Review round 2, P1. Undo could empty the "read-only" snapshot.
`render_snapshot` wrote with bypass_intercept, which leaves ordinary
undo history behind, and `Buffer::undo` reaches the rope through
`ensure_writable` without ever consulting the intercept chain. So a
single `C-/` — or `M-x buffer.undo`, which needs no keymap at all —
replaced a freshly rendered snapshot with an empty buffer.
`set_round_trip_input` does not help: it routes the key into the daemon
command path, which is exactly where undo runs.
Rebinding the undo chords buffer-locally would not have closed this,
and `compile.lua` already says so in a comment: "command/menu undo
stays dispatchable". `*compilation*` and listview panels therefore
carry the same latent defect today.
Adds `Buffer::set_generated_contents` (Lua:
`pmacs.buffer.set_generated_contents`): lift `read_only`, replace the
contents skipping intercepts, discard the resulting history, re-assert
`read_only`. This ships the framing's deferred immutability lane as ONE
primitive rather than exposing the setter — a bare `set_read_only`
would let a caller lock a buffer it can no longer refresh, which is
precisely why that lane was deferred. Discarding history is
load-bearing twice: it removes what undo would replay, and it stops a
periodically refreshed buffer accumulating rope clones that `read_only`
guarantees nothing can ever pop.
New acceptance 16c drives the real M-x path
(`command.invoke_interactive`), the chord, and redo, and asserts the
owner's own refresh still works — the operation plain `read_only` would
have broken. Acceptance 16b flips from asserting `is_read_only()` is
false to true, because the property it documented is the one that was
wrong. Three `buffer.rs` unit tests cover the primitive directly,
including that ten refreshes leave an empty undo stack.
Bite: restoring the delete+insert render reproduces the report exactly
— `left: Some("")` against the full snapshot — failing 16c and 16b.
Still open, and now named in the framing, COHERENCE.md §14 and the
ledger: `*compilation*` and listview have not adopted the primitive and
remain emptiable by `M-x buffer.undo`; a streaming-friendly variant is
needed for the append case. In CRDT mode `read_only` is what refuses
undo, since loro's UndoManager exposes no clear through `CrdtState`.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016gGQC6eqHJVbZJ5Hg7aLer
Four findings, all real, and they rhyme in pairs. Two implementation
defects and two vacuous pins, all four tracing to one root: a name is
not an identity, and a context-free readout is not a state observation.
A foreign buffer carrying the snapshot's name was adopted and then
overwritten. `pmacs.buffer.create` accepts any caller-chosen name and
snapshot writes use bypass_intercept, so found-by-name adoption
clobbered user data — the reviewer reproduced "do not clobber" becoming
23 newlines. Now follows dired's F7 rule: ownership means "in copy
mode's own handle table", never "found by name", and a taken name yields
a `<2>` variant.
Snapshot identity was keyed by terminal NAME.
`TerminalManager::open` uniquifies only the derived name — an explicit
`name = ...` is inserted verbatim — so two valid terminals can share
one, and a name-keyed table handed them a single snapshot: the second
invocation retargeted it, `q` returned to the wrong terminal, and
killing either removed the shared buffer. Identity is now the terminal
buffer, compared in an array, because BufferIdLua implements `__eq` but
each wrapper is a distinct table key: comparison works, hashing does
not. The kill-with-terminal callback now closes over its own record
rather than looking the name up again.
The refresh pins were vacuous. Acceptance 19 compared a quiet
terminal's snapshot against itself and 18 counted buffers, so both
passed with render_snapshot replaced by a no-op. The child is
`exec cat`, so the tests now type a marker into the focused terminal,
require it ABSENT from the existing snapshot, and only then refresh —
via `g` and via re-invocation respectively.
The tail-follow pin could not observe view state.
`TerminalManager::snapshot(buffer_id)` is context-free and always
returns the live screen, so it reported "at the tail" even for a view
forced to the oldest retained row. Now read through
`snapshot_for_view`'s at_bottom and its projected cells.
