Closing notebook during startup can cause infinite loop setting preferred kernel

[amunger]

I opened vs code with several notebooks open, and started closing them while the extension was still activating.
The logs show that there is some code stuck in a loop. Not much of a usability impact, but really blows up the logs

verbose 15:53:55.651: Jupyter Extension: Notebook document c:\src\test\3\otherlanguages\julia.ipynb got closed
extensionHostProcess.js:144
verbose 15:53:55.703: Jupyter Extension: Preferred Remote kernel for c:\src\test\3\otherlanguages\julia.ipynb is undefined
extensionHostProcess.js:144
verbose 15:53:55.743: Jupyter Extension: Notebook document c:\src\test\3\otherlanguages\julia.ipynb got closed
extensionHostProcess.js:144
verbose 15:53:55.818: Jupyter Extension: Preferred Remote kernel for c:\src\test\3\otherlanguages\julia.ipynb is undefined
extensionHostProcess.js:144
verbose 15:53:55.865: Jupyter Extension: Notebook document c:\src\test\3\otherlanguages\julia.ipynb got closed
extensionHostProcess.js:144
verbose 15:53:55.946: Jupyter Extension: Preferred Remote kernel for c:\src\test\3\otherlanguages\julia.ipynb is undefined
extensionHostProcess.js:144
verbose 15:53:55.973: Jupyter Extension: Notebook document c:\src\test\3\otherlanguages\julia.ipynb got closed
extensionHostProcess.js:144
verbose 15:53:56.065: Jupyter Extension: Preferred Remote kernel for c:\src\test\3\otherlanguages\julia.ipynb is undefined
extensionHostProcess.js:144
verbose 15:53:56.272: Jupyter Extension: Notebook document c:\src\test\3\otherlanguages\julia.ipynb got closed
extensionHostProcess.js:144
verbose 15:53:56.417: Jupyter Extension: Preferred Remote kernel for c:\src\test\3\otherlanguages\julia.ipynb is undefined
extensionHostProcess.js:144
verbose 15:53:56.476: Jupyter Extension: Notebook document c:\src\test\3\otherlanguages\julia.ipynb got closed

[DonJayamanne]

This looks like a bug in VS Code,
This is the only place we log when a notebook is closed

        workspace.onDidCloseNotebookDocument(
            (e) => {
                traceVerbose(`Notebook document ${getDisplayPath(e.uri)} got closed`);
                this.disposeOldKernel(e.uri);
            },
            this,
            disposables
        );

Given this event can only be fired when a notebook is closed, it looks like VS Code code into a state where the event was fired more than once and leading to this crazy loop.

@rebornix any idea what could cause this?
I'm assuming its a flaky issue.

@amunger Please can you try to replicate this again, I cannot replicate this.

[amunger]

I only hit it once, haven't seen it since

[DonJayamanne]

Closing this for now, as there's really nothing in jupyter extension that we can to do address this.
Must have been a flaky vscode issue.