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This Day In History For 2027-07-31

1 Year Ago (more context)

2026-07-31
21:51
sync: name the HTTP status the peer answered with

"the peer answered with an unexpected HTTP status" sends an investigation nowhere. 500 (the server could not build a reply), 413 (the request exceeded the body ceiling), 400 (a malformed container) and 417 (a rejected Expect: 100-continue) are four different bugs, and the message distinguished none of them. Issue #22 has been open on exactly that sentence.

transport.zig discarded the code at the status check because Zig errors carry no payload and the closed error set is deliberate. Rather than widen TransportError with a variant per status, the status is left on the Transport as last_status for the caller to read after the error, and syncRunFail names it: "the peer answered HTTP 500 (Internal Server Error)".

Immediately useful: re-running the issue #22 gate against the fossil corpus with this build turns its failure_reason from the old sentence into HTTP 500, which -- together with the reply-size arithmetic -- narrows the cause to OutOfMemory or ServerStorage and eliminates every 4xx path. The issue's own hypothesis, a per-round shun-snapshot readiness problem, is not among the candidates: that arm is documented unreachable and the code agrees.

Also corrects three comments Slice 2 falsified, all on the same read path:

logstore's open no longer CRC-verifies payloads, so the serve snapshot's contentImpl/wireImpl read faults are no longer "post-scan EIO or bitrot after a verified scan" -- ordinary stored corruption now reaches serve there, on the read. That is a better shape (one bad frame fails the round that touches it rather than making the server refuse to serve at all) but it makes that arm live traffic, and anything reasoning about how often it fires must start from that.

runPack and runShun both claimed their read-only open was an "integrity pre-flight" that aborted a corrupt source before a byte was written. It no longer verifies payloads. The guarantee still holds -- packLog pulls every artifact through srcContent, which propagates error.Corrupt rather than skipping the frame, and readFrameAt CRC-checks every read, so a rotted payload still aborts with the temp deleted and .zit untouched -- but it is now collected during the copy loop instead of at open. Both verbs RENAME OVER the original, so runPack's comment now states the consequence plainly: if srcContent is ever changed to answer null on a corrupt read, the rewrite would silently omit the damaged artifact and then delete the only copy of it.

Verified: fmt clean, test 2327/2327, gate, e2e 671/671. The new message checked against a stub server answering 500. check-in: b4637e26df user: dmestas tags: issue22-diagnostics

21:15
merge logstore-slice2: the open-cost work reaches production

openReadOnly is what every CLI verb opens through, and until now it still checksummed every payload byte on every invocation -- so nothing users ran had gotten faster. It scans header-only now:

10k frames 42 MB 42.2ms -> 10.3ms 10k frames 410 MB 298.0ms -> 12.3ms 100k frames 416 MB 511.9ms -> 115.4ms 100 frames 419 MB 321.4ms -> 0.10ms

Open cost is a function of frame count rather than repository size. On a store of a few large artifacts it is effectively free.

This completes the sequence: vendor a faster crc, measure the path production actually takes, scan header-only on the append path, ship the fsck verb, then delete the eager check. Each step was gated on the one before it, and the deletion was deliberately last because it is the only one that gives something up.

What is given up: opening a repository no longer detects payload corruption. It surfaces on the read instead -- readFrameAt crc-checks every frame unconditionally now -- or on demand through "zit verify". That is the split git draws between ordinary operation and fsck, and it was signed off knowing the tradeoff. A damaged store also stays usable for everything that does not touch the damaged bytes, which the old eager check made impossible.

Slices 0 and 4 are closed too: the 4 KiB chunk widening landed inside verify, the only place that loop still runs, and the sidecar index is dead on its own gate -- the 100k-frame shape was to justify it by exceeding 150ms and came in at 119ms. mmap is dead alongside it, separately, because a mapping would keep shunned bytes resident and readable until every mapping dropped, which defeats reclamation rather than merely slowing it. Neither rejection is recorded at the logstore extension comment yet; that is the one piece of follow-up this leaves behind.

