Client crashes while adding sync connection after deselecting all remote folders

[anon-pradip]

Steps to reproduce

1. Create a couple of files and folders in server
2. Add account to desktop client with Configure synchronization manually enabled.
   
3. In Deselect all remote folders setup window, deselect all remote folders ⚠️
   

Important

This issue occurs with the client build built with cmake from client repo but does not occur with the build built using openbuild

5. Click Add Space 💥

Expected Behavior

The client should remain open, allow selection of the "Personal" space, and continue with the sync setup without crashing.

Failing CI:

https://ci.opencloud.rocks/repos/11/pipeline/394/49#L1276

Crash Logs:

OpenCloud crash log (first run)

OpenCloud 3.1.0 5556ba Libraries Qt 6.9.2, OpenSSL 3.5.4 30 Sep 2025 Using virtual files plugin: xattr OS: ubuntu-6.8.0-90-generic (build arch: x86_64, CPU arch: x86_64) QPA: xcb OpenCloud
26-01-26 10:34:26:760 [ info gui.account.state ]:	checkConnectivity blocking: false "Admin@host.docker.internal:9200"
26-01-26 10:34:26:760 [ info sync.connectionvalidator ]:	No system proxy set by OS
26-01-26 10:34:26:766 [ info sync.checkserverjob ]:	status.php returns:  QJsonDocument({"channel":"","edition":"rolling","installed":true,"maintenance":false,"needsDbUpgrade":false,"product":"OpenCloud","productname":"OpenCloud","productversion":"4.1.0+e372ae0c","version":"0.1.0.0","versionstring":"0.1.0"})   QNetworkReply::NoError  Reply:  QNetworkReplyHttpImpl(0x594d189c8a60)
26-01-26 10:34:26:766 [ info sync.connectionvalidator ]:	** Application: OpenCloud found:  QUrl("https://host.docker.internal:9200")  with version  "4.1.0+e372ae0c"
26-01-26 10:34:26:766 [ info sync.networkjob ]:	Created OCC::JsonJob(OCC::Account("Admin@host.docker.internal:9200"), "https://host.docker.internal:9200/graph/v1.0/me", "GET", Original-Request-ID: "a13a357c-bd53-46ef-a03c-e37dde6ba6bf", X-Request-ID: "a13a357c-bd53-46ef-a03c-e37dde6ba6bf") for QObject(0x0)
26-01-26 10:34:50:316 [ info sync.networkjob ]:	Created OCC::PropfindJob(OCC::Account("Admin@host.docker.internal:9200"), "https://host.docker.internal:9200/dav/spaces/c50314c6-2268-4985-85a7-378b9086586b$adde1820-9659-43c5-843f-abc0118bf7a5/", "PROPFIND", Original-Request-ID: "716eaa56-a592-4892-bffb-9049ff121bbc", X-Request-ID: "716eaa56-a592-4892-bffb-9049ff121bbc") for OCC::SelectiveSyncWidget(0x594d1866d960)
26-01-26 10:34:50:363 [ info sync.networkjob.propfind ]:	LSCOL of QUrl("https://host.docker.internal:9200/dav/spaces/c50314c6-2268-4985-85a7-378b9086586b$adde1820-9659-43c5-843f-abc0118bf7a5/") FINISHED WITH STATUS "OK"
26-01-26 10:34:50:760 [ info sync.networkjob ]:	Created OCC::GraphApi::Drives(OCC::Account("Admin@host.docker.internal:9200"), "https://host.docker.internal:9200/graph/v1.0/me/drives", "GET", Original-Request-ID: "2ab22bac-e86d-444a-b667-f80ba2ae2e31", X-Request-ID: "2ab22bac-e86d-444a-b667-f80ba2ae2e31") for QObject(0x0)
26-01-26 10:35:20:760 [ info sync.networkjob ]:	Created OCC::JsonApiJob(OCC::Account("Admin@host.docker.internal:9200"), "https://host.docker.internal:9200/ocs/v2.php/apps/notifications/api/v1/notifications?format=json", "GET", Original-Request-ID: "dee9fa12-1107-47da-81c0-999a400c644d", X-Request-ID: "dee9fa12-1107-47da-81c0-999a400c644d") for OCC::AccountSettings(0x594d186c4be0, name = "OCC__AccountSettings")
26-01-26 10:35:20:760 [ info sync.networkjob ]:	Created OCC::GraphApi::Drives(OCC::Account("Admin@host.docker.internal:9200"), "https://host.docker.internal:9200/graph/v1.0/me/drives", "GET", Original-Request-ID: "b64a9c87-5e1c-4e48-aed8-8119e797b613", X-Request-ID: "b64a9c87-5e1c-4e48-aed8-8119e797b613") for QObject(0x0)
26-01-26 10:35:21:582 [ info gui.account.settings ]:	Folder wizard completed
26-01-26 10:35:21:582 [ info sync.plugins ]:	Created VFS instance from plugin "OpenCloud_vfs_xattr"
26-01-26 10:35:21:583 [ info sync.database ]:	sqlite3 version "3.50.2"
26-01-26 10:35:21:583 [ info sync.database ]:	sqlite3 locking_mode= "exclusive"
26-01-26 10:35:21:583 [ info sync.database ]:	sqlite3 journal_mode= "wal"
26-01-26 10:35:21:589 [ info sync.database ]:	sqlite3 synchronous= "NORMAL"
26-01-26 10:35:21:593 [ info sync.database ]:	Forcing remote re-discovery by deleting folder Etags
26-01-26 10:35:21:593 [ info sync.configfile ]:	Adding system ignore list to csync: ":/client/OpenCloud/theme/universal/sync-exclude.lst"
26-01-26 10:35:21:593 [ info gui.folder.manager ]:	Adding folder to Folder Map  OCC::Folder(0x594d17d198f0) "/home/pradip/Desktop/temp-folder/Personal/"
26-01-26 10:35:21:603 [ fatal default ]:	ENSURE: "folder && !config.useVirtualFiles" in file /home/pradip/pradip/JankariTech/oc-desktop/desktop/src/gui/accountsettings.cpp, line 183 void OCC::AccountSettings::slotFolderWizardAccepted()

When repeated same:
OpenCloud-crash.log

[anon-pradip]

cc @TheOneRing

[TheOneRing]

#788 will fix the crash.
However, the test fails as we now have vfs for Linux. Which is not yet ready for testing.