[wp-trac] [WordPress Trac] #50100: Native domain mapping does not handle both WWW and non-WWW versions of a domain - both should work

[WordPress Trac]

#50100: Native domain mapping does not handle both WWW and non-WWW versions of a
domain - both should work
--------------------------------+------------------------------
 Reporter:  jodamo5             |       Owner:  (none)
     Type:  defect (bug)        |      Status:  new
 Priority:  normal              |   Milestone:  Awaiting Review
Component:  Networks and Sites  |     Version:  5.4.1
 Severity:  normal              |  Resolution:
 Keywords:  needs-testing       |     Focuses:  multisite
--------------------------------+------------------------------

Comment (by jodamo5):

 Thanks @jeremyfelt

 To clarify, the [https://wordpress.org/support/article/wordpress-
 multisite-domain-mapping/ WP domain mapping documentation] does not state
 that multiple domains can be mapped. So the documentation is correct,
 however it fails to mention the enormous problem of not handling both www
 and non-www within the native domain mapping setup.

 However, to update the ticket, I have investigated further, and found that
 the code you mentioned does indeed work.  So my second example was
 incorrect.

 To confirm, if the domain is mapped without www e.g. `abc.com` then if a
 visitor types `www.abc.com` the domain mapping automatically finds and
 swaps them to `abc.com`.  So that is good.

 However, the other half of the problem still exists. It is a huge
 usability issue that when a domain is mapped as `www.` the bare domain
 does not redirect to the site, but instead shows a multisite registration
 page.

 Redirecting a bare domain to www, if the www version is mapped, is
 standard practise across all other domain mapping plugins - and the
 documentation says we no longer need to use these other plugins since
 domain mapping is now native.

 I strongly expect WordPress multisite users who map `www.abc.com` as their
 domain would be shocked and frustrated when `abc.com` does not redirect to
 their site and instead takes users to the registration page.  I know that
 was my experience.

 Thanks very much for pointing to the right place in the code. It was
 exactly the right section for handling this problem.

 I would like to propose that, to solve this usability problem, we simply
 add "www." to queries for bare domains, so that both www and non-www
 domains are checked. The code in ms-load.php already handles building the
 array of two domains and checking if either matches an existing site, so
 it would only be a small change that would greatly improve the usability.
 It would mean that every domain array has two domains - a www and non-www
 version.

 == Proposed Change

 === Existing Code

 {{{
         // Either www or non-www is supported, not both. If a www domain
 is requested,
         // query for both to provide the proper redirect.
         $domains = array( $domain );
         if ( 'www.' === substr( $domain, 0, 4 ) ) {
                 $domains[] = substr( $domain, 4 );
         }

         $args = array(
                 'number'                 => 1,
                 'update_site_meta_cache' => false,
         );

         if ( count( $domains ) > 1 ) {
                 $args['domain__in']               = $domains;
                 $args['orderby']['domain_length'] = 'DESC';
         } else {
                 $args['domain'] = array_shift( $domains );
         }
 }}}


 === Proposed New Code
 {{{
         // Whether a www or non-www domain is requested,
         // query for both to provide the proper redirect.
         $domains = array( $domain );
         if ( 'www.' === substr( $domain, 0, 4 ) ) {
                 $domains[] = substr( $domain, 4 );
         } else {
                 $domains[] = 'www.'. $domain;
         }

         $args = array(
                 'number'                           => 1,
                 'update_site_meta_cache'           => false,
                 'domain__in'                       => $domains,
                 'orderby' => array('domain_length' => 'DESC')
         );

 }}}


 I have tested this within a multisite environment, and it produces the
 exact same array that was previously produced when a www. domain was
 requested. It now produces that array whether a www or non-www domain is
 requested. So the code works well.  (It will of course need thorough
 testing.)

 I can set this up as a pull request, but first wanted to get feedback
 about it.

 I expect this would a barely measurable performance impact, while greatly
 improving the usability of domain mapping.  What are your thoughts on this
 enhancement?

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/50100#comment:5>
WordPress Trac <https://core.trac.wordpress.org/>
WordPress publishing platform