Terminal Crash/Hangs when closing second-last tab quickly

[TBBle]

Feedback Hub Link: https://aka.ms/AA6xn1u

Environment

Windows build number: Microsoft Windows NT 10.0.18363.0
Windows Terminal version (if applicable): 0.7.3451.0

Any other software?

Two shells have been involved in reproductions.
* PowerShell Core 7.0.0-rc1 auto-added as a shell. This is my default.
* MSYS has been added as a shell per https://github.com/microsoft/terminal/issues/1669#issuecomment-562082594

Steps to reproduce

Open Terminal, with alwaysShowTabs: false and showTabsInTitlebar: false.
Hit Control-Shift-1, Control-Shift-Tab, Control-Shift-W in sequence repeatedly until terminal crashes.

Note sure if it's the same problem, it showed up when I was trying to repro this more reliably.

Open Terminal, with alwaysShowTabs: false and showTabsInTitlebar: false.
Hit Control-Shift-1 (PowerShell Core my this case), then Control-Shift-W repeatedly until terminal hangs.

Expected behavior

Closing a tab should not crash Terminal.

Actual behavior

Closing a tab occasionally hangs or crashes terminal.

The behaviour of "Open Terminal, Start a different shell, Close the existing shell" is something I do frequently, and I see this crash once or twice in a work-day.

I think it generally happens when I'm just starting a session, but I cannot say with absolute certainty that it hasn't happened when closing a long-lived tab.

I also don't recall having ever triggered it by mouse activity, just Control-Shift-W.

[mkitzan]

Tried a repro, and couldn't get the crash (and I can input pretty fast). @TBBle, is it possible that when you're inputting during a hang it might miss inputs to launch a new tab but receive the inputs correctly to close a tab (causing an extra tab to be closed without launching a new one)? This could close the window if the only remaining tab is closed.

[TBBle]

I doubt that's it, because I was definitely getting Application errors in my Event Viewer, and sometimes it would hang Terminal rather than closing it.

That said, a new version of Terminal was just released which fixed #3908 in Terminal v0.8.10091.0, so it's possible I was hitting that, and if you happened to already have that update, then it wouldn't repro. So I'll try and repro it with the version I listed above, if I still have it, and then update to the newer version and try again.

[TBBle]

Turns out both the machines I have here have auto-updated to the new version of Terminal, and didn't reproduce the issue on brief testing. So if I'm lucky and my home box has not updated, I can try there. Otherwise, I'll probably have to close this as "Probably #3908 until proven otherwise".

[mkitzan]

I just noticed the version in your issue! Yeah, that PR fixed some crashes which repro-ed by opening-closing tabs quickly. It's highly likely that your crash was covered by that PR (or another related PR).

[TBBle]

Repro is a little hard, because I often get stopped due to triggering this with my repro steps:

I suspect this dialog is really a PowerShell Core bug (I just installed 7.0.0-rc2, perhaps it's new), complaining about STATUS_DLL_INIT_FAILED because the terminal it was expecting to write to has disappeared.

[TBBle]

Okay, sounds good. Closing this provisionally as "Fixed by #3908"/"Duplicate of #2947", unless I trigger it again.

For anyone who comes across this later, I didn't originally trigger this by fast-open-close loops, it was just sometimes happening on fast "Start Terminal, start non-default shell, close default shell".

[mkitzan]

The PS App Error is a PS thing - I think. If you open and close quickly a stand alone PS shell it does this (if I remember correctly when I tried it last).

[zadjii-msft]

For the record, I think the 0xc0000142 dialog is because the conhost.exe process that we're spawning to host pwsh.exe closes before pwsh is able to successfully connect. I see this a good amount whenever I write code that accidentally causes conhost to crash immediately on startup :P. In this case, closing the tab this quickly is just closing the conhost too fast.