fix: prevent crash when changing proxy settings with logged out account

[Copilot]

Description

The desktop client segfaults when proxy settings are changed while an account is logged out. AccountManager::accountFromUserId() returns nullptr for logged-out accounts, but NetworkSettings::saveProxySettings() dereferences it unconditionally.

Changes

src/gui/networksettings.cpp

• Add null check before calling freshConnectionAttempt() on accountState returned by accountFromUserId()

const auto accountState = AccountManager::instance()->accountFromUserId(_account->userIdAtHostWithPort());
if (accountState) {
    accountState->freshConnectionAttempt();
}

test/testnetworksettings.cpp (new)

• Add regression test that creates NetworkSettings with an unregistered account

test/CMakeLists.txt

• Register NetworkSettings test

Impact

Proxy settings save correctly regardless of account state. Connection attempt skipped when accountState unavailable.

Signed-off-by: Copilot 198982749+Copilot@users.noreply.github.com

Original prompt

---

This section details on the original issue you should resolve

<issue_title>[Bug]: Client crashes when switching proxy settings while account is logged out</issue_title>
<issue_description>### ⚠️ Before submitting, please verify the following: ⚠️

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

Bug description

The client segfaults when proxy settings are when the account is logged out.

Steps to reproduce

1. Start client
2. Open settings
3. Switch to a offline account
4. Ensure client is logged out (in german is says "Abgemeldet von https://myinstance.com as myusername").
5. Switch to connection settings
6. Change the proxy settings from "System-Proxy" to "No proxy" or "Setup proxy manually"

Expected behavior

The application should not segfault.

Which files are affected by this bug

desktop/src/gui/networksettings.cpp

Operating system

Linux

Which version of the operating system you are running.

Arch

Package

Distro package manager

Nextcloud Server version

32.0.2

Nextcloud Desktop Client version

4.0.3daily (Arch)

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

Updated from a minor version (ex. 3.16.1 to 3.16.2)

Are you using the Nextcloud Server Encryption module?

Encryption is Enabled

Are you using an external user-backend?

• Default internal user-backend
• LDAP/ Active Directory
• SSO - SAML
• Other

Nextcloud Server logs

There are no logs as the account is logged out.

Additional info

nb.zip</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes [Bug]: Client crashes when switching proxy settings while account is logged out #9193

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[github-actions]

Artifact containing the AppImage: nextcloud-appimage-pr-9194.zip

Digest: sha256:e7846db472496bcc032e2e1b4d0e96ea59d69a04631ee37efc264bfb36f54894

To test this change/fix you can download the above artifact file, unzip it, and run it.

Please make sure to quit your existing Nextcloud app and backup your data.

[sonarqubecloud]

Quality Gate failed

Failed conditions
4 New Code Smells (required ≤ 0)
D Maintainability Rating on New Code (required ≥ A)

See analysis details on SonarQube Cloud

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[mgallien]

@copilot this is not enough to get the test to run the modified code in NetworkSettings class
can you also modify the settings and get them saved to ensure we run the modified code ?