All four closure gaps in one correction. Three of them are defects in
what I committed as G1-G4; the fourth overturns a claim I made about
what could not be witnessed.
**THE KEY IS NOW EXACT, NOT PROBABILISTIC.** It was a `DefaultHasher`
digest, so authoritative equality rested on the absence of collisions
--- and a collision silently ACCEPTS a stale gesture, which is precisely
the failure the key exists to prevent. It is a `PanelMappingSnapshot`
struct compared structurally now. The emitted `mapping_generation`
stays a `u64` on the wire; only the daemon's own comparison changed.
**THE TERMINAL DOMAIN WAS ABSENT, AND THE BUFFER REVISION WAS WRONG.**
The key hashed the panel buffer's content revision for every target
kind. For a terminal that is doubly wrong: SS5b says the buffer revision
does not decide the mapping, and what does --- the screen --- was not
consulted at all. `PanelMappingContent` now splits by kind, and
terminals carry the screen's mapping revision plus the view's scroll
anchor.
That revision had to be built. `Screen::generation` cannot serve:
it advances from 39 sites including style, title, bell, tab stops and
cursor motion, none of which changes what a coordinate denotes.
`Screen` now carries `mapping_revision`, and the classification FAILS
SAFE --- `changed()` bumps both by default, and only the eleven
explicitly display-only arms call `display_only_changed()`. Anything
unclassified is treated as content, because over-cancelling a gesture
is a nuisance while under-cancelling one lets a stale coordinate reach
a child.
**"NO PRODUCTION PATH REACHES A TRANSPOSITION" WAS WRONG.** I recorded
the rows/cols product mutation as unwitnessable and kept the separate
hashing on principle. Resize plus redeclare reaches it: 4x80 -> 8x40
holds the area at 320 while swapping the dimensions, and
`last_content_cols` is not refreshed until the next render, so the two
grid fields are isolated. The row exists and the product mutation now
fails.
**G3 WAS INCOMPLETE.** It covered idle and cursor only. Focus is added
at the daemon level --- the tempting error is folding the whole frame,
which carries a `focused` flag, into the key. Styling is pinned
structurally instead: the snapshot has no style field, so there is
nothing a recolour could touch. The terminal controls live in
`screen.rs`, at the level the classification lives, with a positive
half so a revision that never advanced at all cannot pass them.
**AND MUTATION TESTING FOUND ANOTHER UNWITNESSED BRANCH.** Routing
terminal panels through the DOCUMENT arm left all thirty-five rows
green --- the `is_terminal` branch had no daemon-level witness at all.
A row now pins that the snapshot picks its domain by target kind, and
that mutation fails.
Mutations: display-only events bumping the mapping revision (the
screen-level control fails); terminal panels keyed on the buffer
revision (the domain row fails); rows*cols as an area (the
transposition row fails); plus G1-G4's original five, still biting.
Verified: focused suite 36/36, `cargo test --lib` green, clippy clean.
Full `--protocol` gate reserved for the checkpoint after bilateral
gating, per the standing procedure.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
Levi Neuwirth
42efc3618f