- restore the success-path debug log the old git-pull guard had
- drop the dead 'tag' test-helper param and unused snapshot return
- hoist the repeated get_hermes_home() call
The #68474 post-update integrity guard verified only the root home's state.db, but the pre-update snapshot already covered every sibling profile (#66140 create_pre_update_snapshots_all_profiles). A profile database corrupted by the update was never detected and never auto-restored - that profile's sessions were silently gone while the update reported success (#97994).
Both guard sites (ZIP path and git-pull path) now route through a shared _verify_and_restore_state_dbs_post_update() that verifies the root DB plus every _sibling_profile_homes() DB, restoring each from its OWN most recent valid snapshot with per-profile operator-visible reporting. Refactors the two near-identical inline guards into one helper - behavior for the root DB is unchanged.
Tests: corrupt-sibling-with-snapshot gets restored while root stays untouched; valid-sibling not touched; corrupt-sibling-without-snapshot reported without raising. Fixes#97994.
Addresses review feedback on the regression test. The test previously parsed
the update_cmd.py AST to assert that each auto-restore call site cleared the
destination's sidecars before copying. That bound the fix to source text rather
than behaviour, and would break on unrelated refactors.
Extract _restore_state_db_from_snapshot(state_path, snap_state), which performs
the clear -> copy -> verify sequence as one unit and returns whether the
restored file passes its integrity check. Both auto-restore paths now call it,
so the ordering is guaranteed by construction instead of by inspection, and the
two byte-identical blocks collapse to a single call each.
The regression test now exercises that helper directly against a database that
still owns a hot WAL: removing the clear from inside the helper fails it with
201 rows where 400 were expected, so the guard remains bound to behaviour.
Also covers the two failure modes the callers already handle: a snapshot that
does not survive the copy returns False, and a missing snapshot raises OSError.
The post-update integrity guard (#68474) restores state.db from a pre-update
quick snapshot with a plain shutil.copy2, at both auto-restore sites: the
ZIP-update path in _update_via_zip and the git-pull path in _cmd_update_impl.
The snapshot image is produced by backup._safe_copy_db through sqlite3.backup(),
so it is already checkpointed and owns no WAL. That is precisely why
backup._EXCLUDED_SUFFIXES refuses to ship -wal/-shm/-journal inside a snapshot:
"shipping the live WAL / shared-memory / rollback-journal alongside would pair a
fresh snapshot with stale sidecar state and produce a torn restore on the next
open." The backup side excludes sidecars for that reason; the restore side never
cleared the destination's.
copy2 replaces only the main database file. A state.db-wal belonging to the old,
corrupt database survives the copy and is replayed over the fresh image on the
next open. The restored file then passes PRAGMA integrity_check while serving
the discarded database's contents, so _restored_ok reports valid and the CLI
prints "Auto-restored from snapshot" over data the user has lost. The first
subsequent checkpoint folds the stale WAL in permanently.
A hot -wal is reachable at exactly this moment: a second Hermes holder the
updater's drain did not stop, or the crash that corrupted state.db in the first
place, which is the very trigger for this code path.
Clearing the destination's sidecars is safe here specifically -- they belong to a
database the caller has already declared corrupt and is about to discard.
Contrast preflight_db_writability, which correctly refuses to delete a live WAL.
Reproduced against real SQLite: restoring a 400-row snapshot over a database
with a hot WAL yields 0 of the 400 rows, all 201 visible rows coming from the
old WAL, with integrity_check reporting ok.
kshitijk4poor