Stage 1 of generated-buffer immutability
(docs/generated-buffer-immutability-framing.md, revision 5). Closes the
two families the bug is reachable on WITHOUT `M-x`: `compile.lua` and the
search panel rebind all seven undo chords to a no-op, but `dired.lua` and
`listview.lua` rebind nothing, so a bare `C-/` emptied a listing and a
panel. The cheap half is also the exposed half.
An intercept is not read-only. `Buffer::undo` reaches the rope through
`ensure_writable` and never consults the intercept chain, so the
erroring-intercept-plus-`bypass_intercept`-over-a-writable-rope idiom
guarded the edit path and left the history path open. Rebinding chords
does not close it: `M-x buffer.undo` is dispatchable on every buffer in
the tree.
- `dired.lua`'s `paint` and `listview.lua`'s `render` write through
`pmacs.buffer.set_generated_contents` — lift the lock, whole-buffer
replace skipping intercepts, discard history, re-assert the lock, fan
the `Edit` out. Zero `bypass_intercept` writes remain in either file.
- Both keep their named erroring intercept and `set_round_trip_input`.
The layering at `terminal.lua:351-366` is unchanged: the rope lock
protects the daemon copy, round-trip input protects a semantic
frontend's own mirror, and neither substitutes for the other.
- Q#GB13 — `listview.ensure_panel` stops adopting a same-named foreign
buffer. Ownership is the `panels` table; a collision disambiguates
`<2>`..`<99>` and raises at the limit, matching `dired.lua:476-504`.
This is a prerequisite of the lock, not a follow-up: the arc removes
the `M-x buffer.undo` that was the only recovery from a clobber.
- Q#GB18 — `panels` becomes a compacting list keyed by identity. It was
written under the requested name and read back under the actual name,
which a disambiguated panel breaks: `RET`, `g` and `q` fail closed and
silently, and `listview.open`'s capture guard fails OPEN, capturing a
panel as its own `q` target — the chained-panel loop its comment says
it prevents. Ships in the same commit as the disambiguation by the
framing's ordering constraint.
- Q#GB6 — `EditorCore::notify_buffer_edit` clamps each window coordinate
against its own post-edit bound, unconditionally. `cursor` is a byte
position bounded by `Buffer::len`; `view_top` is a line index bounded
by `TextView::line_count`, and a replace can grow in bytes while
collapsing lines, so "the buffer shrank" is not a usable trigger. This
fixes a shipped defect that reaches terminal copy mode.
- Q#GB16(a) — locking these families disables fold CREATION on them,
because `document_bytes` is spelled `is_read_only()`. Accepted and
stated rather than shipped silently; the status string now names the
read-only lock instead of claiming "not a document buffer".
Acceptance: 10 new criteria in `listview_acceptance` (16 total), 6 in
`dired_acceptance` (31 total), 2 in `terminal_copy_mode_acceptance`.
Every criterion's falsifying mutation was run: 5 bite by revert against
`githubsucks/main`, 9 by a named one-line mutation.
Two framing corrections, both recorded in the tests rather than worked
around silently:
- Stage 1 criterion 5 is unreachable as written. `Buffer::apply_edit`
(`src/buffer.rs:773`) and `begin_edit` (`:725`) call `ensure_writable`
as their FIRST statement while the intercept chain runs later inside
`apply_edit_inner` (`:1072`), so once this arc's lock is installed an
ordinary edit can never reach the intercept. Restated at the one point
where the two are distinguishable — the lock lifted — which is the
state the intercept genuinely still covers.
- Criterion 7 cannot bite at the listview adopter. `listview.refresh`
and `listview.open` both follow `render` with `window.switch_buffer`,
which rebuilds the `TextView` from scratch and masks a dropped
fan-out. `dired.revert` does not, so the dired half carries the bite;
it fails under the mutation with the reported
`assertion failed: end <= self.len()`.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Lv428Fth9LRtffwJSsqH7T
F1 (real, small-window misbehavior). `dired.revert`'s re-seat runs after
the read settles, and `pmacs.editor.move_to_line` is AMBIENT -- it moves
whatever window is active. A user who switched buffers (or hit `q`)
while the re-read was in flight had an unrelated buffer's cursor moved
to a line index that only means something in the dired listing. The
paint was already safe because it names its buffer; the seat now runs
only while dired is still the active buffer, and `seat_cursor`'s doc
says which callers are unconditionally in the right place and why.
Pinned by a test that starts the revert, switches to a six-line file
before the pump, and asserts that buffer's cursor never moved -- and
that the dired buffer still reverts when it IS active.
F2 (a trap set for Stage 3). `fmt_size` used `%10d`, so a size past ten
digits -- 10 GB and up, ordinary for VM images and core dumps -- widened
the field and shifted mtime and name right on that line alone. Cosmetic
today, but `_layout` is exported as a contract and Stage 3's
column-classifying intercept is planned against it. It now takes
`fmt_mtime`'s discipline: exact bytes while they fit, else a
fixed-width magnitude, so precision yields to the invariant rather than
the other way round. This is not the deferred human-readable column --
the exact count still shows right up to where it cannot. Pinned with a
sparse 12 GB fixture that skips if the filesystem refuses it.