Adds acceptance 18a (a foreign same-named buffer is never adopted or
clobbered) and 18b (two same-named terminals get two independent
snapshots, each `q` returns to its own source, and killing one leaves
the other's snapshot alive).
Four new bites, all discriminating: restoring adopt-by-name fails 18a
AND 18b; restoring name-keyed identity fails 18b; making
render_snapshot a no-op fails BOTH 18 and 19, which is the vacuity
demonstrated rather than argued; and forcing the view off the tail
fails 20.
Criterion 17 stays a named follow-up, per review agreement, until the
real GPU probe is non-skipping and CI-executed.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016gGQC6eqHJVbZJ5Hg7aLer
Stage 2 of docs/terminal-config-and-copy-mode-framing.md (rev 4,
approved). `M-x terminal.copy-mode`, or `C-t` in a terminal buffer —
physically `C-c C-t`, since every unescaped key goes to the child —
materializes the retained scrollback into an ordinary read-only,
path-less buffer, with `g` to re-snapshot and `q` to return.
No protocol change.
Materializing is the whole design. isearch, motion, selection and the
kill ring work with no new substrate because the snapshot is a rope, so
SearchStore and the existing match painting apply unchanged. And "keys
must not reach the child" dissolves structurally rather than being
guarded: the transport arm keys on is_terminal(buffer_id), and a
snapshot is not a terminal, so the arm never fires. The
dispatch-shadow count stays at six and describe-key keeps telling the
truth — asserted directly, since that is the observable difference
between the buffer-local idiom and a shadow.
One serializer, not two (Q#TC7). `copy_retained` builds a whole-range
selection and hands it to `copy_selection_bytes`; a second walk would
re-derive soft-wrap joining, wide-glyph continuation, cluster bytes and
per-row trailing-blank trimming, and the two would drift. Four unit
pins in view.rs assert exact bytes against the same projection fixtures
that pin the serializer itself.
Q#TC6a is implemented as two calls, and the second is the load-bearing
one: an intercept guards dispatch only, and no Lua binding sets
Buffer::read_only, so set_round_trip_input is what keeps a replica
frontend from applying optimistically and emitting an op that would
pass ensure_writable and mutate both sides. Acceptance 16 pins that
UNGATED, because CI never compiles the crdt feature.
Eight of nine criteria. Criterion 17's semantic-frontend end-to-end pin
is deliberately absent: the optimistic apply lives only in
pmacs-gpu/src/main.rs and the headless SemanticClient has no optimistic
path, so a faithful test needs the real GPU binary — the a37
foundation, which CI never compiles, silently returns ok when the
binary is unbuilt, and is load-sensitive. Both halves of the mechanism
are pinned ungated instead (16, and 16b for the hazard); the wire-level
half stays an explicit obligation of the CI crdt-coverage lane.
Substrate fact found while wiring lifecycle: TerminalManager::prune
REACTS to a buffer already gone from the registry rather than removing
one, so a child exiting leaves both the terminal and its snapshot
alive. That is why on_removed is a sound teardown hook, and why a
finished command's output stays readable.
Five bites, five different wrong implementations, each failing exactly
one test: removing set_round_trip_input fails acceptance 16 in the
DEFAULT configuration; a naive independent serializer fails all four
unit pins, with the diffs naming each drift mode; making re-invoke
create a fresh buffer fails 18; dropping the kill-with-terminal
teardown fails 18; removing the intercept fails 16b.
COHERENCE.md: §6 gains this as the worked example that a modal-looking
feature need not become a shadow; §11 records the scope="global"
deferral's second live case, making the argument for both registry
deferrals cumulative; §2 step 8 gains copy mode and keeps the
still-missing close command named.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016gGQC6eqHJVbZJ5Hg7aLer
Levi Neuwirth