02971efcfe
assertCleanBranchAtBase now checks each foreign-attributed commit against `git merge-base --is-ancestor <sha> main`. If the commit is already on local main, it was promoted through integration regardless of whose Fusion-Task-Id trailer it carries — treating it as foreign contamination is wrong and was the root cause of the FN-5475 cascade (downstream worktrees inherited a sibling task's tip during the brief fast-forward window before main moved further). Audit cost: O(N) extra git calls per audit run, where N is the number of foreign-trailer commits in baseSha..branchName. Each call is ~5-10ms and N is typically 1-5. Negligible relative to the surrounding I/O. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
1.1 KiB
@fusion/engine
| @fusion/engine |
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| patch |
fix(engine): treat foreign-attributed commits already on main as promoted
assertCleanBranchAtBase flagged any commit in baseSha..branchName
whose Fusion-Task-Id trailer pointed at a different task as
contamination. That misclassified the FN-5475 cascade: the engine
fast-forwards local main with single-parent task commits, and any
worktree created during the brief window where local main carried a
sibling task's tip inherited that commit. The audit later (correctly)
saw the commit as not-yet-on-main from its merge-base perspective and
threw BranchCrossContaminationError.
The audit now skips foreign-attributed commits that are reachable from
local main (git merge-base --is-ancestor <sha> main). Commits on
main were promoted through integration regardless of whose trailer
they carry, and downstream branches that inherited them via main are
not contaminated.
Resume verifier (FN-5475 fix #2) and the auto-recovery handler fallback (FN-5475 fix #3) remain in place as defense-in-depth for the rarer variants (local main rewound, foreign commit not yet on main when the audit fires).