[Bug]: JavaScript support detection broken on non-top level hosting

[BastienDurel]

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

Hello,

The mjs support detection does not seems to work when nextcloud is not hosted on the root of the domain (when it's in a subdirectory)

My instance is hosted in the /owncloud directory (I did not wanted to disrupt my users), but the test tries to connect to /owncloud/owncloud/apps/settings/js/esm-test.mjs

/var/log/apache2/access.log:10.126.0.42 - - [16/Sep/2024:12:41:26 +0200] me "HEAD /owncloud/owncloud/apps/settings/js/esm-test.mjs HTTP/1.1" 404 5678 "-" "Nextcloud Server Crawler"

This URL is invalid

I did not dig down very much, but at

server/apps/settings/lib/SetupChecks/JavaScriptModules.php

Line 58 in 619dd93

$testFile = $this->urlGenerator->linkTo('settings', 'js/esm-test.mjs');

it seems to generate a complete URL, then at

server/apps/settings/lib/SetupChecks/JavaScriptModules.php

Line 60 in 619dd93

[$this->urlGenerator->getAbsoluteURL($testFile)],

it generates it again, which may lead to double-adding the base directory

Steps to reproduce

1. host nextcloud in a subdirectory
2. go to settings/admin/overview

Expected behavior

no message "Unable to run check for JavaScript support."

Nextcloud Server version

30

Operating system

Debian/Ubuntu

PHP engine version

PHP 8.2

Web server

Apache (supported)

Database engine version

PostgreSQL

Is this bug present after an update or on a fresh install?

Upgraded to a MAJOR version (ex. 28 to 29)

Are you using the Nextcloud Server Encryption module?

None

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

{
    "system": {
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "pgsql",
        "version": "30.0.0.14",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbtableprefix": "oc_",
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "forcessl": true,
        "theme": "",
        "debug": false,
        "maintenance": false,
        "default_phone_region": "FR",
        "trusted_domains": [
            "***REMOVED SENSITIVE VALUE***",
            "***REMOVED SENSITIVE VALUE***"
        ],
        "secret": "***REMOVED SENSITIVE VALUE***",
        "memcache.local": "\\OC\\Memcache\\Redis",
        "loglevel": 1,
        "log_type": "file",
        "logfile": "\/var\/log\/nextcloud\/nextcloud.log",
        "trashbin_retention_obligation": "auto",
        "updatechecker": false,
        "htaccess.RewriteBase": "\/owncloud",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "port": 0
        },
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "mysql.utf8mb4": false,
        "mail_smtpmode": "sendmail",
        "mail_sendmailmode": "smtp",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "updater.release.channel": "stable",
        "maintenance_window_start": 3,
        "check_for_working_wellknown_setup": false
    }
}

List of activated Apps

No response

Nextcloud Signing status

No response

Nextcloud Logs

No response

Additional info

No response

[BastienDurel]

NB: this also breaks the JavaScriptSourceMaps check

NB2: One can workaround by adding a link : ln -s . owncloud but it's dirty ;)

NB3: OCA\Settings\SetupChecks\SecurityHeaders seems to be affected too, as I get this in apache logs :

/var/log/apache2/access.log:10.126.0.42 - - [16/Sep/2024:18:02:34 +0200] me "GET /owncloud/owncloud/heartbeat HTTP/1.1" 404 10566 "-" "Nextcloud Server Crawler"

But for this one, the link is ineffective as a workaround

[kesselb]

Thanks for your report 👍

The problem is hopefully solved with 30.0.0.1 and 29.0.8 (both scheduled for 2024-10-10)

More details #47950

[BastienDurel]

Oups, sorry, I did not checked the closed bugs :$

[kesselb]

Don't worry

[Gwyll]

Hello,

Since we still have 5 days until 2024-10-10 here is a moderately dirty solution.
Add this to the vhost config:

RedirectMatch "^/(value of htaccess.RewriteBase)/(value of htaccess.RewriteBase)/(.*)" "/nextcloud/$3"

If
'htaccess.RewriteBase' => '/nextcloud',

then
RedirectMatch "^/(nextcloud)/(nextcloud)/(.*)" "/nextcloud/$3"