Timeline

feat(horizon): re-pin to zit caeef421ee: repository-wide seed D and the receive rule check-in: 7b6f43f1dc user: [email protected] tags: main, trunk

zit 0.7.2 (tag version-0.7.2, check-in 1dcb2d4a29) dates a seed at the repository's latest tag event, as go-libfossil now does. Its horizon draft is the caeef421ee text pinned here (artifact ab18fa7f89).

- ZIT_VERSION is 0.7.2, and ZIT_SHA256 is the checksum of zit-0.7.2-linux-x86_64.tar.gz, checked against the release's SHA256SUMS. - REQUIRE_ZIT_SEED_DATE=1 sits next to REQUIRE_ZIT_BIN, so TestHorizonSeedDateZit cannot skip in CI. - The README, horizons.md, CHANGELOG and test comments now say interop is pinned to zit 0.7.2. check-in: 0c30e0d32e user: [email protected] tags: feat/horizon-dfloor-receive, main, trunk

TestHorizonSeedDateZit has zit mint the seed for a repository whose newest tag event is a cancel, and requires it to match go-libfossil's byte for byte. Both now date a seed at the repository's latest tag event (§5.2.2).

No string in the binary tells a zit from before caeef421ee apart: its version still reads 0.7.1. So the test recognises an older zit by an earlier D in an otherwise identical seed, and skips it unless REQUIRE_ZIT_SEED_DATE=1. CI's pinned zit 0.7.1 skips. A zit built at caeef421ee passes with the variable set. leaf check-in: ad82b4a46d user: [email protected] tags: feat/horizon-dfloor-receive, main, trunk

Re-pins draft-fossil-horizon-00 to zit trunk check-in caeef421ee (file artifact ab18fa7f89), which changes §5.2.2, §5.2.3 and §6.2.3 and adds two Appendix C bullets. This brings in the local feat/seed-receive-drop branch, which implements the receive rule, and resolves it against main (#477 chain-walk bounds, #478 seed binding).

§5.2.2, the seed's D (tracked in #479): - Mint dates a seed at max(tagxref.mtime) over every row in the repository, cancels and propagated rows included, as zit's latestTagEvent does. It was the latest of the rows the seed summarizes. - A cancel of the newest tag, or a reopened closed branch, therefore no longer mints a seed earlier than the one a clone holds, which the clone's D floor refused as a replay.

§5.2.3, the receive rule: - A pull, clone or sync drops a seed by this store's label or by a binding card when it can read it, and the link step refuses one completed later. - The draft also requires that a delta kept without its base, pushed or received, is not announced or served while it cannot be expanded. feat/seed-receive-drop only withheld pushed ones. The pending mark moves into storeDeltaContent, so a pull marks too, and a clone marks what is still unreadable when it ends (seedcheck.WithholdUnreadable). That avoids judging every dangling file delta of a clone a second time. - Since #478 minted seeds carry a binding card. The seed-shaped-ordinary cases therefore strip it, and a new test checks that a seed with the card is never linked.

Conformance rows: - HZ-5.2-2 takes the new D text. - HZ-5.2-4 loses the old ordinary-artifact sentence. - HZ-6.2-6 says the D is fixed by the repository's tag events. - New rows: HZ-5.2-14 (the receive-path drop; PARTIAL, since a seed completed in a later round is kept inert, and was counted when its delta arrived), HZ-5.2-15 (the dropped-hash record) and HZ-5.2-16 (withholding unexpandable deltas). - New cases: two D cases mirroring zit's "horizon seed date" regression, a cancel on C and a cancel at an ancestor below it, and five receive cases. - The deepen-floor case now replays an older seed, since an honest origin no longer mints one. check-in: 5d0ef566aa user: [email protected] tags: feat/horizon-dfloor-receive, main, trunk

chore(release): v0.16.0 check-in: 2f1e5f1e3d user: [email protected] tags: main, trunk, v0.16.0

Review of a067c6e. JudgeFilled treated content.Expand's chain-bound error as a store fault and returned it, and DeltaStored failed storeDeltaContent with it.

A pusher could plant a dangling chain longer than maxDeltaChainDepth under a basis R, building it by re-rooting. After that, every honest push, pull or clone that supplied R as a delta failed for good.

Fix: - content now wraps its cycle and depth errors in ErrChainUnresolvable, and exports MaxDeltaChainDepth. - seedcheck counts ErrChainUnresolvable as unreadable, alongside a hash mismatch and a delta that does not apply or fails its checksum. Such a row is skipped and stays pending, so it stays withheld. - Real faults are still returned, such as content that does not decompress. - The classification uses errors.Is on the sentinel, so the expansion JudgeFilled already performs is not repeated.

Tests: - TestHorizonOverDeepPendingChainDoesNotBlockFill plants a pending row one node past the bound under R, then pushes R as a delta on a held basis. The push succeeds, R is stored and readable, and the over-deep row stays withheld. - TestUnresolvableChainSentinel pins the sentinel for a cycle and for a chain past the bound. - Dropping the classification, or either wrap, fails a test.

