Controlbox disappears on logout for an untrusted device

[chrzaszcz]

Describe the bug
When the user unchecks "This is a trusted device", the storage is cleaned up on logout. However, the whole controlbox is lost in the process, making the whole Web UI empty, i.e. the whole login screen disappears.

To Reproduce
Steps to reproduce the behavior:

1. Uncheck "This is a trusted device"
2. Logout
3. UI is empty

Expected behavior
Login screen should appear again.

Screenshots
Completely blank UI, so no screenshot needed.

Environment (please complete the following information):

• Desktop
• Latest Firefox.
• Converse.js 10.1.5

Additional context
I spent some time debugging this, and I found that commenting out the following lines resolves the issue:

export async function onClearSession () {
    if (shouldClearCache()) {
        await Promise.all(
            _converse.chatboxes.map(c => c.messages && c.messages.clearStore({ 'silent': true }))
        );
        //const filter = o => o.get('type') !== _converse.CONTROLBOX_TYPE;
        //_converse.chatboxes.clearStore({ 'silent': true }, filter);
    }
}

It looks like the clearStore function in skeletor is supposed to take the filter into consideration, and only clean up the boxes that are not filtered out. However, it calls this._reset() which deletes all models, making the controlbox disappear when the UI is later updated.

Is my reasoning correct?

My configuration:

converse.initialize({
            dark_theme: "default",
            allow_dragresize: true,
            view_mode: 'embedded',
            websocket_url: 'ws://m:5280/ws-xmpp',
            discover_connection_methods: false,
            loglevel: "debug",
            show_controlbox_by_default: true,
            allow_user_trust_override: true,
            allow_registration: false,
            auto_reconnect: true
        });

[jcbrand]

Is my reasoning correct?

Yes I think it's correct. I think the fix is to update clearStore in Skeletor to pass the filtered out model(s) to this.reset() so that those models are kept.

See here: https://github.com/conversejs/skeletor/blob/69b49b4cfcb2db323ac0bed5472ebb8cd714b6c5/src/collection.js#L277