Four audit findings (2026-07-14), each reproduced on crafted mboxes; the
Takeout corpus has proven 8-bit header bytes, so all are real re-import risks.
1. Whole-run crash on 8-bit Message-ID. compat32 .get() returns an
email.header.Header (not str) for raw 8-bit bytes; the old
Header.strip() raised AttributeError. _message_id ran BEFORE the
per-message try, so one bad header killed the entire import.
Fix: str() + sanitize_surrogates() before strip; and move
_message_id/_parse_date/_parse_attachments INSIDE the per-message try —
a broken message is now errors += 1, never run death.
2. Poison batch. pending.clear() ran only AFTER a successful insert, so a
failed flush (DB down / bad row) left pending intact and every later
message re-flushed the doomed batch; the final flush sat in try/finally
with no except and propagated out, losing all stats. Fix: _flush always
clears pending and counts a failed insert as db_insert_failed; the run
always reaches import_complete.
3. Stats didn't reconcile with the DB. imported counts archive writes, not
DB rows, so a partial-insert drift was invisible. Fix: separate
db_inserted/db_insert_failed counters; main() exits non-zero on any
error, DB drift, or a processed = imported + skipped + errors imbalance.
4. 8-bit Date → needless epoch_fallback. parsedate_to_datetime(Header)
raised even when str(header) parses fine. Fix: str() before the epoch
fallback.
Shared helper: _sanitize moved from gmail-header-backfill into
packages/kb-mail (kb_mail.text.sanitize_surrogates) and used by both jobs;
gmail-header-backfill now depends on kb-mail.
Tests: regression coverage for all four findings in gmail-bulk-import
(8-bit id/date, per-message guard, failed-insert non-poisoning, stats
balance) plus kb_mail.text unit tests. Full suites green:
kb-mail 27, gmail-bulk-import 33, gmail-header-backfill 43.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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