PHP Error - preg_replace_callback(): Compilation failed

[Pantos]

IMPORTANT

Read and tick the following checkbox after you have created the issue or place an x inside the brackets ;)

• I have read the CONTRIBUTING.md and followed the provided tips
• I accept that the issue will be closed without comment if I do not check here
• I accept that the issue will be closed without comment if I do not fill out all items in the issue template.

Explain the Problem

After upgrading to NC 30.0.6 i get the PHP error:
[PHP] Fehler: preg_replace_callback(): Compilation failed: digits missing after \x or in \x{} or \o{} or \N{U+} at offset 3 at /www/nextcloud/www/apps/news/vendor/pear/net_url2/Net/URL2.php#1200 von ? von -- um 14.02.2025, 22:30:07

Steps to Reproduce

The error occurs every time the cronjob updates the feeds.

System Information

• News app version: 25.2.0
• Nextcloud version: 30.0.6
• Cron type: system cron
• PHP version: 8.3.16
• Database and version: MySQL 10.11.10
• Browser and version: Firefox 135.0
• OS and version: FreeBSD 14.2

Contents of nextcloud/data/nextcloud.log

{"reqId":"qhP25lmMuX7zj3Tk9Mzd","level":3,"time":"2025-02-14T21:30:07+00:00","remoteAddr":"","user":"--","app":"PHP","method":"","url":"--","message":"preg_replace_callback(): Compilation failed: digits missing after \\x or in \\x{} or \\o{} or \\N{U+} at offset 3 at /www/nextcloud/www/apps/news/vendor/pear/net_url2/Net/URL2.php#1200","userAgent":"--","version":"30.0.6.2","data":{"app":"PHP"},"id":"67afb5dff2211"}

[Pantos]

The bug still exists in version 25.2.1.

[nomoo]

also hit that.

News app version: 25.2.1
Nextcloud version: 30.0.6
Cron type: system cron
PHP version: 8.2.27
Database and version: MySQL 8.0.39
OS and version: FreeBSD 14.2

[Pantos]

I had entered the OS version incorrectly in the bug report. I also use FreeBSD. With a fresh install on Linux with NC 30.0.6 and News 20.5.1 I could not reproduce the bug. Maybe the problem is OS related?

[hc42]

Hi, I can also reproduce the issue on FreeBSD. The reason is that the Net_URL2 library uses an invalid regex at the mentioned line. The single \x is invalid here.
See for example, the definition here: https://pcre.org/pcre.txt (or ask your favorite LLM).

There is an issue here at the library repository about this problem: pear/Net_URL2#17
It seems \x was used as shorthand for \x00. This however, is problematic and support was removed in PHP v8.3.16 and v8.4.3.
I wonder why that was allowed in the first place?

[hc42]

This behavior was changed in the pcre2 project, where this broken regex support was removed. PCRE2Project/pcre2@4d2bb33

It is part of version 10.45. The FreeBSD port was updated on 6 Feb 2025 https://www.freshports.org/devel/pcre2/ . This is why it probably affects our systems now (At least I updated the package to 10.45).
As a temporary hotfix, you could build an older version of this port until this issue is resolved here and see if that will work.

[Pantos]

That works perfectly! Instead of building a new (old) pcre2 version, I simply added the two zeros to line 1201 in /www/nextcloud/www/apps/news/vendor/pear/net_url2/Net/URL2.php (pear/Net_URL2@2639e87):

'([\x00-\x20\x22\x3C\x3E\x7F-\xFF]+)',