F3 (honesty and a doubled read). The symlink arm claimed the probe cost
"one syscall"; it was a full `read_dir` -- opendir plus one lstat per
child -- and on success `open_directory` immediately read the same
directory again. Since `open_directory` reads before touching editor
state and raises having changed nothing (acceptance 15's invariant), its
failure IS the "not a directory" answer: the probe is gone, one read
remains, and the comment says what it actually does. New test pins both
arms -- a symlink to a directory descends under the path the user walked
(canonicalization is lexical, so the link is not resolved), and a
symlink to a file opens with the target's contents.
F4 (deliberate failure mode). A tolerant listing recorded readdir
iterator errors without bound, and `std::fs::ReadDir` need not terminate
after yielding one. Cancellation is NOT an adequate backstop here --
which is the reason for a constant rather than a comment saying it is: a
dired listing carries no supersede key, so nothing cancels it. A
directory whose iterator produces nothing but errors now fails with the
last error the way an unopenable directory does, after
READDIR_MAX_CONSECUTIVE_ENTRY_ERRORS; the counter resets on any entry
that materializes. Documented as untested and why: faking a failing
iterator needs the walk generic over it, a refactor with no other
consumer.
Smaller notes, all taken: READ_ONLY_LIMIT renamed NAME_VARIANT_LIMIT (it
caps `<2>`..`<99>`, nothing read-only); `fmt_perms`' omission of
setuid/setgid/sticky documented as a decision tied to the M8.3 fixture's
nine-bit parser; `format_outcome` binds the slice in the pattern instead
of re-traversing; and `pmacs.path.canonicalize`'s `to_string_lossy` is
noted as inside the existing non-UTF-8-path deferral rather than an
exception to it.
Process note, learned the hard way twice now: the round-1 dired.lua
fixes were briefly wiped because a mutation-bite helper restores with
`git checkout --`, which reverts to HEAD -- so a fix must be committed
BEFORE it is bitten, not after.
`describe_key_identifies_every_default_binding` iterated every binding
in the stack and asserted `pmacs.describe.key` resolves it context-free.
That held only because no builtin had ever bound a mode-scoped key:
dired is #129's first non-detection consumer, so its `n` / `p` / `g`
correctly resolved to nothing and the test went red on the feature
rather than on a defect.
It now sets the effective context per binding -- the mode for a
mode-scoped default, and explicitly NO mode for a global one, because a
leaked mode legitimately shadows a global chord of the same name
(dired's `RET` shadows `edit.newline-and-indent`, which is the point of
the mode) and would make the assertion compare the wrong pair. A floor
assertion keeps the new arm from going vacuous if the last mode-scoped
default is ever removed.
Also corrects a doc comment rather than leaving it to be believed:
acceptance 3c does not pin the descent ROUTING. Dired holds focus in its
own panel, so a raw `switch_buffer` lands in the same window and the
mutation is vacuous against that test; dedication is what distinguishes
the two paths, so the discriminating pin is the dedicated-panel test
next to it. Verified by mutation, not assumed.
Dired is the file surface, not a rider on one: before Stage 0 (#162)
pmacs had no way to open a file by path, and browsing is the half a
user reaches for when they do not already know the path. Stage 1 ships
the view.
builtin/runtime/dired.lua: one buffer per directory named by the
canonical path (Q#DR2) with an ownership check before any paint (F7);
read-only intercept plus round-trip input (Q#DR3); a `dired` major mode
carrying mode-scoped keys (Q#DR8) -- RET/f visit, ^ parent, n/p, g
revert, q quit, s sort; cursor re-seated by basename across every
wholesale repaint (Q#DR9); file visits through
`pmacs.window.display_file` and directory descent through dired's own
window (Q#DR10); `C-x d` / `C-x C-j`; and `dired.kill-when-opening`
through the config registry.
Two Rust changes, both narrow:
* `read_dir` grows per-entry tolerance behind an opt (Q#DR6). Five
per-entry conditions used to fail the entire listing, so a plain
refresh of a busy directory could just fail; the module doc's claim
that a tolerant wrapper was "the package's job" was false, because
the primitive hands Lua one structured error and no partial vec.
Per-entry readdir/lstat/readlink failures and non-UTF-8 symlink
targets now land in an `errors` channel; parent-level failures and
non-UTF-8 *names* stay fatal. The tolerance travels in the settled
payload, so the Lua boundary keeps the bare-array shape the frozen
M8.2 fixture consumes and never has to look the job back up. The read
ops' opts parsing now rejects unknown keys, so a typo'd `tolerant`
cannot silently degrade to the fatal contract.
* `normalize_buffer_path` is exposed as `pmacs.path.canonicalize`
rather than mirrored in Lua. Q#DR2 named exposure the preferred end
state; it needs no borrow plumbing, so dired's name-dedup and
`display_file`'s `find_buffer_for_path` dedup cannot fork, and the
mirror's Stage 2 removal is not owed.
tests/dired_acceptance.rs covers framing items 1-16 (22 tests), driven
through real key dispatch. Item 17 is the m8_1/m8_2/m8_3 gate.
One framing claim is corrected by the substrate: R2-3 expected a
dedicated dired panel to carry its dedication across a descent, but
`display_buffer` never replaces the buffer in a slot dedicated to
another one -- it discards every side-specific parameter and falls back
to the document window (Q#BP3 2.iii). Dired does not try to unpin the
user's panel; both arms are pinned.
Levi Neuwirth