No join to user meta table if key doesn't exist yet.

[timfield]

I want to filter all members by a meta key.

add_filter('bp_before_has_members_parse_args',function($args){

    if(!isset($args['scope']) || $args['scope']=='all')
    {
        $args['meta_key']='primary_blog';
        $args['meta_value']=get_current_blog_id();
    }
    
    return $args;
});

This works, but only if at least one member has that meta key. I would expect this to always cause a join to the user meta. If no users have this meta key then none should show up.

The problem is here "public/wp-content/plugins/buddypress/bp-core/bp-core-classes.php"

// 'meta_key', 'meta_value' allow usermeta search
// To avoid global joins, do a separate query
if ( false !== $meta_key ) {
        $meta_sql = $wpdb->prepare( "SELECT user_id FROM {$wpdb->usermeta} WHERE meta_key = %s", $meta_key );

        if ( false !== $meta_value ) {
$meta_sql .= $wpdb->prepare( " AND meta_value = %s", $meta_value );
        }

        $found_user_ids = $wpdb->get_col( $meta_sql );

        if ( ! empty( $found_user_ids ) ) {
$sql['where'][] = "u.{$this->uid_name} IN (" . implode( ',', wp_parse_id_list( $found_user_ids ) ) . ")";
        }
}

[imath]

Well i guess we could force the query to fail..

[boonebgorges]

5904.patch seems like a reasonable solution. Needs unit test, please.

[imath]

5904.unittests.patch adds two unit tests :

• 1 to check if querying with user meta arguments is ok
• the other to check results are empty if no user has the user meta

[boonebgorges]

Looks good to me. Thanks, imath.

[imath]

In 9051:

When using BP_User_Query with meta_key and meta_value arguments, make sure no results are displayed if no user match the meta arguments.

Fixes #5904