Cannot retrieve value of undefined directive Core.RemoveBlanks

[FadeFx]

Hi,

I am using nextcloud and its news app, which actually is an RSS reader and uses your library. Since its latest alpha build it constantly floods nextcloud logs with

{"reqId":"S9A6V7FoXrzh4bT1hs1U","level":2,"time":"2024-11-16T08:50:24+00:00","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"Cannot retrieve value of undefined directive Core.RemoveBlanks invoked on line 75 in file /var/www/nextcloud/apps/news/vendor/ezyang/htmlpurifier/library/HTMLPurifier/Lexer/DOMLex.php at /var/www/nextcloud/apps/news/vendor/ezyang/htmlpurifier/library/HTMLPurifier/Config.php#901","userAgent":"--","version":"30.0.2.2","data":{"app":"PHP"},"id":"67385db8a6022"}

And the Dev suggested to post this here, as it seems to be an upstream issue in your library. Please also check this bugreport in nextcloud/news https://github.com/nextcloud/news/issues/2883

[ezyang]

We didn't remove this directive. What if you reinstall HTML Purifier?

[bytestream]

The directive was added in 4.18 (latest release), but I cannot replicate the issue when using DOMLex. $config->get('Core.RemoveBlanks') returns false

[castle-giant]

I'm also experiencing this in nextcloud news. Is there anything specific I can dig into to help investigate?

[FadeFx]

I don't really know much about HTML Purifyer, but I guess it is bundled with nextcloud news as an external library would I just need to replace a file to reinstall it? Or is it actually installed in the os?

[FadeFx]

OK, so this is shipping with the nextcloud-news app, nothing I could do there I guess

[ezyang]

I am guessing they botched their bundle. Go complain back at them.

[FadeFx]

So you confirm everything is working from your side? I guess that "RemoveBlanks" function is widely used and it would surface immediately if there was a bug at your side, right?

[SMillerDev]

I am guessing they botched their bundle. Go complain back at them.

News just ships whatever Composer gives us, is there a way to further debug this?

The initialisation in news is done like this: https://github.com/nextcloud/news/blob/594be805c85c8b06c9b9918f90453309cfd1ade3/lib/AppInfo/Application.php#L103

[ezyang]

I'd go look at the ConfigSchema ser and manually check it matches what's in Git

[yvonnewat]

Hello, I am not using nextcloud and have also noticed this exact issue when using the latest version of htmlpurifier v4.18.0. We have temporarily fixed it by reverting to v4.17.0.

[kavanagh21]

I also have the same issue, and I'm installing it directly from Composer.

[FadeFx]

It seems the nextcloud news team have narrowed the issue down to another app using htmlpurifier as well, causing dependency issues, if I got it right. Check here: https://github.com/nextcloud/news/issues/3017

[kavanagh21]

Sorry, I didn't write that very clearly; I'm installing HTMLPurifier directly from composer. I don't have nextcloud installed and have never used it. I've tried rolling back to 4.17.0 but that didn't fix it either, sadly.

[FadeFx]

What I wanted to asy, is there anything else, using htmlpurifier on your system that could cause cross dependencies?

[bytestream]

My understanding is that this is not a HTMLPurifier issue. They had the news app running v4.17.0 and the mail app running v.4.18.0. That created a conflict as Core.RemoveBlanks was only introduced in v4.18.0