Clicking on a parent directory link after viewing a source file doesn't work

[marco-c]

STR:

1. Open https://coverage.moz.tools/#revision=latest&path=browser%2Fbase%2Fcontent%2FaboutDialog-appUpdater.js&view=file;
2. Click on one of the breadcrumbs

The "loading" message is displayed, but loading never happens. TypeError: n.coverage is undefined is logged in the console.