Uncaught TypeError: fivefilters\Readability\Nodes\NodeUtility::getNextNode(): … DOMProcessingInstruction returned

[blizzz]

I know of web pages on one domain, where parsing results in a type error.

Following minimal test code shows the behaviour. The first page succeeds, the second on fails with the Type Error:

<?php

require __DIR__ . '/vendor/autoload.php';
use fivefilters\Readability\Readability;
use fivefilters\Readability\Configuration;

$readability = new Readability(new Configuration());

$content = file_get_contents('https://support.mozilla.org/en-US/kb/firefox-reader-view-clutter-free-web-pages');
$success = $readability->parse($content);

if ($success) {
	print("The mozilla.org page is fine!" . PHP_EOL);
}

$content = file_get_contents('https://weddingweiser.de/das-serratonin-erzeugt-gluecksgefuehle/');
$success = $readability->parse($content);

if ($success) {
	print("The weddingweiser.de page is fine!");
}

exit($success ? 0 : 1);

Output:

$ php repro.php 
The mozilla.org page is fine!
PHP Fatal error:  Uncaught TypeError: fivefilters\Readability\Nodes\NodeUtility::getNextNode(): Return value must be of type fivefilters\Readability\Nodes\DOM\DOMNode|fivefilters\Readability\Nodes\DOM\DOMComment|fivefilters\Readability\Nodes\DOM\DOMText|fivefilters\Readability\Nodes\DOM\DOMElement|fivefilters\Readability\Nodes\DOM\DOMDocument|null, fivefilters\Readability\Nodes\DOM\DOMProcessingInstruction returned in /home/blizzz/repos/readability-test/vendor/fivefilters/readability.php/src/Nodes/NodeUtility.php:135
Stack trace:
#0 /home/blizzz/repos/readability-test/vendor/fivefilters/readability.php/src/Readability.php(929): fivefilters\Readability\Nodes\NodeUtility::getNextNode(Object(fivefilters\Readability\Nodes\DOM\DOMElement))
#1 /home/blizzz/repos/readability-test/vendor/fivefilters/readability.php/src/Readability.php(177): fivefilters\Readability\Readability->getNodes(Object(fivefilters\Readability\Nodes\DOM\DOMElement))
#2 /home/blizzz/repos/readability-test/repro.php(17): fivefilters\Readability\Readability->parse('...')
#3 {main}
  thrown in /home/blizzz/repos/readability-test/vendor/fivefilters/readability.php/src/Nodes/NodeUtility.php on line 135