[Bug]: "Could not set global default apps"

[fulldecent]

⚠️ 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

Cannot set an external link as the global default app

Steps to reproduce

1. Install app: External sites
2. Create an external site (will show up on top bar)
3. Install app: Theming
4. Go to Administration settings > Theming
5. Turn on: Use custom default app
6. X out one of the existing ones (there seems to be a limit of two)
7. Add your own external site that you created above

Expected behavior

External site is added as the custom default app

---

Actual behavior: error message:

Could not set global default apps

Installation method

Official All-in-One appliance

Nextcloud Server version

28

Operating system

Debian/Ubuntu

PHP engine version

PHP 8.1

Web server

Apache (supported)

Database engine version

MySQL

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

Fresh Nextcloud Server install

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

No response

List of activated Apps

No response

Nextcloud Signing status

No response

Nextcloud Logs

No response

Additional info

No response

[susnux]

This is a bug of the external sites app, the problem is that they do not register the entry correctly.
app is a required key of the navigation entry, but it is not set.

https://github.com/nextcloud/external/blob/d9de3e5788651fce1f474cd72d874660fd6838d1/lib/AppInfo/Application.php#L76

There it is missing 'app' => 'external' (the app id)

[provokateurin]

Thanks @susnux, I'll take over!

[provokateurin]

I investigated a little bit and this is actually not a bug of the external sites app, but rather server. I'll continue to investigate and hopefully fix it though.

[provokateurin]

Unfortunately it is quite a severe bug that needs a bunch of refactoring.
Luckily this issue doesn't have a high impact since most apps register one navigation entry at most and use the same value for id and app.

[fulldecent]

@provokateurin thank you for looking into this. Could you please spell out the details of your research and the parts necessary for such a refactor?

[provokateurin]

I'm already working on it! You'll be able to see it in the PR (both the changes and the explanation of the problem).