redirect_canonical() – Undefined indexes 'host' and 'scheme'

[theamila]

Hello, We have a problem on our Blog (​http://blog.mila.com). Since over half a year, we get these notifications on top of our wordpress blog:

Notice: Undefined index: HTTP_HOST in /opt/wordpress/wp-includes/canonical.php on line 66 Notice: Undefined index: HTTP_HOST in /opt/wordpress/wp-includes/nav-menu-template.php on line 558

The notifications come and go, so i don't know what the problem is.. This is line 66 in the canonical file:

<?php
$requested_url .= $_SERVER['HTTP_HOST'];

And this is line 558 in nav-menu-template.php:

<?php
$current_url = set_url_scheme( 'http://' . $_SERVER['HTTP_HOST'] . $_root_relative_current );

We know that the notification is shown because the variable HTTP_HOST is not set, but we don't know how to fix that. It would be great if you could help

[theamila]

canonical.php file

[theamila]

nav menu template file

[swissspidy]

Duplicate of #32229. This is fixed in 4.4.

[theamila]

I have inserted the lines from issue 32229 now i get this error:

Notice: Undefined index: host in /opt/wordpress/wp-includes/canonical.php on line 424
Notice: Undefined index: host in /opt/wordpress/wp-includes/canonical.php on line 425
Notice: Undefined index: host in /opt/wordpress/wp-includes/canonical.php on line 425
Notice: Undefined index: host in /opt/wordpress/wp-includes/canonical.php on line 426
Notice: Undefined index: host in /opt/wordpress/wp-includes/canonical.php on line 428
Notice: Undefined index: scheme in /opt/wordpress/wp-includes/canonical.php on line 445
Notice: Undefined index: host in /opt/wordpress/wp-includes/canonical.php on line 424
Notice: Undefined index: host in /opt/wordpress/wp-includes/canonical.php on line 425
Notice: Undefined index: host in /opt/wordpress/wp-includes/canonical.php on line 425
Notice: Undefined index: host in /opt/wordpress/wp-includes/canonical.php on line 426
Notice: Undefined index: host in /opt/wordpress/wp-includes/canonical.php on line 428
Notice: Undefined index: scheme in /opt/wordpress/wp-includes/canonical.php on line 445

[swissspidy]

Looks like $redirect['scheme'] and $original['host'] are not correctly set. Those two arrays are returned by parse_url, so it's certainly possible that those keys aren't set.

[itproitserviceflcom]

I have same warnings and found that it was produced by "HEAD" requests. "GET" and "POST" requests doesn't give the warning.

[SergeyBiryukov]

#39880 was marked as a duplicate.

[SergeyBiryukov]

Related: #39827

[Andy Schmidt]

This bug is still littering the log files in v4.9.4, out of the box. Spent time tracking down the cause and was going to report it, now realizing this is a known issue.

In my case, problem is that several times daily, redirect_canonical() is called with $_SERVER[HOST] empty and $_SERVER [URI] = '/'.

As a result $original[host] is never set and the code will eventually fail starting at lines 461 - 463:

<?php
        if ( strtolower($original['host']) == strtolower($redirect['host']) ||
                ( strtolower($original['host']) != 'www.' . strtolower($redirect['host']) && 'www.' . strtolower($original['host']) != strtolower($redirect['host']) ) )
                $redirect['host'] = $original['host'];

It should be trivial to fix at lines 70-73, currently:

<?php
        $original = @parse_url($requested_url);
        if ( false === $original ) {     // <-- this line requires a fix!
                return;
        }

by simply validating that a 'host' was actually set, since the code does expect one later:

<?php
        if ( false === $original or !isset( $original['host'] ) ) {

[Andy Schmidt]

I have confirmed that my proposed fix for 4.9.4 does address this problem. There was no recurrence in the past 4 days, and no ill effects!

Now that a confirmed fix is available, may I suggest moving it from some "future release" milestone to the next update, so that this may be closed after 2 years.

[archon810]

While we're waiting for this fix, I'm also seeing a similar issue in wp-includes/class-wp-http-ixr-client.php.

ErrorException: Undefined index: host
#7 wp-includes/class-wp-http-ixr-client.php(27): handleError
#6 wp-includes/class-wp-http-ixr-client.php(27): __construct
#5 wp-includes/comment.php(2652): pingback
#4 wp-includes/comment.php(2486): do_all_pings
#3 wp-includes/class-wp-hook.php(286): apply_filters
#2 wp-includes/class-wp-hook.php(310): do_action
#1 wp-includes/plugin.php(515): do_action_ref_array
#0 wp-cron.php(126): null

Same for

Undefined index: scheme

Examining the $bits variable, I see this:

bits	
{
    path: /wordpress/xmlrpc.php
}

The function this happens in:

<?php
public function __construct($server, $path = false, $port = false, $timeout = 15) {
                if ( ! $path ) {
                        // Assume we have been given a URL instead
                        $bits = parse_url($server);
                        $this->scheme = $bits['scheme'];
                        $this->server = $bits['host'];
                        $this->port = isset($bits['port']) ? $bits['port'] : $port;
                        $this->path = !empty($bits['path']) ? $bits['path'] : '/';

All such errors are caused by wordpress/wp-cron.php?doing_wp_cron.

Perhaps the fix here can also be applied to class-wp-http-ixr-client.php?

Thank you.