Index: tests/phpunit/tests/multisite/getMainSiteId.php
===================================================================
--- tests/phpunit/tests/multisite/getMainSiteId.php	(revision 41550)
+++ tests/phpunit/tests/multisite/getMainSiteId.php	(working copy)
@@ -105,6 +105,15 @@
 	public function filter_get_main_site_id() {
 		return 333;
 	}
+
+	public function test_sunrise_set_blog_id(){
+		global $current_site;
+
+		$my_site_id = 99999;
+		$current_site->blog_id = $my_site_id;
+		$this->assertSame( $my_site_id, get_main_site_id() );
+
+	}
 }
 
 endif;