Verified on the merged tree: fmt clean, test 2327/2327, gate 19/19. On the branch tip, additionally e2e 671/671 and dst 6 seeds x 1000 steps. check-in: 6d9172d488 user: dmestas tags: trunk

21:12 • Edit [b224ffeb40]: Edit check-in comment. artifact: df955ecee4 user: dmestas
21:12
logstore: openReadOnly scans header-only; verified_on_open is gone

The speedup reaches production. openReadOnly is the path every CLI verb takes -- Repository.open falls back to it, and Repository.logStore, the content channel behind cat, artifact, checkout and sync, calls it with no cache in front. It scanned every payload byte on every invocation:

10k frames 42 MB 42.2ms -> 10.3ms 10k frames 410 MB 298.0ms -> 12.3ms 100k frames 416 MB 511.9ms -> 115.4ms 100 frames 419 MB 321.4ms -> 0.10ms

Open cost is now a function of frame count, not repository size.

verified_on_open was the flag openReadOnly set to tell readFrameAt that the scan had already checked every frame, so reads could skip their own crc. With no scan doing that, the exemption had nothing left to rest on and the flag is deleted. readFrameAt now crc-checks unconditionally: it is the only thing standing between a rotted payload and a caller that believes it, and restoring any skip there means restoring the scan.

Detection is relocated, not removed. A payload bitflip no longer voids the open -- the rest of the repository stays usable -- and surfaces the first time anyone reads those bytes: "zit cat" and "zit artifact" both refuse with 'repository is corrupt', and "zit verify" names the artifact and the offset. That verb shipped first for exactly this reason.

openForVerify is deleted. It existed because openReadOnly both aborted on a damaged store and granted read-time trust, neither of which verify could accept; both properties are gone, it became byte-identical to openReadOnly, and its own doc comment said to remove it in this commit.

The DST prove-it-can-fail arm is inverted rather than deleted. It asserted that openReadOnly WOULD serve latent rot silently, across a seed range where at least one corpus lands a payload rot on a raw frame whose header survived. That hazard is gone, so the same range now asserts the opposite: the read path never serves rot as success. trust_on_read goes with it -- there are no longer two paths to select between. Losing the eager whole-log scan cost nothing here, because per-read verification is what was catching this all along.

Net -40 lines.

Verified: fmt clean, test 2327/2327, gate, e2e 671/671, dst 6 seeds x 1000 steps. The Slice 1 tripwire -- the assertion that openReadOnly still rejected eagerly, written to fail if the flag was deleted without an fsck verb -- fired on this commit, which is the one it was aimed at. closed check-in: b224ffeb40 user: dmestas tags: logstore-slice2

20:55
import-git: pack the refs, and split the budget they shared with payload

zit now imports sqlite at defaults: 36,416 commits, 2,109 refs, 44m35s, no flags. Two independent walls stood in front of that.

Refs (issue 21). One file per ref made a ref's name a path, so the filesystem got a vote on which repositories are representable. sqlite has refs/remotes/origin/EQP-improvements and .../eqp-improvements at different commits -- legal, distinct git refs -- and on APFS the second landed on the first as a bare PathAlreadyExists, raised during publication after the whole import had run. Case was only the reachable instance; path length, reserved device names and each platform's own Unicode fold table are the same bug in other clothes.

They are one sorted file now, "refs", whose lines pair a canonical name with its target. Nothing reads it back -- "refs" is a reserved root the working-tree scan skips, and branches resolve through repostate's sym- tags -- so it is interop output and its job is to be legible. Sorting makes it byte-identical for a given ref set, so two imports of one repository can be compared.

This supersedes the ASCII-fold refusal from the previous commit. That was the right interim while a ref was a filename; with one file the collision is representable, so refusing it would be gratuitous. What survives is the genuine collision -- distinct sources normalizing to a byte-identical canonical name, refs/heads/./release against refs/heads/release -- which no layout can hold, and which now names both sources instead of only failing.

