[3.x]: Argument 1 passed to craft\helpers\Html::_namespaceInputs() must be of the type string, null given

[birdkiwi]

What happened?

Description

When filling the field with a large amount of data CraftCMS returns TypeError: Argument 1 passed to craft\helpers\Html::_namespaceInputs() must be of the type string, null given, called in /app/vendor/craftcms/cms/src/helpers/Html.php on line 601

With the help of Xdebug I found out that the problem is $html variable stored as null. Null value returns because of PREG_BACKTRACK_LIMIT_ERROR inside preg_replace_callback(). pcre.backtrack_limit is "1000000" by default.

https://github.com/craftcms/cms/blob/develop/src/helpers/Html.php#L854

$markers = [];
$html = preg_replace_callback('/(<textarea\b[^>]*>)(.*?)(<\/textarea>)/is', function(array $matches) use (&$markers) {
    $marker = '{marker:' . StringHelper::randomString() . '}';
    $markers[$marker] = $matches[2];
    return $matches[1] . $marker . $matches[3];
}, $html);
return $markers;

I know that storing such a large amount of text is not a good idea, but I think that such an error should be handled in Craft to avoid customer problems.

I haven't tested it with Craft 4 yet, but looking through source I see the same issue as well.

Steps to reproduce

1. Create a custom textarea field up to 16mb size limit
2. Attach it to some section and fill this input in the entry. There should be more then 1 million chars in the field
3. Try open / refresh entry in CP again

Expected behavior

CP should not throw an Exception but show an error or notification maybe? I still don't know the best way to to avoid this behavior.

Actual behavior

Internal Server error

Craft CMS version

3.8.5

PHP version

7.2.34

Operating system and version

Linux 5.15.90.1-microsoft-standard-WSL2

Database type and version

MySQL 5.7.40

Image driver and version

Imagick 3.4.4 (ImageMagick 7.0.10-48)

Installed plugins and versions

Blitz | 3.12.8
Blitz Recommendations | 1.3.0
Blitz | 3.12.8
Blitz Recommendations | 1.3.0
CP Field Inspect | 1.4.4
Groupie | 1.0.8
Incognito Field | 1.3.0
Minifier | 3.0.0
Password Policy | 1.2.0
Position Fieldtype | 1.0.17
Protected Links | 0.0.4
Redactor | 2.10.12
Sentry Logger | 1.3.1
SEOmatic | 3.4.51
SessionSync | 0.0.1
Splash | 3.0.5
Store Hours | 2.2.0
Super Table | 2.7.4
Typed link field | 1.0.25

[i-just]

Hi, thanks for reporting and for the clear reproduction steps! I raised a PR for it.

[brandonkelly]

Fixed for the next Craft 3 and 4 releases via #13085

[brandonkelly]

Craft 3.8.8 and 4.4.8 are out with that fix! Thanks again for reporting.