Closing a conpty terminal can hang the window

[Tyriar]

microsoft/terminal#1810

[Tyriar]

This is causing integration tests to fail under conpty #75689

[Tyriar]

Console team's issue: microsoft/terminal#1810

[Tyriar]

@alexr00 this is caused by inherit cursor position which was a fix for terminals that have already been written to before the process launches (just tasks). We have 2 options to workaround the crashes:

• Only enable the flag for ter minals that have already been written to, we don't need to pass around as I just need to know if TerminalInstance.write was called. There's still a chance of a crash but it should rarely happen as the most common repro is creating a bunch of terminals and killing them immediately.
• Disable the flag completely and move tasks to winpty again.

[alexr00]

Option 1. Conpty is the way of the future and I'd rather we keep finding new bugs there than seeing the same old winpty bugs.

[Tyriar]

I'm going to call this fixed in August with this workaround, while a hang likely can still occur it should be very tough to reproduce just with tasks. If people are hitting it they can avoid using the flag completely by configuring the task to not show the intro line and not reuse terminals.

[Tyriar]

I'm getting reports that this is still happening with the workaround:

• Entering and exiting cmd, then killing the terminal causes vscode to freeze #79303
• Often getting full window hangs #71966 (comment)

[usernamehw]

The upstream issue microsoft/terminal#1810 (comment) was fixed. Will the fix be included in 1.39 or does it depend on Windows update?

[Tyriar]

@usernamehw depends on a Windows update and the fix is too complicated to backport.

[Tyriar]

Fixed upstream, closing. You may see this until updating to Windows >1903, other windows crashes tracked in #71966

[Tyriar]

Not sure why I reopened this, see #71966