A cycle never reaches seedcheck: the receive pass's own basis-chain walk (receive_pass.go chainEnd) refuses it first. check-in: 8b946de415 user: [email protected] tags: main, trunk

Two review nits.

Liveness. A pushed artifact pending on a basis P stayed withheld for good when a pull supplied P as a delta: - Only MarkPending re-rooted, and only for a pushed delta. - Filling a phantom with a delta runs no cascade, so nothing judged the waiting rows if the delta was readable, or moved them to P's own root if it was not. A later fill of that root never reached them.

The fix is one hook at the choke point every received delta passes, storeDeltaContent: seedcheck.DeltaStored. - If the stored delta is readable, the rows pending on it are judged. - If not, they move to its chain root, so whatever finally resolves the chain judges them. - It replaces MarkPending's push-only re-root.

Error surfacing. JudgeFilled still skips a row whose own bytes cannot be read (a delta that does not apply or fails its checksum, or bytes that are not the artifact named) and judges the rest of the batch. Any other failure is now returned, a broken chain to the filled root included: check-in and tag return it, and the cascade logs it, as it already did for JudgeFilled errors. The separate availability skip went with it.

Tests: - A pushed plain file and control artifact pending on a basis that a pull supplies as a delta, on a held basis or on one that arrives in the next round. Both become readable and stop being withheld, are announced on a push-on, and the control artifact is linked. - A row whose content does not decompress is reported. - A checksum-failing row is skipped like an invalid one. - Each hook branch and each error class fails a test when changed. check-in: 584c55d1fd user: [email protected] tags: main, trunk

Takes the client-side announcement fix. A seed refused at the link step without a pending row (one a pull or clone completes in a later round) leaves unclustered through refuse(). A push-on from that store never names it, and a test now pins this. check-in: 9f0b995575 user: [email protected] tags: feat/horizon-dfloor-receive, main, trunk

Review of 0e28b6a: when the origin pushed on to a peer, its own client announced artifacts its replies withhold. A pending seed went out from unclustered, and after verify.Rebuild (which marks every blob unclustered and unsent again) a refused seed went out too. The peer kept asking, loadFileCard withheld it, and the push ran out of rounds.

Fixed in the tables the client announces from, not in each reader: - MarkPending takes a pending row out of unclustered. - decide puts it back once judged not a seed; a seed stays out. - rebuildBookkeeping leaves withheld rids out of unclustered and unsent. - That also keeps them out of cluster minting, which reads unclustered. - sendPrivate and the private gimme answer, which read the private table, skip withheld rids. - sendUnclustered needs no filter of its own, and sendAllClusters lists only linked clusters, which a withheld row never is.

JudgeFilled now skips a row that does not expand (it stays pending) and judges the rest of the batch, instead of returning.

Tests: - A pending seed is not announced on a push-on, publicly or privately. - A peer asking for a private pending seed outside a private sync is not told it exists. - After a rebuild, a push-on converges and never names the refused seed. - A pending file, once judged, is announced again on a push-on. - An unreadable row does not stop the next fill in the batch being judged. - Every new mechanism fails a test when disabled. check-in: df78b8aee9 user: [email protected] tags: main, trunk

Takes feat/471's no-delete model: a refused seed stays stored, refused by its hash, and is never linked or served. Its effect on the receive side:

- A seed a pull or clone can read on arrival is still never stored. - One completed in a later round is refused by the link step and kept, inert, rather than swept. The clone's sweep is gone. - Refusing a seed at the link step takes it out of unclustered, as a push-side refusal does. - A dropped seed's phantom row stays inert, since deleting it would free its rid under a receive pass. loadDBPhantoms skips refused hashes, so it is never asked for again. - The client's addPhantom filter is gone: a refused hash always has a row by then. - The handler keeps feat/471's recordStored, which refuses a re-push whose row is already held.

A test now pins the client's verified-delta refusal (a seed sent as a delta on a held basis), and seeds dropped on receipt are asserted not stored (assertDropped). check-in: 5b43d4fe38 user: [email protected] tags: feat/horizon-dfloor-receive, main, trunk

Final review of c077fa4. F.1 requires recording a refusal, not deleting the bytes, and every finding came from the deletion:

- A delta built on a swept seed lost its basis, was withheld forever, and could not be re-pushed, because it counted as held. - The end-of-sync sweep ran outside a transaction. - A refused hash pulled from an upstream was dropped, which is a receive-side behaviour F.1 does not have.

So a refused seed stays stored: - Its hash is recorded in seedrefused. - It leaves unclustered, so no inventory or cluster names it. - It is withheld from every reply, and the link step never links it. - Deltas on it stay readable and are judged like any other pending row. - Pulling the same hash stores nothing new: the row is held, and stays refused. - A re-push of it is refused on its bytes. Every form (full text, delta on a held basis, delta whose own row is held) expands to the seed.

