All four findings were correct.
F1 (major) — the Lua widening keyed on the POINT, not the edit site.
Q#FD19 condition (iii) is `edit.range.start`; `run_buffer_edit` discarded
`op` and opened whatever fold contained `window.cursor`. Two wrong
behaviors followed: a command inserting elsewhere opened an unrelated
fold at the point, and — worse — a command editing INTO a fold from an
outside point left its edit hidden. `run_buffer_edit` now reads
`edit_start_of(&op)` before `op` is consumed and passes it down. The
`apply_active_edit` funnel stays point-keyed, which is correct and
deliberate: the six primitives, yank, and query-replace all place point
at the edit site first, and only the Lua path can diverge — now said so
in the doc comment.
The acceptance test encoded the wrong behavior (inserted at byte 0,
expected the cursor's fold to open). Replaced by two tests that pin both
directions, plus the framing's named **comment-toggle** case driven
through the real `M-;` on a file-backed Rust buffer rather than a
synthetic mutator.
F2 (major) — hidden-cursor motion normalized only the row. `move_up` /
`move_down` clamped `coord.row` but derived `goal` from the hidden
line's raw column, and returned early at a buffer boundary without
normalizing at all, so `Up` inside a fold headed on line 0 left the
logical cursor hidden. Added `normalize_cursor_to_visible`, which
projects the whole POSITION through `visible_position` as a real
mutation before any step is computed (and drops the sticky goal column,
since the jump is discontinuous). Paging shares it — the same latent
bug. The old test used equal-width lines and asserted only the line, so
it could not tell the two apart; the new fixture is deliberately ragged
and asserts the resulting BYTE in both directions, plus the boundary
case.
F3 (moderate) — `set_view_top` bypassed the fold clamp. Q#FD12/Q#FD18
say `view_top` is always set through `clamp_view_top`, naming the
`set_view_top` contract specifically. Rendering repaired it at the next
frame, but until then `view_top()` handed out a hidden line and
command/event reckoning could start from a non-visible origin. The
clamp now lives in the setter — the contract's home, what `saveplace`
and `pmacs.editor.set_view_top` call. New test reads `view_top()`
directly after the setter, before any paint.
F4 (moderate) — the suite claimed items 1–14 but omitted approved
clauses. Added: peer SELECTION endpoint projection with hidden interiors
dropped; the crossing-fold repeat for the peer cursor AND a peer
selection endpoint; a style/syntax span straddling a fold (alignment on
the shifted row); the completion popup anchored below a fold; and peer
presence in the split-buffer case using the RECIPIENT window's map.
Suite: 35 -> 45 tests. Eight new bite cases, each falsifying exactly the
line that implements its claim.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Q5BkezMppbpCgGAYk2ftxV
Levi Neuwirth
90bb86d355