PHP 8.1 fwrite(): Passing null to parameter #2 ($data) of type string is deprecated in Masterminds\HTML5\Serializer\OutputRules->wr()

[jkamizato]

This is an error that shows up, using Drupal.

In that case, this method is called: Html::serialize($dom); , but $dom->nodeValue is null, and its causing the error.

Propose a solution: upcasting fwrite function with string:

    /**
     * Write to the output.
     *
     * @param string $text The string to put into the output
     *
     * @return $this
     */
    protected function wr($text)
    {
        fwrite($this->out, (string) $text);

        return $this;
    }

[ohader]

Thanks for your report. Can you please provide a stack-trace that is leading up to this error? Thx!

[Tregonia]

I am also encountering this issue in Drupal. This is triggered when setting Trimmed limit: 550 characters to the Summary or trimmed of the body field in a node display,

Drupal Version: 10.2.7
PHP Version: 8.1.29

Here is the stack trace:

Deprecated function: fwrite(): Passing null to parameter #2 ($data) of type string is deprecated in Masterminds\HTML5\Serializer\OutputRules->wr() (line 451 of /home/ide/project/vendor/masterminds/html5/src/HTML5/Serializer/OutputRules.php).
Masterminds\HTML5\Serializer\OutputRules->wr(NULL) (Line: 308)
Masterminds\HTML5\Serializer\OutputRules->namespaceAttrs(Object) (Line: 326)
Masterminds\HTML5\Serializer\OutputRules->openTag(Object) (Line: 229)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 122)
Masterminds\HTML5\Serializer\Traverser->children(Object) (Line: 241)
Masterminds\HTML5\Serializer\OutputRules->element(Object) (Line: 93)
Masterminds\HTML5\Serializer\Traverser->node(Object) (Line: 77)
Masterminds\HTML5\Serializer\Traverser->walk() (Line: 319)
Drupal\Component\Utility\Html::serialize(Object) (Line: 258)
Drupal\Component\Utility\Html::normalize('
REDACTED
') (Line: 25)
Drupal\filter\Plugin\Filter\FilterHtmlCorrector->process('
REDACTED
', 'und') (Line: 118)
Drupal\filter\Element\ProcessedText::preRenderText(Array)
call_user_func_array(Array, Array) (Line: 111)
Drupal\Core\Render\Renderer->doTrustedCallback(Array, Array, 'Render #pre_render callbacks must be methods of a class that implements \Drupal\Core\Security\TrustedCallbackInterface or be an anonymous function. The callback was %s. See https://www.drupal.org/node/2966725', 'exception', 'Drupal\Core\Render\Element\RenderCallbackInterface') (Line: 859)
Drupal\Core\Render\Renderer->doCallback('#pre_render', Array, Array) (Line: 421)
Drupal\Core\Render\Renderer->doRender(Array, ) (Line: 240)
Drupal\Core\Render\Renderer->render(Array) (Line: 475)
Drupal\Core\Template\TwigExtension->escapeFilter(Object, Array, 'html', NULL, 1) (Line: 125)
__TwigTemplate_fcad470fa4233122af416288d028227d->doDisplay(Array, Array) (Line: 394)
Twig\Template->displayWithErrorHandling(Array, Array) (Line: 367)
Twig\Template->display(Array) (Line: 56)
__TwigTemplate_184dc6b5d4c992e0d8dbfc0de219c348->doDisplay(Array, Array) (Line: 394)
Twig\Template->displayWithErrorHandling(Array, Array) (Line: 367)
Twig\Template->display(Array) (Line: 379)
Twig\Template->render(Array) (Line: 38)
Twig\TemplateWrapper->render(Array) (Line: 39)
twig_render_template('REDACTED/themes/custom/REDACTED/templates/field/field.html.twig', Array) (Line: 348)
Drupal\Core\Theme\ThemeManager->render('field', Array) (Line: 480)
Drupal\Core\Render\Renderer->doRender(Array) (Line: 493)
Drupal\Core\Render\Renderer->doRender(Array, ) (Line: 240)
Drupal\Core\Render\Renderer->render(Array) (Line: 475)
Drupal\Core\Template\TwigExtension->escapeFilter(Object, Array, 'html', NULL, 1) (Line: 266)
__TwigTemplate_56c4f556221d1328ab3c9466e3243bae___38191478->block_main(Array, Array) (Line: 171)
Twig\Template->displayBlock('main', Array, Array) (Line: 104)
__TwigTemplate_b1b3a8183820adf16dc64dee09387b6a->doDisplay(Array, Array) (Line: 394)
Twig\Template->displayWithErrorHandling(Array, Array) (Line: 367)
Twig\Template->display(Array, Array) (Line: 216)
