[dborgards]

What does this change?

Adds the channel-level reserved-FlowStatus characterization missing from #353. After a CTS-controlled block, reserved FS 3 and 15 must leave the send pending and preserve its original N_Bs deadline, then end with an N_Bs timeout. Advancing virtual time before the reserved FC distinguishes dropping it from incorrectly treating it as Wait.

This tests the current documented contract. The ISO 15765-2 decision between dropping a reserved FS and immediately aborting remains open; no production behaviour or conformance claim changes.

Refs #353

Type of change

• feat — new behaviour (minor release)
• fix / perf — bug or performance fix (patch release)
• docs / test / refactor / chore / ci — no release
• Breaking change

Checklist

• Build with -p:CI=true, test (net10.0), dotnet format --verify-no-changes, and fresh pack + eng/verify-packages.py all pass locally
• Public API changes are documented with XML comments — no public API change
• New behaviour is covered by a test — existing documented behaviour characterized; two real source mutations detected
• The requirement or ADR this relates to is referenced — ISO-TP: verbleibende ISO-15765-2-Normfragen und Reserved-FS-Integrationstest #353; existing N_Bs contract

Validation

• Full restored-source net10.0 suite: 3127 passed, no failures/skips. Targeted new theory: both rows passed.
• net48 test-project compile: zero warnings/errors. Runtime execution on net48 is left to Windows CI.
• Both mutations compiled and failed at runtime for both rows: reserved FS decoded as Wait (500 ms remaining instead of 300 ms); decoded as Overflow (premature completion). Sources restored before the final passing build/suite.
• Format check passed (workspace-loading warning); nine fresh packages verified; all 50 engineering tests passed; requirements traceability reports no new gaps.

Only the integration-test file changes. Remaining norm-dependent #353 items stay open.

Final CI and reviews

Final head: 89bb779f9283ea63484d755288da434ee63dcb4e. CI 41235246091 is fully green: Linux/macOS/Windows net10.0, Windows net48, format, release configuration, traceability, commit subjects and pack/SBOM dry run. CodeQL 41235245969, Codecov patch and Snyk pass. Codex and Cursor Bugbot completed on this head without findings; no review threads are open.

[cursor]

PR Summary

Low Risk
Test-only change with no production or public API impact.

Overview
Adds a channel integration Theory test (reserved FS 3 and 15) for issue #353, documenting how the stack treats reserved Flow Status frames mid multi-frame send.

After CTS with block size 1 and one CF, virtual time advances 200 ms before injecting a reserved FC. The test asserts the send stays in flight, N_Bs is not re-armed (unlike Wait), the timer still shows 300 ms remaining, and the transfer eventually fails with IsoTpTimeoutException on N_Bs. Comments note this pins the current documented contract, not a final ISO 15765-2 interpretation.

^{Reviewed by Cursor Bugbot for commit 89bb779. Bugbot is set up for automated code reviews on this repo. Configure here.}

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-31T19:40:19.231740Z	89bb779	PR opened

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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