ConPTY(?) inserts broken control codes into tmux sessions.

[Efreak]

Environment

Windows build number: Microsoft Windows [Version 10.0.18363.959]
Windows Terminal version (if applicable): N/A.

Any other software?
OpenSSH_for_Windows_7.7p1, LibreSSL 2.6.5
tmux 2.6

Steps to reproduce

Open an ssh (other?) session with a running tmux session with default configuration.

Expected behavior

tmux session opens as you've left it.

Actual behavior

tmux opens with 1;0c appended to whatever was at the prompt/cursor previously. Applications that consume control characters attempt to do something with them. (I haven't run into any issues with that yet, but it's possible; mostly I'm just in nano, which only complains about Unknown sequence).

---

Fix

Add a line to tmux.conf: set -s escape-time 10. Do this on every remote server you log into.

I should note that this is not actually an issue with WT per say--it also affects cmd.exe (which is what I primarily use for quick, single-command sessions). However, the fix I found was located
here, which links to here as the correct place to file an issue.

Screenshots

Screenshots

Connecting to my laptop running Ubuntu 18.04.3 via WSL

Running on a remote VPS with Ubuntu 18.04.3:

If nano is running, I get a ding and an Unknown sequence message:

This one with a running editor has gotten me several times before, as I tend to leave files open, sometimes with modifications to finish later.

[DHowett]

Would you mind trying this with SSH 8.1 from the Win32-OpenSSH releases page? This seems very similar to the issue where Vim starts in replace mode because Win32-OpenSSH 7.7 won’t pass the escape sequence through unmodified and WT/conhost is replying to a DSR

[ghost]

This issue has been automatically marked as stale because it has been marked as requiring author feedback but has not had any activity for 4 days. It will be closed if no further activity occurs within 3 days of this comment.

[zb140]

Not the OP, but I just came across this issue by searching because I'm seeing the same issue. I tried it with SSH 8.1 and I can confirm it does indeed fix the problem. And the good news is, the SSH issue tracker says v8.1 is expected to ship in the next version of WIndows (PowerShell/Win32-OpenSSH#1646) so I can be lazy about updating all my computers if I'm willing to live with it another couple months 😉

Thanks!

[idl0r]

Sorry but is there any chance to get an official openssh client bump that's been installed through the feature list / window?

[DHowett]

I’m sorry, we don’t own that component. The best place to ask would be on their repository 😄

[idl0r]

Is https://github.com/PowerShell/Win32-OpenSSH the official repo for this? is that's the one that's being installed through the features setup? I just thought that you know someone there by chance, since this is an official (or kind of)Microsoft one as well?

[shivanshu3]

I am not able to repro this behavior on cmd.exe. It only repros on Windows Terminal for me.