Budget (issue 20). The 4 GiB payload default refused sqlite's 12.2 GiB stream, and could not simply be raised: fileCommandCeiling divided the same number, so a larger allowance for a whole history was also a larger allowance for one commit's retained command list. Those bound different things and only one is memory -- payload streams and is released per event (sqlite's import held 21 MiB), while a commit's command list is held whole. The arena has max_command_arena_bytes of its own now and keeps the old 4 GiB; the cumulative total goes to 1 TiB.

The file-command ceiling is therefore structural: about 104 million commands in one commit, and no flag raises it. Its diagnostic says so rather than pointing at a knob that no longer moves it. The help text claimed the payload flag fixed both; it only ever fixed one. check-in: 8ae7041c2c user: dmestas tags: sub-manifest

20:54
merge logstore-open-cost: header-only open scan and the verify verb

Opening a repository checksummed every payload byte, so open cost scaled with the whole store rather than with what the caller asked for. The append path now scans header-only:

10k frames 42 MB 42.2ms -> 11.2ms 10k frames 410 MB 298.0ms -> 12.7ms 100k frames 416 MB 511.9ms -> 119.2ms 100 frames 419 MB 321.4ms -> 0.10ms

openReadOnly -- the path every CLI verb reaches -- deliberately still verifies payloads. Nothing has moved on the production path yet. That is Slice 2, and it is gated on this merge's other half: zit verify, the on-demand fsck that has to exist before eager detection is removed.

The 100k-frame run settles a question the plan left open. Slice 4's gate was 'build the sidecar index only if that shape exceeds 150ms after the scan change'; it lands at 119ms. The sidecar is dead, and mmap with it -- separately, a mapping would keep shunned bytes resident and readable until every mapping dropped, which defeats the reclamation guarantee rather than merely slowing it. Both should be recorded as evaluated-and-rejected at the logstore extension comment; that is not done here.

Also adds --mode append|read-only to the open benchmark. Every open number this effort had produced measured LogStore.open, which no CLI verb enters; the two modes agreed within noise before the scan change, which is what makes the after numbers above a comparison rather than two guesses.

Verified on the merged tree: fmt clean, test 2327/2327. gate 19/19 and e2e 671/671 were watched green at the branch tip, which is content-identical -- trunk did not move between the branch point and this merge. check-in: 90bd1b8015 user: dmestas tags: trunk

20:52
verify: the explicit fsck verb

Slice 2 will extend header-only scanning to openReadOnly and delete verified_on_open, which removes eager corruption detection entirely. This is the on-demand replacement that has to exist first -- the same split git makes between normal operation and git fsck.

Two passes over the store. FrameVerifier walks every frame under .verify_payloads, which is the mode the open paths are shedding; it is built on StorageFile rather than an opened LogStore, so it still works on a store that will not open -- the case an fsck exists for. Then openForVerify opens .headers_only and reconstructs each artifact, which catches a frame whose checksum is honest about bytes that are not what their name claims.

Both passes report rather than abort. A payload CRC fault carries a header-proven frame_len, so the walk steps over it and inventories the rest; only a header-window fault, whose length cannot be trusted, stops the walk. A torn tail is not a fault -- open recovers it silently, and it means an interrupted write, not rot. An unreadable payload is a finding too, not the end of the inventory.

Exit codes stay 0/1/2 as every other verb documents them; 2 remains usage error and never corruption. Findings stream to stderr as they are found, the clean summary goes to stdout, and on any fault stdout is empty.

Scope stops at content artifacts. A manifest whose bytes hash correctly is byte-identical to what commit wrote and what sync validated on ingest, so re-parsing it would catch a zit bug rather than storage rot. The help text says so.

openForVerify is deliberately not openReadOnly: openReadOnly sets verified_on_open, which makes readFrameAt skip the per-read whole-frame CRC, and it scans .verify_payloads, so on exactly the damaged store an operator is fsck-ing it aborts before pass 2 runs. Slice 2 makes the two identical and openForVerify is deleted in that commit; its doc comment says so.