__TwigTemplate_56c4f556221d1328ab3c9466e3243bae___38191478->doDisplay(Array, Array) (Line: 394)
Twig\Template->displayWithErrorHandling(Array, Array) (Line: 367)
Twig\Template->display(Array) (Line: 43)
__TwigTemplate_56c4f556221d1328ab3c9466e3243bae->doDisplay(Array, Array) (Line: 394)
Twig\Template->displayWithErrorHandling(Array, Array) (Line: 367)
Twig\Template->display(Array) (Line: 379)
Twig\Template->render(Array) (Line: 38)
Twig\TemplateWrapper->render(Array) (Line: 39)
twig_render_template('REDACTED/themes/custom/REDACTED/templates/content/node.html.twig', Array) (Line: 348)
Drupal\Core\Theme\ThemeManager->render('node', Array) (Line: 480)
Drupal\Core\Render\Renderer->doRender(Array, ) (Line: 240)
Drupal\Core\Render\Renderer->render(Array) (Line: 475)
Drupal\Core\Template\TwigExtension->escapeFilter(Object, Array, 'html', NULL, 1) (Line: 73)
__TwigTemplate_77f21acad24f3f954ddf379229baf499->doDisplay(Array, Array) (Line: 394)
Twig\Template->displayWithErrorHandling(Array, Array) (Line: 367)
Twig\Template->display(Array) (Line: 379)
Twig\Template->render(Array) (Line: 38)
Twig\TemplateWrapper->render(Array) (Line: 39)
twig_render_template('core/modules/views/templates/views-view-list.html.twig', Array) (Line: 348)
Drupal\Core\Theme\ThemeManager->render('views_view_list', Array) (Line: 480)
Drupal\Core\Render\Renderer->doRender(Array) (Line: 493)
Drupal\Core\Render\Renderer->doRender(Array, ) (Line: 240)
Drupal\Core\Render\Renderer->render(Array) (Line: 475)
Drupal\Core\Template\TwigExtension->escapeFilter(Object, Array, 'html', NULL, 1) (Line: 140)
__TwigTemplate_beb756bff590a6c8b103ffa703e86c4b->doDisplay(Array, Array) (Line: 394)
Twig\Template->displayWithErrorHandling(Array, Array) (Line: 367)
Twig\Template->display(Array) (Line: 56)
__TwigTemplate_fea8893c3a0dc0e19734e7d5a45223ba->doDisplay(Array, Array) (Line: 394)
Twig\Template->displayWithErrorHandling(Array, Array) (Line: 367)
Twig\Template->display(Array) (Line: 379)
Twig\Template->render(Array) (Line: 38)
Twig\TemplateWrapper->render(Array) (Line: 39)
twig_render_template('REDACTED/themes/custom/REDACTED/templates/views/views-view.html.twig', Array) (Line: 348)
Drupal\Core\Theme\ThemeManager->render('views_view', Array) (Line: 480)
Drupal\Core\Render\Renderer->doRender(Array) (Line: 493)
Drupal\Core\Render\Renderer->doRender(Array, ) (Line: 240)
Drupal\Core\Render\Renderer->render(Array, ) (Line: 238)
Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}() (Line: 627)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 239)
Drupal\Core\Render\MainContent\HtmlRenderer->prepare(Array, Object, Object) (Line: 128)
Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse(Array, Object, Object) (Line: 90)
Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray(Object, 'kernel.view', Object)
call_user_func(Array, Object, 'kernel.view', Object) (Line: 111)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch(Object, 'kernel.view') (Line: 186)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 76)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 58)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 28)
Drupal\Core\StackMiddleware\ContentLength->handle(Object, 1, 1) (Line: 32)
Drupal\big_pipe\StackMiddleware\ContentLength->handle(Object, 1, 1) (Line: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 272)
Drupal\shield\ShieldMiddleware->bypass(Object, 1, 1) (Line: 130)
Drupal\shield\ShieldMiddleware->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 36)
Drupal\Core\StackMiddleware\AjaxPageState->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\StackedHttpKernel->handle(Object, 1, 1) (Line: 704)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

[Tregonia]

On further debugging, found some copypasta from a Microsoft source into CKEditor.

In my instance, non-standard elements were found in the source. Specifically, these elements wrapping images:

<w:wrap type="square"></w:wrap>
<wrap type="square" xmlns:w=""></wrap>

Editing the content, and removing the non-standard HTML, resolved this issue for us.