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2 commits

Author SHA1 Message Date
7ad52937b2 fix(db2-keys): delete on a keys-resident table was memory corruption
- wo_row_remove read the id map's value as a slot, but on a keys table
  that value is a LOG OFFSET (hput(t, id, wal_off + 1)). slot_row does
  no bounds check, so a delete indexed t->slabs[] with a byte offset and
  then called db_val_free on whatever it landed on — arbitrary frees,
  not a wrong answer
- keys tables now take their own arm: no slab slot, no bitmap bit, no
  free-list entry to return. The index hook needs the row's values, so
  the row is borrowed from the log for exactly that long
- wo_row_ptr carried the same trap and is public. It cannot refuse keys
  tables outright (insert legitimately calls it while the map still
  holds a slot), so it now detects the offset case — index past the
  slabs, or bitmap bit clear — and returns NULL. Callers all handle NULL
- test_keys_resident_delete pins it; it SEGVs against the old code,
  verified by reverting the fix rather than assumed
- found while auditing every hget() reader before narrowing the loader
  refusal to allow benchmarking. The refusal was justified in the docs
  by "updates are unimplemented" while actually standing in front of
  this too: a guard whose stated reason is narrower than its real one
  gets removed by someone who believes the stated reason

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
(cherry picked from commit 76b8fd944af9ed062467bdf9ab93c2e96dd198cf)
2026-08-30 20:37:27 +02:00
97c7c40fd8 docs(db2-chain-review): review the databasev2 chain and dependency graph
- chain is a cross-track field (1-6); only databasev2 3 and 4 carry it,
  and iteration 2 — critical path, in-progress — carries none, so the
  board's chain query cannot see it
- 00-story.md's ASCII graph draws 3 before 4; the chain field and the
  history both say 4 first (4 part A 08-28, 3 08-29). Graph is wrong
- graph also contradicts its own prose on edge direction, and still
  draws the 2-5-6 path the 2026-08-27 amendment retired
- iteration 3's hazard section is stale: it says nothing fails "because
  iteration 2's storage half is unimplemented", which 5c/5d ended
- and it was incomplete: it named offsets going stale, but compaction
  walked the bitmap, which a keys row has no bit in, so those rows
  would have been dropped from the new log outright — data loss, not a
  bad pointer, and offset-rebuilding would not have caught it
- coupling is now bidirectional: wal.c compaction calls iteration 2's
  wo_row_next_id / wo_row_offset1 / wo_row_set_offset
- nothing in the track is blocked on anything else in the track

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
(cherry picked from commit 2ecaf0c95f40c6d6c8cc2fde687c82d63cda1f7e)
2026-08-30 20:37:21 +02:00