The chunk buffer in scanOneFrame's payload loop widens from 4 KiB to 64 KiB, matching cloneInto's existing precedent. Post-Slice-2 that loop runs only under verify, where an operator's wall-clock is what it costs.

zit verify is not an RFC-mandated verb. repo-state 7.3 blesses full rebuild as a fallback, but the verb's shape is a local design decision, not a protocol requirement.

Verified: fmt clean, test 2327/2327, gate 19/19, e2e 671/671. Four mutants, all compiling, each red for its own semantic reason: pointing the frame pass at .headers_only, stubbing artifact.verify to true, dropping the unreadable-store tally, and reverting the payload read to a hard error. Exit arms smoke-checked against the built binary. closed check-in: bcb9f8eb6e user: dmestas tags: logstore-open-cost

19:25
import-git: refs that differ only by case collide, and say so

sqlite carries refs/remotes/origin/EQP-improvements and .../eqp-improvements pointing at different commits. Both are legal, distinct git refs. Zit stores a ref by creating a file at its canonical path, so on APFS the second one landed on the first: bare PathAlreadyExists, raised by writeRefs during publication, after 49 minutes of completed import. No ref name, no cause.

The refusal already existed. finalizeRefs rejects two source refs that resolve to one canonical leaf -- 'refs/heads/./release' against 'refs/heads/release' is a tested case. It just compared bytes, and a filesystem does not. Keying the canonical index by an ASCII fold makes the existing rule see the collision it was written to catch, uniformly, instead of leaving it to whichever disk the import ran against.

ASCII rather than Unicode is deliberate and documented at the fold: APFS, HFS+ and NTFS each fold a different frozen table, so following them would make the importable set depend on the volume. A-Z is what they agree on.

The error now names both source refs, both canonical spellings, and whether case alone separates them -- a normalization clash and a case clash want different fixes from the operator. Retained on the importer and formatted by the CLI, the same split FileCommandOverrun uses.

This refuses on Linux what Linux tolerated, which is the point: the repository means the same thing everywhere or it is not portable. Making sqlite importable rather than merely diagnosable is a layout question -- one file per ref cannot represent it -- and stays open. check-in: f0331d2f5a user: dmestas tags: sub-manifest

19:24
logstore: scan header-only on the append path

The open-time scan streamed every payload byte through the crc, making open cost O(repository bytes) rather than O(what the caller asked for). ScanMode.headers_only validates each frame's header window and then steps over the payload by frameSpan arithmetic, leaving open cost O(frame count).

Measured, same binary, both modes in one run:

10k frames 42 MB 42.2ms -> 11.2ms 10k frames 410 MB 298.0ms -> 12.7ms 100k frames 416 MB 511.9ms -> 119.2ms 100 frames 419 MB 321.4ms -> 0.10ms

Every fault that lives in a header window is still caught: readFrameHeader runs unchanged, so a bad prefix crc, a bad header crc, an out-of-range hash_len and an unknown flag kind all still void the open. Torn-tail detection survives intact -- a torn frame is a clean prefix, never damaged bytes, so offset + frame_len > total catches every truncation the payload and trailer short-read checks used to, using a length the header window already proved trustworthy. What is no longer caught at open is a bitflip in already-landed payload bytes, which becomes content()'s job; it crc-checks the frame it reads regardless.

openReadOnly -- the path every CLI verb reaches -- deliberately keeps .verify_payloads. No guarantee has moved on the production path yet, and none should until the explicit fsck verb exists to replace it. This half is what makes the cost measurable without taking on that decision.

The one test that changed is the one that had to: a corrupted payload on a complete frame no longer voids open. It now asserts the fault surfaces on the first content() read AND that openReadOnly still rejects the file eagerly. That second assertion is the tripwire for deleting verified_on_open without shipping the verb first. check-in: bae910f00e user: dmestas tags: logstore-open-cost

19:23
bench: measure openReadOnly, not just open

benchOpen timed LogStore.open -- the append path. Production never takes it: Repository.open falls back to openReadOnly, and Repository.logStore, the lazy content channel behind blob, cat, checkout and sync, calls openReadOnly with no cache in front. Every open number this effort has produced described a path no CLI verb enters.

