PROPOSED. Framing only; still no runtime code.
Answers five review findings on PR #188 at 9101bf5 (three P1, two P2),
plus the two sweeps the review asked for by class.
P1-1: Stage 2 criteria 3, 4 and 5 all passed on the pre-image. Ordinary
edits are already refused by the existing intercept, and Buffer::undo
checks read_only before it inspects history, so "undo returns false"
passes against an implementation that locks and never clears. Rewritten
to use a bypass write or Rust-side is_read_only for the lock, and to lift
the lock inside a Rust test before asserting NothingToUndo.
P1-2: ownership by handle is now a prerequisite of the stage that locks
each writer. Measured: a foreign *references* is clobbered and left
permanently un-editable, a pmacs.compile.run that raises on validation
still leaves a foreign *compilation* un-editable, and M-x buffer.undo is
currently the only recovery -- which this arc removes.
P1-3: revision 1 was wrong that is_modified drives only the mode line.
autosave.rs:363 and desktop.rs:302 read it. The rule chosen: a generated
write refuses a buffer that has a file_path.
P2-4: view_top is a line index, cursor is a byte position. The clamp is
now per-coordinate and ungated.
P2-5: re-measured at ad41cf1, 276 dark, with the command shown.
Sweep A found Stage 1 criterion 7's stated bite was wrong, and that eight
criteria pass on main by design without saying so; every criterion now
carries a pre-image class. Sweep B found the two halves of the protection
are asymmetric -- the intercept is removable, the rope lock is not --
which falsifies revision 1's reason for deferring the unlock, so Q#GB7 is
upgraded to Stage 1 work.
Adds the PR #188 lane to docs/active-work.md, which the ledger now
requires for every open PR.
PROPOSED. Framing only; no runtime code.
Buffer::undo gates on ensure_writable() and never consults the intercept
chain, so the add_intercept "read-only" idiom leaves the rope writable
and the owner's own bypass_intercept paint on the undo stack. Four writer
mechanisms across five buffer families are affected; every one was
reproduced by execution at ad41cf1, not inferred.
The document carries the measured reproductions, the full classified
census with its arithmetic shown, the primitive decision with numbered
alternatives, per-criterion bite obligations, and the staging proposal.
Recommended primitive: Buffer::apply_generated_edit(op), exposed as a
{ generated = true } option on the existing Lua mutators, with
set_generated_contents reimplemented as its whole-buffer wrapper. It is
the only candidate in which the buffer is never observably unlocked.
Levi Neuwirth