* sync: correct the clone cfile comment to match the actual code path (#140)

The comment claimed clone "retransmits the repository's stored compressed content verbatim... blob.Load returns exactly that." That is not what the code does: blob.Load decompresses the stored blob and encodeCFile then re-compresses it with zlib before it goes on the wire. The wire result is correct because the decompress/re-compress round-trip is byte-deterministic, but nothing forwards the stored compressed bytes untouched. Correct the comment to describe the real mechanism (decompress via blob.Load, re-compress via encodeCFile) and state explicitly why the round-trip is still stable.

Documentation-only; no behavior change.

* sync: retransmit deltas during clone instead of expanding them (#141)

The clone send path expanded every deltified row to full content before putting it on the wire, giving up the delta-transmission bandwidth the xfer protocol is designed for. Restore delta transmission on the clone send path.

Send ordering. content.Deltify deltifies the OLDER artifact against the NEWER one, so a delta's source almost always has a greater rid than the delta and would not yet have been sent under the ascending-rid clone cursor. Rather than reorder the whole cursor, buildCloneArtifact walks each artifact's delta chain toward its full-content tip and emits the chain source-first, mirroring canonical fossil's recursive send_file: the tip (or the lowest still-sendable anchor) leads, each delta follows the source it names, and the requested rid is last. A per-round "sent" set skips any source a dependent's chain already pulled in ahead of its ascending position, matching fossil's per-request bag. The snapshot bound (#17) is preserved: a delta whose source lies outside the clone snapshot, is a phantom, or is private under a public clone degrades to full content so no out-of-snapshot row is ever leaked.

Wire format. A delta goes out as an uncompressed "file UUID DELTASRC SIZE" card, exactly as canonical fossil's send_delta_native does, not as a "cfile". Full content still rides a compressed cfile, preserving the #98/#113 wire-size win.

Scope. This is a bandwidth win, verified content-identical for libfossil<->libfossil clones by the self-round-trip tests, with the source-before-dependent invariant guarded by TestEmitCloneBatchSourcePrecedesDelta. The receive side already re-deltifies via content.Deltify on the crosslink path (#114), so store and tip fidelity are unchanged. Measured on a 120-artifact, 59-delta corpus, a full clone's reply bytes drop from 32,551 (expand-before-send) to 17,419, a 46% reduction, close to the 14,941-byte stored size.

This does NOT make a real fossil client's clone usable. Full content still rides a compressed cfile, which go-libfossil emits as bare zlib while fossil expects [4-byte size][zlib] framing, so a real fossil client decodes full content to garbage and rebuilds to zero check-ins. That is a separate, pre-existing bug (present on unmodified main), tracked as #152. TestCloneRealFossilWithDeltaChain asserts real usability and skips against

* test(sync): update real-fossil delta test doc to the #141 mechanism

* test(sync): prove clone usability, drop false real-fossil interop claim (#141)

TestCloneRealFossilWithDeltaChain asserted only that `fossil clone` exits 0, which a real fossil client does even when the clone is empty and its content is undecodable. Strengthen it to prove usability: rebuild the clone and count its check-ins. The count is zero -- a real fossil client decodes go-libfossil's full-content cfile payload (bare zlib) to garbage because fossil's on-disk cfile format is [4-byte size][zlib] -- so the test skips against the tracking issue (#152) instead of silently passing on corrupt content. When #152 lands the clone materializes all six check-ins and the test passes for real.

Also correct the doc comment and the handler.go send-path comment, which claimed #141's send-order + uncompressed-delta-card change keeps a real fossil 2.28 client's rebuild from failing. It does not: that change is a libfossil<->libfossil bandwidth win (verified content-identical by the self-round-trip tests); real-fossil interop for delta-bearing clones remains blocked on the separate cfile-framing bug (#152), present on unmodified main. check-in: 5f66319ea3 user: [email protected] tags: trunk