The rollback restored files, announced 'Libation restored your previous install
files', and deleted the pending marker without ever reading back what it had
written. It also could not tell the difference between an overlay that had not
started, where putting the backup back returns the install to one version, and
an overlay that got partway, where the backup covers a dozen names out of the
few hundred in the folder and cannot.
Grade the outcome instead. Verify each restored file against its backup, and
use the manifest files that did match the upgrade package as the signal that
the overlay had begun. Report which files could not be restored, and keep
restoring the rest rather than abandoning them at the first failure.
Libation has to close either way, since the files underneath it just changed,
so the wording and the offer now follow the grade: back on the previous version
asks to restart, a mixed install asks but says a fresh install would be better,
and a restore that could not finish only offers OK. A relaunched process never
offers again, so a pending marker we failed to delete cannot become a loop.
Co-authored-by: rmcrackan <rmcrackan@gmail.com>
