Reported in Discord by @spherohero: `sessions recover --allow-partial` copied
20,817 of 20,824 message rows, then orphan cleanup deleted every one of them
because no session row was salvageable. Final output: 0 sessions, 0 messages.
The salvage worked and then threw the result away -- the exact opposite of
what --allow-partial exists to do.
_cleanup_partial_orphans() removed dependent rows whose session_id had no
matching sessions row. That is correct when a few sessions are lost; it is
catastrophic when the sessions b-tree is damaged worse than messages, which
is the common shape (sessions is small and hot, messages is large).
Reproduced exactly: 500 readable messages, unreadable sessions -> 500
copied, 500 removed, empty output.
Now _reconstruct_missing_sessions() runs FIRST, inside the same transaction,
synthesizing a minimal row per orphaned session_id (only id/source/started_at
are NOT NULL). started_at comes from the earliest surviving message.
Placeholders carry source='recovered' and an explicit title so a fabricated
session can never be mistaken for an original. Same repro now retains all
500 messages under 1 reconstructed session.
Reconstruction is reported as LOSS, not a clean recovery: session metadata
(title, model, timestamps, cost) is genuinely gone even though the
conversation text survived. loss_detected=True, partial=True,
complete=False, with a warning naming the counts.
Also fixes total_removed_or_relinked, which summed every dict value and would
now have counted retained messages as removed.
Sabotage-verified: removing the reconstruction call restores the wipe and
fails the test. 942 targeted tests green.
Second round of @helix4u review on #71779. Both findings reproduced before
fixing.
1. My previous fix turned a crash into SILENT DATA LOSS. Returning
status="missing" for a present-but-unusable state_meta looked like a safe
degrade, but _verify_recovered_database only escalates "failed"/"partial"
into a warning + loss_detected. Measured on the branch: a run that dropped
a real metadata table reported warnings=[], loss_detected=False,
partial=False, complete=True. Strictly worse than the ValueError it
replaced -- that at least failed loudly.
Now "failed" when the table exists but lacks key/value, "missing" only
when genuinely absent. The damaged case yields
warnings=['state_meta copy status is failed'], loss_detected=True,
partial=True, complete=False, while staying verified=True so the output
is still installable-with-review.
2. The race test I wrote had its own scheduling race: after the guard
released the lock, the racer could win before the main thread set the
release event, failing on a correct implementation. Rewritten per
helix4u's design -- copy runs in a worker parked inside the patched
copy, a second worker attempts connect_tracked(), assert it stays blocked,
release, assert it then opens. Deterministic and ~1.1s instead of 10s;
12/12 stable.
Sabotage-verified. Note the third scenario only failed after adding a
unit-level test: recover_session_database short-circuits on the inspection
result when state_meta is entirely absent, so the helper's absent-branch is
unreachable end-to-end and a regression there was invisible. Both statuses
are now pinned directly.
939 targeted tests green.
Post-merge follow-up to #71770. Both defects were found by @helix4u in review
and reproduced against merged main before fixing.
1. Check/use race in _copy_source_bundle (my bug, from the #71770 follow-up
commit). It called has_live_connection(), released the registry lock, and
only then ran shutil.copy2() over the bundle. A tracked connection could
open in that window; the copy's close() then cancels its POSIX advisory
locks -- the exact class #71724 closed. Measured on main: a racer thread
opened a connection mid-copy after blocking 0.000s.
Adds sqlite_safe_read.offline_file_access(), a context manager that holds
the connection-lifecycle lock across an entire multi-step raw access, and
routes the bundle copy through it. Same racer now blocks 10.0s until every
raw descriptor is closed. Any future raw read of a database file (hashing,
moving a bundle aside) should use this rather than a bare pre-check.
2. _copy_state_meta_salvage assumed a 'key' column. A damaged state_meta can
keep 'value' and lose 'key'; columns.index("key") then raised ValueError
and aborted the whole partial recovery. The mirror case (key without
value) would have copied key-only rows and reported the table complete.
Now requires both, matching the non-partial _copy_state_meta, so an
unusable optional table is recorded as missing/failed and --allow-partial
still recovers sessions and messages.
Both regression tests verified by sabotage: reinstating the bare pre-check
fails the race test, removing the key/value requirement fails the other.
937 targeted tests green.
Follow-up to the partial-recovery salvage. _copy_source_bundle() raw-copied
the source state.db and its -wal/-shm sidecars with no live-connection check.
Copying a database file is an open()/close() on it, and close() cancels every
POSIX advisory lock the process holds on that file -- including a running
VACUUM's EXCLUSIVE lock (fe431651c5). hermes_state._backup_db_file already
refuses that situation; this path did not, leaving two policies for one
hazard. Verified against the merged guard: with a tracked connection open,
_backup_db_file returned None (refused) while _copy_source_bundle copied
anyway.
Recovery normally runs as its own short-lived CLI process against an
offline/quarantined file, so this should never fire in practice. It is a
consistency fix, not a live corruption path -- but it is exactly the drift
that reintroduces the bug later.
Regression test verified by sabotage: removing the guard fails it.
