Ambiguous Artifact ID

The artifact hash prefix 4109 is ambiguous and might mean any of the following:

1. 4109721c84a3ee2f76ca9b97a046e7d9ecfaa9f957c63203d52f0bac9eb14cbe -

   • File conformance/repostate_trunk_test.go — part of check-in [c2795c4f48] at 2026-10-13 11:14:15 on branch main — feat(repo): name the current trunk and a branch's open leaf (#411)

     * feat(repo): name the current trunk and a branch's open leaf

     Repo.CurrentTrunk resolves the main-branch setting's name the way ResolveVersion does, as fossil does for update outside a checkout and open with no version (repo-state-01 Section 9). Repo.BranchOpenLeaf names the open leaf of a branch with the greatest mtime, or reports the branch not open; fossil's branch info takes whichever open leaf its query meets first, and this follows the draft. checkout.BranchLeaves and the new checkout.BranchOpenLeaf share one open-leaf query.

     RS-9-1 and RS-9-4 lose their scope notes and gain cases.

     * fix(repo): resolve the current trunk as a check-in, reject an empty branch name

     Tracked in the stacked work on repo-state-01 Section 9. (user: [email protected], size: 5117) [annotate] [blame] [check-ins using]

2. 4109910717d9691bf660d9837b08ca56e8bd88bb4589af1c59ee537c79d88cb9 -

   • File internal/sync/clone.go — part of check-in [18bfbc166c] at 2026-07-27 23:31:22 on branch trunk — fix(sync): derive the project code, and write artifact visibility inside the storing transaction (#204)

     * fix(sync): derive the project code from the repo instead of panicking (#199)

     Supplying User/Password made SyncOpts.ProjectCode mandatory in practice: buildLoginCard passed the caller's raw value straight to computeLogin, which asserts it is non-empty, so an authenticated Sync on a repo whose project code the caller had not repeated took the process down. Nothing in the public API signalled that a password made the field required, and a server embedding the library died with it.

     buildRequest already fell back to the repo's stored project-code for the push/pull cards; that fallback was local to one function, which is exactly how the login path drifted out of step with it. Resolve the code once when the session is built — caller value first, the repo's own config second — and let buildRequest and buildLoginCard both read it. A code that genuinely cannot be determined now returns a descriptive error from the site that needs it rather than panicking.

     Sync's deferred result-not-nil assertion fired during panic unwinding, where err and result are both nil, replacing the original cause with its own message. The invariant only holds on a normal return, so it no longer asserts while a panic is in flight.

     * fix(sync): write received artifacts' visibility inside the storing transaction (#200)

     Receiving an artifact cost three write transactions, not one. The blob was stored in a transaction, its dephantomize cascade committed another, and then applyPrivateStatus re-derived the rid on the pool and issued a bare DELETE FROM private -- an implicit transaction of its own, with its own BEGIN IMMEDIATE and fsync, for a row that a transaction microseconds earlier had guaranteed did not exist. Every igot card announcing an artifact already held cost one more. Measured against a real fossil peer: 1509 statements executed outside a transaction to receive 1504 artifacts.

     That is minutes of pure commit overhead on a large repository -- roughly 200,000 write transactions for a 67k-artifact pull -- and it is fragile as well as slow. Each of those writes contests the database's single write lock independently, so N artifacts means N chances to lose that contest and fail outright rather than one chance to wait at a single BEGIN.

     Visibility now travels with the content it describes: storeReceivedFile takes the visibility a private card announced and records it inside the transaction that stores the blob, using the rid that transaction already has. The status is now atomic with the content rather than a separate write that could be interrupted between the two. The igot path buffers its updates and writes them once per round. The same three-transaction shape on the server's receive path goes with it.

     The same real-fossil pull now executes 2 statements outside a transaction for those 1504 artifacts, down from 1509. db.DB.PoolExecs makes that budget assertable, which is how the regression test pins O(rounds) rather than O(artifacts) without needing a large corpus.

     On the failure originally reported: the "database is locked" error came from a harness that copied a live SQLite database out from under a running server without its WAL, so that specific lock holder is not a product defect and this does not claim to fix it. The transaction storm above is a real performance and robustness defect on its own evidence, and is what this changes.

     * test(sync): pin the transaction budget, not just writes outside a transaction

     The budget tests measured PoolExecs, which counts statements issued outside a transaction. That pins one half of the defect and misses the other: moving a per-artifact write from the pool into its own WithTx leaves PoolExecs unchanged while every artifact still pays a BEGIN IMMEDIATE and an fsync, and still contests the single write lock on its own. That is the cost issue #200 actually measured -- roughly three write transactions per received file, about 203,000 for one clone-sized pull.

     Verified by mutation: reverting the batched visibility flush to one transaction per update left both budget tests green. They now count transactions too, via a new db.DB.WriteTxns counter, and the same mutation fails with "began 51 write transactions for 50 igot cards over 1 rounds; want <= 4".

     Also stop the contention test from starving the pull it is meant to observe. The rival connection re-acquired the write lock immediately on release, so on a loaded machine it could hold the pull's single BEGIN past busy_timeout and fail the test even when the batching under test is perfect -- which is what happened on CI. It now yields between bursts, modelling another process doing occasional writes rather than testing SQLite's fairness. (user: [email protected], size: 17501) [annotate] [blame] [check-ins using]