sshfs freezing on cd with >=1.13.0 version

[soredake]

Describe the bug
sshfs freezing with >=1.13.0 version when doing cd/tab-completion.

To Reproduce
How, and what happened?

1. sudo multipass set local.driver=virtualbox
2. multipass set local.privileged-mounts=yes
3. multipass set client.gui.autostart=no
4. multipass launch --name primary -c 4 -m 4G --mount C::/mnt/c_host
5. multipass exec primary bash wsl.sh (https://github.com/soredake/dotfiles_windows/blob/60fa0a1d92391d9d77c59c4b985da09abc19a508/wsl.sh)
6. Go to newly created instance
7. Do tmux
8. Do cd /mnt/c_host/Users/<your user>
9. Do cd ..
10. Fail
11. In another pane, try to do cd /mnt/c_host/Users/user
12. Also fail

Expected behavior
Sshfs mount should work without freezing.

Logs
Export.txt

Additional info

• OS: Windows 11 Pro
• multipass version:

multipass   1.13.0+win
multipassd  1.13.0+win

• multipass info --all:

Warning: the `--all` flag for the `info` command is deprecated. Please use `info` with no positional arguments for the same effect.
Name:           primary
State:          Stopped
IPv4:           --
Release:        --
Image hash:     fa2146bb04e5 (Ubuntu 22.04 LTS)
CPU(s):         --
Load:           --
Disk usage:     --
Memory usage:   --
Mounts:         E:/           => /mnt/e_host
                    UID map: -2:default
                    GID map: -2:default
                C:/Users/user => Home
                    UID map: -2:default
                    GID map: -2:default
                D:/           => /mnt/d_host
                    UID map: -2:default
                    GID map: -2:default
                C:/           => /mnt/c_host
                    UID map: -2:default
                    GID map: -2:default

• multipass get local.driver: virtualbox

Additional context
Add any other context about the problem here.

[townsend2010]

Hi @soredake,

I could not reproduce on my Windows machine. However, I looked through the log you provided. There is an unhandled exception occurring with an error string in Russian. I translated this and it says, A Unicode character has no mapping in the final multibyte code page. It appears the problem is that it is not handling localized paths correctly and then errors out.

This is is caused by or related to #1314 which we should fix.

[soredake]

I tested older version, 1.12.2+win works fine, no freezes.

Rewrite of some parts of the cross platform SFTP server used for classic mounts to use std::filesystem instead of QFile. This avoids some bugs in Qt along with using more of the stdlib when we can.

Maybe this change broke sshfs.