[maria-rcks]

Problem

Cancelled terminal control sequences can swallow subsequent output from saved history. Text visible live then disappears when the terminal reconnects or reopens.

Change

Recognize CAN and SUB as cancellation boundaries in CSI and string sequences, retaining the original implementation without refactoring the parser. Extend the existing regression matrix to OSC, DCS, PM and APC in ESC and C1 forms, plus both CSI forms, with split and single-chunk output.

Scope and approval

This is an obvious bug fix: valid cancellation bytes must end a pending control sequence so later terminal output survives replay. This maintainer-directed takeover is limited to that parser behavior and its existing test file.

Verification

• All 10 regression cases fail on current main (888a3d47d3) before the fix; all 53 terminal manager tests pass after it.
• Blacksmith vp run check:changed passes formatting, lint, both dependency checks, GraphQL checks, affected package typechecks, and the terminal manager suite.
• Real PTY output through the web client in system Chrome: a cancelled OSC preserves the following line live and after reload. Main loses that line on reload. Matching 1440×1000 captures below.
• GitHub CI is green, including all eight server test shards. Macroscope and CodeRabbit found no actionable code issues; two independent reviews approved 25d718f6fb.
• Native desktop/mobile clients and remote/relay connections are unverified. They share this server history parser; no client or protocol changes.

Before, after reload:

After, after reload:

Before, live output followed by reload:

After, live output followed by reload:

Takeover

Replaces #23417, with thanks to @yashranaway for the original implementation.

Built with GPT-6.1-Sol in the Codex harness on T3 Code.

[macroscopeapp]

Approvability

Verdict: Approved at 25d718f

Macroscope's review found this PR approvable — This is a focused server bug fix that preserves terminal output after cancelled control sequences, with targeted regression tests covering the supported sequence forms. It does not alter product defaults, schemas, deployment behavior, or static-analysis settings.

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[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	5.0 KiB	5.0 KiB	−7 B (−0.1%)	6.8 KiB	✅
Codex	Thread snapshot wire	3.8 KiB	3.8 KiB	0 B (0.0%)	4.9 KiB	✅
Codex	Live turn WebSocket wire	1.2 KiB	1.2 KiB	−7 B (−0.6%)	2.0 KiB	✅
Codex	Live turn WebSocket decoded	20.9 KiB	20.9 KiB	0 B (0.0%)	29.3 KiB	✅
Codex	Live turn messages	2	2	0 (0.0%)	8	✅
Claude	Total thread wire	5.0 KiB	5.0 KiB	+7 B (+0.1%)	6.8 KiB	✅
Claude	Thread snapshot wire	3.8 KiB	3.8 KiB	0 B (0.0%)	4.9 KiB	✅
Claude	Live turn WebSocket wire	1.2 KiB	1.2 KiB	+7 B (+0.6%)	2.0 KiB	✅
Claude	Live turn WebSocket decoded	21.2 KiB	21.2 KiB	0 B (0.0%)	29.3 KiB	✅
Claude	Live turn messages	2	2	0 (0.0%)	8	✅

Baseline: 122c5f8 · PR result: 25d718f · Source CI: success

Scenario and decoded snapshot size

10 historical turns, 5 command tools per turn, 878.9 KiB retained MCP result per historical turn, and a 1.05 MiB retained result in the measured turn.

• Codex decoded thread snapshot: 108.5 KiB
• Claude decoded thread snapshot: 108.8 KiB

Updated in place by a trusted workflow. PR artifacts are strictly validated and never executed.

[coderabbitai]

No actionable comments were generated in the recent review.

Recent review info

Run configuration

• Source mode: Auto
• Repository: pingdotgg/t3code
• Branch: maria/takeover-pr-23417
• File: .coderabbit.config.ts
• Commit: 25d718f
• Layers: Repository TS config
• Review profile: CHILL
• Plan: Advanced
• Run ID: f0c65ffd-a79a-4a16-998e-9b819e51f677

Commits

Reviewing files that changed from the base of the PR and between 122c5f8 and 25d718f.

