Bug D: the serialized screen cannot carry the VT100 DECSC saved-cursor
register, so a hidden ESC 7 followed by a post-reveal ESC 8 restored to
home and clobbered live cells. The snapshot epilogue now re-saves at the
source's saved position before the final absolute CUP
(readSavedCursorRegister + serializeWithAbsoluteCursor; the active
buffer's own register, so alt screens carry theirs). Position-only by
design; never-saved terminals are left untouched.
Bug E: a PTY read ending mid-escape leaves the sequence in the emulator's
parser, so serialize dropped it and the racing tail's continuation bytes
rendered literally after reveal (~24% of the fuzz corpus). The emulator
now tracks the unparsed trailing partial at ingest
(terminal-partial-escape-tail.ts, committed post-parse like the mouse
mirror) and ships it as TerminalSnapshot.pendingEscapeTailAnsi.
applyMainBufferSnapshot writes it LAST, after POST_REPLAY reset — any
later ESC would abort the dangling sequence. Seq accounting is unchanged:
the tail is a suffix of bytes the snapshot seq already counts, so
reconcile slicing needs no adjustment.
Fuzz suites: unskip the Bug B/C repros (fixed on this branch) and the new
D/E repros; remove the B/C/E tolerance predicates so regressions fail
loudly. Only Bug A (upstream wrap null-cell) stays tolerated + counted.
Green at FUZZ_ITERATIONS=2000 (fidelity) and 1000 (reconciliation).
Co-authored-by: Orca <help@stably.ai>
- Fidelity suite: add snapshotHasSelfCancellingBoldReset (Bug B) and
isMarginWrapPendingCursorOffByOne (Bug C) predicates so the corpus tolerates +
counts them like Bug A. FUZZ_ITERATIONS=2000 is now green (~113s) and fails
only on genuinely new divergences; each tolerance keeps its <50% degeneracy
guard. Default 300 unchanged (~17s).
- Reconciliation suite: drop SGR 7 (inverse) from the append-only tail. Inverse
marks trailing blanks with an inverse-fg the serializer round-trips slightly
differently by capture depth — a Bug-B-class serialize nuance, not seq
reconciliation. FUZZ_ITERATIONS=1000 is now green; default 200 unchanged.
- Notes updated: every bug class is both pinned (skipped repro) and tolerated in
its corpus; combined default runtime ~19s.
Regex uses String.fromCharCode(27) to stay oxlint no-control-regex clean.
Co-authored-by: Orca <help@stably.ai>
Property-tests the reveal seq-reconciliation byte-stitch (getChunkDataAfterSnapshot
/ reconcileChunkAgainstRestoredSnapshot in pty-connection.ts), mirrored exactly:
N=200 seeded hide/reveal scenarios with a rich agent-TUI hidden prefix snapshot
and an append-only racing tail, chunked with seq/rawLength meta, seq-domain
restarts, unmetered chunks and droppedOutput markers. Asserts snapshot-at-S +
reconciled tail == snapshot-of-everything (seq-neutral) and == always-visible
(end-to-end). Runtime ~5s at 200; FUZZ_ITERATIONS override documented.
Two NEW real snapshot-limitation garbles found while building it, both distinct
from suite 1's serialize bugs and pinned as standalone it.skip repros:
- Bug D: the DECSC saved-cursor register is not serialized. A hidden TUI that
saves the cursor (ESC 7 / CSI s) and restores it on reveal (ESC 8 / CSI u)
lands the restore at home. Repro: 'AB\x1b7\x1b[4;10HCD' + '\x1b8X' -> 'XB' vs 'ABX'.
- Bug E: a snapshot taken mid-escape-sequence (a PTY read split an escape) drops
the partial sequence (it's parser state, not buffer), so the tail's
continuation renders literal. Repro: 'AB\x1b[3' + 'mCD' -> 'ABmCD' vs 'ABCD'.
Fired on ~24% of the corpus (tolerated + counted via prefixEndsMidSequence).
The append-only-tail design isolates seq reconciliation from these and the Bug C
cursor cascade. Full evidence + fix directions in notes. No production changes.
Co-authored-by: Orca <help@stably.ai>
Scanned seeds 1..2000. Beyond the pre-documented serialize wrap-null-cell bug
(A, 27 seeds, tolerated), the fuzz surfaced two NEW real @xterm/addon-serialize
0.15.0-beta.287 round-trip defects, both of which garble a revealed hidden pane:
- Bug B (seeds 435, 770, 1321): serializing a dim cell followed by a bold-only
cell emits \x1b[1;22m; SGR 22 clears bold too, so restored bold is lost.
Minimal repro: '\x1b[2mA\x1b[22m\x1b[1mB' -> restored 'B' loses bold.
- Bug C (seeds 454, 1696): a final content row filled to the right margin leaves
xterm wrap-pending; the serializer's relative cursor restore lands one column
short. Minimal repro: '0123456789\x1b[3;5H' at cols=10 -> cursor x=3 not x=4.
Both isolated to pure serializer replay (no Orca preamble), confirming upstream.
Parity fixture verified faithful to the renderer pane's buffer options. Each is
pinned as a standalone it.skip repro; full evidence + classification in
notes/garble-fuzz-divergences.md. Seed 113 (handoff's DECSC/DECRC case) does not
diverge on the current harness. No production code changed.
Co-authored-by: Orca <help@stably.ai>
Conflict resolutions:
- terminal-stream-protocol: Metadata keeps opcode 12 (shipped to mobile
in v1.4.120); branch-only Ack renumbers to 13.
- scheduler: keep HIGH_PRIORITY_MAX_WRITES_PER_DRAIN=8 (perf fix) over
main's 2 (#7139 landed there with the old constant).
- headless-emulator: keep chain structure (scanner classes, query-reply
forwarding); graft main's pathFlavor/remotePosixFileUriAuthority OSC7
options through TerminalOscCwdTitleScanner. Main's
TerminalPrivateModeTracker is logic-identical to the chain's
TerminalMouseModeMirror (kept, with pre-filter).
- orca-runtime: keep chain factory; graft main's pathFlavor wiring and
snapshot cwd fallback; keep both teardown lines.
- pty-connection: keep both chain reconcile and main's ordered-seq
tracking; clear the chain's restored-snapshot baseline on pty exit
(same seq-domain boundary main's reset enforces) — fixes revive with
restarted seq counter dropping chunks as duplicates.
- subscribe-buffer tests: updated to merged semantics — main's inline
overflow recovery ships current data as the FIRST snapshot; the
chain's resized/pending-output-overflow follow-up remains as backstop.
Validation: typecheck clean; 7,548 tests green across daemon/ipc/
runtime/pane-manager/terminal-pane/shared/mobile-transport (1 documented
pre-existing WSL failure).
Co-authored-by: Orca <help@stably.ai>
Jinwoo-HandOrca
Jinwoo Hong