Index: wp-includes/ms-blogs.php
===================================================================
--- wp-includes/ms-blogs.php	(revision 20117)
+++ wp-includes/ms-blogs.php	(working copy)
@@ -31,7 +31,7 @@
  */
 function get_blogaddress_by_id( $blog_id ) {
 	$bloginfo = get_blog_details( (int) $blog_id, false ); // only get bare details!
-	return esc_url( 'http://' . $bloginfo->domain . $bloginfo->path );
+	return esc_url( $bloginfo->siteurl );
 }
 
 /**