Removed: - Sweep, sweepRow and its no-root marking. - Every Sweep call: handler request end, end of sync, check-in, tag and rebuild. - requestPhantoms' refused-hash filter (a refused seed is held, so never a phantom). - ownSeedReadable's refused-hash check and its Clear (the fill's JudgeFilled already clears a non-seed). - JudgeFilled's lazy re-root, which nothing reached: only full text fills a root JudgeFilled hears of.

Kept, each pinned by a test: - Pending rows keyed by chain root, with MarkPending moving the rows waiting on a rid when that rid is itself pushed as a dangling delta. Filling a phantom with a delta triggers no cascade, so this is the re-root that matters. - JudgeFilled examining only its subtree, and its hash-mismatch skip. - The link-step judge and the refused-hash check in it. - The push-time atomic refusal. - Withholding pending and refused rows, and Purge forgetting pending rows (rids are reused).

Only pushed dangling deltas are marked pending. A dangling delta stored by a pull onto a pending row's basis is not, so rows waiting on it stay withheld until the link step reaches them; a plain file among them stays withheld.

Tests: - The reviewer's probe, for a control artifact and a plain file built on a pending seed, pushed after it and before it: after the base arrives both are readable and not withheld, and the control artifact is linked and served. - A plain file after a forged delta is still cleared. - Every judge, filter and mark fails a test when disabled, except two performance mechanisms no behaviour shows: the per-transaction table cache and IsSeedBytes' byte prefilter. check-in: 6083693442 user: [email protected] tags: main, trunk

A store keeps a seed only through a horizon-seed announcement. This lands with the zit 0.7.2 draft re-pin, after feat/471's F.1.

- storeReceived refuses, before storing, a seed it can read: full text, or a delta verified against a held basis (errSeed). The push handler turns it into the atomic refusal. The client and clone drop it: not stored, not counted, and its in-memory phantom forgotten. Its hash is refused. - A hash refused earlier is dropped when sent again, even as a dangling delta, and a client never makes a phantom of one, so it is not asked for again. - The link step refuses any seed-shaped artifact it reaches, whatever stored it. An announced seed is held outside the artifact store, so it never reaches the link step. This catches a seed completed in a later round of a pull or clone, through the dephantomize cascade or the clone's receive linker, from the deck the link step has already parsed. - Received dangling deltas are not marked pending. A clone's history chains arrive newest first, and judging each would expand it a second time. - A clone sweeps refused rows after its linker finalizes.

B.2's last sentence follows F.2. A seed-shaped artifact outside an announcement is ordinary only with neither this store's label nor a binding card. hzSeedOrdinary mints under zit's label, and the docs and the HZ-5.2-4 scope note cite F.2 and F.3.

Tests: - A pull dropping a seed by label and by card, counted correctly and not asked for again by a second peer. - A seed delta completed in a later round, dropped on pull and on clone. - A clone dropping label, card and a re-sent form, counting none. - A refused seed re-sent to a client as a dangling delta. - Disabling any of these mechanisms fails a test. check-in: 21746b5036 user: [email protected] tags: feat/horizon-dfloor-receive, main, trunk

Horizon F.1, push side, and the fourth review's blocking finding.

Refusal by hash: - seedcheck keeps two store-local tables, carried by no config group: seedpending(rid, root) and seedrefused(uuid). - A seed judged after the request that pushed it, because a later push, pull, check-in or tag filled its basis, has its hash refused. Its rows are deleted by Sweep, and only where no receive pass holds rids: end of request, end of sync, check-in, tag and rebuild. A deleted rid is reused by the next row, and a pass's caches are keyed by rid. - Until swept, such a row is withheld and never linked. A delta on a refused seed is left unreadable and pending under no root. - requestPhantoms never asks for a refused hash. ownSeedReadable refuses a re-push of one, and a full-text re-push is refused on its bytes. - A purge still forgets pending rows (ForgetDeleted). Refusals are keyed by hash, so rid reuse cannot pass them on.

Judging only what a fill grounds: - JudgeReadable rescanned every pending row on each fill. A pusher could plant dangling deltas without bound and make every later fill pay for all of them. - Pending rows now record the root of their basis chain, re-rooted when that root is itself stored as a dangling delta. - JudgeFilled judges only the rows pending on the rids just stored, and reports how many it examined. - Callers: AfterDephantomize and its batch, manifest.Checkin (its files and manifest) and tag.AddTag. linkArtifact still judges a pending row it reaches, caching which tables exist per transaction. - The sweep no longer judges.

A seed-shaped artifact received by pull or clone stays ordinary, per the 0.7.1 B.2. Docs and the HZ-5.2-4 scope note cite F.1.

Tests: - A seed package test: one fill examines its own row, not 200 planted elsewhere. Run as a rescan mutant, it fails. - A tag whose control artifact is a seed's basis refuses the seed. - The link step refuses a seed made readable by a raw store. - A re-push refused by hash, and an igot of the hash not gimme'd. - A delta on a refused seed withheld. - A purged pending rid reused by an innocent blob. - Disabling any judge call (cascade, check-in, tag, link) or any Sweep call (request, sync, check-in, tag) fails a test. check-in: ed5e3ce5b5 user: [email protected] tags: main, trunk