That was survivable while the two paths ran the same scan. It stops being survivable the moment either one scans header-only, at which point the bench would report the optimized path while production still paid the full cost. --mode append|read-only defaults to append so existing invocations report unchanged numbers, and the mode is in the output line because the two are only comparable when a captured log can tell them apart.

Calibration on this tree, before any scan change: the modes agree within noise on all four shapes -- run B is 1% apart. That agreement is the check that the flag measures what it claims. check-in: e56a663b7a user: dmestas tags: logstore-open-cost

19:06
import-git: the payload refusal names its numbers

ExportPayloadLimitExceeded was a bare error name. Importing sqlite cost 17 minutes to learn a single integer, and the operator still had to guess it: the stream is 12.2 GiB against a 4 GiB default.

One error carried two unrelated bounds. max_total_data is the operator's --max-export-payload-bytes; max_data is a fixed 1 GiB per-payload ceiling no flag reaches. Reporting the wrong one sends an operator to a knob that cannot help, so PayloadOverrun records which bound refused, and the single -payload arm says plainly that no option raises it.

The cumulative arm refuses to name a remedy value. Parsing stops at the overrun, so the observed total is a lower bound; 'above 9' would name a number that fails again. It reports the bound and says the full payload is larger, which is the honest shape of what the parser knows.

Also corrects the budget's own doc comment, which claimed four GiB was 'the working set an import may claim on a commodity machine'. Measured resident size importing sqlite's 12.2 GiB stream: 21 MiB. Payload is streamed and released per event. What the cumulative half actually bounds is total history, so the default over-provisions memory by three orders of magnitude while refusing a mainstream repository. check-in: ee703cde16 user: dmestas tags: sub-manifest

04:56
merge trunk: shun, the release-assert guard, and the split test lanes

Trunk since d186a44e brought the repository shun table and its whole- branch verification fixes, the release-assert guard, the `test`/`gate` lane split, the structurally bounded logstore priority window, and the vendored crc32. Eight files conflicted. The decisions worth naming:

Lanes. `git-import-e2e` was a compile-only proof hanging off `test`; that is exactly the cost trunk moved to `gate`, so it moves with `e2e` and `smoke`. `import-git-bench` stays on `test` because it registers a real unit-test run rather than a compile proof. `declared_steps` is the union plus `gate`.

Sync ingest. Both sides rewrote it: trunk added the §7.7 receive-side shun admission, this branch added §7.1 phantom minting for a pushed tree's missing sub-manifests. They compose in one direction — admission is asked first, so a card §7.7 refuses is never stored and mints no phantoms either. The S references of an artifact this repository declines to hold are not names it should then go begging for.

Client construction. Trunk factored the three verbs' `Client` literal into `syncClient` and threaded `RepoAdmission`; this branch had widened `project_code` into `RepoSyncIdentity`. The helper now carries both, which is what trunk's own comment asked for: three copies of that literal is how a repository filter comes to be wired into two verbs and not the third.

Per-round server refresh. Trunk made the snapshot mandatory — `error.ServerStorage` rather than serving with no shun table — where this branch read its four sub-manifest fields through fail-open defaults. Trunk's reading wins for all six fields: serving a stale default is the failure, not the fallback.

Two guards trunk owns caught real defects in this branch's code, which is the whole point of them:

The total switch in `shunConsequence` refused to compile against the `submanifest` artifact type, exactly as its comment promised. It has an arm now.

