MotD duplicated when called from PowerShell Core

[FranklinYu]

Please answer the following

If it is a terminal issue then please go through wiki
https://github.com/PowerShell/Win32-OpenSSH/wiki/TTY-PTY-support-in-Windows-OpenSSH

"OpenSSH for Windows" version
7.7.2.0

Server OperatingSystem
Ubuntu 16.04.5 LTS (Note: this issue doesn't seem to affect Ubuntu 18.04. Very weird.)

Client OperatingSystem
Windows 10 Enterprise

What is failing
MotD is displayed twice when calling from PowerShell Core 6.1.0. No such issue in PowerShell 5.1 from Windows 10.

Expected output
Display MotD once when logging in.

Actual output
Display MotD twice when logging in.

[FranklinYu]

If I use a build introduced in PowerShell/openssh-portable#338 then PowerShell 5.1 is also affected. Shall this hold that PR back?

[bagajjal]

Are you sure it's win32-openssh ssh client issue?
Have you tried the other ssh clients (WSL, Putty)?

I didn't see this issue when I tried to login from win10 machine to Ubuntu 16.04.5 LTS

[DHowett-MSFT]

I see this on roughly 80% of connections to all servers. It's probably a clientside buffer reuse issue, not a server issue.

[FranklinYu]

@bagajjal PuTTY and the SSH from Git Bash works with the same servers without issue. If you are not able to reproduce it, would you like a Vagrantfile showing the issue? I can try to come up with one.

There is some interesting issue with one of the servers. Part of MotD is duplicated. Not sure if this helps debugging.

[bagajjal]

@FranklinYu - After multiple retries, I am able to repro the issue.
Will try to fix it for the next release.

[janorn]

Any updates?

[janorn]

I get a random nr of motd between 1-3.

[DHowett-MSFT]

This also happens when the alternate screen buffer is exited (like when vim is closed.)

[maertendMSFT]

Fixed via: PowerShell/openssh-portable#426