Guest content may prevent search suggestions from being displayed

[Kirby]

Affected version

2.3.6

$iconHtml = null;
$templater = \XF::app()->templater();
if ($user)
{
    $iconHtml = $templater->func('avatar', [
        $user,
        'xxs',
        false,
        ['href' => ''],
    ]);
}

return [
    'text' => $text,
    'url' => $url,
    'iconHtml' => $iconHtml,
    'desc' => $desc,
];

This sets iconHtml to null if the content was created by a guest which later on casues an exception when rendering the Mustache template.

Suggested Fix
1) Pass a guest user entity with the correct Username
or
2) Add an additional param for the guest username and change the above code to pass that to templater function avatar