The release-assert guard found nine asserts on untrusted input across six functions. Two were reachable faults, not style: `lookupTree` asserted §4.4 on a sub-manifest a peer supplies, so a malformed node panicked a ReleaseSafe reader and was walked anyway under `--release=fast`. It returns `SubUnresolvable` now, which §5.2 already defines as "absent, or is not a SUBMANIFEST". The empty-S-run assert became an early `null`. The two sub-manifest writers refuse an empty group through a new `SubmanifestWriteError` rather than asserting; the builder's internal path keeps its allocation-only surface through `serializeLeafCore`, since the partitioner is what establishes non- emptiness there. The rest were tautologies or restatements of invariants the card parser already enforces, and now say so in a comment instead of carrying a panic.

Verified on the merged tree: `gate`, `e2e`, `dst` (6 seeds x 1000 steps), `smoke` (S1-S10, including trunk's new shun interop), and `git- import-e2e` all green, `zig fmt --check` clean. Beyond the suite, the importer was run for real: the empty-email repro imports and its check- in carries `U mohye77`, and marktext imports end to end with the analyzed pin at k=5. check-in: 562cf5be74 user: dmestas tags: sub-manifest

03:13
fast-export: accept an author with an empty email

parseIdentity refused an identity carrying an empty address twice over, once as `open + 1 == close` and again as `email.len == 0`. That is not malformed input. Setting `user.email` to the empty string is ordinary git configuration; `git fast-export` writes the identity with an empty angle-bracket pair, and `git fast-import` reads that same stream back to the same commit. The construct is valid by git's own definition on both sides of its own tooling, and we rejected it.

The cost was not cosmetic. Two such commits, reachable only through a merge's second parent, aborted the import of an entire 437 commit repository with `import-git: import failed: Malformed`, naming neither the line nor the rule.

Only the email clauses are relaxed. The name clauses stay: git's own porcelain refuses an empty ident name, and the importer maps the identity's name onto the U card login, so a nameless identity would produce a nameless check-in. The two questions were conflated in a single condition, which is a large part of why this went unnoticed, so the guard now separates them and says why.

This is the third defect on this branch of the same shape: a property of our own fixtures promoted into a rule about the world. The first two were bounds tuned to the width of our benchmark corpus. This one is sharper, a refusal of input the tool we integrate with emits by default. Every identity fixture in the parser tests carried a non-empty email, so a uniform corpus could not falsify a rule that keys on emptiness.

Both tests are witnesses rather than decoration: each fails with Malformed against the previous parser and passes against this one. The unit test pins the construct and the empty-name refusal beside it; the differential test has git itself produce the commit and then asserts the imported check-in carries the login mohye77 rather than an empty user. check-in: 1f21f96558 user: dmestas tags: sub-manifest

02:56
git-import: translate a Git fast-export stream into a zit history

`zit import-git SOURCE DEST` reads a Git repository through `git fast- export` and builds a zit repository from it. The destination appears only after the export, artifact creation and publication have all completed, so a failure anywhere leaves no half-published repository behind; this is the first caller of the logstore artifact batch added earlier on this branch, which is what makes a check-in's blobs arrive as a unit.

Mode 160000 now parses as a gitlink instead of error.UnsupportedMode. That completes the split begun in the previous check-in: reporting what the stream said is the parser's job, and deciding that zit has no submodule concept is the importer's. The refusal still happens, but it now explains itself instead of failing as a parse error on input git legitimately emits.

Signed commits are refused by default rather than imported with the signature silently dropped. Fossil has no signature card, so importing one is a loss the operator should choose; --drop-signatures accepts it explicitly.

The sub-manifest parameter is analyzed, not guessed. Preflight measures the source's own name set and pins its measured optimum, and --submanifest-k overrides that only to match another repository's existing pin, which is what lets two repositories share sub-manifests by content address. On a 100,000 file corpus the analyzed value cuts the objective by roughly 3.4x against the fixed default it replaces.

Correctness is checked differentially against real Git rather than against fixtures we wrote: every materialized tree is compared to `git ls-tree` for the corresponding commit, refs and annotated tags are compared to the source, and both comparators now assert that a gitlink is absent rather than merely tolerating it, so the omission is a contract instead of an accident.

