mapping). The current site hasn't been determined at this point, and therefore the site-specific properties of $wpdb haven't yet been populated.