Files selected for processing: 2

• apps/server/src/terminal/Manager.test.ts
• apps/server/src/terminal/Manager.ts

Included review availability: This review used your included allowance. Your plan provides up to 10 included reviews per hour; 0 remain after this review.

Walkthrough

Terminal history sanitization now recognizes CAN and SUB as control-sequence cancellation characters. It ends control-string scans at these characters and retains canceled CSI sequences. Tests verify that following output remains available after the terminal is closed and reopened.

Changes: Terminal history sanitization

Layer / File(s)	Summary
Cancellation-aware history parsing apps/server/src/terminal/Manager.ts, apps/server/src/terminal/Manager.test.ts	The sanitizer recognizes CAN and SUB in control-string and CSI parsing. Parameterized tests check that output following canceled ESC and C1 sequences is retained in reopened history.

Priority: Normal

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix

Possibly related PRs

• pingdotgg/t3code#23819: Updates the same terminal-history sanitizer’s terminator scanning for ESC- and C1-prefixed string sequences.

Suggested labels: bugfix, size:S, takeover

Suggested reviewers: t3dotgg

Merge Risk: Minimal · up to 25d71

No actionable merge-blocking risk is identified; merge after normal checks.

Pre-merge checks: 4

Check name	Status	Explanation
Title check		The title clearly and concisely describes the primary server change: preserving terminal history after cancelled sequences.
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.
Description check		The pull request includes all required sections: Problem, Change, Scope and approval, and Verification. It explains the bug, fix, approval basis, focused test results, manual verification, screenshots…

Full details: Description check

Explanation

The pull request includes all required sections: Problem, Change, Scope and approval, and Verification. It explains the bug, fix, approval basis, focused test results, manual verification, screenshots, unverified environments, and agent details.

Finishing Touches

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🧪 Generate unit tests (beta)

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• Autofix · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts

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[maria-rcks]

Note

Written by gpt-6.1-sol on behalf of Maria

Verified in a real dev environment

verified unchanged head 25d718f6fb2d0ce319fe0238a75c088fafad5ecf on this linux boat vm. reproduced the bug first on current github/main (49a9e80e0b) in a separate worktree, installed each checkout with vp i, and ran one background dev server at a time with isolated application state. drove system google chrome with the repository's playwright dependency.

added a project pointing at a real git repository through the app, created a thread, selected codex gpt-6.1-sol, and completed a real provider turn on both revisions. the turn ran pwd and git status --short and returned TERMINAL_VERIFICATION_READY. no mocks, fixtures, replay provider, or seeded conversations were used.

typed this command into the web terminal on both revisions:

printf '\033[2J\033[HBEFORE_CANCEL\n\033]0;unfinished\030AFTER_CAN\nNORMAL_OUTPUT\n'

main, live:       BEFORE_CANCEL / AFTER_CAN / NORMAL_OUTPUT
main, reloaded:   BEFORE_CANCEL
pr, live:         BEFORE_CANCEL / AFTER_CAN / NORMAL_OUTPUT
pr, reloaded:     BEFORE_CANCEL / AFTER_CAN / NORMAL_OUTPUT
pr, drawer reopen: all three lines retained

also ran a real node process through the web terminal producing 40 combinations: osc/dcs/pm/apc/csi in esc and c1 forms, can/sub cancellation, and single/split writes. the terminal snapshot delivered over the running server's websocket after reload contained all 40 unique following-output markers. normal osc termination and ansi color output remained; dcs and csi queries remained stripped from saved history. these checks cover retained server output, rather than claiming full native c1 rendering support.

blacksmith: vp test run apps/server/src/terminal/Manager.test.ts passed all 53 tests. the pr status reports 29 successful checks, none pending or failing. no code changes or pushes were necessary.

main after reload, where the following lines disappear:

pr after reload with the same terminal command and project:

pr terminal drawer close and reopen retains the output:

inspected the captures and verified uploaded video playback and seeking in t3's browser.

Not verified

native electron, ios/android, macos/windows shells, and remote/relay/tunnel connections were not exercised on this linux vm. other providers were not exercised; the changed terminal history parser is shared server code. full c1 visual interpretation is outside this parser check. check:changed was not rerun because this was verification without source changes; the focused suite above was rerun this session.