The rest is wiring. extras learns the import provenance names, root.zig exports the importer modules across the executable and library boundary, tidy and the CI step guard learn the new test roots and build steps, and the e2e help check learns that a verb spelled import_git in Zig is import-git on the command line. check-in: dc0aa2f858 user: dmestas tags: sub-manifest

02:43
build: split the unit lane from the full gate

zig build test was 9m13s, and the tests it actually ran were a small fraction of that: it also compiled the e2e and smoke harnesses in the pinned ReleaseSafe and then never executed them. test is now unit tests only -- 2m54s cold, 1m42s warm -- and the new gate step carries those two compile proofs.

The dst, bench and smoke UNIT tests deliberately stay on test. They are unit tests despite their siblings' names, zig build dst/smoke run the simulation and the interop check rather than them, and CI invokes the lanes one by one and never invokes gate -- so moving them would have dropped them from CI while every step still looked green. ci_test's declared_steps records gate as intentionally not-in-CI, and names that failure mode for the next lane someone adds. check-in: 7363238ad5 user: dmestas tags: trunk

02:39
submanifest: incremental apply must equal canonical construction

The incremental tree editor diverged from buildTree on realistic filename distributions. OldTreeCursor.appendPrefixAtHeight read the retained native-prefix list without consuming it, so one descriptor could be spliced into two different output levels: buildUnpublished placed the height-1 prefixes into the leaves, and mergeRootPrefixes then prepended the identical descriptor again before finishRootLevel. The emitted interior node carried the same S key twice, which fails artifact.parse's ascending-S guard, so an import aborted partway through a real history with a SyntaxError raised by our own grammar.

finishCheckpoint already guarded its own splice with a height test. That guard was an ad-hoc workaround for this same double-append, and mergeRootPrefixes never had one. The splice now consumes what it emits, so a retained descriptor lands in exactly one level and the guard becomes unnecessary rather than duplicated.

Found by importing marktext, not by the suite. Every name corpus here was uniform, and a duplicated prefix descriptor requires names that share prefixes at differing depths, so 55 tests could pass over a defect that breaks real repositories. The new seeded differential sweep generates four corpora of 136 to 240 paths with mixed depth, shared directories, dotfiles and 1 to 43 byte basenames, over every supported k with twelve batches each, and asserts it reached a tree at least three levels deep so it cannot quietly degrade into testing flat roots. It diverges in 20 of 452 batches against the unfixed editor, every divergence unparseable.

The decoded-root validation memo lands alongside it: repeated lookupTree validation against an unchanged root is answered once instead of rebuilt, which takes this file's own 56 tests from 1701 to 450 seconds over identical assertions. check-in: 4a95e436af user: dmestas tags: sub-manifest

02:28
fast-export: derive the per-commit file-command ceiling

Limits.max_file_commands_per_commit was a standalone number, and the caller pinned it to the width of our own benchmark corpus. That is a fixture size promoted to policy: no headroom, no way to raise it without a rebuild, and it refused legitimate histories. `git fast-export` lists an entire tree for a root commit and for any commit whose first parent was not exported, so the ceiling is reached by ordinary repositories whose initial commit lands a whole codebase at once.

The bound itself is necessary. admitData is the parser's only byte admission and it sees the byte count in a `data` header alone; every file command additionally allocates a list slot and a duplicated path into the per- commit arena with nothing charging for them, so the command loop is otherwise unbounded against a subprocess pipe.

It is now computed: fileCommandCeiling(limits) = max_total_data divided by min_retained_bytes_per_file_command, where that constant is @sizeOf(FileCommand) plus one -- a command's list slot plus the shortest path it can carry, the empty path being rejected. Nothing smaller is representable, which is what makes it safe to divide a byte budget by. The ceiling restates the arena authorization the caller already granted, in commands rather than bytes, and moves when that authorization moves.

