id	summary	reporter	owner	description	type	status	priority	milestone	component	version	severity	resolution	keywords	cc
12065	Clean up cache re-init code in Multisite	nacin		"During MS load we initialize the object cache again.

{{{
wp_cache_init(); // need to init cache again after blog_id is set

if ( function_exists('wp_cache_add_global_groups') ) { // need to add these again. Yes, it's an ugly hack
	wp_cache_add_global_groups(array ('users', 'userlogins', 'usermeta', 'site-options', 'site-lookup', 'blog-lookup', 'blog-details', 'rss'));
	wp_cache_add_non_persistent_groups(array( 'comment', 'counts', 'plugins' ));
}
}}}

Assuming re-initialization indeed needs to occur (a comment says we need to after blog_id is set), we can clean this up now that we have wp_start_object_cache() in wp-includes/load.php.

It is also missing the site-transients group, so that will fix this.

Hypothetically, we could replace that with wp_start_object_cache() and be done with it, but to save CPU cycles and an unnecessary filesystem check, we should modify wp_start_object_cache() while we're at it.

We can either split the function into two, or first check if wp_cache_init() exists before setting $_wp_using_ext_object_cache, checking for the object-cache.php drop-in, and including either wp-content/object-cache.php or wp-includes/cache.php.

Patch attached with one of these options."	defect (bug)	closed	normal	3.0	Multisite		normal	fixed	has-patch