Crash when navigating in the profiler, around the hidden tracks feature

STR:

1. Open https://share.firefox.dev/3iSSFyB
2. Click “Full Range” at the top left.
3. Press the browser’s “back” button

=> There’s a crash. Surprisingly when pressing F5 then this works.

The stack trace with the development server looks like:

Uncaught Error: Could not look up the hidden local tracks from the given PID
    ensureExists flow.js:177
    getTimelineHeight app.js:250
    memoizedResultFunc index.js:70
    defaultMemoize index.js:30
    selector index.js:84
    defaultMemoize index.js:30
    mapStateToProps ProfileViewer.js:151

The crash happens in https://github.com/firefox-devtools/profiler/blob/0ecc660cb4fc6877dff6cb8db08d08451453ff36/src/selectors/app.js#L246-L249, but this is very likely a problem with updating the state we use here when pressing the “back” button. Do we use some state that’s not handled in UrlState here?

[jhabarsingh]

I am working on this issue.

[julienw]

I’m not sure what changed, but this doesn’t seem to crash anymore.