Refusal retains the observed count, the ceiling, and the budget that produced it, so the diagnostic names all three rather than only its own error. The remaining limits gain distinct names -- Data, Event, FileCommand, Line, Merge and Path -- in place of one LimitExceeded that could not say which bound was hit. Exact-count data may carry an optional trailing LF, so only the first following empty line is ambiguous with the commit terminator; readDataExact and readCommitData split that decision instead of guessing. check-in: 85d510d361 user: dmestas tags: sub-manifest

02:15
repostate: resolve a stored sym- selector directly

Names beginning with `sym-` are ambiguous in this repository. A user tag written `sym-x` is stored under the canonical spelling `sym-sym-x`, so resolving `sym-x` correctly looks for `sym-sym-x`. An imported repository, though, can carry a tag whose stored canonical spelling already begins with `sym-`, and nothing could address it: the ordinary lookup rewrote the name and missed the artifact that was actually there.

Resolution now attempts the ordinary user-tag path first and consults the stored spelling only when that fails. The precedence is deliberate. A user tag continues to win over an imported canonical name, so no existing repository changes meaning, and the fallback is reachable only where the ordinary answer does not exist at all. check-in: fc9bcb81bd user: dmestas tags: sub-manifest

01:58
logstore: all-or-nothing artifact batch append

Callers publishing several artifacts together had only putArtifact, one at a time, so a failure partway left the store holding a prefix of the set with nothing naming what was missing. Each caller that cared wrote its own compensation, or quietly did not.

putArtifactBatch takes the whole set and appends it under a single transaction: either every item is durable or the store is byte-identical to its prior state. ArtifactBatchItem carries the hash, the bytes, and an optional delta base, so a batch may mix full and delta-encoded members without the caller resolving storage order first.

Nothing calls it yet. The importer, which needs a check-in's blobs to arrive as a unit or not at all, is the first caller and lands later on this branch. check-in: 7cf522fa5b user: dmestas tags: sub-manifest

01:41
control_paths: one worktree-path admission policy

Two layers decided independently what a reserved path is. update carried its own validateWorktreePath — an absolute/backslash/dot-dot check plus a hand-rolled case-insensitive comparison against the .zit family — while extras carried isControlName, which tested only the first /-delimited component of a path. They agreed by coincidence rather than construction, and the extras form admitted `.zit-managed/entries` because it asked about the component instead of the root.

control_paths now owns both questions. validateWorktreePath and isReservedRoot are the single definitions; update delegates to the first and extras to the second. isControlName takes the full root-relative key that add and move already hand it, so a path rooted in a control entry is refused at any depth rather than only at depth zero. firstComponent goes with its last caller.

The update test that pinned the old list is now a case table naming what is reserved and what merely resembles it, including the case-insensitive spellings the previous ad-hoc comparison happened to get right. check-in: 581db6e5ba user: dmestas tags: sub-manifest

01:26
update: materialize symlink worktree entries

A check-in's F card can name a symlink (§4.7.6-m5), but update refused one outright with error.SymlinkUnsupported, so any history carrying such a card could not be checked out, reverted, or updated to. The refusal was cheap to write and wrong: the reader already represents the entry, and only the worktree side lacked a branch for it.

materializeEntry and writePayload now create the link from the card's target bytes instead of writing a regular file containing them, and isCurrentState compares against .sym_link and the recorded target rather than the size and mode of a file that is not there. The managed-set walks accept .sym_link beside .file, so a materialized link reads as a tracked entry instead of an intruder the admission check rejects.

`zit revert` on a symlink card previously exited 1 naming the refusal. It now restores the entry, and the test reads the link back with readLink, which distinguishes native materialization from a regular file that merely holds the target's bytes. check-in: bb96853a0f user: dmestas tags: sub-manifest

01:24
build: forward --test-filter to the e2e test root

The e2e root is one test binary holding every scenario, and its runner took no filter, so narrowing to a single scenario meant editing build.zig or paying for the whole root. `zig build e2e -- --test-filter NAME` now compiles the filter into the test artifact, accepting both the two-argument and the `--test-filter=NAME` spellings and passing nothing through when the arguments do not name a filter. check-in: cd70f19286 user: dmestas tags: sub-manifest